- Ok Tedi Mining Limited

Transcription

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(19 May 2007)
Dr K W Bentley
Director
Centre for Environmental Health Pty Ltd
PO Box 217
WODEN ACT 2606
AUSTRALIA
email: [email protected]
2
Table of Contents
List of Tables
4
List of Figures
5
List of Appendices
5
Glossary
6
Executive summary
8
1.1 Background
15
1.2 The Ok Tedi-Fly River and Lake Murray Community Health Study
19
2.0 Project location, physical, demographic and socio-economic characteristics
22
3.0 Health status in the Ok Tedi Fly Rivers communities
26
4.0 Health Risk Assessment methodology
28
4.1 Units of measurement for contaminants in the environment
28
4.2 Exposure pathways
28
4.3 Regulatory limits
29
4.4 Definition of exposure and related terms
29
4.5 Approaches to quantification of exposure
30
5.0 Hazard assessment
30
5.1 Data summaries for contaminant metals
31
5.2 Data summaries for essential trace metals
37
6.0 Exposure assessment
40
6.1 Drinking water
40
6.2 Recreational water
46
6.3 Air quality assessment
51
6.4 Soil and sediments
56
6.5 Food
68
7.0 Risk characterisation
76
7.1 Estimating intake
77
8.0 Ok Tedi-Fly River OTML CHS exposure model
84
8.1 Typical and reasonable maximum exposures
84
8.2 Dermal exposures to air, water and soil
85
8.3 Inhalation bioavailability
87
8.4 Bioavailability using soil oral absorption coefficients
88
8.5 Estimation of cancer risk
88
9.0 Risk characterisation for the Ok Tedi-Fly River OTML CHS regional communities
89
3
10.0 Ok Tedi Fly River community exposure scenarios and risk analysis
100
10.1 Exposure scenarios for the soil and sediment compartments
100
10.2 Single compartment risk analysis
106
10.3 Multicompartment risk analysis
108
10.4 Cancer risk from arsenic exposure
119
11.0 Conclusions of the OTML community health study
120
11.1 Reliability considerations
120
11.2 Conclusions and recommendations relevant to public health
123
12.0 Acknowledgements
123
13.0 References
124
4
List of Tables
Table No
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Table 9
Table 10
Table 11
Table 12
Table 13
Table 14
Table 15
Table 16
Table 17
Table 18
Table 19
Table 20
Table 21
Table 22
Table 23
Table 24
Table 25
Table 26
Table 27
Table 28
Table 29
Table 30
Table 31
Table 32
Table 33
Table 34
Table 35
Title
Ok Tedi-Fly OTML CHS region and village location
characteristics
OTML CHS demographic and household characteristics
International drinking water health guidelines
Ok Tedi-Fly community drinking water supplies – total and
dissolved metals
International surface water recreational guidelines
Ok Tedi-Fly River surface water – total metals
WHO guidelines for metals in ambient air
National criteria and guidelines for airborne particulate matter
Respirable air particulate metals
Respirable particulates PM 10 and PM 2.5 - comparison with
the Australian NEPMs
National health-based soil investigation levels
Village and village garden surface soils total extractable
metals
Natural (non-impacted) sediments total metals
Road impacted soils total metals
Active flood plain sediments total metals
Comparison between village soils and sediment samples
WHO Provisional Tolerable Weekly Intakes
Total dietary metal intake from food
Adjusted body weight weekly intake of metals from food
Description of the assumptions made for the main exposure
routes
Fiftieth percentile total body surface area and soil adherence
Absorption coefficients for oral and inhalational exposures
Comparison of input parameters used in typical residential
exposure scenarios
Mean weight by region for deriving the input parameters for
the health risk analysis
Dermally absorbed doses from surface waters in Region 2
impact for all age groups
Dermally absorbed doses from soil exposures for child 2
years of age
Comparison between total ambient air metal intake and intake
using bioavailable metal values
Multicompartment exposure Region 1 by age group
Soil exposure scenarios for metal intakes (Region 1)
5
Table 36
Table 37
Table 38
Multicompartment intakes from all sources by region (worst
case scenario including all soil and sediment compartments)
List of Figures
Figure No
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Title
Map of PNG indicating principal centres and mining areas
Community health study regional villages map
Ok Tedi-Fly River drinking water quality - comparison with
health guidelines
Ok Tedi-Fly surface water quality - comparison with WHO
health guidelines
Respirable particle concentrations – peak values at OTML
CHS sampling locations
Metal concentrations in respirable air at OTML CHS
locations and reference sites
Village soil concentrations of arsenic, copper and zinc
showing natural soil signatures
Arsenic and lead in soil and sediments compared with
Australian HILs
Copper and zinc in soil and sediments compared with
Australian HILs
Weekly intakes of contaminant metals from food
Weekly intakes of essential metals from food
Total copper intake for children 1 – 5 years of age and adults
compared with dietary reference values
Total selenium intake for children 1 – 5 years of age and
adults compared with dietary reference values
Total zinc intake for children 1 – 5 years of age and adults
compared with dietary reference values
Total arsenic (inorganic) intakes for children 1 – 5 years of
age and adults
Total cadmium intakes for children 1 – 5 years of age and
adults
Total mercury intakes for children 1 – 5 years of age and
adults
Total lead intakes for children 1 – 5 years of age and adults
Lead intakes by compartment for children 1 – 5 years of age
and adults
List of Appendices
Appendix No
Appendix 1
Appendix 2
Appendix 3
Title
QHSS analytical data for drinking water and recreational water
Team Ferrari Porgera Respirable Particle Air Sampling Study
QHSS analytical data for village soils and riverine sediments
6
Glossary
ADI
ATSDR
CDC
CHS FFS
CHS MBS
CHS UFC
CMCA
Codex
Control villages
CSIRO
DAD
DL (LoD)
DRI
EQG
FSANZ
HHRA
Highland
HIL
IARC
ICRP
Impact villages
IOM
IPCS
JECFA
LADD
LL
LLG
Lowland
MAC
MCL
Acceptable Daily Intake: expressed on a body weight basis the
amount of material that can be ingested for a lifetime without
appreciable risk to health
Agency for Toxic Substances and Disease Registry (United
States)
Centers for Disease Control and Prevention (United States)
The OTML Community Health Study Food Frequency Survey
The OTML Community Health Study Market Basket Survey
(total diet study)
The OTML Community Health Study Unit Food Consumption
measurement study
Community Mine Continuation Agreements
The FAO/WHO Codex Alimentarius Commission
Control villages are located away from the zone of impact of
the OTML mine operations. Generally located on a control
river or other water body these villages do not receive
contaminant metal impacts from the OTML mine operations
Commonwealth Scientific and Industrial Research
Organisation
Dermally absorbed dose
Analytical Detection Limit (Limit of Detection)
Dietary Reference Intakes for nutritional sufficiency endorsed
by the US Institute of Medicine
Environmental Quality Guidelines (Canada)
Food Standards Australia New Zealand
Human Health Risk Assessment
The mine-area communities in Region 1 of the present study.
All are located at altitudes between 500 - 1000 metres above
sea level
Health Investigation Levels for contaminated land (Australia)
International Agency for Research on Cancer (WHO/UNEP)
International Commission on Radiological Protection
Villages within the Ok Tedi-Fly River system that potentially
receive contaminant metal impacts from the OTML mine
operations
Institute of Medicine, US National Academy of Science
International Program on Chemical Safety
WHO/FAO Joint Evaluation Committee for Food Additives
Lifetime average daily dose (for carcinogenic chemical
assessments)
Lower Intake Level recommended for nutritional sufficiency
(US IOM)
Local Level Government areas (Papua New Guinea National
Statistics Census division)
The communities in Regions 2 - 5 of the present study. All are
located at altitudes < 300 metres with the majority < 50 metres
above sea level
Maximum Acceptable Concentrations (Environment Canada)
Maximum Contaminant Levels (US Drinking Water Standards)
7
MCLG
NEPM
NHMRC
NOAEL
NSO
NSR
ORWB
OTDF
OTML CHS
pica
PJV
PLSLM HHRA
PM 10, PM 2.5
QA/QC
QHSS
Region, impact or
control
Sediments:
Impacted flood plain
sediments
Natural sediments
Roadside sediments
Village and garden
soils
TSP
µg/kg bw/wk
UK FSA
UL
US EPA
US FDA
US NRC
WHO
WHO PTWI/TWI
Maximum Contaminant Level Goal (US Drinking Water
Guideline protective of public health)
National Environment Protection Measures (Australia)
National Health and Medical Research Committee (Australia)
No Observed Adverse Effect Level
National Statistics Office of Papua New Guinea
NSR Environmental Consultants Pty Ltd (now Enesar Pty Ltd)
Off river water bodies
Ok Tedi Development Foundation
The Ok Tedi Mining Limited Community Health Study
Behaviour in young children associated with the consumption
of soil
Porgera Joint Venture operators of the Porgera mine in Enga
Province
Porgera-Lagaip-Strickland-Lake Murray Human Health Risk
Assessment
Respirable particulates of mean aerodynamic diameter of 10
and 2.5 micron
Laboratory quality assurance and quality control
Queensland Health Scientific Services Laboratories, Brisbane
The five geographic regions within the OTML CHS survey
area (see Figure 2)
- The soils in these zones include mine derived sediments
(from both the tailings and waste rock streams – commonly
referred to as “mine-derived sediments”) and are impacted by
the OTML mining operation.
- Naturally occurring sediments. These soils are not impacted
by the OTML mining operation.
- Soil materials within this category have been impacted by
road construction and associated drainage controls, and the
dust generated from daily traffic movements.
- Villages and gardens are established above any active
flooding levels. Consequently, these soil materials are not
impacted by the OTML mining operation.
Total suspended particulates (air)
Microgram per kilogram body weight per week (for human
dietary and environmental metal intake assessment)
United Kingdom Food Standards Authority
Tolerable Upper Intake Level for nutritional elements (US
IOM)
United States Environmental Protection Agency
United States Food and Drug Administration
United States National Research Council
World Health Organization
The WHO Provisional Tolerable Weekly Intake values
represent permissible human weekly exposure to a contaminant
which has a cumulative effect on the body and is unavoidably
present in otherwise wholesome and nutritious food
8
Executive summary
Ok Tedi Mining Limited (OTML) commissioned a quantitative Community Health
Study (OTML CHS) to address the key questions:
Do the mine area communities and people resident down river of the mining
operations suffer discernible health effects attributable to the off-site releases of
contaminant metals either directly from the mining operations or from tailing
release to the catchments?
Are there ongoing environmental health problems for the local and down river
communities arising from the mining activities at Ok Tedi?
The OTML CHS Volume 2 report primarily uses data for food, air, water and soil
generated in the period April 2004 to July 2006, to provide information and analysis to
assess the current health risk to the mine area and the Ok Tedi–Fly River system’s
communities. All food and environmental samples generated for the study were
analysed for the essential trace elements copper, selenium and zinc, and the contaminant
metals arsenic, cadmium, lead and mercury. Details of the food consumption and
nutrition studies are provided in OTML CHS Volume 1.
The principal methodology adopted by the study was to:
(a)
undertake sampling and analysis in each of five distinct geographic regions
proximal to impact and control villages for all environmental media, food
and drinking water and compare these values with international health
guideline values and national standards and criteria; and
(b)
develop risk assessment scenarios for potential chronic toxic effects and
induction of cancer.
The OTML CHS was conducted in 23 villages between the OTML mine area and the
Fly River estuary. For each region, a minimum of two impact and two control villages
were selected. The criteria for selection were:
•
•
impact villages proximal to the OTML mine site, communities having direct
access to the Ok Tedi- Fly River corridor or settlements that had re-located,
adjacent to the main road between Tabubil and Kiunga; and
control villages located on non mine-impacted river systems away from the
Ok Tedi-Fly River corridor, in the north western reaches of Lake Murray or
non-impacted coastal area communities further to the west coast of the Fly
River estuary.
The communities were diverse in social, economic and cultural characteristics, varying
between the semi-urban villages of the Tabubil area to rural and remote villages, having
very limited access to social and health infrastructure.
The diverse geographic locations and agronomic circumstances introduced widely
varying access to bush-sourced and different varieties of village-grown food products.
For example, in the Region 1 mine-area communities, store purchased rice and flour
supplemented by sweet potato and other tubers were the predominant energy source,
whereas banana, sago and tubers were co-staples of the villagers in the Middle Fly-
9
Lower Fly Regions 3 and 4. Those in Region 5 Fly estuary communities, having
employment opportunities and access to the provincial capital of Daru, again reverted to
rice as a major carbohydrate staple.
The mine-area villagers’ consumption of fresh fish was very low, largely replaced as a
protein source by chicken and tinned fish and meats. Fish and other aquatic foods were
also a minor protein source in the Ok Tedi villagers’ diets, but comprised the main
protein source of the Middle Fly and Lake Murray villagers. Fish consumption at
Regions 4 and 5, while important was supplemented increasingly by other protein-rich
foods, particularly bush meats.
In considering the main findings (accepting that these were derived using very
conservative assumptions for each exposure compartment) the overall conclusions were
that:
•
•
•
•
•
•
•
total contaminant metal intakes for the drinking water and ambient air
compartments were not significantly different between potentially impacted
villages and the matched control communities within each of the five
geographic regions and between the five regions;
excluding the unique local circumstances regarding dietary mercury intakes
in the Middle-Lower Fly and Lake Murray (Regions 3 and 4), the lead
intakes in Regions 2 and 3 (impact) and Region 4 (control) and the elevated
arsenic intake in Region 5 (control) total metal intakes were somewhat
similar within and between regions;
total copper intakes from recreational waters were elevated in the Region 2
impact villages of Ieran and Ningerum. There were also minor increased
intakes discernable in the Middle-Lower Fly River impact areas. The metal
intakes in the mine-area villages from recreational water were low. The
copper and other metal intakes at all OTML CHS monitored villages were
of no public health significance;
village and garden soil and natural (non-impacted) sediments resulted in
somewhat higher copper, lead and zinc intakes in the mine area and Ok
Tedi impact and control villages (Regions 1 and 2) resulting from natural
background mineralisation. For the Fly estuary regional villages (Region 5),
both impact and control, the intakes of arsenic were somewhat elevated due
to a natural arsenic geochemical soil signature in this region. All values for
the contaminant metals in village and garden soil and natural (nonimpacted) sediments in all regions were of no health significance;
the intakes from exposure to roadside in Regions 1 and 2 were generally
comparable with those from the natural non-impacted sediments and village
soils at the same villages albeit there were two samples that appeared to be
comprised of flood plain sediment-like materials;
for the impacted flood plain sediments there were marked differences in
intakes between the impact and control villages in Region 2 for copper and
lead, with the impact villages generally some 15 – 20-fold higher;
for each of the five regions and impact or control communities, the metal
intakes from the recreational waters and impacted flood plain sediments
were significantly less than that from dietary intakes for all population age
groups;
10
•
•
the release of mine waste from the OTML mine had not had any
discernable impact on the levels of contaminant or essential trace metals in
locally-sourced food; and
in the absence of time-activity data for the different age-sex populations, it
was not possible to accurately quantify total exposures for specific groups.
However, using realistic assumptions, it can be concluded that with the
exceptions noted above, and taking into account the very conservative
assumptions adopted by the OTML CHS for each media compartment, the
total metal intakes in the OTML study population for each of the
contaminant metals are of no health concern.
Comparison with Papua New Guinea and international guidelines and
standards
Criteria adopted
In order to evaluate whether exposure to the metals in mine waste from the OTML mine
poses a threat to human health, the mean metal concentrations in the environmental
media air, water, soil and sediment and food have been compared with standards
established by Papua New Guinea, the World Health Organization and national criteria
from the United States, Canada and Australia. Metals that are present at concentrations
below the applicable standards, guidelines and criteria do not pose concerns for human
health.
Drinking water
All monitored rainwater tanks, springs and creeks used as primary community drinking
water sources had metal values markedly below the WHO, Canadian and Australian
(NHMRC) drinking water guideline values, the Papua New Guinea standards for raw
drinking water and the United States drinking water health criteria.
Recreational waters
The mean dissolved metal concentrations for recreational waters for all of the target
contaminants at all monitored impact and control communities within the five
geographic regions were within the limits derived from criteria established in the WHO
Recreational Water Guidelines. Total extractable metal concentrations for copper were
as markedly elevated at the Region 2 riverine impact villages (Ningerum, Ieran) and to a
lesser degree at the Regions 3 – 5 impact communities. All other metals analysed,
generally were present at or below the respective analytical detection limits. All total
metal concentrations at all locations were an order of magnitude below the respective
WHO recreational water guidance values.
Air
The arsenic concentrations in respirable air particulates at all of the monitored locations
were less than 20% of the WHO Guideline level, while the concentrations for mercury
and lead were generally some two orders of magnitude below the respective WHO
Guideline values.
During analysis no cadmium was detected, confirming that cadmium concentrations in
the air samples were consistently below the detection limit of 35 ng/m3. While the
WHO Guideline value for cadmium is 5 - 20 ng/m3, from the available data there was
no evidence that this had been exceeded. WHO does not give guidance values for
metals in ambient air for copper, zinc or selenium, but the observed values were typical
of background ambient air levels in rural and remote environments in other countries.
11
Soil and sediments
The level of metal contamination or naturally-occurring concentration can be compared
with the values established in Australia for the assessment of contaminated land. Under
this scheme, a HIL is set for each metal of concern. If measured concentrations are
below the HIL, then there is considered to be no risk to human health. The mine-area
(Region 1 impact and control) and Region 2 impact villages indicated some natural soil
enrichment in copper, lead and zinc. This was to be expected from the known
mineralisation in the Mt Fubilan area. There was also an apparent natural enrichment of
arsenic at the Region 5 (impact and control) villages. All values were well below the
respective residential HIL values.
The metal levels in the natural (non-impacted) sediments were generally comparable
with the corresponding village and garden soils. Typically, the observed values were:
Regions 1 and 2 arsenic 4% – 9%; cadmium 2%; copper 2.5% – 10%; mercury 3%; lead
3% – 10% and zinc 1% of the respective HILs.
In the Regions 3 – 5 villages the levels of metals in soils and natural sediments were
consistently < 5% of the respective HILs with the exception of arsenic at Region 5
which was 20% – 25% of the HIL.
The metal concentrations in impacted flood plain sediments were markedly elevated for
arsenic, copper, lead and zinc in samples sourced from the Region 2 impact villages,
with maximum concentrations of arsenic 46%; copper 230%; lead 100% and zinc 16%,
of the respective HILs. The highest mean copper value from all locations was about
three-fold the residential HIL.
The Regions 3 – 5 metal values were typically between 5% – 10% of the respective
residential HILs with the exception of a single sample (Manda). Naturally occurring
arsenic at the Region 5 villages was < 25% of the HIL. The values for cadmium and
mercury were all well below the respective HILs. Selenium does not have a soil health
investigation level.
Food
The OTML CHS Market Basket Survey (OTML CHS MBS), conducted as part of the
present health risk assessment provided a picture of the dietary patterns and dietarycontaminant intakes of the people within the mine-area villages and in communities
downstream of the OTML mine. To a very significant degree, the observed contaminant
and essential trace metal levels in food are a result of the very conservative nature of the
assumptions adopted both by the OTML CHS and by WHO in formulating the PTWI
values.
The comparability of data on the levels of contaminant metals in food both within and
between impact and control villages in all five regions, excluding mercury at the
Middle-Lower Fly River regions and Lake Murray, supported the conclusion that the
tailing release to the river system from the OTML mine had not impacted on the levels
of metals in the villagers’ diets. The high mercury levels at the Middle-Lower Fly River
regions and Lake Murray are demonstrably not mine related.
The WHO PTWI value for mercury was markedly exceeded in both the impact and
control communities in the Middle-Lower Fly River regional villages for children 1 – 5
years of age. At Lake Murray, the WHO PTWI was exceeded for all age groups by
between three- and 15-fold. The level of exceedance reported is likely an
12
underestimation for all groups, since the value adopted for the WHO PTWI is based on
the 1989 JECFA value of 5 µg/kg bw/wk total mercury. The principal source of
mercury intakes from the food pathway for the Middle-Lower Fly River and Lake
Murray communities is almost certainly methylmercury from fish and the JECFA value
of 1.6 µg/kg bw/wk for methylmercury would appear to be a more valid comparison
(JECFA 2003).
The OTML CHS clearly demonstrated that the dietary intakes of the essential trace
elements copper, zinc and selenium were adequate and safe.
Comparisons between the impacted and control sites
Drinking water
The Ok Tedi-Fly River system is generally not used as a drinking water source. Within
the OTML CHS community supplies, there was no statistical difference in metal
concentrations between the impact and control village rainwater tank and creek drinking
water sources, with all samples having very low total extractable and dissolved
concentrations for all of the metals monitored. The Lake Murray surface waters have
been reported as an intermittent-use drinking water source, with all mean metal values
reported in the present work and from the routine monitoring program conducted by
Porgera Joint Venture (PJV) below the WHO Drinking Water Guideline values, which
set an upper limit on concentrations that are safe to drink.
Recreational waters
Concentrations of total extractable metals in the mine area and Ok Tedi-Fly corridor
impact villages were characterised by elevated copper levels. These decreased rapidly
with increasing distance from the OTML mine. The levels of other metals were
generally at, or below the respective limits of detection (LoDs), apart from a minor
increase in the lead concentration in surface water samples at the Region 2 villages,.
The concentrations of total extractable metals at the control villages were also below the
respective LoDs other than a minor elevation in copper and zinc at Ok Ma, were also
below the respective LoDs.
Air
The levels of metals in the PM 10 and PM 2.5 respirable air samples were uniformly
low with no significant difference between samples from the impact and control sites.
Mean impact (and control) levels of PM 10 were 8.2 ng/m3 (1.3 ng/m3) for copper, 2.4
ng/m3 (3.8 ng/m3) for zinc and 2.3 ng/m3 (0.3 ng/m3) for lead respectively. Arsenic
levels were also below 2.7 ng/m3 for all impact and control samples. Cadmium and
mercury were not detected above the respective LoDs in any of the samples. Observed
concentrations were comparable with those observed at international baseline sites (eg
Cape Grimm, Tasmania) and at least an order of magnitude below values recorded in
urbanised centres such as Sydney and Jakarta.
The range of respirable particle concentrations (PM 10) ranged from between 24 µg/m3
at Gre to 15 μg/m3 at Ningerum Tamaro. The sampling method of the study did not
permit direct comparison of the PM 10 values against the Australian Standard, which is
based on a daily average not being exceeded for more than five days a year at any site.
Taking into account all measurements during the 2005 sampling period, no site
exceeded the NEPM 24-hour value on any occasion.
Soil and sediments
13
There was little difference between the levels of arsenic in village and garden soils, or
natural (non-impacted) sediments in the impact and control villages in the five regions,
other than a minor natural elevation in the sediments in all Region 5 locations and
somewhat elevated in the Regions 2 and 3 impact communities.
These latter elevated levels were clearly a result of soils being overlaid with minederived materials. All elevated samples had a characteristic tailing signature and were
< 35% of the Australian recreational (Exposure setting E) HIL value.
The mean concentrations for copper, lead and zinc in the village soils and natural
sediments were somewhat elevated at the impact and control communities in Region 1,
almost certainly resulting from natural mineralisation. At the Region 2 impact
communities, the mean levels in village soils would appear to be influenced by the
presence of impacted flood plain sediments in some village soils at Ieran. Copper, lead
and zinc concentrations in village soils and non-impacted sediments at Regions 3 – 5
were comparable between impact and control locations, and were similar to reported
international baseline concentrations.
Copper, lead and zinc in the impacted flood plain sediments were characterised at
Region 2 impact (and a single sample at Manda in Region 3) by a characteristic minederived sediment signature for these metals. At Regions 4 and 5, the levels are generally
low for copper and lead. It would appear that zinc at the Region 4 impact and Region 5
impact and control locations were marginally elevated from natural local zinc
mineralisation.
Mercury, cadmium and selenium concentrations at all of the Regions 1 – 5 impact and
control communities were generally, at or below the respective limits of detection.
Food
There were only minor differences in the metal concentrations for the same food
product between the impact and control villages in any of the regions, and with the
exception of mercury at the Middle-Lower Fly region and Lake Murray, between the
five geographical locations. Those products that were targeted for inclusion on the basis
of their known bioaccumulation of the metals of concern, almost without exception,
proved to have metal concentrations comparable with similar foods reported by the
Australian Market Basket Surveys.
Cancer risk from arsenic exposure
The published literature indicates that arsenic exposure induces a range of health effects.
It is clear that the severity of adverse health effects is related to the chemical form of
arsenic, and is also time- and dose-dependent. Arsenic in food is mainly in the organic
form and food regulators such as FSANZ (Australia) and the US FDA generally assign
a value of 10% to the inorganic proportion of total arsenic in food products. Arsenic in
other environmental media is generally accepted as being 100% in the inorganic form.
Both the WHO and US EPA have derived estimates for the expected increased
incidence of lung cancer from life time exposures to 1µg/m3 total arsenic in air (US
EPA 4.3 x 10-3, WHO 3 x 10-3). For the OTML CHS villages impacted populations, the
lifetime fatality risk from lung cancer can be regarded as insignificant since the
inhalational intake was minuscule.
14
The WHO and US EPA have also given numerical estimates of the lifetime skin cancer
fatality risk from lifetime ingestion of 1 µg/day of arsenic (US EPA 2 x 10-7, WHO. 1.7
x 10-6).
The most reliable figures for the OTML CHS communities for cancer induction by
arsenic are based on adult lifetime exposure. Calculation of total intakes for Regions 1 4 and Region 5 (impact) gave exposure values between 2 - 3 μg/kg bw/week of
inorganic arsenic. These values are very similar to the US EPA oral reference dose of
2.1 μg/kg bw/week (reported as 0.3 μg/kg bw/day) and considerably less than the WHO
numerical estimate of lifetime skin cancer fatality risk. For Region 5 (control) where
there were some naturally elevated arsenic levels in soil, the intakes of inorganic arsenic
was about 6 μg/kg bw/week. While marginally exceeding the very conservative US
EPA RfD (oral) this value is below that the WHO Guideline. The arsenic intakes in all
regions and villages can be considered to be of no health consequence.
Risk characterisation modelling and exposure scenarios
The data showed that for all age groups in all zones the weekly intakes of the essential
metals were generally within internationally recommended dietary reference guidelines
and do not pose a risk of adverse effects through excessive intake.
The WHO PTWI for arsenic is based on inorganic arsenic. In order to compare directly
with the WHO PTWI, the present work has adopted values of 100% inorganic arsenic
for drinking water and other environmental media and 10% inorganic arsenic in all
foods.
The results indicated that there were no significant differences in intakes between
Regions 1 – 4, with all inorganic arsenic levels for children 1 – 5 years of age less than
50% of the WHO PTWI value. For Region 5, impacted and control villages, where there
is naturally elevated environmental arsenic, the total inorganic arsenic intakes in
children 1 – 5 years of age, approximated the WHO PTWI value of 15 µg/kg bw/wk.
For adults, comparable intakes were between 20% - 40% of the WHO PTWI
respectively.
The mercury intake results indicated that there were no significant differences between
Regions 1 and 2, or the impact and control groups in these regions. The situation at
Region 3 again confirmed that the Lake Murray control villagers had very high mercury
intakes, which for the infants and 5 – 10 years of age group, were at least an order of
magnitude higher than the WHO PTWI value. While the intakes for the Middle-Lower
Fly villagers were substantially less than those at Lake Murray, the WHO PTWI was
exceeded for children 1 – 10 years of age.
The cadmium results indicated that for all regions and impact and control groups, the
total intakes were between 40% – 60% of the WHO PTWI value.
Lead intake from food was elevated in Regions 2 and 3 (impact) and Region 4 (control),
with the WHO PTWI being exceeded in the children 1 – 5 and 6 – 10 years of age
groups. Total lead intake in Region 2 impact was significantly increased by the
contribution from the impacted flood plain sediments. The WHO PTWI for this group
was exceeded some two-fold and was indicative that lead in the Ok Tedi River impact
zone will be the critical contaminant for future management controls.
15
1.0 Introduction
1.1 Background
Ok Tedi Mining Limited (OTML) commenced operations in the Star Mountains of
Papua New Guinea in the headwaters of the Ok Tedi River in 1984 with gold
production from an open pit on Mount Fubilan (Figure 1). Subsequently, large scale
open pit copper mining and processing has replaced the gold operation. Processing of
the ore to produce copper concentrate is carried out in the mill facility adjacent to the
open pit. The copper concentrate, also containing gold and silver, is pumped along a
156 km pipeline to the Upper Fly River port of Kiunga. Specially designed barges
transport the copper concentrate down the Fly River, approximately 820 river
kilometres to a floating silo vessel anchored either at the mouth of the estuary or in Port
Moresby harbour. Ocean-going vessels are loaded for worldwide copper smelter
destinations.
Figure 1: Map of PNG indicating principal centres and mining areas
Under approval from the Government of Papua New Guinea the OTML operation
discharges approximately 30,000,000 tonnes per year of copper-rich tailing and
60,000,000 tonnes per year of waste rock to the headwater tributaries of the Ok Tedi.
The copper and other metal concentration of the finely grained tailing particulates vary
according to the type of ore being processed, but for copper this is typically 1000mg/kg.
About 60% of the particles are < 100 µm diameter and are transported as suspended
sediment load throughout the entire length of the river system to the Fly River estuary
(Salomons & Eagle1990). The natural sediment load of the Ok Tedi-Fly River system
above Everill Junction is about 13 million tonnes per year. A further approximately 77
million tonnes per year of natural sediment joins the system from the Strickland River
system.
16
The tailing and waste rock release from the OTML operation, has resulted in significant
river bed aggradation of the Ok Tedi and the Upper-Middle reaches of the Fly River.
These effects include increased frequency of flooding, deposition of silt and fine sand
on the flood plain, development of forest dieback, a significant reduction of the fish
population (some 85% – 90% by weight catch reduction in the Lower Ok Tedi) and the
loss of a substantial area of village food gardens, natural resources and amenities.
The river bed aggradation and the sediment load on the Ok Tedi has been markedly
reduced since the introduction in 1998 of a dredging operation at Bige in the Lower Ok
Tedi, some 110 kilometres from the mine. The dredge recovers 10 million tonnes per
annum of sediment which is deposited in engineered stockpiles on the adjacent flood
plain.
The Ok Tedi flows approximately another 50 river kilometres south to D’Albertis
Junction where it joins the Fly River. From D’Albertis Junction, the Fly River meanders
some 400 river kilometres through a flood plain (the “Middle Fly”) extending over 5800
square kilometres to the confluence with the Strickland River at Everill Junction. This
part of the flood plain system contains numerous large off-river water bodies, which
receive from, and discharge water to, the Fly River.
Below Everill Junction, the river over a further 400 river kilometres (the “Lower Fly”)
evolves into a large estuary and delta covering over 7000 square kilometres. The Fly
River is affected by tidal influences downstream of the Middle Fly River village of
Manda.
Annual rainfall varies widely across the Fly River catchment varying between 1500 –
2000 millimetres at the coast to 10-12,000 millimetres in the vicinity of the OTML mine.
Prior to the development of the OTML mine, the sparse population of the immediate
mine area had very limited exposure to the outside world. At the present time there have
been movements of a substantial indigenous population into the mining centre of
Tabubil (population about 10,000) and the regional town and shipping port of Kiunga
(population about 8300). A number of the more remote villages have also relocated to
the Kiunga-Tabubil road area. There continues to be a significant population resident
along the reaches of the Fly River, increasing in density at the Fly estuary (Figure 2).
OTML both directly, and using numerous consultants, has for many years undertaken an
extensive environmental monitoring program with a substantial database having been
developed for contaminant metal levels in various environmental media and aquatic and
terrestrial biota. This monitoring program is periodically supplemented by targeted
socio-economic and environmental studies.
Parametrix-URS undertook a human health and ecological risk assessment to examine
waste mitigation options for an OTML Mine Waste Management Project between 1997
- 1998. The Screening Level Risk Assessment concluded that “no assessment of direct
risks (risk from exposure to mine-related chemicals) to human health was warranted
based on screening level results that indicated no significant risks” (Parametrix 1999a).
The final Parametrix Detailed-Level Risk Assessment made almost no reference to
human health, other than a global comment that “potential risks to humans are
uncertain at this time” (Parametrix 1999b).
17
Figure 2: Community health study regional villages map
18
Relating to human health issues, the SLRA and DLRA reports have been the subject of
significant criticism by the OTML international Environment Peer Review Group,
which noted that “the report frequently relied inappropriately on modelling efforts, and
that the risk to humans is poorly examined” (PRG 2000).
Analysis of the SLRA identified other serious deficiencies including:
•
•
•
•
selection of inappropriate human health exposure assumptions based on
developed country urban population parameters and “best professional
judgment”;
exposure compartments were based on inadequate data (eg food metal
intakes, normally the largest exposure source were revised only for fish and
other aquatic resources);
village drinking water sources were largely ignored with no data presented;
and
no consideration was given to the mine-area communities (Bentley 2004b).
The passage of the Ok Tedi Mine Continuation (Ninth Supplemental Agreement), and
the adoption of the OTML Environmental Regime at the end of 2001 refocused the
OTML environmental monitoring program to six key environmental values (OTML
2001). Three of these values were central to the objectives of the OTML CHS. In
essence, in so far as these values were impacted by mining activities, they can be
summarised as:
“Is the water in the main channels available to the downstream communities’
drinkable?
“Are the fish and other aquatic resources in the Ok Tedi-Fly Rivers and the Gulf
of Papua adjacent to the Fly River estuary safe to eat?
“Are the village crops and natural bush-sourced foods, safe to eat?”
To address these key environmental values, OTML commissioned the CSIRO
Australian Centre for Environmental Contaminants Research to assess the impact of
cadmium, copper, lead and zinc on the edibility of food crops produced in the Fly River
flood plain (Hamon & McLaughlin 2003).
The CSIRO report reviewed the key factors affecting metal phytoavailability from both
natural and impacted soil and sediments on the plant crops banana, cassava, corn, sago,
sweet potato and taro. While the report undertook an assessment of the feasibility of
deriving soil thresholds and compared the existing OTML data with international values
for the level of the metals in foods, the study had some difficulty in correlating this data
with human health assessment (NSR 2003).
The CSIRO review included within its recommendations the need for the actual
measurement of metal concentrations in core and bioaccumulator foods “ready for
table”, the measurement of human intakes of food and drinking water and the
measurement of child soil intakes.
In mid-2003, some 18 months after the adoption of the OTML Environmental Regime,
OTML contracted NSR Environmental Consultants Pty Ltd (now Enesar Pty Ltd) to
19
conduct an independent review of the compliance and science of the OTML monitoring
activities for the riverine environment downstream of the mining operation (NSR 2003).
The NSR report made a number of recommendations for further work to address issues
of human health and wellbeing. In particular, the report proposed that OTML should
undertake a cross-sectional human health risk assessment for the Environmental Regime
values relating to the down river safety of the food and drinking water resources. NSR
proposed that the scope of the work should encompass “investigations into the
contaminant metal content in core food items and metal bioaccumulator foods and
develop itemised food intake patterns, frequencies and quantities for the villagers’ diets
for the river corridor communities and comparable control populations. The proposed
work would also need to establish the main sources and intakes of water used for
drinking, cooking and for recreational purposes. Finally the study would need to
undertake an examination of other exposure pathways such as soil ingestion, drinking
water and recreational water.”
OTML in early 2004, commissioned the Centre for Environmental Health Pty Ltd to
conduct a quality-assured Community Health Study (OTML CHS) of the mine area and
down river villages. The scope of the study included quantitative estimates of the level
of metal contaminants for each of the exposure compartments air, water, soil and food
for the potentially impacted villages both in the mine area and along the river system,
together with matched (non-impact) control villages having similar demographic
characteristics and social, agronomic and economic circumstances. The present report
and a companion report, examining the demographic, anthropometric and food and
nutrition of the Ok Tedi-Fly Rivers communities, is the outcome of this activity.
As a first step in the conduct of the OTML CHS, the availability and quality of the
existing data for each of the proposed regions/communities were evaluated using a
framework that prioritised the data in accord with its value for health (Bentley 2004a).
For clarity, the historical data in respect of public and environmental health is
summarised in Chapter 3, while that relating to demographics/anthropometrics, food
and community nutrition are discussed in the companion Volume 1 Food and Nutrition
Report.
1.2 The Ok Tedi-Fly River and Lake Murray Community Health Study
An analysis of the human health impacts of the OTML mining operations on the
populations of the mine area communities and those living along the Ok Tedi and Fly
River can be considered a tripartite process.
The first requirement was to have an understanding of the population affected, including
their health, socio-economic circumstances and cultural practices, which in the broadest
sense, are the major determinants of baseline health status.
The second requirement was to be able to quantify the ongoing environmental changes
brought about by mining, ie the presence of contaminant metals and other chemicals in
each part of the human environment.
The third requirement was to be able to quantify any health impacts resulting from the
interaction between the people and their environment.
There are a number of features of a data-rich health risk assessment, based on
international guidelines and national standards, when compared with a probabilistic risk
20
modelling approach, derived from multiple layers of assumptions. The international risk
model was based on comparing the actual measured exposures for the impacted
populations, summed over the various pathways, with the independently derived simple
but robust Tolerable Weekly Intake (TWI) values for each contaminant.
The principal benefits are that the end product is transparent and readily understood by a
wide lay audience. Additionally, the Tolerable Weekly Intakes for each contaminant are
simple but robust. They can be used in the process of planning interventions to reduce
exposure from critical pathways ie the development of alternative exposure scenarios
utilising different input parameters for the impacted regions.
The disadvantage, is that a quantitative CHS is based on extensive datasets gathered
from every exposure route and from control (non-impacted) as well as potentially
exposed (impact) communities. Hence there needs to be a good argument to omit any of
the required datasets. For example, for air quality a case can be made for the use of a
single site to represent all rural and remote river villages outside the mine area and road
impacted regions. By contrast, it would be difficult, in view of the known elevated
mercury levels in human biomarker samples to justify not treating the Middle Fly-Lake
Murray area as a distinct region for all exposure routes.
Unless there is a clear justification, it is essential to have data for all exposure
compartments from both control and potentially exposed populations for each defined
exposure group. In the present case, this was achieved by establishing air monitoring
stations at the mine-area communities (Finalbin), the potentially road-impacted villages
(Ningerum) and at Gre near Kiunga township. Data was already available for other
remote locations including the Ok Om-Lagaip River junction and at Lake Murray to
represent the control communities.
As the purpose of the CHS was to gain an understanding of the impact of the OTML
mining activities on the impacted populations, the choice of “impact” and “control”
populations was critical. These populations needed to represent the communities that
were clearly “potentially impacted” or “non-impacted”, but both groups must at the
same time represent the exposure circumstances appropriate for people living in
environments of varying degrees of natural mineralisation, with the consequent
variation in background exposure to metals. Hence, it would be meaningless to
selectively choose controls from a pristine, low mineralised area, and equally futile to
choose the “worst case” highly mineralised areas to represent background levels of
exposure.
The ideal situation was to choose a non-impacted area within each of five discrete
geographic regions, from which to collect samples for control or background levels. In
an environment of such diverse communities, there was a need for innovative selection
of the control sampling strategies to achieve a balance between pragmatic achievement,
cost-effectiveness and scientific rigour. A careful choice has been made of what were
considered to be the appropriate control samples for each exposure medium to allow
meaningful comparison with the diverse populations and exposure circumstances within
the different geographic regions.
In deciding the approach to be adopted, consideration also needed to be given to the
influence of various factors on the baseline health data. These factors included
demographics (including total potentially impacted population), socio-economic and
cultural divisions, food and climate - altitude variations, which determine the
21
agricultural patterns and food availability and village/regional factors such as nutritional
status and the prevalence of anemias, communicable diseases (eg malaria) and intestinal
parasites.
In all geographic regions there are groups of sensitive sub-populations within the
normal population. There are some critical groups that apply to all regions, such as
children under 5 years of age, pregnant and lactating mothers and health-challenged
groups. There are also region-specific issues. The Middle Fly-Lake Murray region, for
example, has high mercury baselines, dietary variations in consumption between
communities and significantly different tissue mercury levels between fish species used
as food sources. The Finalbin and Bultem communities, by contrast, have access to the
health and social infrastructure and other urban benefits at Tabubil.
While not all potentially impacted villages in the mine-site communities and the Ok
Tedi and Fly River could be included within the sampling matrix, there was a minimum
of two representative communities from the impacted and control communities for each
region. Matching of populations between impact and control villages within a region
was based on both altitude, which is a major determinant of the range of garden crops
that can be grown, and proximity to the Ok Tedi-Fly River. At Lake Murray, the
villages of Buseki and Usokof were selected based on their geographic location and the
benefits to be derived from comparative data sets generated during the PJV PorgeraLagaip-Strickland-Lake Murray Food and Drinking Water Health Risk Assessment
conducted between 2002 – 2005 (Bentley 2005).
The success and credibility of the whole CHS depended on there being a transparent and
realistic set of criteria justifying the selection of each community. To the degree
practical, the selected villages were representative of all the villages within the region.
The impact and control villages within one region were also matched in cultural, social,
economic and demographic circumstances. This was somewhat confounded in Region 1
for the impact (mine-area) villages with their access to the urban centre of Tabubil,
when matched with their more remote (Region 1 control) communities who had limited
access to health and social infrastructure.
The historical OTML environmental media analytical database was until 2004, focused
on the potentially mine-derived metals, cadmium, copper, lead and zinc.
For reasons of compatibility with international norms, comparison with national Market
Basket Survey databases, the public health benefit of nutrition programs in Papua New
Guinea and the known elevated mercury in some of the riverine communities, it was
agreed early in the study development that the suite of metals to be analysed by the
OTML CHS, would also include arsenic, mercury and selenium.
Taking the above into consideration, the main objectives of the OTML CHS were to:
•
•
determine the potential for human health impacts from the OTML operation
in the mine-area villages, the Ok Tedi and Fly River communities and
villages along the Tabubil-Kiunga Highway using matched impact and
control populations in five distinct regions;
generate data for each exposure compartment (air, food, soil and sediment,
drinking and recreational waters) for a suite of contaminants and essential
trace metals;
22
•
•
•
compare the data for each environmental media directly with recognised
international health standards;
derive total weekly contaminant metal intakes for a range of different age
groups; and
develop “most realistic” and “worst case” exposure scenarios for each
region.
2.0 Project location, physical, demographic and socio-economic
characteristics
Twenty-three villages in five distinct geographic regions between the OTML Mine and
the Fly River estuary were selected in consultation with the Environment Department,
Community Relations and the Development Planning Unit of the Ok Tedi Development
Foundation. The criteria adopted for selection of particular villages encompassed a wide
range of parameters, including social, economic and health circumstances. These
included:
•
•
•
•
•
•
•
•
the range of locally available food crops and use of bush resources (eg
altitude, availability and soil characteristics of village gardens;
drinking water sources eg independent sources (tanks etc), flood plain offriver water bodies, river system;
use of the riverine environment for transportation, aquatic food collection
and food preparation including cooking, swimming and other recreational
uses;
economic, cultural and ethnic similarities;
access to health and other social services;
consideration of databases from existing OTML environmental and
community relations monitoring sites and historical health patrol data;
community awareness and levels of concern on health issues at village
level; and
security issues and anticipated levels of co-operation with field survey staff.
The villages of Buseki and Usokof were included as control villages for the Community
Health Study Region 3, on the basis that there were already extensive health and
environmental data for these communities from the PJV database. This includes all of
the seven target contaminant and trace metal analytes proposed for the OTML CHS.
PJV kindly gave their permission for these data to be used in the present work.
In summary, the Highland Region 1 included the OTML mine-area communities of
Bultem and Finalbin, together with the control populations of Ok Ma and Derengo,
being somewhat more isolated from the range of urban services and social, educational
and health infrastructure. The villages in the Highland region are situated at altitudes of
between 580 and 840 metres above sea level. All four communities have their
recreational water access from local creeks.
The Lowland regions, Regions 2 - 5 included:
•
Region 2: villages between Ningerum at an altitude of 50 metres above sea
level and the junction of the Ok Tedi River at D’Albertis Junction, some 80
– 170 kilometres below Tabubil (Region 2 impact). The control populations
for this group (Songty Valley and Walawam) are located near the Ok Mat
23
•
•
and an unnamed spring respectively. Both are distant from any possible
mine-derived sediment impacts;
Region 3: villages between D’Albertis Junction and Everill Junction
(Middle Fly) on the Fly River above the Strickland River (Region 3 impact).
The control villages are located either away from the river or within the
north western reaches of Lake Murray. These communities are
characterised as having some limited access to social and health facilities
and derive some income eg from the sale of crocodile and turtle products;
and
Regions 4 and 5: villages on the Lower Fly River (Region 4 impact) and
Fly estuary communities (Region 5 impact). The Region 4 control
communities of Kiru and Aewa are located near to Lake Suki/Suki Creek,
while the control communities for Region 5 are located either adjacent to
the Oriomo River (Abam) or are coastal (Kadawa).
All of the villages in the Lowland regions with the exception of Kwiloknae (altitude 280
metres) are situated at altitudes less than 50 metres. The details of the OTML CHS
regional classification, local government unit, altitude and location are given in Table 1.
The study villages comprise a number of diverse ethnic, cultural and language groups.
The majority are adherent to the Christian faith with a large number of denominations
represented. The availability of a cash-based economy in the study area, is closely
reflected by the presence and number of trade stores and consumption of products such
as tinned meat, tinned fish, flour and rice.
To the degree practical, the identified communities were surveyed and samples
collected. However, due to unresolved social issues, alternative locations within the
same region had to be substituted for some data. Where this has occurred, it has been
noted in the text.
24
Table 1: Ok Tedi-Fly OTML CHS region and village location characteristics
Village
OTML CHS
classification
LLG
Altitude
(metres)
Region 1
Star Mountains
840
800
Star Mountains
580
Ningerum
580
Region 2
Ningerum
< 50
Finalbin
Bultem
Ok Ma
Derengo
Region 1
impact
Region 1
control
Ningerum
Tamaro
Ieran
Kwiloknae
Gre
Walowam
Songty Valley
Region 2
impact
Komovai
Manda
Usokof
Buseki
Region 3
impact
Region 3
control
Lake Murray
rural
Sapuka
Sialowa
Kiru
Aewa
Region 4
impact
Region 4
control
Morehead
Gogodala
Morehead
Tapila
Sagero-Koavisi
Wapi
Abam
Kadawa
Region 5
impact
Gogodala
Kiwai
Region 5
control
Oriomo Bituri
Kiwai
Region 2
control
Kiunga Rural
Ningerum
Kiunga Rural
Ningerum
Latitude
Longitude
05 12′- 51.06″
05 12′ 33.12″
05 23′ 10.04″
05 23′ 2.66″
141 11′ 34.51″
141 12′ 46.28″
141 10′ 40.69″
141 05′ 55.82″
05 40′ 14.95″
141 8′ 43.83″
< 50
280
< 50
< 50
< 50
05 59′ 56.84″
05 32′ 17.27″
06 0′ 58.65″
05 28′ 30.44″
05 42′ 40.00″
141 6′ 38.48″
141 16′ 28.89″
141 18′ 28.43″
141 14′ 26.99″
141 17′ 40.00″
< 50
< 50
< 50
70
07 32′ 29.71″
07 00′ 05.49″
06 54′ 4.23″
06 47′:07″
141 16′ 21.58″
141 06′.45″
141 8′ 44.07″
141:24′:42″
< 50
< 50
< 50
< 50
08 10′ 1.35″
08 9′ 43.41″
07 57′ 0.9″
08 2′ 23.85″
141 59′ 52.05″
142 15′ 33.98″
141 44′ 46.01″
141 41′ 55.57″
< 50
< 50
< 50
< 50
< 50
08 25′ 25.34″
08 14′ 3.56″
08 27′ 12.99″
08 55′ 26.90″
09 1′ 45.22″
142 56′ 5.04″
143 32′ 15.95″
143 31′ 31.10″
143 11′ 29.17″
143 11′ 20.05″
Region 3
Region 4
Region 5
The most reliable demographic data for the study villages is that compiled by the Ok
Tedi Development Foundation 2002 supplemented by more recent census data for the
CMCA communities (OTDF 2002, 2006). However, this data does not necessarily
represent the entire village populations, since it was collected as part of the OTDF
program for compensating indigenous communities and does not include settlers who
may have migrated into the villages. Where data is unavailable from the OTDF census,
the Papua New Guinea National Census 2000 data for Western Province has been used
(NSO 2002).
A summary of the demographic and household characteristics of the study communities
is given in Table 2. Detailed demographic data and study village population profiles are
presented in Volume 1, Health and Nutrition Report. In summary, the demographic
profile for Region 1 is that anticipated for a rapidly urbanising population. For Regions
2 – 4 the broad-based population pyramids are typical of rural Papua New Guinea and
indicate high fertility rates and early premature mortality and/or increased out migration
of the adult group. The data is similar to the patterns reported by Taufa (Taufa 1997).
Region 5 communities are in the middle of these two profiles.
25
Table 2: OTML CHS demographic and household characteristics
Region
Region 1
Finalbin (2000)
Finalbin (2005)
Bultem (2002)
Ok Ma (2002)
Derengo (2002)
Region 2
Ningerum
Tamaro (2002)
Ieran (2002)
Kwiloknae
(2002)
Gre (2002)
Walowam (2002)
Songty Valley
Region 3
Komovai (2002
Manda (2000)
Buseki (2003)
Usokof (2003)
Region 4
Sapuka (2002
Sialowa (2002)
Kiru (2002)
Aewa (2002
Region 5
Tapila (2002)
Sagero-Koavisi
(2002)
Wapi (2002)
Abam (2000)
Kadawa (2002)
Population
615
313
422
300
314
Males
341
Females
Nos
Households
Mine area communities
274
78
Members/Household
(mean)
7.8
6.1
6.7
8.9
109
214
208
69
150
150
45
182
132
35
Ok Tedi and Highway communities
63
46
31
100
485
44
244
21
49
4.8
9.9
522
143
257
282
81
149
6.7
7.5
6.7
298
450
184
550
154
241
88
270
583
496
341
320
299
257
155
174
246
324
138
184
240
78
62
19
108
32
Middle Fly communities
144
31
209
72
96
31
280
Suki Fly Gogo communities
284
96
239
76
186
55
146
54
South Fly communities
108
44
140
94
310
238
680
150
126
347
56
241
160
112
333
28
48
117
3.5
9.6
6.3
6.0
6.1
6.5
6.2
5.9
5.6
3.4
11.1
5.0
5.8
Notes:
1.
2.
3.
4.
The data for 2000 is from the PNG National Census (NSO 2002). The data for 2002 and 2005 is
from the OTML CMCA village census surveys. The data for Buseki and Usokof is from a PJV
census conducted in 2003.
The population for Sagero-Koavisi is the combined data for both villages, which are located less
than 4 kilometres apart.
The South Fly communities include both North and South Bank villages and communities from
the Kiwai Islands.
The population of the North Fly district, Middle Fly district and South Fly district (National
Census 2000) is 50,914, 55,853 and 46,537 respectively, of which 8,649 live in the Tabubil Urban
LLG and 8,295 in the Kiunga Urban LLG (PNG NSO 2002) .
26
3.0 Health status in the Ok Tedi Fly Rivers communities
The health situation for the present study communities divides into two distinct groups.
The development of the OTML mining operation has strongly impacted on the socioeconomic and health status of the mine-area villages, within the Tabubil town
catchment and the Ningerum LLG area communities, particularly those with access to
the river port of Kiunga.
For many of these communities, increased diversity in food sources and hence better
nutrition are clearly evident. Infant mortality has decreased some 20-fold and the
average lifespan has increased by at least 10 years. The incidence of malaria has also
decreased some five-fold in both children and adults, due to implementation of vector
control programs. The transition to urban lifestyles has resulted in an increased
prevalence of “lifestyle diseases”, including coronary disease, diabetes and sexually
transmitted infections.
Quantitative data for the health status of rural and remote village communities in the Fly
River corridor, Lake Murray and the Fly estuary regions remains sparse. The main
health threats to these communities are those typical of other rural and remote, socioeconomically disadvantaged areas in Papua New Guinea. This is characterised by an
environment of limited health or social support, inadequate housing, malnutrition, lack
of environmental infrastructure (water, sanitation and food safety) and enhanced
susceptibility to parasites and communicable diseases.
These communities have seen some improvements in health status, resulting from
infrastructure development both in co-operation with the Government of Papua New
Guinea and the Monfort Catholic Mission at Kiunga, and more recently, directly
through the Ok Tedi Development Foundation. Regrettably, in most villages there are
few regular government health surveys to evaluate the impacts of health service access.
Preliminary health studies were conducted in the Star Mountains Wopkaimin
communities in the 1970s (Taukuro 1980). This report identified that malaria, anaemia,
malnutrition and respiratory and other infectious diseases were predominant and the life
expectancy was about 30 years of age. The level of infant mortality was particularly
high.
The first significant study of health and nutrition of the Ok Tedi communities
(Wopkaimin, Ningerum and Awin villages) was conducted between 1982 and 1986
(Lourie 1985, 1987, Lourie et al 1987). The 1982 – 1983 pre-mine baseline study of the
Wopkaimin indicated very high crude infant mortality rates (230/1000), some three-fold
the average for Papua New Guinea. Respiratory diseases and malaria appeared the most
common contributors to both infant and adult mortality. There were widespread skin
diseases, ulcers, ear and eye infections, and characteristic of multiple infection
challenges, extensive splenomegaly and lymph node enlargement.
The 1983 – 1985 prospective study indicated that both the Ningerum and Awin
populations had lower crude infant mortality rates (170/1000) and in general, a lower
prevalence of disease indicators than the Wopkaimin. The follow-up study of the
Wopkaimin people in 1986 indicated that crude infant mortality rates had fallen by 40%.
Unquestionably, part of this improvement could be attributed to the introduction of
childhood immunisation programs for this population in 1984. Malaria prevalence had
27
also markedly been reduced, as had the incidence of spleen, lymph node and liver
enlargement.
The second comprehensive assessment, the OTML Ok-Fly Social Monitoring Program
(1991 – 1995) undertook a broadly-based assessment of cultural, social economic and
health circumstances for each of the Wopkaimin, Ningerum, Awin and Yonggom
communities (Burton 1991, 1993a, b, Schuurkamp et al 1992, Kirsch 1993).
Between 1986 and 1991, there had been increasing health service uptake by those
communities close to Tabubil having access to the OTML-sponsored hospital and health
facilities. Similarly, there had been significant movement of people from the more
isolated Ningerum villages to the Tabubil-Kiunga highway, resulting in improved health
access, particularly to the Ningerum Health Centre. For the more remote Yonggom
villagers, their health status remained poor, with malaria, filariasis and tuberculosis
being prevalent, together with additional ill health from introduced diseases.
A review of the entire village-based medical database concluded that malaria was the
principal cause of ill health. Lower respiratory tract disease, both chronic and acute
pulmonary and glandular tuberculosis were present, although the major cause of adult
mortality was pneumonia.
An OTML-sponsored medical patrol was conducted at nine of the 16 Alice (Ok Tedi)
River Trust villages in 1997. The main findings of the study included that the crude
birth rate (37.8/1000 range 9.4 – 78.5) was comparable with that of Western Province in
1990 (40.8/1000) (NSO 1990, Taufa 1998). Sanitation in the communities was poor,
with the high prevalence of respiratory disease attributed to poor housing conditions. In
contrast, vaccination coverage of the under 5 years of age was exceptionally high.
Haemoglobin values (male mean 13.8, female mean 12.4) were generally consistent
with the hyperendemic status of malarial infection.
There are very few health studies relevant to the Middle Fly-Fly estuary communities.
Dr Stephen Flew undertook a number of medical patrols and a major baseline health and
nutrition study between 1994 and 1998. The baseline human health assessment survey
was conducted in 10 villages (618 individuals) in the Fly River between D’Albertis
Junction and the Fly estuary (Flew 1999). Of these communities, Komovai, Sapuka,
Sialowa and Sagero-Koavisi are included in the OTML CHS. The Flew study is the
most definitive assessment of clinical health status in the Middle-Lower Fly River and
Fly estuary communities. The study used a randomised selection of households and
implemented each of social and nutrition questionnaires, anthropometric measurements,
clinical examinations and bioassay measurements (blood, hair, urine and stool samples).
The results provided a good cross-sectional assessment of communicable, respiratory
and parasitic disease prevalence. Regrettably, only summary statistical data are
available.
A study conducted at Lake Murray in 1996, indicated a profile of poor health, with a
high prevalence of acute respiratory infections in children, filariasis, malaria and
tuberculosis and significant rates of childhood malnutrition and stunting (Taufa 1997).
Environmental sanitation was generally poor in all of the villages, resulting in a high
prevalence of both diarrhoeal and internal parasitic infections. There was also a
significant prevalence of respiratory infections, attributed to significant overcrowding
and from the cooking of food indoors.
28
The overall conclusions from these studies may be summarised as:
•
•
the health of the village communities outside of the OTML mine operation
impact area is typical of similar Highland and Lowland communities in
rural and remote Papua New Guinea; and
the medical surveys do not indicate any clearly discernable changes in the
long-term trends, or any emergence of novel disease patterns since the
establishment of the OTML mining operations and disposal of mine waste
to the river system.
4.0 Health Risk Assessment methodology
4.1 Units of measurement for contaminants in the environment
The conventional metric units of measurement and terminology have been adopted in
this report. In drinking and surface waters, chemical contaminants are expressed in
milligrams per litre (mg/L). In soil, food and other solids, chemical contaminant levels
are expressed in milligrams per kilogram (mg/kg). Concentrations of particulates in air
are expressed as micrograms per cubic metre (µg/m3). Metals in air are expressed as
nanograms per cubic metre (ng/m3).
4.2 Exposure pathways
In general, an exposure pathway describes how a contaminant travels through the
environment from its source to humans or other living organisms. An exposure pathway
consists of five elements: source of contamination, environmental media, point of
exposure, exposed population and route of exposure.
The riverine disposal of mine waste was the principal (and for Regions 2 - 5
communities the sole) source of mine-derived contamination analysed in the OTML
CHS. In the Region 1 impact mine area villages of Bultem and Finalbin there were also
potential exposures from other mine-derived sources, including mine-sourced dust that
may contribute to the local air shed, local creeks and drainage channels and exposed
mine wastes and freshly deposited waste rock and tailing materials.
Once released from its source, a contaminant will travel through environmental media
to points where human exposure can occur. In humans, the major environmental media
include water, air, food, soil and sediments.
The water compartment includes village drinking water sources (generally rainwater
tanks, springs, creeks and occasionally off-river water bodies and Lake Murray) and
surface waters (water from rivers, off-river water bodies and Lake Murray). Exposure
occurs through drinking, bathing, washing of clothes, agriculture, hunting and fishing
and recreational use.
The ambient air environment may have contributions from respirable particulates and
contaminant gases from mine-derived dust and other sources such as diesel generators
and motor vehicle exhausts.
The food compartment includes exposure to foods grown with contaminated water, or
grown in areas where the soil is contaminated. Exposure may also occur when
consuming contaminated plants, native fruits, fish and other wildlife gathered during
hunting and fishing trips.
29
The soil compartment includes exposure to bare ground (inhalation, ingestion and skin
contact with soil), contaminated soil blown as dust in the air and particles deposited on
other surfaces (such as food) and contaminated active river sediments.
The point of exposure is the location where contact with a contaminant occurs. For
example, people can be exposed to contaminants in the home, at work, in a play area, in
a lake, river, creek or other body of water. Villagers may be exposed while bathing in a
contaminated river, or hunters and fishermen and their families may be exposed by
consuming contaminated bush meats or fish.
The route of exposure describes how a contaminant enters the human body. There are
three routes by which humans may take contaminants into their bodies:
•
•
•
ingestion - swallowing something containing the contaminant. This can
include food, water or small amounts of soil containing the contaminant;
inhalation - breathing in a substance, as airborne particles. This can include
small amounts of soil and dust that can be inhaled into the lungs; and
skin contact - some contaminants in water, soil and air can be absorbed
through the skin.
4.3 Regulatory limits
Traditionally, one avenue of protection of human health has been through the
establishment of exposure limits (variously referred to as standards, quality criteria, etc).
These are established in a two-step process, the first involving consideration of the
health-based scientific data and the second involving the establishment of regulatory
limits, taking into account the health-based recommendation along with other factors.
These regulatory limits provide estimates of chemical-specific doses, which if not
grossly exceeded, may be regarded as safe or having no adverse effects.
Examples of health-based exposure guidelines include the Acceptable Daily Intake
(ADI) and Tolerable Daily Intake (TDI).The term ADI is commonly used for additives
to food that impart some beneficial characteristic (and hence are considered acceptable).
TDI commonly refers to environmental contaminants that are undesirable.
Acceptable/Tolerable Intakes are the amounts of a food contaminant, expressed on a
body weight basis that can be ingested over a lifetime without appreciable risk to health.
The present study largely uses the WHO Provisional Tolerable Weekly Intake (PTWI).
It is important to note the statement by the Joint FAO/WHO Expert Committee on Food
Additives that: “the PTWI is not a limit of toxicity and does not represent a boundary
between safe intake and intake associated with a significant increase in body burden or
risk. Long-term exposure slightly above the PTWI would not necessarily result in
adverse health effects but would erode the safety factor built into the calculation of the
PTWI.”(JECFA 2001).
4.4 Definition of exposure and related terms
The objective of exposure assessment is to determine the nature and extent of contact
with chemical substances experienced or anticipated under different conditions.
Approaches for assessing exposure and characterising uncertainties and/or variability in
resulting estimates presented here, are derived primarily from the US Exposure
Assessment Guidelines (US EPA 1988, 1989, 1992) and the WHO (IPCS 1994, 2000).
30
An exposure assessment is the quantitative or qualitative evaluation of the contact
between the chemical substance and the human system, which includes consideration of
the intensity, frequency and duration of contact, the route of exposure (eg dermal, oral
or respiratory), rates (chemical intake or uptake rates), the resulting amount that actually
crosses the boundary (a dose) and the amount absorbed (internal dose).
Doses are often presented as dose rates, or the amount of a chemical dose (applied or
internal) per unit time (eg mg/day). They may also be presented as dose rates on a per
unit body-weight time (eg mg/kg/day). Because intake and uptake can vary, dose rate is
not necessarily constant. An average dose rate over a period of time is a useful number
for many risk assessments. These averages are often in the form of Average Daily or
Weekly Doses expressed, for example, in microgram per kilogram body weight per
week (μg/kg bw/wk).
Depending on the purpose of an exposure assessment, the numerical output may be an
estimate of the intensity, rate, duration and frequency of contact exposure or dose (the
resulting amount that actually crosses the boundary). The OTML CHS is based on doseresponse relationships, as represented in the regulatory health limits with the outputs
usually expressed as an estimate of dose.
For effects such as cancer, where the biological response is usually described in terms
of lifetime probabilities, even though exposure does not occur over the entire lifetime,
doses are presented as Lifetime Average Daily Doses (LADDs).
4.5 Approaches to quantification of exposure
Exposure (or dose) is assessed generally by one of the following approaches:
•
•
•
the exposure can be measured at the point of contact (the outer boundary of
the body) while it is taking place, measuring both exposure concentration
and time of contact and integrating them (point-of-contact or personal
measurement);
the exposure can be estimated by separately evaluating the exposure
concentration and the duration of contact, and combining this information
(scenario evaluation) - this is the approach used in this present report; and
the exposure can be estimated from dose, which in turn can be reconstructed
through internal indicators (biomarkers, body burden, excretion levels, etc)
after the exposure has taken place (reconstruction).
Data to support this last, reconstruction, approach is available as a means of adding
additional supporting evidence to the OTML CHS from the biomarker hair sampling
and analysis conducted in Regions 1 – 4. These results are presented and discussed in
the supplement to this report.
5.0 Hazard assessment
In order to evaluate whether exposure to metals in mine waste materials poses a threat
to health, the mean metal concentrations in the environmental media have been
compared with standards and guidelines, established by the Government of Papua New
Guinea, the World Health Organization and national criteria from the United States,
Canada and Australia. Metals that are present at concentrations below the applicable
criteria do not pose concerns for human health.
31
The World Health Organization has considered the possibility of synergism in toxicity
between contaminant metals. For the metals being considered in the present report there
are only three known synergisms in health impacts:
•
•
•
copper and zinc where an excess of zinc can reduce the absorption of
copper, particularly in children and adolescents resulting in copper
deficiency;
increased uptake of lead in severely iron-deficient individuals, particularly
infants and pregnant or breastfeeding mothers; and
on average 5% of ingested cadmium is absorbed by humans, however,
absorption is enhanced when the iron status of the body is sub-optimal.
5.1 Data summaries for contaminant metals
5.1.1 Arsenic
The following short synopsis on arsenic has been prepared from several excellent
reviews namely: US NRC 1999, ATSDR 2000, IPCS 2001a, WHO 2004 and JECFA
1989.
Natural concentrations of arsenic in the earth’s crust average 2 mg/kg. The major
natural sources of arsenic are volcanic activity and burning of vegetation (forest fires).
Mining and smelting of non-ferrous metals and burning of fossil fuels present major
anthropogenic sources of arsenic in air, soil and water. In areas not affected directly by
industrial sources, total arsenic concentrations in air, water and soil have been reported
as: air (rural) 0.02 to 4 ng/m3, air (urban) 3 to ~200 ng/m3, surface and drinking water <
10 µg/litre, ground water 1 - 2 µg/litre except in areas with volcanic and sulphide rocks
where concentrations up to 3 mg/litre have been measured, and background
concentrations of arsenic in soil 1 - 40 mg/kg (average 5 mg/kg).
Arsenic has been found in all foodstuffs analysed with varying ratios of organic to
inorganic species. The actual total arsenic concentration will vary depending upon the
food type (marine fish/shellfish, vegetables, etc), growing conditions and processing
techniques. It has been estimated that the percentage of inorganic arsenic is about 75%
in meats, 65% in poultry, 75% in dairy products and 65% in cereals. In fruits,
vegetables and seafood, inorganic arsenic contributes between 0 and 10% of the total
amount.
In non-occupationally exposed adults, the major source of arsenic exposure is through
the diet. However, in areas where concentrations of arsenic in drinking water exceed 10
µg/litre, water may also provide a significant source of inorganic arsenic ingestion. In
adults, the total daily intake of arsenic from diet and water in the USA averaged 56.6
µg/day, while in Canada it averaged 59.2 µg/day. In children the ingestion of soil must
be considered an additional source of inorganic arsenic.
Although soluble inorganic arsenic is acutely toxic with large doses leading to death, the
concerns of adverse health effects from the non-occupational exposure to arsenic by
ingestion relate to the production of cancer in skin, lungs, bladder and kidney and other
skin changes such as hyperkeratosis and pigmentation changes (based on studies of
arsenic in drinking water). Arsenic in drinking water has been classed as a human
carcinogen by the International Agency for Research on Cancer (IARC 1987). The US
EPA has also classified inorganic arsenic as a Group A carcinogen (“known to produce
cancer in humans”).
32
The US EPA has used data from a large study of skin cancer in Taiwan to derive an oral
cancer slope factor for arsenic, and this value is used in risk assessment to estimate
cancer risks from arsenic ingestion from environmental media in general (ie water, soil
and sediments). The estimates of the incremental risk of lung cancer from lifetime
exposure to 1 µg/m3 are 4.3 x 10-3 and 3 x 10-3 by US EPA and WHO respectively (US
EPA 1984, WHO 2000).
5.1.2 Derivation of a tolerable weekly intake
JECFA/WHO assigned a Provisional Tolerable Weekly Intake (PTWI) for inorganic
arsenic of 15 µg/kg bw/wk. However, JECFA acknowledged that there was a narrow
margin between the WHO PTWI and intakes reported to have toxic effects in
epidemiological studies. The available data was insufficient for JECFA to set a PTWI
for organic arsenic in food, however, it was noted that organic arsenic intakes of about
50 µg/kg bw/day (ie 3000 – 3500 µg/day for adults) produced no reports of ill effects,
and that organoarsenicals found in fish, although almost completely absorbed, were
rapidly excreted, unchanged, by humans.
Australian data indicate that for children, dietary exposure to arsenic accounts for about
50% of the WHO PTWI, based on the Australian Market Basket surveys. The other
major intake is from soil exposure/ingestion, and based on a child 2.5 years of age,
weighing 13.2 kg and ingesting 100 mg of soil per day. The Health Investigation Level
(HIL) for arsenic was determined to be 100 mg/kg soil (equivalent to 40% of the WHO
PTWI) for a standard residential exposure scenario (NEPC 1999).
5.1.3 Cadmium
The following reviews on cadmium have been used to prepare this review summary:
IARC 1993, IPCS 1992, ATSDR 1999a and JECFA 2001.
Cadmium has no known biological function in humans.
The major natural sources of cadmium in the human environment include weathering of
minerals, volcanic emissions and forest fires. Typical background concentrations in
environmental media from areas not considered polluted are: air (rural) 0.001 to 0.005
ng/m3, air (urban) 0.005 to 0.040 ng/m3, fresh surface and drinking water < 1 µg/litre
and background concentrations of cadmium in soil (rural/urban) 0.01 to 1 mg/kg except
in areas with volcanic activity where soils may contain as much as 4.5 mg Cd/kg.
Cadmium has been detected in nearly all samples of food analysed worldwide, where
sensitive analytical methods were utilised. The metal is taken up and retained by aquatic
and terrestrial plants and is concentrated in the liver and kidneys of animals. This is
reflected in the analytical results of foodstuffs which have shown liver and kidney meats
as well as shellfish have the highest concentrations of cadmium (up to 1 mg/kg), with
levels of cadmium in fruits, vegetables and grain ranging between 0.01 and 0.1 mg/kg.
The major route of exposure to cadmium for the adult non-smoking population is
through food. In the United States, adult intake of cadmium from food has recently been
estimated to be about 30 µg/day, with the largest contribution being from grain and
other cereal products, potatoes and vegetables. Indigenous people worldwide consuming
organ meats and/or shellfish on a regular basis, would have a far larger intake of
cadmium than 30 µg/day. Tobacco is an important source of cadmium uptake in
33
smokers. Cigarettes contain approximately 1.5 – 2 µg cadmium per cigarette. The
average adult smoker has double the intake of cadmium of a non-smoker.
Once absorbed, cadmium accumulates in the liver and kidney with a half-life of about
17 years. In those exposed to cadmium from the environment only, it is the
accumulation of cadmium in the kidney that results in adverse health effects.
The primary toxic effect of chronic exposure to cadmium from environmental sources is
renal dysfunction. This results from the accumulation of cadmium in the renal cortex
over many years of exposure, and can lead to impaired reabsorption of proteins, glucose
and amino acids. A characteristic sign of this renal impairment is the excretion of low
molecular weight proteins. Based on a biological model, an association between
cadmium exposure and increased urinary excretion of low molecular weight proteins
has been estimated to occur in humans with a life-long daily intake of about 140 - 260
µg cadmium. There is some evidence that the threshold for nephrotoxicity may be as
low as a lifetime exposure of 100 µg Cd/day in some individuals.
The International Agency for Research on Cancer (IARC) classifies cadmium and its
compounds as a group 2A (probable human carcinogen) based on exposure of workers
(IARC 1987). WHO reports no elevated cancer incidence in animal studies, but
induction of lung tumours in occupational workers following high dose inhalation of
inorganic cadmium compounds (IPCS 1992). WHO concludes that it is not yet possible
to determine if cadmium exposure causes cancer in humans.
The Joint FAO/WHO Expert Committee on Food Additives established a Proposed
Tolerable Weekly Intake (PTWI) for cadmium of 7 µg/kg body weight for adults and
also for infants and children (JECFA 1989). JECFA also estimated the dietary intake of
cadmium to be usually within the range 1 – 4.7 µg/kg bw/wk, and cautioned that there is
only a small safety margin between normal dietary exposure and exposure that may
produce adverse effects.
5.1.5 Lead
The published literature on lead exposure and effects in humans is very extensive. The
following reviews were used in preparing this summary on lead: US EPA 1986, IPCS
1995, ATSDR 1999b, JECFA 2000, CDC 2002 and NHANES 2003.
Lead has no known biological function in humans.
The concentration of lead in the earth’s crust, is between 10 – 20 mg/kg. The major
natural sources of lead are volcanic emissions, geochemical weathering and emissions
from sea spray. Anthropogenic sources include use of lead additives in petrol,
production and recycling of storage batteries, the burning of fossil fuels and the mining
and smelting of lead ores. The major lead mineral is lead sulphide (galena), usually
found in association with other minerals, particularly those containing zinc.
In most countries, the levels of environmental lead and lead in human tissues have
fallen markedly since the removal of organic lead additives from motor fuels and lead
solder in food tins. Typical background concentrations in environmental media are: air
(rural) 0.3 - 9 ng/m3, air (urban) 100 - 300 ng/m3, fresh surface and ground water < 10
µg/litre, drinking water 2 - 5 µg/litre (up to 100 µg/litre in soft water areas) and soils
(rural/urban) 5 - 100/83 - 1881 mg/kg.
34
Food, air, water and dust/soil are the major potential routes of exposure pathways for
infants and young children. In the general non-smoking adult population, the major
exposure pathway is from food and drinking water. The concentrations of lead found in
air, soil/dust, water and food vary widely worldwide and depend on the degree of
industrial development, urbanization and lifestyle factors.
The WHO maintains an extensive ongoing database detailing data on lead intakes. The
country data submitted includes both lead analysis in individual food products and data
from the national nutrition studies. Typical dietary intakes for countries that have
introduced lead-free petrol and other lead abatement initiatives, reported as µg/kg
bw/week, are: Australia (adults) 1.6 – 6.3, (child 2 years of age) 7 – 11.9, Canada
(adults) 3.3, (children 1 – 4 years of age) 5.25 and the United States (adults) 0.3 – 0.4,
(children 2 years of age) 1.1. The levels in children are generally two to three times the
adult intakes in the same country when evaluated on the basis of body weight.
Not only do children have a greater intake than adults on a body weight basis, the
efficiency of lead absorption depends on the route of exposure, age and nutritional
status. Adult humans absorb about 10% – 15% of ingested lead, whereas children may
absorb up to 50%. The rate of absorption is heavily influenced by food intake, with
absorption being much higher in fasted individuals.
Children are more sensitive to lead exposure than adults. The most important and best
documented effect of lead is the neurobehavioral development of children of mothers
who have been exposed to lead. Neuropsychological impairment and cognitive (IQ)
deficits are sensitive indicators of lead exposure, particularly after in utero exposure.
There have been a number of cross-sectional and longitudinal studies of children since
1979. Despite these extensive studies, it has not been possible to establish a threshold
below which lead has no effect on the IQ of children.
The US EPA has classified inorganic lead as a probable human carcinogen, although the
studies supporting this contention are from occupational exposures, and to multiple
contaminants. WHO and IARC both consider that the overall evidence for
carcinogenicity is inadequate and there is a lack of control of confounding factors in the
available studies.
The Provisional Tolerable Weekly Intake (PTWI) of 25 µg/kg body weight/week was
maintained at the fifty-third meeting of JECFA in 2000. This value, originally endorsed
in 1987, is based on evidence that a mean daily intake of 3 – 4 µg/kg body weight/week
of lead by infants and children was not associated with an increase in blood lead levels.
The committee considered the results of a quantitative risk assessment, and concluded
that the concentrations of lead currently found in food would have negligible affects on
the neurobehavioral development of infants and children.
5.1.7 Mercury
The following reviews were used in the preparation of this summary: IPCS 1990, 1991,
2003, ATSDR 1999c, JECFA 2003, NHANES 2003, UK FSA 2003 and US NRC 2000.
Mercury has no known biological function in humans.
35
Natural concentrations of mercury in the earth’s crust average 0.08 mg/kg. The major
natural sources of mercury are degassing of the earth’s crust, forest fires, emissions
from volcanoes and evaporation from natural bodies of water. Elemental and inorganic
mercury are transported in the environment by air and water, and after microbiological
conversion to organic forms, through the food chain.
Typical background concentrations of mercury have been reported as: air (rural) 2 - 6
ng/m3, air (urban, non-industrialized) 10 - 20 ng/m3, drinking water < 1 µg/litre, fresh
surface water 0.5 - 104 µg/litre, ground water 2 - 4 µg/litre and soil (rural/urban) 0.02 0.625 mg/kg.
The change in speciation of mercury from inorganic to methylated forms is the first step
in the aquatic bioaccumulation process. This can occur non-enzymically or through
microbial action. Methylmercury enters the food chain of predatory species where
biomagnification occurs. Highest methylmercury concentrations occur in such species
as barramundi, tuna and shark. Non-aquatic foodstuffs are generally very low in total
mercury 0.002 mg/kg. About 80% of the total mercury in aquatic foods is
methylmercury.
Estimates of average daily intake of inorganic mercury (elemental and compounds)
include by inhalation 0.04 – 0.2 µg, ingestion of drinking water 0.05 µg, ingestion of
food (excluding fish) 3.6 µg and ingestion of fish 0.6 µg (total intake 4.4 µg/day). The
value for fish assumes 20% of mercury in fish is inorganic mercury. In high fishconsuming populations, the total inorganic mercury intake from this source may
increase by up to an order of magnitude.
Fish and shellfish consumption is the primary source of methylmercury exposure, with
blood mercury known to increase with greater fish consumption. The United Kingdom
Ministry of Agriculture Forestry and Fisheries survey (UK MAFF 1998) included both
freshwater and marine species. Of the species covered, all but three had mean mercury
levels falling within the range 0.008 – 0.88 mg mercury/kg fish. This range is in line
with the values recommended by Codex and included within the European Community
Regulations (0.5 mg Hg/kg fish for fish in general, and 1.0 mg Hg/kg fish for large
predatory species (FAO/WHO Codex 1991). Three species, shark, swordfish and marlin
had mean mercury levels above the EC Regulations (1.52 mg/kg, 1.36 mg/kg and 1.09
mg/kg respectively). Many countries have recommended pregnant women, or those
likely to become pregnant within 12 months and breastfeeding women, to limit their
intake of marlin, swordfish and tuna. For example in the United Kingdom, the
recommendation is to limit intake of these three species to one portion per week (UK
FSA 2003).
The health effects of mercury are diverse, depending upon the form of the mercury
encountered and the intensity and duration of exposure. At levels below those that cause
lung injury, low dose or chronic inhalation may affect the nervous system, with the
severity increasing as exposure duration and/or concentration increase. Symptoms
include weakness, fatigue, loss of weight (with anorexia), gastrointestinal disturbances,
salivation, tremors and behavioural and personality changes, including depression and
emotional instability.
Organic mercury (eg methylmercury) is more toxic than inorganic mercury. The effects
of organic mercury include changes in vision, sensory disturbances in the arms and legs,
cognitive disturbances, dermatitis and muscle wasting. The developing central nervous
36
system is far more sensitive to the adverse effects of methylmercury than the adult
nervous system. Adults consuming very large quantities of fish, particularly the predator
species in fresh and salt water, may attain hair methylmercury concentrations of 50
mg/kg, which is associated with a 5% risk of paresthesia in adults.
The foetus and early post-natal infant are at particular risk from methylmercury toxicity.
Methylmercury readily crosses the placental barrier. Foetal brain mercury levels are
approximately 5 – 7 times higher than in maternal blood. Methylmercury readily
accumulates in hair and the ratio of hair mercury level (µg) to blood mercury level
(µg/litre) is approximately 1:4.
There have been many studies on the dose-effect relationships in infants born from
mothers exposed to methylmercury, primarily from fish consumption. Two large cohort
studies have recently been carried out in the Faroe Islands and the Seychelles and have
provided much needed data on the dose-response relationship at exposures that result in
maternal hair concentrations < 20 µg methylmercury/g. Both of these studies were
designed to establish the lowest dietary mercury exposure associated with subtle effects
on the developing nervous system of children. Both the Seychelles and Faroe Islands
study groups, have as their principal exposure sources, methylmercury from fish
consumption (Grandjean et al 1997, Davidson et al 1998, Myers et al1998, Crumps et
al2000). Based on hair analyses, the mean mercury exposures during pregnancy of both
groups were similar (Seychelles arithmetic mean 6.8 mg/kg, Faroe Islands geometric
mean 4.27 mg/kg). Although the two groups have now been studied to 7 years of age
(Seychelles) and 5.5 years (Faroe Islands), the outcome of results from regression
analysis are conflicting. For the Seychelles group, there are no adverse impacts on
neurological development, whereas in the Faroe Islands there is an association between
methylmercury exposure and impaired performance. This lack of consistent evidence of
neurodevelopmental affects for children, where the mothers had hair mercury levels of
< 20 mg/kg, remains unresolved.
The WHO considers that mercury is not carcinogenic in humans. The US EPA
considers inorganic mercury is not classifiable owing to the absence of any significant
human database, and the animal and supporting data are inadequate. Neither
organisation has evaluated methylmercury for its potential carcinogenicity.
In 2003, JECFA re-evaluated its PTWI for methylmercury, based on an examination of
the Seychelles and Faroe Islands studies (JECFA 2003). Using the average between a
No Observed Adverse Effect Level of 15300 µg/kg mercury in hair (Seychelles) and a
benchmark dose Lower Confidence Limit of 12000 µg/kg mercury (Faroe Islands), a
steady state intake of methylmercury of 1.5 µg/kg bw/day was derived. This value was
considered to have no appreciable adverse effects in the offspring of these populations.
Allowing a factor of 3.2 for inter-individual variability, and a factor of 2 for variability
in the hair to blood ratio, gave a PTWI of 1.6 µg/kg bw/week for the most sensitive subgroup in the population.
The US NRC in 2000 also assumed the developing nervous systems of the foetus and
infants to be the most critical organ in the most sensitive sub-group in the population.
The US NRC identified a benchmark dose of 58 µg/L corresponding to12 mg/kg in
maternal hair. Using a number of assumptions, the US NRC recommended a reference
dose of 0.1 µg/kg bw/day. This reference dose was approximately 40% of the JECFA
2003 WHO PTWI for methylmercury of 1.6 µg/kg bw/week. However, the US NRC
37
conclusions were based only on the data from the Iraq poisoning cases and the Faroe
Islands study. The negative findings in the Seychelles study were not considered by the
US NRC for setting a reference dose for methylmercury (US NRC 2000).
5.2 Data summaries for essential trace metals
5.2.1 Copper
There is an extensive literature on the nutritional needs and toxicity of copper in humans.
The following reviews were used to prepare this short overview: ATSDR 2002, US
NAS 2000a, IPCS 1998 and IOM 2001.
Copper is an essential micronutrient for humans. Adverse health effects may result from
intakes below that needed for good health (deficiency) as well as concentrations well
above the nutrient requirement (toxicity). As an essential nutrient, copper concentrations
within the human body are regulated by homeostasis. Adverse health effects from
deficiency or toxicity will only be observed when these homeostatic mechanisms are
unable to maintain internal copper concentrations within normal ranges, due to any
marked change from normal copper intakes.
Copper is a natural component of the human environment, occurring in rocks, soil,
sediments, water and food. The earth’s crust contains an average of 60 mg copper/kg.
The various compounds, both inorganic and organic, found naturally have markedly
different solubilities in water, and therefore, bioavailability, toxicity and nutrient value
in humans.
Copper is released into the environment by both natural processes and anthropogenic
activities. Natural sources include volcanic eruptions, wind blown dust, forest fires and
leaching from rocks and sediments. Copper is a natural constituent of human diets.
Global environmental concentrations in areas not directly impacted by point sources of
copper are: air (rural) < 10 ng/m3, air (urban) 50 - 7320 ng/m3, drinking water 20 - 75
µg/litre and soil (rural/urban) 13 - 175 mg/kg.
For healthy, non-occupationally-exposed humans the major route of exposure to copper
is through food consumption. Concentrations of copper in human diets vary
considerably depending upon type of foods consumed, sources of the foods and the
methods used in preparation. Organ meats and seafood have the highest concentrations
of copper, while nuts and grains also have high concentrations of copper. The mean
daily dietary intake of copper in adults ranges between 0.9 and 2.2 mg/day, with most
intakes nearer the lower end of this range.
Copper has long been recognised as an essential trace element for humans. The major
role for copper is catalytic as a component of many copper-containing enzymes
involved in energy metabolism, antioxidant defence processes and hematopoiesis. In
humans the most consistent clinical signs of copper deficiency are anaemia, nonresponse to iron therapy, blood dyscrasias, including neutropenia, reduced reticulocyte
counts and osteoporosis and bone fractures. However, clinically evident deficiency is
relatively infrequent in humans.
The major target organ in humans from chronic oral exposures to copper is the liver.
Although far from robust, the data indicate that a chronic intake of 10 mg copper/day as
an oral supplement does not result in liver damage.
38
Based on the results of a number of animal studies, involving exposure to copper
compounds, copper and its salts do not cause cancer in humans.
Based on a NOAEL of 5mg/kg bw/day for the end point of liver toxicity in dogs, and
taking into consideration the essentiality of copper, a provisional tolerable daily intake
of 0.5 mg/kg bw/day was recommended by JECFA (JECFA 1982). An allocation of
10% to drinking water gave a guideline value in water of 2 mg/L. It was considered that
the safety margin adopted would ensure that the value was equally appropriate for
infants and children.
The US Food and Nutrition Board recommended a Dietary Reference Intake (DRI)
range of 0.9 to 10 mg/day of copper for adults. Intakes of copper within this range were
considered to meet the essential needs of adults, while not resulting in toxic effects
(IOM 2001).
5.2.3 Selenium
Additional details on selenium can be found in the following reviews: Nord 1995, US
NAS 2000b and ATSDR 2003a.
Selenium is an essential trace element for humans. It is a biologically active part of a
number of important human and animal proteins, particularly enzymes involved in
antioxidant defence mechanisms, thyroid hormone metabolism and redox control of
intracellular reactions. Adverse health effects have been reported for intakes below the
required amount as well as for exposures in excess of the required intake.
Selenium is distributed widely in nature and is found in most rocks and soils at
concentrations between 0.1 and 2.0 ppm, the average crustal abundance being about
0.05 mg/kg. Natural atmospheric releases of selenium result from volcanic activity and
volatilization of selenium by plants and bacteria. Typical concentrations of selenium
found in the natural environment are: air (rural) 0.067 ng/m3, air (urban) 0 - 10 ng/m3,
fresh surface water 1 - 7.5 µg/litre, ground water 0.01 - 1 µg/litre, drinking water 0.05 160 µg/litre (high selenium area in China) and soil 0.05 - 1200 mg/kg, (depending upon
the geological origin and organic content).
Meat and fish products have the highest concentration of selenium while vegetables and
fruits have the lowest. The selenium concentration of grains and cereals, vary greatly
depending upon the soil type. In the USA 0.063 to 0.67 mg Se/kg was measured in a
variety of grains and grain products. Total daily intakes of selenium (µg/day) vary
widely worldwide depending on types of foodstuffs consumed, degree of processing and
selenium content and speciation in soil. In Keshan, China intakes were 33 – 22, Finland
100 – 110, Norway 28 – 89, USA 68 - 727 and Canada 113 – 220 µg/day.
In humans, selenium deficiency is uncommon, however, it has been associated with two
endemic diseases found in the selenium-poor regions of China, Keshan Disease and
Kashin-Beck Disease. Keshan Disease is reported to occur primarily in children and
women of child-bearing age and has been successfully treated by selenium
supplementation. The long-term intake of selenium from food and water (well in excess
of 400 µg/day) may result in selenosis. The Tolerable Upper Intake Level (UL)
recommended by the US NAS (400 µg Se/day) was based on the prevention of selenosis.
39
The majority of epidemiological studies in humans and animals have revealed no
association between oral selenium intake and the incidence of cancer. Some
epidemiological and experimental evidence suggests that selenium exposure, under
certain conditions, may contribute to a reduction in cancer risk.
In 2000, the United States Food and Nutrition Board recommended a Dietary Reference
Intake range of 0.055 to 0.4 mg Se/day for adults. The range for pregnant women was
0.06 to 0.4 mg/day and for lactating women it was 0.07 to 0.4 mg/day. The
recommended UL for selenium in adults of 0.4 mg/day, was considered to be the
highest level of daily nutrient intake that was likely to pose no risk of adverse health
effects to almost all individuals in the general adult population.
5.2.5 Zinc
The material in this summary was taken from the following reviews: ATSDR 2003b,
IOM 2001 and IPCS 2001b.
Zinc is an essential element for all living organisms. The human health effects
associated with zinc deficiency are numerous, and include growth retardation, delayed
wound healing, immune disorders, neuropsychological functions, neurosensory changes,
immune disorders and dermatitis. There is no single, specific and sensitive biochemical
index of zinc status.
Zinc is a naturally-occurring element found in most rocks within the earth’s crust at
concentrations between 20 and 200 mg/kg. Zinc is released into the environment
through weathering of rocks, leaching from soil, wind-blown dust, volcanic eruptions
and forest fires. Typical background concentrations in environmental media are: air
(rural/urban) 0 -300 ng/m3, fresh surface water 0.1 - 50 µg/litre, ground water 10- 40
µg/litre, drinking water 0.1 - 1.5 mg/litre and soils (rural/urban) 59.8 mean and 1.5 to
2000 mg/kg range.
The most significant source of zinc for the general population is from food. In general,
meat, eggs and dairy products contain more zinc than plants. However, certain
vegetables, grain and grain products, nuts and oysters contain high concentrations of
zinc. Low dietary intakes of zinc have been reported for populations in Papua New
Guinea (7 mg/day) from diets containing mainly roots, tubers and leaves. The dietary
intakes of adults in developed countries range from 8.5 to 14.4 mg/day. In all cases the
bioavailability of the zinc present and/or the presence of high levels of phytate are more
important in determining the adequacy of the diet than is total zinc content.
There is no evidence of adverse health effects from either the acute or chronic
consumption of naturally occurring zinc in foods. Adverse effects associated with the
chronic oral intake of supplemental zinc (soluble salts) include suppression of immune
response, decrease in high-density lipoprotein cholesterol and reduced copper status.
No evidence was found of reproductive effects in humans associated with increased zinc
intake. Also there is insufficient evidence of carcinogenicity from mutagenicity tests,
animal bioassays and human epidemiology studies.
Given the essential nature of zinc, its relatively low toxic potential in humans and the
limited sources of exposure, the totality of scientific data supports the conclusion that
40
healthy, non-occupationally exposed humans are more at risk from zinc deficiency than
from the toxic effects of normal environmental exposures to zinc.
Zinc has been assessed as non-carcinogenic by both the IARC and US EPA.
JECFA proposed a daily dietary requirement for zinc of 18 mg/day and a PTWI of 7000
µg/kg bw/wk (JECFA 1982). It was concluded that the derivation of a health-based
guidance value was not required.
Based on the extensive literature on human nutrition and toxicity of zinc, the US Food
and Nutrition Board/Institute of Medicine recommended a Dietary Reference Intake
range for several age-gender groups. For adult males the recommended range was 11 to
40 mg zinc/day and for females it was 8 to 40 mg zinc/day. The UL (40 mg/day) is
based on the reduction in erythrocyte copper-zinc superoxide dismutase activity (IOM
2001).
6.0 Exposure assessment
6.1 Drinking water
6.1.1 International guidelines
Table 3 lists the international drinking water health guideline and national standard and
criteria values for the contaminant metals from WHO, Papua New Guinea, Canada, the
United States and Australia. For copper and zinc there are also aesthetic values based on
soiling and colour.
Table 3: International drinking water health guidelines (values mg/L)
WHO Drinking Water
Guidelines 1, 2
Papua New Guinea
Standards for raw
drinking water3
Aust NHMRC
Guidelines4
Canada (MAC)5
United States (MCL)6
1.
2.
3.
4.
5.
6.
Arsenic
0.01(P)
Cadmium
0.003
Copper
2.0
Lead
0.01
Mercury
0.001
Selenium
0.01 (T)
0.007
0.002
2 health
1 aesthetic
0.01
0.001
0.01
3.0
aesthetic
0.007
0.002
0.01
0.001
0.01
0.025
0.005
2 health
1 aesthetic
1 aesthetic
0.01
0.001
0.01
0.01
0.005
1.3
0.015
0.002
3.0
aesthetic
<5
aesthetic
-
-
Zinc
-
WHO Guidelines for Drinking Water Quality Third Edition (WHO 2004). For excess skin cancer
risk of 6 x 10-4 Table A2.2. (T) Total concentrations (unfiltered).
Mercury is for Total mercury including both organic and inorganic. (P) for arsenic is a Provisional
Value.
Environment (Water Quality Criteria) Regulations 2002 (DE&C 2002).
Australian Drinking Water Guidelines (NHMRC 2004).
Guidelines for Canadian Drinking Water Quality (Health Canada 2006). All values are Maximum
Acceptable Concentrations except arsenic, which is an interim value.
Maximum Contaminant Levels used as enforceable standards. US Drinking Water Standards and
Health Advisories (US EPA 2005).
6.1.2 Ok Tedi-Fly Rivers community drinking water
The results from OTDF surveys, indicated that the Ok Tedi and Fly Rivers were not
regularly used as drinking or cooking water sources (OTDF 2002). The Ok Tedi
Development Foundation has provided rain water tanks to many of the communities
included in the OTML CHS study. The OTDF periodically reviews the status of these
41
sources for their ongoing reliability. For the Lake Murray communities, rain water tanks
have been provided by PJV. There are some reports of occasional use of the lake waters
for drinking and cooking (Taufa 1997).
The compliance OTML monitoring of settled raw water as a surrogate for drinking
water is conducted at two sites, Atkamba on the Ok Tedi and Nukumba on the Fly River
and are located below and above D’Albertis Junction respectively. Monitoring is
undertaken for cadmium, copper, lead and zinc.
Analysis of drinking water quality is not routinely performed on rain water tanks, or
shallow surface water sources in the Ok Tedi-Fly River communities. The historical
data available on metals and faecal contamination in community drinking water sources
is largely from the OTML Human Health Survey (Flew 1999).
Table 4: Ok Tedi-Fly community drinking water supplies – total and dissolved metals (all mean values mg/L)
Location
Source
As-D
As-T
Cd-D
Cd-T
Bultem
Finalbin
Tank
Tank
0.005
0.006
0.005
0.005
0.001
0.001
0.001
0.001
Derengo
Ok Ma
Stream
Stream
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Gre
Ieran
Kwiloknae
NingerumT
Waterhole
Tank
Tank
Tank
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
Songty V
Walawam
Spring
Tank/spring
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Komovai
Manda
Tank
Tank
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Buseki
Usokof
Tank
Tank
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Sapuka
Sialowa
Tank
Tank
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Aewa
Kiru
Tank
Tank
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
Sagero
Tapila
Wapi
Tank
Tank
Tank
0.005
0.005
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
0.001
0.001
Cu-D
Cu-T
Pb-D
Region 1 impact
0.005
0.005
0.004
0.038
0.005
0.014
Region 1 control
0.013
0.014
0.005
0.009
0.010
0.005
Region 2 impact
0.005
0.005
0.005
0.012
0.012
0.005
0.005
0.014
0.005
0.022
0.022
0.005
Region 2 control
0.006
0.007
0.004
0.005
0.005
0.005
Region 3 impact
0.015
0.007
0.004
0.005
0.005
0.004
Region 3 control
0.005
0.005
0.004
0.011
0.011
0.004
Region 4 impact
0.005
0.005
0.004
0.018
0.007
0.005
Region 4 control
0.007
0.008
0.004
0.005
0.005
0.002
Region 5 impact
0.005
0.005
0.004
0.006
0.005
0.004
0.005
0.005
0.005
Pb-T
Hg-D
Hg-T
Se-D
Se-T
Zn-D
Zn-T
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.04
0.02
0.02
0.005
0.005
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.005
0.005
0.005
0.005
0.0002
0.0002
0.0002
0.0002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.03
0.05
0.02
0.09
0.03
0.04
0.02
0.09
0.004
0.005
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.05
0.02
0.05
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.03
0.03
0.09
0.03
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.66
0.05
1.20
0.06
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.04
0.13
0.08
0.13
0.004
0.002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.06
0.02
0.08
0.12
0.004
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.01
0.01
0.51
0.10
0.09
0.79
0.18
0.19
43
Table 4: Ok Tedi-Fly community drinking water supplies – total and dissolved metals (all mean values mg/L) (cont’d)
Location
Source
Abam
Kadawa
River
Tank
As-D
As-T
Cd-D
Cd-T
Cu-D
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
0.014
0.009
Mean
sd
0.005
0.000
0.005
0.000
0.001
0.000
0.001
0.000
0.011
0.010
Mean
sd
0.005
0.000
0.005
0.000
0.001
0.000
0.001
0.000
0.008
0.003
Cu-T
Pb-D
Region 5 control
0.005
0.005
0.038
0.004
All impact
0.008
0.005
0.005
0.003
All control
0.011
0.004
0.010
0.001
Pb-T
Hg-D
Hg-T
Se-D
Se-T
Zn-D
Zn-T
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.03
0.02
0.03
0.004
0.001
0.0002
0.0000
0.0002
0.0000
0.010
0.000
0.010
0.000
0.088
0.132
0.130
0.206
0.004
0.001
0.0002
0.0000
0.0002
0.0000
0.010
0.000
0.010
0.000
0.094
0.199
0.161
0.367
Notes:
1.
Tank water at Bultem and Finalbin is piped to these tanks from Bultem creek and Yak creek respectively. Other tanks are serviced by rainwater.
2.
It is important to appreciate that for all drinking waters, the OTML CHS uses the Total (T) values as a conservative estimate of intake. This assumes 100%
bioavailability by the ingestion route for the metals. Dissolved (D) sample data (ie the 0.45 μ filtered metal values) are frequently used for intakes in risk
assessments. However, this approach does not capture all of the potentially bioavailable metal in the surface waters. The adoption of the Detection Limit as the
analytical default value, introduces a further layer of conservatism.
6.1.3 Conclusions - drinking water
Within the Ok Tedi and Fly River and Lake Murray, there were no substantial
differences between the metal results for the drinking water sources sampled in different
regions or in impact and control villages within a single region. The results indicated
that all primary use water supplies have relatively low total and dissolved
concentrations of the metals of concern. All values are markedly less than the WHO,
Canadian, United States and Australian Drinking Water Guideline and criteria values
and the Papua New Guinea standards for raw drinking water (Figure 3).
There was little difference in the metal concentrations of the impact communities in all
five regions. For later use in the exposure assessment model, the mean results for all
impacted communities have been derived (all impacted in Table 4). The mean value for
all control communities has similarly been calculated (all controls in Table 4).
45
Figure 3: Ok Tedi-Fly River drinking water quality - comparison with health
guidelines (all results mean values)
0.012
All impact sites
Concentration (mg/L)
0.01
All control sites
0.008
PNG standard
WHO Guideline
0.006
0.004
0.002
0
As-D
As-T
Cd-D
Cd-T
Pb-D
Pb-T
Hg-D
Hg-T
Contaminant metal
0.35
Concentration (mg/L)
0.3
All impact sites
0.25
All control sites
0.2
PNG standard (Cu/10 Zn/10)
0.15
WHO Guideline Cu/10)
0.1
0.05
0
Cu-D
Cu-T
Se-D
Se-T
Zn-D
Zn-T
Essential metal
Note: Yellow bars are Papua New Guinea water quality standards (2002). Green bars are WHO
Drinking Water Guidelines 2004. The guideline values for copper and zinc are shown as one-tenth
scale. There are no drinking water health values for zinc. The value shown for the Papua New
Guinea standard is an aesthetic value. (D = dissolved; T = Total)
46
6.2 Recreational water
The potential risks from chemical contamination of recreational waters is usually small.
Even repeated exposure is unlikely to result in discernable ill effects at the
concentration of contaminants generally found in water and with the exposure patterns
of recreational water users. In all cases chemical and physical contamination must be
assessed on a local basis (WHO 2003). Potential routes of exposure are skin, eyes and
mucus membranes, inhalation and ingestion. An appreciation of the frequency, extent
and likelihood of exposure is a crucial part of the evaluation. Generally, skin and
mucous membrane surface exposure is the greatest contributor to intake, but for
activities involving immersion or partial immersion, ingestion may become a significant
factor. Young children (5 – 10 years of age) are likely to ingest proportionally greater
amounts of water than adults.
There are no specific rules that can easily be applied to calculate guideline values for
chemical contaminants in recreational waters. However, the WHO Guidelines for Safe
Recreational Water Environments provide a starting point for deriving values since
these guideline values relate, in most cases, to lifetime exposure (WHO 2003). Mance et
al (1984) assumed a contribution for recreational water use, such as bathing of an
equivalent of 10% of drinking water consumption, which is generally accepted to be 2
L/day. This corresponds to an intake of 200 ml per day from recreational contact with
water.
There are no metal values for recreational water use published by the health agencies in
Australia or Canada (NHMRC 2005, Health Canada 2006). The Australia and New
Zealand Environment and Conservation Council and the Agriculture and Resource
Management Council of Australia and New Zealand have developed recreational water
guidelines (ANZECC 2000). The Papua New Guinea Water Quality Standards (DE&C
2002) has developed water quality standards for recreational and aesthetic uses in fresh
and marine waters, however, these are for microbiological and physico-chemical
parameters only. The standards for fresh waters proposed for the protection of aquatic
life are inappropriate for human recreational exposures. The WHO, Australian and US
EPA values are shown in Table 5.
Table 5: International surface water recreational guidelines (values mg/L)
WHO1
ANZECC
US EPA2: MCL and
(MCLG)
1.
2.
MCL
(MCLG)
Arsenic
0.1
0.05
0.1 (0)
Cadmium
0.03
0.005
0.05
(0.05)
Copper
20
1
13
Lead
0.1
0.05
0.15
Mercury
0.01
0.001
0.02
(inorganic)
Selenium
0.01
0,01
0.05
Using the 10-fold adjustment factor applied by WHO.
US EPA, Office of Water, Drinking Water Regulations and Health Advisories (US EPA
2005).
=
=
Maximum Contaminant Level in water delivered to a user of a public water supply.
Maximum Contaminant Level Goal, value protective of adverse human health effects
incorporating a safety margin
Zinc
5
-
47
6.2.2 Ok Tedi-Fly River community surface waters
There have not been any studies of community river-use patterns for villagers living in
the five OTML CHS geographic regions. Recreational water-use patterns would almost
certainly differ greatly between the OTML mine-area villagers, the Ok Tedi-Fly River
and Lake Murray communities. For example, river use by the mine area villagers and
the Ok Tedi region communities would be limited, with little use for subsistence fishing
or other activities. In the Middle-Lower Fly River regions and at Lake Murray, people
regularly use the waterways as a transportation corridor, for subsistence fishing and
harvesting of sago crops and for washing of clothes, bathing and recreation.
The mean results for total extractable metals in surface water samples are shown in
Table 6. The sampling, field data records, analytical and QA/QC results and summary
statistics are presented in Appendix 1.
Copper in total extractable samples from the impact villages was elevated at the Region
2 villages of Ieran and Ningerum (mean values 0.208µg/L and 0.187 µg/L respectively).
Copper was also discernable at Manda (0.029 µg/L) in Region 3 and at the lower
Middle Fly and Fly estuary locations. Zinc albeit at low levels, was also present at all of
the Region 5 impact communities. For all of the other measured analytes, concentrations
of total extractable metals in the OTML CHS impact village surface water samples were
generally at or below the method limits of detection (Table 6). All analytes at all
monitored impact locations were order of magnitude below the respective WHO
Recreational Water Guideline values (Figure 4).
The Region 1 control communities monitored sources, drain from potentially highly
mineralised areas. However, other than a minor elevation in copper and zinc at Ok Ma,
this did not result in significantly elevated mean background levels of any metal. At the
Region 3 Buseki control location, one sample contained a higher than expected zinc
value, which is unexplained. The observed concentrations of metals at all of the control
sites were all at least an order of magnitude below the WHO Recreational Water
Guidelines, and similar to non-impacted rivers in other Papua New Guinea and
international environments (Figure 4).
6.2.3 Conclusions – recreational waters
At the Regions 1 impact village of Bultem and control village of Ok Ma, the levels of
copper were slightly elevated, resulting from local natural mineralisation. Copper was
identified as somewhat elevated at the Regions 2 – 5 impact communities. The
concentrations of the other total extractable metals, used in the OTML CHS to represent
the “worst case” circumstance, was consistently order of magnitude below the
respective WHO Recreational Water Guidance values.
Table 6: Ok Tedi-Fly River surface water – total metals (all values mg/L)
Location
Source
Bultem
Finalbin
Mean
Median
Bultem Creek
Yak Creek
Derengo
Ok Ma
Mean
Median
Ok Mamin River
Kanadgo Creek
Gre
Ieran
Kwiloknae
Ningerum Tamaro
Mean
Median
Wai Gre Creek
Ok Tedi River
Unnamed spring
Unnamed spring
Songty Valley
Walawam
Mean
Median
Ok Mat River
Unnamed spring
Komovai
Manda
Mean
Median
Lake Pangua
Fly River
Arsenic
Cadmium
Copper
Region 1 impact
0.005
0.001
0.014
0.005
0.001
0.005
0.005
0.001
0.009
0.005
0.001
0.005
Region 1 control
0.005
0.001
0.005
0.005
0.001
0.012
0.005
0.001
0.008
0.005
0.001
0.005
Region 2 impact
0.005
0.001
0.005
0.005
0.001
0.208
0.005
0.001
0.007
0.005
0.001
0.187
0.005
0.001
0.111
0.005
0.001
0.005
Region 2 control
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.005
0.005
0.005
0.001
0.001
0.001
0.001
0.007
0.029
0.020
0.009
Lead
Mercury
Selenium
Zinc
0.004
0.004
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.005
0.005
0.005
0.005
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.31
0.17
0.02
0.005
0.013
0.005
0.007
0.007
0.005
0.0002
0.0002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.01
0.01
0.04
0.06
0.02
0.04
0.04
0.02
0.004
0.005
0.004
0.005
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.004
0.003
0.003
0.002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.08
0.02
0.04
0.02
49
Table 6: Ok Tedi-Fly River surface water – total metals (all values mg/L) (cont’d)
Location
Source
Buseki
Usokof
Mean
Median
Lake Murray
Lake Murray
Sapuka
Sialowa
Mean
Median
Fly River
Fly River
Aewa
Kiru
Mean
Median
Lake Suki/Suki Creek
Lake Suki/Suki Creek
Sagero-Koavisi
Tapila
Wapi
Mean
Median
Sagero River/Fly estuary
Fly estuary (seawater)
Fly estuary (seawater)
Abam
Kadawa
Mean
Median
Oriomo River
Gulf of Papua (seawater)
Arsenic
Cadmium
Copper
Region 3 control
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
Region 4 impact
0.005
0.001
0.010
0.005
0.001
0.009
0.005
0.001
0.009
0.005
0.001
0.009
Region 4 control
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
0.005
0.001
0.005
Region 5 impact
0.005
0.001
0.009
0.005
0.001
0.018
0.005
0.001
0.005
0.005
0.001
0.011
0.005
0.001
0.006
Region 5 control
0.005
0.001
0.005
0.005
0.001
0.036
0.005
0.001
0.020
0.005
0.001
0.005
Lead
0.004
0.004
0.004
0.004
Mercury
Selenium
Zinc
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.61
0.03
0.32
0.03
0.004
0.004
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.06
0.03
0.05
0.03
0.004
0.002
0.003
0.002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.05
0.12
0.07
0.07
0.004
0.005
0.004
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.01
0.32
0.11
0.17
0.20
0.11
0.004
0.004
0.004
0.004
0.0002
0.0002
0.0002
0.0002
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
Figure 4: Ok Tedi-Fly River surface water quality - comparison with WHO health
guidelines
Impact villages
0.25
Metal concentration (mg/L)
As-T
Cd-T
0.2
Cu-T
Pb-T
0.15
Hg-T
Se-T
Zn-T
0.1
0.05
0
Region 1
Region 2
Region 3
Region 4
Region 5
WHO
Location
Control villages
0.35
Metal concentration (mg/L)
0.3
As-T
Cd-T
0.25
Cu-T
Pb-T
0.2
Hg-T
Se-T
0.15
Zn-T
0.1
0.05
0
Region 1
Region 2
Region 3
Region 4
Region 5
WHO
Location
Note: The WHO Guideline value for copper (20 mg/L) is off scale, and not shown. There is no health
guideline for zinc.
51
6.3 Air quality assessment
6.3.1.1 Metals
The WHO Inorganic Air Pollutants Working Group (WHO 2000) evaluated the health
effects of arsenic, cadmium, lead, and mercury. Threshold levels were established for
lead and mercury. Quantitative risk estimates for lifetime cancer risk were derived for
arsenic. For cadmium the guideline value was derived based on environmental
considerations. Summary details of the adopted guidelines are given in Table 7.
Table 7: WHO guidelines for metals in ambient air
Substance
Arsenic
Cadmium
Lead
Mercury
1.
Guideline value (µg/m3)
0.01
0.005 -.020
0.5 - 1.0
1.0
Averaging time
UR/lifetime1
Annual
Annual
Annual
UR is the excess risk of dying from cancer following lifetime inhalation exposure. The guideline
value corresponds to a lifetime risk of 3 x 10-5
6.3.1.2 Particulates
Respirable particles are characterised by size, as PM 10 or PM 2.5 (Particulate Matter
10 microns or Particulate Matter 2.5 microns in diameter). For PM 10, WHO considers
that the available epidemiological evidence is insufficient to establish a level below
which no effects would be expected. Therefore, no specific guideline value has been
established, but instead, exposure-effect information is provided, giving guidance to risk
managers about the major health impact for short- and long-term exposure to various
levels of these pollutants.
The standards of Australia, Canada and the United Kingdom for Total Suspended
Particulates (TSP), PM 10 and PM 2.5 are shown in Table 8. The United Kingdom has
not established a PM 2.5 standard on the basis that there is insufficient evidence.
Australia has adopted a 24-hour standard of 25 µg/m3. The United States has adopted a
PM 2.5 standard of 65 µg/m3 daily, but this is based on peak value monitoring and in
practice is comparable with the Canadian guideline.
52
Table 8: National criteria and guidelines for airborne particulate matter (all mean
values µg/m3)
Canada1
NEPC2
TSP
120 – 400
(annual 60 – 70)
90 (annual)
UK DoH3
US EPA NAAQS4
Good
Moderate
Unhealthy
1.
2.
3.
4.
PM 10
60
50 (annual 25)
50 (annual 40)
0 – 75
76 – 260
261 – 375
0 – 50
51 - 150
151 - 350
PM 2.5
30 (24 hours)
25 (24 hours)
8 (annual)
65 (24 hours)
0 – 15
16 – 65
66 – 150
Canadian Council for Ministers for the Environment (CCME 2000).
National Environment Protection Council, Australia (NEPC 2003). The PM 10 standard is not to
be exceeded more than five days per year.
United Kingdom Department of Health.
United States Environment Protection Agency, National Ambient Air Quality Standards (US EPA
1997a).
6.3.2 Ok Tedi-Fly River regional air quality
The ambient air monitoring for the OTML CHS was undertaken at Finalbin in Region 1
and Ningerum Tamaro and Gre in Region 2 under the direction of Team Ferrari
Environmental. Sampling was successfully completed on 16 occasions, (Finalbin (8),
Ningerum Tamaro (2) and Gre (6)). The air quality report and the detailed site
meteorological data are given in Appendix 2.
The remote location data at Ok Om and Lake Murray were also undertaken by Team
Ferrari between January and June 2003 in co-operation with the PJV Environment
Department as part of the PJV PLSLM HHRA (Team Ferrari Environmental 2003).
Permission has been given for this data to be used for the OTML CHS as control sites
for metals in ambient air.
Samplers were sited according to the Australian Standard AS 2922 Guide for the Siting
of Sampling Units. A comprehensive automatic meteorological station, operating to
Australian Standard AS 2923 was run at each of the operating sites throughout the study.
The sample filters were returned to the Australian Nuclear Science and Technology
Organisation, Lucas Heights, Australia for non-destructive ion beam analysis for the
contaminant metals of interest using the method of Cohen (Cohen et al 1993).
6.3.3 Contaminant metals in air
Table 9 reports the mean metal concentrations for all the OTML CHS sampled sites and
the results from the PJV monitoring. The levels of the target contaminant metals in both
the fine and course fractions were consistently low for all monitored sites. The level of
metals in both PM 10 and PM 2.5 were not statistically different between any sites.
53
Table 9: Respirable air particulate metals (mean values ng/m3)
Location/No samples ( )
Copper
Finalbin (8)
Ningerum Tamaro (2)
Gre (6)
Mean (PM 2.5)
Ok Om (8)
Lake Murray (8)
1.9
0.6
1.5
1.6
0.8
0.7
Finalbin (8)
Ningerum Tamaro (2)
Gre (6)
Mean (PM 10)
Ok Om (8)
Lake Murray (8)
Mean (PM 10)
5.8
1.2
13.8
8.2
1.6
1.0
1.3
Zinc
PM 2.5
1.2
0.9
1.1
0.9
2.2
1.3
PM 10
3.3
1.6
1.3
2.4
4.6
3.0
3.8
Cadmium
Lead
Arsenic
Mercury
< 35
< 35
< 35
< 35
< 35
< 35
1.3
1.5
1.7
1.5
0.0
0.1
< 1.3
< 1.5
< 1.7
< 1.5
<0
< 0.1
< 10
< 10
< 10
< 10
< 10
< 10
< 35
< 35
< 35
2.7
2.8
1.8
2.3
0.1
0.4
0.25
< 2.7
< 2.8
< 1.8
< 10
< 10
< 10
< 0.1
< 0.4
< 10
< 10
< 35
< 35
Notes:
1.
2.
3.
4.
5.
6.
The middle bound value has been used to derive means for values below the detection limit.
Particles less than approximately 10 µm (termed PM 10) are inhaled by humans and pass into the
lower respiratory tract where they can be retained. Particles less than approximately 2.5 µm
(termed PM 2.5) pass into the very fine airways.
It is not possible to quantify selenium by ion beam analysis and therefore no data were reported
for this element. Arsenic is not normally reported as the emission line lies near to the lead line,
and for this study was only reported if greater than the lead concentration. In practice, arsenic was
found to be always at a concentration less than the lead concentration in all samples.
The detection limit for mercury was about 3 - 5 ng/m3 for non-volatile mercury. However, as
some mercury salts may be volatile during sampling and storage, a conservative DL of 10 ng/m3
was adopted. The results indicated that levels in the air at the time of sampling were all less than
10 ng/m3.
Cadmium levels in the air sampling were consistently below the detection limit. A value of < 35
ng/m3 has been adopted for all samples.
The detection limits for copper, lead and zinc were 0.1 ng/m3, 0.1 ng/m3 and 0.3 ng/m3
respectively.
6.3.4 Respirable particulate concentrations in air
The Australian NEPM for PM 2.5 is 25 μg/m3 for a maximum daily average and 8
μg/m3 for an annual average. The sampling method used in the study did not permit
direct comparison with the PM 10 values against the Australian Standard, which is
based on a daily average not to be exceeded for more than five days a year at any site.
Taking account of all the values measured during the present study, no exceedances
occurred at any of the monitored locations. The PJV Ok Om monitoring did exceed the
Australian NEPM on 25% of measurements, but this was due to local grass fires during
the period of sampling (Table 10 and Figure 5).
54
Table 10: Respirable particulates PM 10 and PM 2.5 - comparison with the
Australian NEPMs
PM 2.5 concentration (μg/m3)
Maximum
% >NEPM
Maximum
25
11.2
0%
5.8
0%
10.2
0%
16.1
0%
23.9
0%
Location
NEPM
Finalbin
Ningerum Tamaro
Gre
Ok Om
Lake Murray
PM 10 concentration (μg/m3)
Maximum
% >NEPM
50
23
15
24
66
32
Figure 5: Respirable particle concentrations – peak values at OTML CHS
sampling locations (PM 2.5 and PM 10)
70
60
NEPM (Aust)
Finalbin
Concentration (ug/m3)
50
Ningerum-Tamaro
Gre
40
Ok Om
Lake Murray
30
20
10
0
PM 2.5
PM 10
Particle size distribution
0%
0%
0%
25%
0%
55
Figure 6 shows the mean elemental levels measured during the OTML CHS air study
and the PJV studies and compares these with data reported from other locations.
Figure 6: Metal concentrations in respirable air at OTML CHS locations and
reference sites
500
450
Concentration (ng/m3)
400
Copper
350
300
Zinc
250
Lead
200
Arsenic
150
100
50
0
Sydney
Rural NSW
Jakarta
CHS (OTML)
PLSLM (Porgera)
Location
Notes:
1.
Sydney samples from Lucas Heights (suburban).
2.
Rural NSW samples from Albion Park.
3.
Typical PM 10 remote area background levels are (as ng/m3) arsenic 0.02- 4, cadmium 0.005,
copper < 10, lead 0.3 – 9, mercury 2 – 6, selenium 0.07 and zinc 10.
6.3.5 Conclusions – air
The observed metal concentrations in air particulates for lead and mercury were some
two orders of magnitude below the WHO Guideline values. While the WHO Guideline
value for cadmium is 5 - 20 ng/m3 there is no evidence from the available data that this
has been exceeded. WHO does not give guidance values for copper, zinc or selenium.
56
6.4 Soil and sediments
6.4.1 National criteria and guidelines
Soil screening, though requiring some conservative assumptions, is the most costeffective approach in the identification of the hazard potential from soils ingested and
inhaled by resident populations. Levels of the metals are compared with previously
determined Health Investigation Levels (HILs) to assess risks both to the general
population and to specific sub-populations particularly children 2 - 3 years of age. This
age group is well recognised as having disproportionate soil intakes by ingestion due to
hand-to-mouth behaviour.
While the WHO does not provide guidance for soil contamination, various other
national bodies have published “health investigation levels” as shown in Table 11. It is
important to note that these are not “response levels”, which would be far less
conservative. Investigation levels are usually derived by assigning a fixed fraction of the
total theoretical baseline exposure to the soils compartment by using the respective
WHO PTWI values. The adopted values also take into account a range of human
exposure settings for different residential lifestyles and recreational and industrial
circumstances. Note that no jurisdiction has soil criteria for selenium.
Table 11: National health-based soil investigation levels (all values mg/kg)
Substance
Arsenic (total)
Cadmium
Copper
Lead
Mercury (inorg)
Zinc
1.
2.
3.
NEPM Exposure settings HILs1
A: Standard residential
E: Recreational
100 = (40% PTWI)
200
20 = (19% PTWI)
40
1000 (no PTWI)
2000
300 = ( 52% PTWI)
600
15 = (20% PTWI)
30
7000 (no PTWI)
14,000
US EPA2
UK DEFRA3
0.4
8
3100
400
3
12,000
Australian Health-Based Soil Investigation Levels, based on a child 2.5 years of age, weighing
13.2 kg and ingesting 100 mg soil/day. Exposure Setting A (standard residential) includes
contributions from home grown produce and child care centres. Exposure Setting E includes parks,
recreational open space and playing fields (NEPC 1999).
US EPA, Office of Solid Waste and Emergency Response, Soil Screening Guidance May 1996
(US EPA 1996).
UK Department of Environment (DEFRA/EA 2002).
6.4.2 Ok Tedi-Fly River soil and sediments
OTML has a significant database for metals in soils and sediments in both flood prone
and flood free areas. However, there are constraints in using this data for the OTML
CHS. Generally the objectives of the reported studies (eg garden crop phytotoxicity)
were quite different with analysis being generally for the top 0 – 50 centimetre profile.
For the OTML CHS, analytical results representing the top 5 centimetres is required to
ascertain health impacts from soil ingestion. Soil ingestion is an important exposure
pathway, particularly in mine derived sediments and potentially is a major contributor to
exposures in children.
175
7
560
15
57
For the present study, village and garden soils, road-impacted soils, OTML nonimpacted natural sediments and impacted flood plain sediments were collected from the
OTML CHS villages between April 2004 and March 2006.
Soil and sediment samples were collected from “regular use” areas. Soil samples were
collected from within the village boundaries and in the village gardens, often some
considerable distances from the houses. All soil and non-impacted (natural) sediment
samples were collected from sites above the 100-year flood level. The impacted flood
plain sediment samples were frequently sourced from riverbank-deposited materials at
canoe anchorage sites and other community-use areas near to the village, or at sagomaking camps.
Soil and sediment sampling at each site involved the collection of five randomly
selected samples from the top 5 centimetre profile. Each sub-sample was sieved through
a 2 millimetre mesh, and 200 gram of the sieved material retained for inclusion into the
sample composite. The sampling, field data records, analytical and QA/QC results and
summary statistics are presented in Appendix 3
The data for the Region 3 control villages obtained during the OTML CHS was in good
agreement with the results of the PJV PLSLM HHRA study conducted in 2003 t.
Arsenic, cadmium, mercury and selenium from both the OTML CHS and PJV sampling
events at Buseki and Usokof in all village soils, natural sediments and impacted flood
plain sediments approximated, or were below, the respective limits of detection. The
range of values for copper from the OTML CHS work (village soils (31.4 – 55.8
mg/kg); natural sediments (24.3 – 65.0 mg/kg) and flood plain soils (Usokof 31.3
mg/kg) closely matched the earlier PJV results of 27.0 – 38.2 mg/kg, 34.5 – 37.0 and
41.0 respectively. Similarly the values for lead from the OTML CHS work (village soils
(11.4 - 18.6 mg/kg); natural sediments (12.0 – 12.5 mg/kg) and flood plain soils
(Usokof 11.0 mg/kg) were in good agreement with the PJV data of 9.4 – 12.6 mg/kg,
11.5 – 18.5 and 15.5 respectively. The same close match in results from the two
sampling events also occurred for zinc in all soil and sediment types.
6.4.3 Village and garden soils
The mean, median and range of metal concentrations for village and garden soils for the
OTM CHS Regions 1 – 5 are given in Table 12.
The mean concentration of arsenic in village and garden soils in Regions 1 - 4 ranges
between 4 – 11 mg/kg with no substantial difference between the impact and control
villages. The observed levels were typical of those reported in the literature for
international background levels (4.8 – 7.2 mg/kg) and an order of magnitude below the
Australian Health Investigation Level (HIL) for residential soil (Sposito 1989, NEPC
1999).
58
Table 12: Village and village garden surface soils total extractable metals (all
values mg/kg)
Stats
Arsenic
Cadmium
Mean
Median
Min
Max
11.0
7.5
4.0
25.0
0.6
0.4
0.4
1.1
Mean
Median
Min
Max
10.6
7.0
4.0
38.0
0.6
0.5
0.4
1.1
Mean
Median
Min
Max
4.7
4.0
4.0
8.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
7.2
4.0
4.0
32.0
0.6
0.4
0.4
2.6
Mean
Median
Min
Max
4.3
4.0
4.0
7.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
4.3
4.0
4.0
6.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
6.7
6.5
4.0
10.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
5.4
5.0
4.0
9.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
17.4
6.0
4.0
66.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
17.1
8.0
6.0
41.0
0.4
0.4
0.4
0.4
Copper
Mercury
Region 1 control
84.6
0.3
81.0
0.3
8.0
0.2
150.0
0.5
Region 1 impact
114.4
0.3
140.0
0.3
14.0
0.2
200.0
0.6
Region 2 control
92.0
0.5
67.0
0.4
42.0
0.2
210.0
1.0
Region 2 impact
223.1
0.7
36.0
1.0
17.0
0.2
2000.0
1.0
Region 3 control
43.6
1.0
44.0
1.0
23.0
1.0
69.0
1.0
Region 3 impact
34.7
0.9
35.5
1.0
20.0
0.2
52.0
1.0
Region 4 control
29.6
1.0
29.0
1.0
18.0
1.0
43.0
1.0
Region 4 impact
29.2
1.0
28.5
1.0
16.0
1.0
50.0
1.0
Region 5 control
29.0
1.0
26.5
1.0
5.0
1.0
88.0
1.0
Region 5 impact
44.8
1.0
40.0
1.0
23.0
1.0
64.0
1.0
Lead
Selenium
Zinc
31.1
24.0
7.0
72.0
4.0
4.0
4.0
4.0
211.6
220.0
33.0
380.0
22.0
15.0
9.0
59.0
4.0
4.0
4.0
4.0
164.7
150.0
39.0
550.0
10.9
11.0
6.0
14.0
4.0
4.0
4.0
4.0
79.9
73.0
60.0
110.0
38.9
17.0
12.0
220.0
4.0
4.0
4.0
4.0
147.3
63.0
24.0
1000.0
15.0
13.5
8.0
29.0
4.0
4.0
4.0
4.0
57.1
50.0
14.0
160.0
12.9
12.5
8.0
20.0
4.0
4.0
4.0
4.0
27.4
23.5
15.0
55.0
11.3
10.0
8.0
16.0
4.0
4.0
4.0
4.0
19.4
19.0
11.0
29.0
13.7
14.0
7.0
22.0
4.0
4.0
4.0
4.0
121.7
42.0
8.8
490.0
16.6
11.0
4.0
51.0
4.0
4.0
4.0
4.0
86.8
77.5
6.0
320.0
19.1
15.5
7.0
34.0
4.0
4.0
4.0
4.0
108.6
97.5
65.0
180.0
59
Note: For all elemental analytical results, non-detects have been assigned the DL as the value, in
keeping with the conservative approach adopted by the CHS.
In Region 5, for both impact and control villages, the mean arsenic concentrations (17.1
mg/kg and 17.4 mg/kg) and the maximum values (44 mg/kg and 66 mg/kg) respectively
were some two-fold of those recorded in the other regions. This geochemical soil
signature, while of interest, was less than 20% of the arsenic HIL for residential soils.
The background geochemical soil signatures for arsenic, copper and zinc in the five
geographic regions are shown in Figure 7.
The mean concentrations for lead in village soils were somewhat elevated at the mine
area (Region 1 impact) and at Region 1 control communities with levels of 22 mg/kg
and 31 mg/kg respectively. These values are almost certainly due to natural
mineralisation. The maximum lead concentration of 220 mg/kg occurred at Ieran village
in Region 2 impact. This site, while fitting the definition of a village soil clearly was
affected by a deposit of impacted flood plain sediment material. The concentration of
lead in this sample was some 60% of the HIL for residential areas. All samples at
Regions 3 – 5 for impact and control villages were typical of international baseline lead
soil concentrations.
Naturally elevated copper mineralisation was evident at Finalbin, Ok Ma, Bultem and
Derengo (130 – 210 mg/kg). The maximum Region 2 value occurred at Ieran (2000
mg/kg) and was some two-fold the residential HIL. However, this location was properly
classified as an Exposure Setting E recreational area (volleyball/basketball courts)
where a HIL of 2000 mg/kg applied. The mean values at Region 2 for all surveyed
communities were between 10% – 25% of the residential HIL. The mean concentrations
of copper at Regions 3 – 5 were similar for the impact and control villages (range of
means 29.0 mg/kg - 44.8 mg/kg) within and between regions and typical of international
background levels (ie 13 mg/kg – 25 mg/kg) (Sposito 1989).
As expected, the concentrations of zinc in village soils showed a similar grouping to
that observed for copper, with the range of means at Regions 1 and 2 (impact and
control) being influenced by natural mineralisation. At Region 2 impact, the maximum
concentration was at Ieran and likely influenced by flood plain sediment in the village
soil samples. The observed levels were generally less than 5% of the Australian HIL
value. Mean zinc concentrations at Region 3 (impact and control) and Region 4
(control) were low and similar to international background concentrations of 40 mg/kg –
60 mg/kg. At Region 4 (impact) and Region 5 (impact and control) the natural soil zinc
concentrations showed increased values, comparable with the levels observed in the
Regions 1 and 2 villages, indicating that zinc (but not copper) was part of the natural
soil signature in these regions.
The village soil mean concentrations for cadmium and mercury in all of the five regions
and at all villages was < 1 mg/kg (ie < 10% of the respective HIL values). The levels of
selenium were all less than the laboratory method detection limit of 4 mg/kg.
Comparing the observed concentrations for all metals at all locations, with the
Australian HIL values the present results were of no health significance.
60
Figure 7: Village soil concentrations of arsenic, copper and zinc showing natural
soil signatures (all mean values mg/kg)
250.0
200.0
Metal concentration (mg/kg)
Copper
Zinc
Arsenic (x 5)
150.0
100.0
50.0
0.0
Control
Impact
Region 1
Control
Region 2
Control
Impact
Region 3
Control
Impact
Region 4
Control
Impact
Region 5
Location
Note: As discussed in the text, some Region 2 impact village soils contained what would appear to be
mine-derived material. Region 2 impact has not been included into the figure above.
6.4.4 Natural (non-impacted) sediments
For the natural (non-impacted) sediments, the levels of total extractable copper, lead and
zinc were somewhat higher in Regions 1 and 2 (Table 13), and excluding a single
outlier value at Gre (copper 770 mg/kg; zinc 200 mg/kg) were comparable between all
impact and control villages. The observed mean values for all metals were comparable
with the levels in the village garden soils. This is illustrated in Figures 7 and 8. The
mean values approximated: arsenic 4 – 9%; cadmium 2%; copper 2.5 – 10%; mercury
3%; lead 3 – 10% and zinc 1% of the respective residential HILs.
At the Regions 3 – 5 impact and control villages, the concentrations in the natural
sediments did not exceed 5% of the respective HIL value for any metal. Natural
sediment impact and control at the Region 5 villages, had arsenic values between 10% –
36% of the arsenic HIL.
61
Table 13: Natural (non-impacted) sediments total metals (all values are mg/kg)
Stats
-
Arsenic
Cadmium
6.0
0.5
Mean
Median
Min
Max
9.0
5.0
4.0
21.0
0.5
0.4
0.4
0.6
Mean
Median
Min
Max
4.4
4.0
4.0
8.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
6.8
4.0
4.0
18.0
0.4
0.4
0.4
0.5
Mean
Median
Min
Max
4.0
4.0
4.0
4.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
4.7
5.0
4.0
6.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
5.3
4.0
4.0
12.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
10.3
10.5
6.0
14.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
12.8
10.0
5.0
34.0
0.4
0.4
0.4
0.4
Mean
Median
Min
Max
36.2
49.0
7.0
52.0
0.4
0.4
0.4
0.4
Copper
Mercury
Region 1 control
25.0
0.3
Region 1 impact
98.0
0.5
100.0
0.4
61.0
0.2
130.0
0.9
Region 2 control
72.0
0.4
55.0
0.2
22.0
0.2
160.0
1.0
Region 2 impact
155.8
0.3
40.0
0.2
7.0
0.2
770.0
0.4
Region 3 control
32.4
0.5
23.0
0.2
18.0
0.2
65.0
1.0
Region 3 impact
17.6
0.3
20.0
0.3
12.0
0.3
23.0
0.4
Region 4 control
14.0
0.3
13.5
0.2
10.0
0.2
22.0
1.0
Region 4 impact
22.8
0.2
17.0
0.2
11.0
0.2
46.0
0.2
Region 5 control
12.0
0.4
12.0
0.2
3.0
0.2
27.0
1.0
Region 5 impact
19.5
0.2
21.0
0.2
14.0
0.2
23.0
0.3
Lead
Selenium
Zinc
12.0
4.0
69.0
29.0
22.0
8.0
54.0
4.0
4.0
4.0
4.0
93.4
65.0
36.0
170.0
9.6
9.0
5.0
13.0
4.0
4.0
4.0
4.0
76.1
72.0
39.0
110.0
23.3
18.5
13.0
51.0
4.0
4.0
4.0
4.0
54.0
24.0
21.0
200.0
12.4
12.0
11.0
14.0
4.0
4.0
4.0
4.0
53.0
35.0
19.0
96.0
9.6
9.0
8.0
11.0
4.0
4.0
4.0
4.0
28.9
27.0
20.0
41.0
12.1
10.5
6.0
27.0
4.0
4.0
4.0
4.0
36.9
34.0
12.0
70.0
14.5
12.0
11.0
23.0
4.0
4.0
4.0
4.0
51.8
42.0
23.0
100.0
11.4
11.0
9.0
14.0
4.0
4.0
4.0
4.0
65.0
79.0
18.0
100.0
22.3
28.5
7.0
31.0
4.0
4.0
4.0
4.0
127.5
160.0
49.0
170.0
Note: For all metals, non-detects have been assigned the DL as the value, in keeping with the
conservative approach adopted by the CHS.
62
6.4.5 Roadside soil and sediments
The metal concentrations for roadside soils/sediments in Regions 1 and 2 are given in
Table 14.
In general, the results were comparable with the concentrations that were observed in
natural (non-impacted) sediments for all total extractable metals. The exception to this
were two samples, one from a road side site at Ningerum (copper 770 mg/kg; lead 160
mg/kg and zinc 340 mg/kg) and the other from a children’s playground adjacent to the
highway at Gre (copper 560 mg/kg). The sample from Ningerum with elevated copper,
lead and zinc and Gre with only copper was indicative that this material had been
originally sourced from impacted flood plain sediments. The gravel used in road works
is also sourced from the Ok Tedi River.
For all other locations, the levels of metals were consistently < 10% of the respective
residential HIL values.
Table 14: Road impacted soils total metals (all mean values mg/kg)
Stats
Arsenic
Cadmium
Mean
Median
Min
Max
6.0
6.0
4.0
8.0
0.4
0.4
0.4
0.5
Mean
Median
Min
Max
7.0
4.0
4.0
32.0
0.4
0.4
0.4
0.5
Copper
Mercury
Region 1 impact
64.0
0.5
49.0
0.5
28.0
0.2
130.0
0.8
Region 2 impact
149.7
0.6
29.0
0.3
11.0
0.2
770.0
1.0
Lead
Selenium
Zinc
13.8
13.5
11.0
17.0
4.0
4.0
4.0
4.0
52.5
52.0
23.0
83.0
26.1
12.0
9.0
160.0
4.0
4.0
4.0
4.0
77.1
32.0
26.0
340.0
Note: For all metals, non-detects have been assigned the DL as the value, in keeping with the
6.4.6 Impacted flood plain sediments
The metal concentrations for impacted flood plain sediments for Regions 2 - 5 are given
in Table 15. There were no impacted flood plain sediments for Region 1.
The Region 2 impacted flood plain sediments were generally characterised by a minederived sediment signature for arsenic, copper, lead and zinc. The maximum
concentrations when compared with the residential HIL were: arsenic 45%; copper
230%; lead 100% and zinc 15% of the respective values. The maximum copper
concentration exceeded both the residential HIL and that for recreational use sites. The
mean copper concentration at the most impacted community of Ningerum Tamaro was
some three-fold the residential HIL.
63
Table 15: Impacted flood plain sediments total metals (all values are mg/kg)
Stats
Arsenic
Mean
Median
Min
Max
4.0
4.0
4.0
4.0
Mean
Median
Min
Max
23.5
23.5
4.0
43.0
Mean
Median
Min
Max
4.0
4.0
4.0
4.0
Mean
Median
Min
Max
5.3
4.0
4.0
20.0
Mean
Median
Min
Max
4.0
4.0
4.0
4.0
Mean
Median
Min
Max
4.5
4.5
4.0
5.0
Mean
Median
Min
Max
7.0
7.0
4.0
10.0
Mean
Median
Min
Max
26.3
8.0
6.0
65.0
Cadmium
Copper
Mercury
Lead
Region 2 control
0.4
66.0
0.7
13.3
0.4
74.0
1.0
14.0
0.4
46.0
0.2
9.0
0.4
78.0
1.0
17.0
Region 2 impact
1.2
1164.5
0.2
161.0
1.2
1169.0
0.2
161.5
0.4
20.0
0.2
11.0
2.0
2300.0
0.2
310.0
Region 3 control
0.4
31.3
0.7
11.0
0.4
31.0
1.0
11.0
0.4
26.0
0.2
11.0
0.4
37.0
1.0
11.0
Region 3 impact
0.4
121.3
0.6
20.8
0.4
20.5
0.3
10.0
0.4
14.0
0.2
7.0
0.6
1200.0
1.0
130.0
Region 3 impact (outlier excluded)
0.4
23.2
0.5
10.8
0.4
20.0
0.3
10.0
0.4
14.0
0.2
7.0
0.4
40.0
1.0
18.0
Region 4 control
0.4
23.0
0.6
12.3
0.4
23.0
0.6
11.0
0.4
11.0
0.2
10.0
0.4
35.0
1.0
16.0
Region 4 impact
0.4
45.5
1.0
18.5
0.4
40.0
1.0
19.0
0.4
24.0
1.0
13.0
0.4
78.0
1.0
23.0
Region 5 control
0.4
22.7
0.5
20.0
0.4
20.0
0.2
12.0
0.4
8.0
0.2
12.0
0.4
40.0
1.0
36.0
Region 5 impact
0.4
23.8
0.5
20.2
0.4
20.5
0.3
20.5
0.4
16.0
0.2
11.0
0.4
44.0
1.0
28.0
Selenium
Zinc
4.0
4.0
4.0
4.0
133.0
140.0
89.0
170.0
6.0
6.0
4.0
8.0
430.8
433.0
27.0
830.0
4.0
4.0
4.0
4.0
43.7
30.0
29.0
72.0
4.0
4.0
4.0
4.0
75.0
29.5
10.0
510.0
4.0
4.0
4.0
4.0
35.5
29.0
10.0
120.0
4.0
4.0
4.0
4.0
38.0
39.5
7.9
73.0
4.0
4.0
4.0
4.0
107.8
91.5
48.0
200.0
4.0
4.0
4.0
4.0
110.7
58.0
54.0
220.0
Mean
26.7
4.0
126.3
Median
27.0
4.0
119.5
Min
6.0
4.0
44.0
Max
49.0
4.0
250.0
Notes:
1.
For all metals, non-detects have been assigned the DL as the value, in keeping with the
2.
For Region 3 impact, the reported values were very markedly influenced by a single outlier value
at Manda. Table 15 has presented both the summary data and data where the outlier has been
excluded.
64
The samples for Region 3 (impact) from Manda (5 samples) and Komovai (3 samples)
were comparable with the non-impacted Region 3 sediments with the exception of a
single sample at Manda with a characteristic mine-derived sediment signature (arsenic
20 mg/kg; copper 1200 mg/kg; lead 130 mg/kg and zinc 510 mg/kg). Excluding this
outlier value, the results were consistently < 10% of the respective HIL for all metals
and arsenic (arsenic < 4; cadmium < 0.4; copper < 30; mercury < 1; lead < 10 and zinc
< 40 mg/kg).
The Regions 4 and 5 samples showed little variation between the impact and control
villages. Notably, as discussed for the village soils and natural sediments, there was a
characteristic geochemical signature for arsenic and zinc. The HILs for all metals were
typically < 5% of the respective HIL. Arsenic was < 25% of the HIL.
6.4.7 Conclusions – soil and sediments
Table16 and Figures 7 and 8, provide a summary of the data from Tables 11 - 14. There
was little difference between the levels of arsenic in village and garden soils or natural
(non-impacted) sediments, or the impact and control villages in the five regions, other
than a minor natural elevation in the sediments in all Region 5 locations. Arsenic was
also somewhat elevated in the Regions 2 and 3 impact communities, resulting from the
characteristic mine-derived sediment signature in some samples. All samples were <
35% of the Australian recreational (Exposure Setting E) HIL value.
The mean concentrations for copper, lead and zinc in the village soils and natural
sediments were somewhat elevated at the impact and control communities in Region 1,
resulting from natural mineralisation. At the Region 2 impact communities, the mean
levels in village soils would appear to be influenced by the presence of impacted flood
plain sediments in some village soils at Ieran. Copper, lead and zinc in the village soils
and natural sediments at Regions 3 – 5 were similar between impact and control
locations, and were typical of international baseline concentrations.
Copper, lead and zinc in the impacted flood plain sediments were characterised by a
mine-derived sediment signature at Region 2 impact (and a single sample at Manda in
Region 3). At Regions 4 and 5, the levels were generally low for copper and lead. It
would appear that zinc at the Region 4 impact and Region 5 impact and control
locations were marginally elevated due to natural zinc mineralisation. Mercury,
cadmium and selenium concentrations at all of the Regions 1 – 5 impact and control
monitored locations approximated, or were below, the respective limits of detection.
65
Table 16: Comparison between village soils and sediment samples (Total
extractable metal mean values mg/kg)
Type
Arsenic
Cadmium
Village soils
Natural sediments
Roadside sediment
10.6
9.0
6.0
0.6
0.5
0.4
Village soils
Natural sediments
11.0
6.0
0.6
0.5
Village soils
Natural sediments
Impacted flood
plain sediment
Roadside sediment
7.2
6.8
23.5
0.6
0.4
1.2
Copper
Mercury
Region 1 impact
114.4
0.3
98.0
0.5
64.0
0.5
Region 1 control
84.6
0.3
25.0
0.3
Region 2 impact
223.1
0.7
155.8
0.3
1164.5
0.2
7.0
0.4
Village soils
Natural sediments
Natural flood plain
sediment
Lead
Selenium
Zinc
22.0
29.0
13.8
4.0
4.0
4.0
164.7
93.4
52.5
31.1
12.0
4.0
4.0
211.6
69.0
38.9
23.3
161.0
4.0
4.0
6.0
147.3
54.0
430.8
0.6
26.1
4.0
77.1
4.7
4.4
4.0
149.7
Region 2 control
0.4
92.0
0.4
72.0
0.4
66.0
0.5
0.4
0.7
10.9
9.6
13.3
4.0
4.0
4.0
79.9
76.1
133.0
Village soils
Natural sediments
Impacted flood
plain sediment
4.3
4.7
5.3
0.4
0.4
0.4
Region 3 impact
34.7
17.6
121.3
0.9
0.3
0.6
12.9
9.6
20.8
4.0
4.0
4.0
27.4
28.9
75.0
Village soils
Natural sediments
Natural flood plain
sediment
4.3
4.0
4.0
0.4
0.4
0.4
Region 3 control
43.6
32.4
31.3
1.0
0.5
0.7
15.0
12.4
11.0
4.0
4.0
4.0
57.1
53.0
43.7
Village soils
Natural sediments
Impacted flood
plain sediment
5.4
10.3
7.0
0.4
0.4
0.4
Region 4 impact
29.2
22.8
45.5
1.0
0.2
1.0
13.7
14.5
18.5
4.0
4.0
4.0
121.7
51.8
107.8
Village soils
Natural sediments
Natural flood plain
sediment
6.7
5.3
4.5
0.4
0.4
0.4
Region 4 control
29.6
14.0
23.0
1.0
0.3
0.6
11.3
12.1
12.3
4.0
4.0
4.0
19.4
36.9
38.0
Village soils
Natural sediments
Impacted flood
plain sediments
17.1
36.2
26.7
0.4
0.4
0.4
Region 5 impact
44.8
19.5
23.8
1.0
0.2
0.5
19.1
22.3
20.2
4.0
4.0
4.0
108.6
127.5
126.3
Village soils
Natural sediments
Natural flood plain
sediments
17.4
12.8
26.3
0.4
0.4
0.4
Region 5 control
29.0
12.0
22.7
1.0
0.4
0.5
16.6
11.4
20.0
4.0
4.0
4.0
86.8
65.0
110.7
66
Figure 8: Arsenic and lead in soil and sediments compared with Australian HILs
(all mean values mg/kg)
Arsenic
Arsenic concentration (mg/kg)
120
100
Village soils
Natural sediments
80
Flood plain sediments
Roadside soils
60
40
20
0
Impact Control Impact Control Impact Control Impact Control Impact Control
Region 1
Region 2
Region 3
Region 4
Aust
HIL
Region 5
Location
Lead
800
Zinc concentration (mg/kg)
700
Village soils
600
Natural sediments
500
Roadside soil
400
300
200
100
Region 1
Region 2
Region 3
Region 4
Aust
HIL/10
Control
Impact
Control
Impact
Control
Impact
Control
Impact
Control
Impact
0
Region 5
Location
Note: For Regions 1 – 5 impact the flood plain sediments are impacted flood plain sediments, while for
the corresponding Regions 1 – 5 control these are natural flood plain sediments.
67
Figure 9: Copper and zinc in soil and sediments compared with Australian HILs
(all mean values mg/kg)
Copper
1400
Copper concentration (mg/kg)
1200
Village soils
Natural sediments
1000
Roadside soils
800
600
400
200
0
Region 1
Region 2
Region 3
Region 4
Aust
HIL
Region 5
Location
Zinc
800
Zinc concentration (mg/kg)
700
Village soils
600
Natural sediments
500
Roadside soils
400
300
200
100
0
Region 1
Region 2
Region 3
Region 4
Aust
HIL/10
Region 5
Location
Note:
For Regions 1 – 5 impact the flood plain sediments are impacted flood plain sediments,
while for the corresponding Regions 1 – 5 control these are natural flood plain
sediments.
68
6.5 Food
Dietary exposures from individual foods for the OTML CHS were summed to represent
a total dietary exposure and compared with the internationally recognised health
guideline values or Provisional Tolerable Weekly Intakes (WHO PTWIs) shown in
Table 17.
The WHO PTWI values represent permissible human weekly exposure to a contaminant
that has a cumulative effect on the body and is unavoidably present in otherwise
wholesome and nutritious food.
Table 17: WHO Provisional Tolerable Weekly Intakes (µg//kg bw/week)
WHO PTWI
Arsenic
15
Cadmium
7
Copper
3500
Mercury
5
Lead
25
Selenium
350
Zinc
7000
Notes:
1.
For total mercury, the value of 5 µg/kg bw/week has been retained for discussion of population
exposures. Since the allocation for the methylmercury component has been reduced from 3.33
µg/kg bw/week to 1.6 µg/kg bw/week, there is an argument that the new value for total mercury
should be 3.27 µg/kg bw/week (JECFA 2003). However, to date, WHO has not endorsed this
value and recalculations would be simple to apply if required.
2.
The WHO PTWI is for inorganic arsenic. For food, there is general agreement between national
agencies that the fraction of total arsenic represented by inorganic arsenic is about 10%, resulting
in a PTWI (total) of 150 µg/kg bw/week.
The metal concentrations in individual food commodities were also compared with the
mean values and concentration ranges of the Australian and United States total diet
studies conducted between 1991 and 2003 (ANZFA 1998, FSANZ 2001, 2003, US
FDA 2006).
6.5.2 Ok Tedi-Fly Rivers food and nutrition studies
The design, conduct and analysis of the OTML CHS food and nutrition studies have
been presented in Volume 1 of the present report. For convenience, a short summary of
Volume 1 is presented below.
Typical of rural Papua New Guinea, the people of the non-urban Ok Tedi Fly River
system and Lake Murray villages are principally subsistence farmers, sourcing a major
proportion of their diet from home-grown produce, hunting, and in the lowland villages,
non-commercial fishing. The semi-urban villagers at Bultem and Finalbin obtain a
significant proportion of their diet from store-food purchases.
As a basis for identifying priority foods to be incorporated into the OTML CHS Market
Basket Survey and the derivation of total metal intakes for the food compartment, the
usual dietary consumption pattern of the impact villages, together with matched control
populations were established. This was achieved by using a standardised
questionnaire-driven survey of food consumption frequency, the CHS FFS. The study
was conducted in a manner consistent with the WHO published guidelines for collecting
food consumption data from individuals (WHO 1985, FAO/WHO Codex 2006).
69
The CHS FFS and dietary recall provided a picture of current food consumption
patterns, but with no information on quantities consumed. The individual food
consumption values were derived from unit food consumption measurements at a
number of the villages with representation from all five regions (CHS UFC). This
enabled the derivation of the current per capita food consumption by age for the Ok
Tedi-Fly River village communities.
Food samples for metal analyses were sourced from all of the five geographic regions
with equal representation from both impact and control villages in each region. In the
CHS MBS sampling period between May 2004 – July 2006, samples representing 24 of
the 25 food consumption categories were obtained. The category “Eggs, domestic and
wild” was not sampled, owing to a lack of availability at most villages. While not all of
the 24 food categories were available at every survey site, greater than 95% of the target
was achieved. Product substitution by “like commodities” as permitted by Codex was
undertaken. Market Basket samples were averaged to give a single concentration for
each contaminant detected in each food but with separate values for the impact and
control communities within each region. Where samples gave analytical results below
the respective limits of detection, the middle bound value (ie 50% of the detection limit)
was adopted in deriving mean and median values.
6.5.3 Estimation of dietary exposures
Estimates of dietary exposure to chemical contaminants for the study population by
region and for impact and control communities, were obtained by integrating data on the
unit food consumption by age group, together with the results of contaminant levels in
the food actually consumed.
The 25 food consumption categories and weekly food consumption in grams per week,
for each category by age group is given in Volume 1 Tables 11 and 12. For Region 3
adolescents, data construction was required to provide values for use in the dietary
exposure assessment. Inspection of the data revealed that the unit food consumption of
the 11 - 15 years of age group most closely resembled that of the 5 – 10 years of age
group in all regions. The values of the unit food consumption for the Region 3
adolescent group were thus derived by calculating the average difference between the 5
– 10 years of age and 11 – 15 years of age for Regions 1, 2, 4 and 5 for each food, and
then using the derived factors applied to the Region 3, 5 – 10 years of age group
consumption to derive an estimate of the unit food consumption for the 11 – 15 years
age group.
At all communities, only a limited range of food types were consumed during the study
period. For example, while 19 foods from the 25 identified categories were consumed at
Finalbin, only 10 foods from the identified categories were consumed at Aewa and 12
food categories at Kadawa. For the derivation of dietary intakes at each of the impact
and control villages in each region, the foods actually consumed during the survey
period have been used to derive the intakes given in Table 18.
70
Table 18: Total dietary metal intake from food (all values µg/week)
Age group
(years)
1–5
6 – 10
11 – 15
Adult
1–5
6 – 10
11 – 15
Adult
1–5
6 – 10
11 – 15
Adult
1–5
6 – 10
11 – 15
Adult
1–5
6 – 10
11 – 15
Adult
Type
Arsenic
Cadmium
Control
Impact
Control
Impact
Control
Impact
Control
Impact
471
471
644
644
1333
1348
867
867
39
47
44
58
80
104
70
87
Control
Impact
Control
Impact
Control
Impact
Control
Impact
199
199
173
173
183
183
227
227
41
54
36
45
43
48
49
58
Control
Impact
Control
Impact
Control
Impact
Control
Impact
228
243
260
277
283
301
292
314
47
49
54
58
59
63
62
62
Control
Impact
Control
Impact
Control
Impact
Control
Impact
179
323
170
291
366
415
185
313
39
51
35
42
169
181
52
60
Control
Impact
Control
Impact
Control
Impact
Control
Impact
1095
428
1601
581
1801
696
2521
691
31
30
32
28
39
34
34
33
Copper
Lead
Region 1
5810
140
5581
185
7398
208
6992
302
9367
283
9907
275
10257
274
9947
284
Region 2
8469
260
8020
450
6756
239
6698
413
7633
274
7481
442
9189
314
8917
541
Region 3
7249
295
9508
493
9248
325
12159
562
9792
364
14752
609
8864
353
11508
596
Region 4
5710
515
4086
240
5151
394
3729
215
8399
471
9262
245
5371
386
4425
215
Region 5
5125
204
3958
204
5498
195
4445
183
7139
239
5630
231
5804
246
5273
212
Mercury
Selenium
Zinc
35
35
46
40
81
72
66
60
451
461
496
508
1078
1116
821
841
32919
28765
42189
34776
59082
52595
61529
51981
97
62
55
42
69
49
60
50
316
329
211
248
282
301
266
323
27406
30149
19871
22226
24591
27775
27613
30944
873
172
1104
208
1235
234
1158
221
1534
2010
2185
2417
2530
2654
1965
2485
59906
74915
95046
112420
111595
137827
78629
99786
64
75
58
66
81
85
76
74
330
330
294
344
398
393
343
388
49848
29721
41749
28126
42977
30974
41894
29871
103
38
141
42
156
48
237
59
290
282
375
374
438
425
431
485
21899
20025
28794
25240
38534
32651
33840
30365
Table 19 details the calculated intakes for four age groups using the region and impactand control-specific age-related weights determined during the anthropometric data
survey (Chapter 7, Table 24) together with the mean values determined in Table 18.
71
Values that equal or exceed the WHO PTWI are shown in bold. The data is also
illustrated in Figures 9 and 10 for contaminant and essential trace metals respectively.
Exceedances observed for young children, especially the 1 - 5 years of age, were almost
certainly an over-estimate of the metal intakes, since fully and partially breastfed infants
have a lower contaminant metal intake than infants consuming solid food.
The results are presented as weekly intakes per kilogram body weight to allow
comparison with international health guideline values, particularly the WHO
Provisional Tolerable Weekly Intakes (PTWIs) derived from toxicological studies
(IPCS 1994, 1999, 2000). The WHO PTWI for arsenic is for inorganic arsenic. In order
to make a valid comparison between the OTML CHS data and the WHO Guidelines, a
total arsenic WHO PTWI value of 150 µg/kg bw/wk has been adopted.
The contaminant metal dietary intakes of arsenic for all age groups by the Region 1
impact and control villagers, was comparable and somewhat greater than the levels
observed in the Regions 2 – 4 villagers. The Region 5 arsenic levels in the control and
impact villagers with intakes of about 45 µg/kg bw/wk and 12 µg/kg bw/wk
respectively, would appear to be reflective of the impact of arsenic in food levels,
resulting from the naturally-occurring arsenic geochemical signature in the Fly estuary
region, although the difference in food consumption patterns cannot be excluded. All
observed levels were less than 30% of the WHO PTWI value.
The intakes of cadmium from the diet were similar in all regions and at 10% – 60% of
the WHO PTWI value for the different age groups were of no health concern. For lead,
the levels in adults in the Regions 2 and 3 impact communities were somewhat higher
than those in the other groups. For children, in Regions 2 (impact); 3 (impact and
control villages) and 4 (control) the dietary intakes of lead in infants marginally
exceeded the WHO PTWI value of 25 µg/kg bw/wk. For all other age groups, the levels
were below the WHO PTWI. As discussed above, this slight exceedance in the 1 – 5
years of age group was likely a consequence of the adoption of the conservative middle
bound value for non detect samples and is of no particular health consequence.
The dietary intakes for mercury in Region 3 control (Lake Murray) for all age and sex
populations markedly exceeded (between three- and 15-fold) the WHO PTWI values for
mercury. These results were not surprising, since earlier pre-mining era work examining
the concentrations of mercury in aquatic foods, together with mercury in human
biomarker samples (hair and urine) have shown values extraordinarily high for the Lake
Murray communities (Kyle 1980, Kyle & Ghani 1982a, 1982b, Currey et al 1992, Abe
et al 1995). The dietary intakes for children 1 – 5 years of age in Regions 3 – 5 impact
and Regions 4 and 5 control also exceeded the WHO PTWI for mercury, but only
marginally so. This result was unsurprising, with historical mercury in scalp hair and
mercury in fish in these regions showing some elevation in mercury levels when
compared with reference groups from other regions. A detailed discussion is provided in
the supplement to this report.
72
Table 19: Adjusted body weight weekly intake of metals from food (all values
µg/kg bw/wk)
Mean
weight
(kg)
Arsenic
Cadmium
Control
Impact
Control
Impact
Control
Impact
Control
Impact
12.4
12.8
20.4
22.4
35.5
41.5
51.2
57.3
38.0
36.8
31.6
28.8
37.6
32.5
16.9
15.1
3.2
3.7
2.2
2.6
2.2
2.5
1.4
1.5
Control
Impact
Control
Impact
Control
Impact
Control
Impact
13
16.1
22.8
25.6
36.6
40.1
51.2
51.7
15.3
12.4
7.6
6.8
5.0
4.6
4.4
4.4
3.2
3.4
1.6
1.7
1.2
1.2
1.0
1.1
Control
Impact
Control
Impact
Control
Impact
Control
Impact
12.1
13.1
24.6
26
38.9
41.6
56
58.9
18.8
18.5
10.6
10.7
7.3
7.2
5.2
5.3
3.9
3.8
2.2
2.2
1.5
1.5
1.1
1.0
Control
Impact
Control
Impact
Control
Impact
Control
Impact
14.2
11.9
23.8
22.8
37.6
38.6
60.4
58.4
12.6
27.1
7.1
12.8
9.7
10.7
3.1
5.4
2.8
4.3
1.5
1.8
4.5
4.7
0.9
1.0
Control
Impact
Control
6 - 10
Impact
Control
11 - 15
Impact
Control
Adult
Impact
WHO PTWI
11.6
11.4
22.3
24.3
33.1
38.1
56.5
55.4
94.4
37.6
71.8
23.9
54.4
18.3
44.6
12.5
150
2.7
2.6
1.4
1.2
1.2
0.9
0.6
0.6
7
Age
group
(years)
1–5
6 - 10
11 - 15
Adult
1–5
6 - 10
11 - 15
Adult
1–5
6 - 10
11 - 15
Adult
1–5
6 - 10
11 - 15
Adult
1–5
Type
Copper
Region 1
468.5
436.0
362.6
312.1
263.9
238.7
200.3
173.6
Region 2
651.5
498.2
296.3
261.6
208.5
186.6
179.5
172.5
Region 3
599.1
725.8
375.9
467.6
251.7
354.6
158.3
195.4
Region 4
402.1
343.4
216.4
163.6
223.4
239.9
88.9
75.8
Region 5
441.8
347.2
246.5
182.9
215.7
147.8
102.7
95.2
3500
Lead
Mercury
Selenium
Zinc
11.3
14.4
10.2
13.5
8.0
6.6
5.3
5.0
2.9
2.7
2.3
1.8
2.3
1.7
1.3
1.1
36.4
36.1
24.3
22.7
30.4
26.9
16.0
14.7
2654.8
2247.2
2068.1
1552.5
1664.3
1267.3
1201.7
907.2
20.0
27.9
10.5
16.1
7.5
11.0
6.1
10.5
7.5
3.8
2.4
1.6
1.9
1.2
1.2
1.0
24.3
20.4
9.3
9.7
7.7
7.5
5.2
6.2
2108.1
1872.6
871.5
868.2
671.9
692.7
539.3
598.5
24.4
37.6
13.2
21.6
9.4
14.6
6.3
10.1
72.1
13.1
44.9
8.0
31.7
5.6
20.7
3.8
126.8
153.4
88.8
93.0
65.0
63.8
35.1
42.2
4950.9
5718.7
3863.6
4323.9
2868.8
3313.2
1404.1
1694.2
36.3
20.1
16.6
9.4
12.5
6.3
6.4
3.7
4.5
6.3
2.4
2.9
2.1
2.2
1.3
1.3
23.3
27.7
12.3
15.1
10.6
10.2
5.7
6.6
3510.4
2497.6
1754.2
1233.6
1143.0
802.4
693.6
511.5
17.6
17.9
8.7
7.5
7.2
6.1
4.4
3.8
25
8.8
3.3
6.3
1.7
4.7
1.3
4.2
1.1
5
25.0
24.7
16.8
15.4
13.2
11.1
7.6
8.8
350
1887.8
1756.6
1291.2
1038.7
1164.2
857.0
598.9
548.1
7000
73
Figure 10: Weekly intakes of contaminant metals from food (µg/kg bw/wk)
Adults
60
Weekly intake (ug/kg bw/wk)
50
Arsenic
Cadmium
40
Lead
Mercury
30
20
10
0
Control
Impact
Region 1
Control
Impact
Control
Region 2
Impact
Region 3
Control
Impact
Control
Region 4
Impact
PTWI
Region 5
Location
Note: The WHO PTWI for arsenic is shown in Figure 10 as one-third of the true value (ie 150 µg/kg
bw/wk).
Children 1 – 5 years of age
160
140
Arsenic
Cadmium
120
Lead
100
Mercury
80
60
40
20
0
Control
Impact
Region 1
Control
Impact
Region 2
Control
Impact
Region 3
Location
Control
Impact
Region 4
Control
Impact
Region 5
PTWI
74
Figure 11: Weekly intakes of essential metals from food (µg/kg bw/wk)
Adults
8000
7000
Copper
6000
Selenium
5000
Zinc
4000
3000
2000
1000
0
Control
Impact
Region 1
Control
Impact
Region 2
Control
Impact
Region 3
Control
Impact
Control
Region 4
Impact
PTWI
Region 5
Location
8000
7000
Copper
6000
Selenium
5000
Zinc
4000
3000
2000
1000
0
Control
Impact
Region 1
Control
Impact
Region 2
Control
Impact
Region 3
Location
Control
Impact
Region 4
Control
Impact
Region 5
PTWI
75
6.5.5 Conclusions – food
Based on the mean adult and child values, there were no substantial differences in
calculated dietary intakes between the control and impact villages of any single
geographic region, with the exception of mercury which was strongly elevated at Lake
Murray. Between regions the mean metal concentration in specific food categories and
for dietary intakes were generally similar.
With the exception of some elevated dietary intakes of lead in the infant group, which
occurred in the Regions 2 – 5 impact and control villagers, and the elevated mercury
intakes in Regions 3 and 4, all contaminant metal intakes were below the respective
WHO PTWI values.
The levels of essential trace metals were consistently below the respective WHO PTWI
values. When compared with the recommended daily allowance for nutritional
requirements, these were also adequate (IOM 2000, 2001).
76
7.0 Risk characterisation
Health hazard characterisation involves the identification of environmental hazards via
the collection, evaluation and interpretation of the available evidence concerning the
association between environmental factors and health. Health Risk Assessment involves
the quantification of the anticipated health burden due to an environmental exposure in
a specified population.
The primary objective of the OTML CHS was to assess whether there were
environmental health problems from exposures to heavy metal contaminants for
communities living proximal to the mining operations and in the down river
communities to the Fly estuary, as a consequence of the riverine waste disposal from the
OTML mine.
The 2006 baseline CHS provided an evaluation of the potential concerns to human
health from residual contaminants present in the impacted region when compared with
matched control villages. The report primarily used data from food, air, water and land,
generated during the period April 2004 to July 2006 and organised by medium and
geographic area. The data was analysed to determine the extent of heavy metal
contamination in environmental media, to evaluate the potential human health risks
associated with exposure to those media and to provide information and analysis for risk
management.
Many potential confounders normally experienced in health risk assessment studies
were not present in the OTML CHS. In particular there have been few significant
engineering, environmental or public health interventions between 2004 – 2006 that
could impact on the potential exposures to the regional communities.
Limitations to the study were that there had been no recent longitudinal epidemiological
studies conducted in any of the study regions. Hence, as is the case for many
community health assessments, the estimation of risks to health was almost wholly
dependent on the environmental and toxicological databases. The study was also
constrained in that there was an absence of demonstrated causal linkages between the
riverine disposal of mine waste materials and health effects in the impact communities,
and it was therefore, impossible to identify any baseline occurrence (rate, prevalence) of
any proportion of diseases attributable to the mine.
77
7.1 Estimating intake
The main variables that lead to different exposure rates are:
•
•
•
patterns of human activity, such as variations in occupation, diet, recreation
and lifestyle;
differences in water and food consumption, body weight and surface area of
the potentially exposed population; and
adoption of different exposure factors.
Exposure routes taken into consideration for the OTML CHS were: air (inhalation); soil
(ingestion, skin contact); drinking water (ingestion); recreational waters (ingestion, skin
contact) and food (ingestion). Dermal exposure to air contaminants was not considered
as the preliminary modelling in this case (and most HHRAs) indicated that this route
was completely insignificant.
There are many assumptions and inferences normally made in the process of calculating
exposures using the many precise formulas available. The uncertainties associated with
these assumptions are considerably lessened in the current study, because all of the
potential exposure media have been directly measured. The assumptions and inferences
that have been made are shown in Table 20 and discussed in the text below.
Table 20: Description of the assumptions made for the main exposure routes
Air
Pathway
Exposure route
Inhalation
Dietary – food
Oral
Dietary – DW
Oral
Oral
Dermal
Oral
Dermal
Recreational water
Soil
1.
2.
3.
4.
5.
Factors
Inhalation exposure
value (volume)
Frequency and amount
Volume ingested
Modifying factor
4
Nil1, 2 or Owen (1990)
Unit food consumption
extrapolation5
Nil
Nil
3
Bioavailability
3
Bioavailability
4
Bioavailability
Nil: 100% absorption is assumed.
100% retention of PM 10 particulates in lung is assumed.
Bioavailability of contaminants in dermal contact is derived from specific permeability constants
for lead and zinc. For the other metals, selenium and arsenic, default values are applied (US EPA
1992).
Oral and inhalational bioavailability have been calculated both on 100% absorption and using the
values of Table 22.
The present study collected unit food consumption data for a limited number of households and
villages. The constraints on this database are both that it is limited to one impact and one control
village per region and that the degree to which it is representative of all other communities within
the particular region, is unquantified. The data is also less than robust for some age groups, due to
the limited sample size.
78
7.1.1 General considerations
Dietary patterns between children and adults may differ significantly. However, the
OTML FFS, which examined weekly food consumption frequencies for selected
communities for different age groups, indicated that this was not the case for the mine
area and down river villagers. The similarity in diet between the age groups was
attributed both to the rural isolation and family economic circumstances of most of the
communities. For the Finalbin and Bultem semi-urban communities, the potential
existed for children to source a significant part of their diet from trade store “snacks”.
However, a survey conducted at Paiam Town as part of the PJV HHRA of trade store
weekly turnover for snack foods, indicated that on a population basis, the snack food
purchases were a minor contributor (less than 0.5% by weight) to the total food intake.
Fluid consumption exposure factors for affluent populations primarily took into account
the consumption of a significant proportion of the total as “refreshment drinks”. From
the OTML FFS this was clearly not the case for the present village communities, where
fluid intake was primarily via drinking water consumption.
Physiological differences between adults and infants and children include variations in
intake rates of air, food, water and soils (and hence contaminant metals) per unit of
body weight. Other variations in exposure will depend on living habits such as daily
hygiene, hand-to-mouth behaviour, absence of occupational exposure and even dermal
adsorption may be greater in children depending on the skin surface area. There are also
major maturational differences between children and adults that can influence their
ability to respond to chemical exposures. The adsorption, distribution and excretion of
the metals differ between children and adults on a chemical-specific basis. As a result,
infants and children will receive a different effective dose of the contaminants than
adults, even where the concentrations in the environmental media are the same.
The proposed exposure factors used in developing exposure scenarios cannot fully take
into account poverty-related factors among the resident populations. Elevated
prevalence of infectious diseases, generally lower health status and particularly
malnutrition (vitamin and essential nutrient and trace element deficiencies), can
contribute to higher metal intakes in all age groups. For example, iron deficiency
anemias, prevalent in some of the Ok Tedi-Fly Rivers communities are widely
recognised as associated with enhanced uptake of lead and particularly so for infants,
adolescents and pregnant/lactating mothers (Flew 1999).
Subsistence lifestyles in the rural areas may elevate metal exposures through water and
food exposure, the latter particularly from home-grown and home-caught produce.
The consumption of trade store foods in Region 1 varied widely between the impact and
control groups. However, the total consumption of bush meats, fish and crustaceans and
wild nuts and fruit was similar by both the impact and control villagers at each region.
Crude exposure factors have been provided by the WHO International Programme on
Chemical Safety and the WHO Drinking Water Guidelines. These groups use the ICRP
Body Weight and Intake Volumes for Reference Man based on the International
Commission on Radiological Protection to calculate estimates of the intake of a
79
substance that can occur over a lifetime without appreciable health risk (ICRP 1975).
This approach does not take into account varying lifestyle scenarios as compared with
the US EPA, UK and Australian approaches. The US EPA, for example, uses a mixture
of best estimates (eg body weight and life duration) and upper-bound estimates
(drinking water and soil consumption) and combines these to provide a “reasonable
maximum exposure”. This latter approach, was to the extent practicable, adopted for the
OTML CHS.
7.1.1.1 Soil ingestion values
While soil is the most important non-occupational exposure pathway over which
environmental controls can be established, patterns of soil consumption in all age
groups remains contentious. Values adopted for each age group vary widely between
countries. Similarly, there are order of magnitude differences in estimates of the
prevalence, affected age groups and exposures from pica behaviour in children. The
default values adopted for the Ok Tedi-Fly River population (Table 23) are a
compromise between the early US EPA values and more recent values adopted by
Australia (Langley & Sabordo 1996, Taylor & Langley 1998, enHealth 2002) and
Canada (CCME 2000).
7.1.1.2 Inhalation exposure values
The twenty-four-hour respiration rates (minute volumes) used for the Ok Tedi-Fly River
study cohorts are those of the ICRP as adopted by the WHO and corrected for infants
and children 2 and 5 years of age (ICRP 1975). These values are similar to those of the
US EPA (US EPA 1989, 1992) Australia and Canada. For convenience the values have
been presented in Table 23 as m3/day. The US EPA does not propose values for infants
and adolescents. For adult occupational groups, the US EPA has developed a range of
values depending on the intensity of work (from light: 13 - 25 L/min to severe 72 - 100+
L/min). Light activity is defined as domestic or non-manual-occupational (8 hours) and
is approximately three times the resting respiration rates.
7.1.1.3 Drinking water consumption
For its risk assessments the US EPA uses two litres per day for adults and one litre per
day for children weighing less than 10 kg. This value is acknowledged to be an
overestimate for the general population, but is used to represent “a long term average
consumption rate”. Australia, Canada and the United Kingdom have adopted similar
values for their exposure factors. The ICRP fluid intake values determined under a
range of conditions and adopted by the WHO, have proposed the values for people
exposed to high environmental temperatures of 2.84 - 3.41 L/day (ICRP 1975). To
accommodate the wide range of mean ambient temperature, environment characteristics
of the Ok Tedi-Fly River highland and lowland communities, the ICRP/WHO values,
scaled for the child and adolescent age groups have been adopted as a reasonable worst
case for the Ok Tedi-Fly River population (Table 23).
7.1.1.4 Recreational water exposure
There are no specific rules that can easily be applied to calculate guideline values for
chemical contaminants in recreational waters. However, the WHO Guidelines for Safe
Recreational Water Environments provide a starting point for deriving values since
these guideline values relate, in most cases, to lifetime exposure (WHO 2003). The
guidelines quoting an earlier report by Mance assume a contribution for recreational use
80
such as bathing of the equivalent of 10% of drinking water consumption (Mance 1984).
This corresponds to an intake of 200 ml per day from recreational contact with water for
most recreational use. For the Ok Tedi-Fly Rivers communities the WHO value has
been adopted for the 5 + years of age group, and 50% of the WHO value for infants
under 5 years of age.
7.1.1.5 Dermal exposure factors
Absorption of contaminants can occur through dermal exposure to soil and surface
waters, however the absorbed dose varies with factors such as soil adhesion and
permeability constants.
7.1.1.6 Soil adhesion factors
Table 21 shows the amount of soil that might adhere to the skin for people of various
ages. These factors are estimated from the total body surface area for each age group.
The US EPA proposes 1 mg of soil as adhered to each square centimetre of skin,
although lower mean values have also been proposed (Finley et al 1994, US EPA 1996).
The Australian risk assessments use a value of 0.5 mg soil/cm2 skin for their
calculations. The value of 0.5 mg soil/cm2 skin and the ATSDR 50th percentile total
body surface area have been adopted as a realistic estimate for the OTML CHS.
Table 21: Fiftieth percentile total body surface area and soil adherence (mean
values both sex)
Age (years)
2
5
12
20 +
Total body
surface area
(cm2)
5780
9310
14,900
18,200
% area exposed
30
30
28
24
Exposed area
(cm2)
1734
2793
4172
4368
Soil attached
(mg)
867
1397
2086
2184
Note: Soil attached data from ATSDR 1992. Recalculation of the data, taking into account the mean
height/weight of the Ok Tedi-Fly Rivers populations gave a value approximately 80% of the
values quoted in column 5 of Table 21.
The tendency of an individual contaminant to dissociate from the soil particle and
absorb into the skin is often expressed as a dermal absorption factor. The dermal
absorption factor is expressed as a percent of the contaminant, which if present in direct
contact with the skin, will be absorbed into the body. Metals tend to be poorly absorbed
through the skin, unlike many volatile organics and pesticides. Where chemical-specific
data is not available, the default dermal absorption factor for metals given by the US
EPA Soil Screening Guidance Document, is 1% (US EPA 1996). This value has been
adopted for the OTML CHS exposure scenarios.
7.1.1.7 Dietary exposures
To identify the priority foods to be included into the OTML CHS, the usual dietary
intake pattern (frequency of food consumption) of the impacted Ok Tedi-Fly River
communities segregated into five geographical regions, together with matched control
populations from the same regions have been established. This was achieved using a
81
standardised questionnaire-driven survey – the Ok Tedi-Fly River FFS. The results of
this study are reported in Volume 1: OTML CHS Food and Nutrition Studies.
7.1.2 OTML CHS exposure factors
Exposure factors are calculated to estimate average doses over the exposure period.
Generally a lifetime value of 70 years is adopted, unless the contaminant is known to
affect human development in a critical life stage such as childhood. For the
contaminants of concern, only lead and mercury have been demonstrated to have
particular concerns for the infant population.
For non-occupational groups the values of 365 days/year and 70 years lifespan has been
adopted by the WHO and all of the countries represented in Table 23. While the lifespan
of Papua New Guineans is somewhat shorter than those proposed, the value of 70 years
has been retained as a conservative value. The US EPA and Canada have adopted
additional exposure timeframes for specific age groups and occupational groups. For
example Canada adopts a 30-year working lifetime with 5 days per week and 50 weeks
per year. For most Papua New Guinea lifestyles these additional values are irrelevant.
7.1.3 Bioavailability
The bioavailability of metals is typically a function of the physical state, chemical
properties and the ability to take up the specific metal in human physiological processes.
Absorption of contaminants may vary markedly with the exposure routes. Similarly,
uptake is age dependent for some metals and exposure routes. For lead, for example,
there is approximately a five-fold difference in gastrointestinal absorption rates between
children and adults. The WHO and many health agencies (eg Australia and US
Department of Health and Human Services) as a matter of policy, assume 100%
absorption where there is no valid evidence to support adoption of metal-specific values.
Following an extensive review of the literature, Owen derived absorption coefficients
for 39 chemicals via oral and inhalation routes of exposure (summary metals data: Table
22) (Owen 1990). Both the WHO and absorption coefficient approaches have been used
in the development of the OTML CHS exposure scenarios.
Table 22: Absorption coefficients for oral and inhalational exposures1
Element
Arsenic
Cadmium
Copper
Lead2
Mercury (inorganic)
Mercury (organic)
Selenium
Zinc
1.
2.
Oral (range)
0.88 (0.7 - 0.98)
0.06 (0.023 - 0.01)
0.5 (0.32 - 0.9)
0.1 (0.01 - 0.14)
0.15 (0.02 - 0.15)
0.95 (0.8 - 1.0)
0.6 (0.44 - 1.0)
0.5
Inhalation (range)
0.32 (0.3 - 0.34)
0.4 (0.05 – 0.6)
0.5
0.5 (0.2 - 0.62)
0.02 (0.0 - 0.085)
1.0
0.3
0.5
Applicable to all age groups.
The oral exposure coefficient value adopted for lead in children (2 - 3 years of age) are generally
increased to 0.5 to allow for the known elevated gastrointestinal absorption for this group. This
practice has been adopted in the OTML CHS exposure calculations for children 1 - 5 years of age.
82
A comparison between the exposure factors of the WHO and the agencies discussed
above is shown in Table 23 and for the age-related body weight by region in Table 24.
The Ok Tedi-Fly River values represent realistic input parameters for calculating the
total metal intakes of the study populations of different ages under various scenarios of
daily life and are the starting point for the OTML CHS exposure model presented in the
following section.
Table 23: Comparison of input parameters used in typical residential exposure
scenarios (standard default values)
Variable
Age (years)
Child 1 – 6
Child 7 – 19
Adult
Child 2
Air
Child 5
inhalation
Child 12
3
(m /day)
Adult
Child
Drinking
Child 2
water
Child 5
ingestion
Child 14
(L/day)
Adult
DW ingestion Adult 32°C
Soil
ingestion
(mg/day)
US EPA
1989
US EPA
1992
200 - 800
200 – 400
60 - 100
50 – 100
20
20 - 30
1
10
13 – 20
1
15
22
1.4
1.4
1.
2.
3.
4.
5.
1.1
1.5
1.9
3.125
0.2
Recreational water exposure
(L/day)3
Exposure frequency
(days/year)
Exposure duration (years)
Cancer risk4
2
WHO
IPCS
1994
Canada
CCME
2000
50
20
20
350
365
9 - 30
10-6
A30, C 6
10-5
70
25
5 – 10
12
23
1
0.8
0.9
1.3
1.5
0.2 - 0.4
350
Aust
NEPC
1999
50 – 100
2
Ok Tedi-Fly
River study
community1
2002
1002
50
5
10
15
22
1
0.8
1.6
2.25
3
0.1 (2 years)
0.2 (5 - 70
years)
365
Values adopted by the present study for the OTML CHS communities.
Incidental ingestion of soil and dust adopts the OSWER Directive 9850-4 of 200 mg per day for
children 1 - 6 years of age (6 years of exposure with an assumed average body weight of 15 kg)
and 100 mg per day for others (using an assumed 70 kg body weight for 7 years of age and above)
(US EPA 1989). These numbers are believed to represent upper-bound values for soil and dust
ingestion. The US EPA levels for soil consumption by infants (pica) are detailed in (US EPA
1997b).
From WHO based on ingestion (WHO 2003). While Canada, the US EPA and Australia do not
have default ingestion values, the Netherlands assumes 50 ml/day for all age groups.
Risk indices are presented as a probability of developing cancer. The US EPA uses the general
10-4 - 10-6 risk range as a target range with the 10-4 value generally used in making risk
management decisions (US EPA 1989, 1992).
The lifespan of the Ok Tedi-Fly River study communities, is variously identified as between 45 –
60 years of age. The WHO value of 70 years of age has been retained as a conservative value for
calculations of cancer risk.
705
10-5
83
Table 24: Mean weight by region for deriving the input parameters for the health
risk analysis (all values kg)
Location
Region 1
Region 2
Region 32
Region 4
Region 5
1.
2.
Village type
0–5
12.4
12.8
13
16.1
12.1
13.1
14.2
11.9
11.6
11.4
Control
Impact
Control
Impact
Control
Impact
Control
Impact
Control
Impact
Age group (years)1
6 – 10
11 – 15
20.4
35.5
22.4
41.5
22.8
36.6
25.6
40.1
24.6
38.9
26
41.6
23.8
37.6
22.8
38.6
22.3
33.1
24.3
38.1
15 +
51.2
57.3
51.2
51.7
56
58.9
60.4
58.4
56.5
55.4
Preliminary data analysis has confirmed that for children and adolescents, gender appears to be an
unimportant factor in either dietary patterns or total consumption among the study communities.
The control data for Region 3 control (Lake Murray) has been derived from earlier work by Taufa
(Taufa 1997).
Interpolated values for some of the exposure factors have been derived to enable
compatibility with the food intake modelling. These values are shown below:
Age
Soil ingestion (mg/day)
Drinking water (L/day)
Recreational waters (L/day)
Air (m3/day)
2 years
200
0.8
0.1
5
5 - < 10 years
100
1.8
0.2
13
11 - < 15 years
100
2.3
0.2
17
Adults
50
3
0.2
22
84
8.0 Ok Tedi-Fly River OTML CHS exposure model
The previous chapter has discussed the possible routes of exposure and uptake of the
contaminant metals for the Ok Tedi-Fly River village communities. A detailed list of the
necessary assumptions and uncertainties has also been provided. It thus becomes
possible to use the actual measurements of contaminant concentrations in the various
media to provide good estimates of the actual intake of these contaminant metals by the
impacted and non-impacted populations.
8.1 Typical and reasonable maximum exposures
It is possible to calculate a range of estimates to fully describe the likely impact of
exposure and to better reflect the uncertainties in the metal intakes. Values chosen for
inclusion in the models were based on assumptions made using internationally accepted
values where available, and extrapolations from these as necessary to best reflect the
local population and environment. Ranges were quoted for some model parameters.
However, only mean values were used in the actual models. This was partly because the
questions to be answered were limited to providing the most reliable data to identify
whether the riverine disposal of mine waste materials had an impact on the Ok Tedi-Fly
River populations. Monte-Carlo analysis using ranges would give distributions of
exposures but the “tails” of the distributions where exceedances of guidance values
were likely, were the most uncertain/unlikely parts of the distribution. The means give a
“crude” but highly reliable estimate of the exposure.
It is sometimes possible to evaluate all scenarios at two levels of probable contaminant
intake. The Central Tendency (50th percentile of the population) is the most likely
amount of contaminant that a member of the population will absorb for each scenario.
The Upper Bound (95th percentile of the population) represents the largest intake that
can be reasonably expected for any individual member of the population ie except the
most exposed 5%. However, Hattis and Silver propose that there will be greater
uncertainties in estimates for the variability of the mean (standard deviation) than the
actual estimate of the mean itself (Hattis & Silver 1994). A point estimate of a mean
will be more certain than a point estimate of the level intended to represent the 95th
percentile.
In the present study, there was sufficient data to warrant a reasonable estimate of the
actual mean exposure levels to be made for the impacted population. Separate exposure
scenarios have been calculated for the different age groups and some worst case
circumstances based on actual measured contaminant levels.
Table 23 provides a summation of the various exposure factors from the WHO and a
number of national jurisdictions that have been used to establish a transparent exposure
factor matrix for the OTML CHS communities. The values, in all cases, are
conservative estimates. The exposure factors matrix, together with the mean weight data
given in Table 24 enabled exposure to be calculated for each of the media while taking
into account age-related physiological differences. This matrix was used to develop
input data for the development of the exposure scenarios for different age groups.
85
8.2 Dermal exposures to air, water and soil
Dermal exposure to air contaminants was not considered within the intake models.
Preliminary modelling in this case (and most health risk assessments) indicated that this
route was completely insignificant.
Calculation of dermally absorbed doses for recreational waters used the respective
permeability constants (representing the rate at which a chemical penetrates the skin)
recommended by the US EPA. These values are: lead 4 x 10-6 cm/hr, zinc 6 x 10-4 cm/hr
and the default value 1 x 10-3 cm/hr for the other metals and arsenic. The WHO
maximum length of time for daily exposure (2 x 2 hours daily for adults and 50% of this
value for children 0 – 4 years of age) and a surface area of 5,780 (child 2 years of age)
and 18,200 (adult) from Table 25 representing whole body exposures (eg swimming)
were adopted as the most conservative values. This data, together with the mean metal
concentrations for surface waters from the most impacted (Region 2 impact) and the
mean value for all of the control regions was used to estimate the Dermally Absorbed
Doses (DADs) using the Canadian Ministry of National Health and Welfare
methodology (Health and Welfare Canada 1995).
Note: The Canadian (1995) methodology uses the formula:
ED = (C x P x SA x ET)/BW where:
ED
C
P
SA
ET
BW
=
=
=
=
=
=
Estimated Dose through dermal absorption expressed as µg/kg bw/wk;
Concentration of the contaminant (mg/L);
Permeability constant (cm/hour) as discussed in the text above;
Surface Area of the skin (cm2);
Exposure Time (hours/day) converted to ET x 7 for weekly values; and
Body Weight for the age group being considered (see Table 14)
The DAD results for all metals except copper using the Region 2 impact surface water
data were between 10-2 and 10-4 µg/kg bw/wk indicating that the dermal component of
the recreational exposure pathway other than copper, did not warrant further
consideration in the intake modelling and scenarios. For copper the DAD has been
included into the calculated recreational waters multicompartment exposures for the
four age groups in Tables 28 - 32 in Chapter 9.
Table 25: Dermally Absorbed Doses from surface waters in Region 2 impact for all
age groups (all values µg/kg bw wk)
Age (years)
2
5 – 10
10 - < 15
Adult
Arsenic
3.5 x 10-2
6.0 x 10-2
5.9 x 10-2
4.6 x 10-2
Cadmium
0.7 x 10-2
1.2 x 10-2
1.2 x 10-2
0.9 x 10-2
Copper
0.78
1.32
1.32
1.01
Mercury
l.4 x 10-3
2.4 x 10-3
2.4 x 10-3
1.8 x 10-3
Lead
2.0 x 10-4
3.3 x 10-4
3.2 x 10-4
2.6 x 10-4
Zinc
1.1 x 10-3
1.9 x 10-3
1.9 x 10-3
1.5 x 10-3
Note: In deriving the values of Table 25, the following body weights were used. Child 2 years of age,
11.5 kg; children 5 – 10 years of age, 21.8 kg; adolescent 10 – 15 years of age 35.2 kg and adult
55.8 kg.
Dermally absorbed doses for the soils compartment were significant only for copper,
lead and zinc. To illustrate this point, the values calculated for a child 2 years of age,
86
representing the most critical group for this exposure route, are presented in Table 26.
The age-related soil attached (mg) values were calculated from the body surface data of
Table 21 allowing an exposed area of 30% for children 2 years age as proposed by the
ATSDR.
Table 26: Dermally absorbed doses from soil exposures for child 2 years of age
(µg/kg bw/week)
Type
Arsenic
Village soils
Natural sediments
Road impacted
0.056
0.047
0.032
Village soils
Natural sediments
0.058
0.032
Village soils
Natural sediments
Impacted sediments
Road impacted
0.038
0.036
0.124
0.037
Village soils
Natural sediments
Impacted sediments
0.025
0.023
0.021
Village soils
Natural sediments
Impacted sediments
0.023
0.025
0.028
Village soils
Natural sediments
Impacted sediments
0.023
0.021
0.021
Village soils
Natural sediments
Impacted sediments
0.028
0.054
0.037
Village soils
Natural sediments
Impacted sediments
0.035
0.028
0.024
Village soils
Natural sediments
Impacted sediments
0.090
0.191
0.141
Village soils
Natural sediments
Impacted sediments
0.092
0.068
0.139
Cadmium
Copper
Mercury
Region 1 impact
0.003
0.604
0.002
0.003
0.517
0.003
0.002
0.338
0.003
Region 1 control
0.003
0.446
0.002
0.003
0.132
0.002
Region 2 impact
0.003
1.177
0.004
0.002
0.822
0.002
0.006
6.146
0.001
0.002
0.790
0.003
Region 2 control
0.002
0.486
0.003
0.002
0.380
0.002
0.002
0.348
0.004
Region 3 impact
0.002
0.183
0.005
0.002
0.093
0.002
0.002
0.640
0.003
Region 3 control
0.002
0.230
0.005
0.002
0.171
0.003
0.002
0.165
0.004
Region 4 impact
0.002
0.154
0.005
0.002
0.120
0.001
0.002
0.240
0.005
Region 4 control
0.002
0.156
0.005
0.002
0.074
0.002
0.002
0.121
0.003
Region 5 impact
0.002
0.236
0.005
0.002
0.103
0.001
0.002
0.126
0.003
Region 5 control
0.002
0.153
0.005
0.002
0.063
0.002
0.002
0.120
0.003
Lead
Selenium
Zinc
0.116
0.153
0.073
0.021
0.021
0.021
0.869
0.493
0.277
0.164
0.063
0.021
0.021
1.117
0.364
0.205
0.123
0.850
0.138
0.021
0.021
0.032
0.021
0.777
0.285
2.274
0.407
0.058
0.051
0.070
0.021
0.021
0.021
0.422
0.402
0.702
0.068
0.051
0.110
0.021
0.021
0.021
0.145
0.153
0.396
0.079
0.065
0.058
0.021
0.021
0.021
0.301
0.280
0.231
0.072
0.077
0.098
0.021
0.021
0.021
0.642
0.273
0.569
0.060
0.064
0.065
0.021
0.021
0.021
0.102
0.195
0.201
0.101
0.118
0.107
0.021
0.021
0.021
0.573
0.673
0.667
0.088
0.060
0.106
0.021
0.021
0.021
0.458
0.343
0.584
Note: Values were derived using 0.867 mg attached soil 1% absorption per day and a body mass of 11.5
kg ie:
DAD = (mg/kg metal x 0.867 x 0.01 x 7)/11.5 µg/kg bw/wk.
87
The soil attached factor adopted (0.5 mg soil/cm2) was that of the Australian National
Environment Protection Council (NEPC 1999) summarised in the recently published
enHealth report (enHealth 2002). A default dermal absorption factor of 1% was used for
all metals as specific data was unavailable (US EPA 1996). As can be readily
determined from Table 26, the dermal component of the soil exposure pathway warrants
consideration only for copper and zinc in the intake modelling and scenarios. The
dermally absorbed dose values for copper, lead and zinc have been included into the
calculated soil and sediment multicompartment exposures for the four age groups in
Tables 28 - 32 in Chapter 9.
8.3 Inhalation bioavailability
When considering inhalation bioavailability the WHO and many health agencies (eg
Australia, US Department of Health and Human Services) as a matter of policy, assume
100% absorption where there is not valid evidence to support adoption of metal-specific
values. For the OTML CHS metal intakes by the inhalation route of exposure, all age
groups have been calculated using both the default 100% and the published absorption
coefficients (Owen 1990). The latter values are described as air bioavailable values and
these are shown in Table 27. Clearly, the adoption of bioavailability factors makes little
difference to the total weekly intakes for any age groups. The default 100% absorption
has been used for intake by the inhalation route in all further exposure calculations.
Table 27: Comparison between total ambient air metal intake and intake using
bioavailable metal values (all values μg/kg bw/wk)
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
Ambient air
Air bioavailable
As
Cd
Cu
Regions 1 – 2 (children 1 - 5 years of age)
0.008
0.107
0.025
0.002
0.043
0.012
Regions 3 – 5 (children 1 - 5 years of age)
0.001
0.107
0.004
0.0003
0.043
0.002
Regions 1 – 2 (5 - <10 years of age)
0.010
0.146
0.034
0.003
0.058
0.017
0.001
0.112
0.004
0.0003
0.045
0.002
0.008
0.118
0.028
0.003
0.047
0.014
0.001
0.104
0.004
0.0003
0.042
0.002
Regions 1 - 2 (adult 15+)
0.007
0.097
0.023
0.002
0.039
0.011
Regions 3 – 5 (adult 15 +)
0.001
0.096
0.004
0.0003
0.038
0.002
Hg
Pb
Zn
0.0304
0.0006
0.007
0.004
0.007
0.004
0.030
0.0006
0.001
0.0005
0.017
0.0085
0.0417
0.0008
0.010
0.001
0.010
0.005
0.032
0.0006
0.001
0.0005
0.018
0.009
0.0338
0.0007
0.008
0.001
0.008
0.004
0.030
0.0006
0.001
0.0005
0.017
0.0085
0.0276
0.0006
0.006
0.001
0.007
0.003
0.028
0.0006
0.001
0.0005
0.016
0.008
Note: For air inhalation, the control and impact values were identical. For Regions 1 and 2, the values
were derived from the mean metal values from the Tabubil, Kiunga and Ningerum monitoring
88
sites. For Regions 3 – 5, the values were derived from the mean metal values from the recently
conducted health risk assessment for Porgera Joint Venture at their remote Ok Om and Lake
Murray monitoring sites (Bentley 2004c).
8.4 Bioavailability using soil oral absorption coefficients
The OTML CHS has applied oral absorption coefficient bioavailability modifying
values for the village and garden soils, natural sediments and impacted flood plain
sediment intakes. Undertaking this approach makes a marked difference to the soil and
sediment compartment attributed intakes. Separate metal-specific values for soils have
been developed to take this into consideration as reported in Tables 28 – 32.
8.5 Estimation of cancer risk
Although arsenic is capable of producing a variety of adverse health effects, the effect
currently of greatest concern from chronic, low-level exposure, such as from
environmental media, is carcinogenicity. Ingestion of arsenic in drinking water has been
associated with increased risk of cancers of the skin, bladder, lung, liver, kidney and
prostate. The International Agency for Research on Cancer (IARC) classifies inorganic
arsenic compounds as a Group 1 (carcinogenic to humans). The US EPA has also
classified arsenic as a Group A carcinogen (“known to produce cancer in humans”)
using data from a large study of skin cancer in Taiwan. Cancer risks for arsenic are
calculated under the assumption that there is no level without risk. These cancer risks
are calculated over the entire lifetime for both adults and children.
Both the WHO and US EPA have derived incremental risk estimates of lung cancer
from lifetime exposures to 1 µg/m3 total arsenic in air the respective values are US EPA
4.3 x 10-3 and WHO 3 x 10- 3 (US EPA 1984, WHO 2000).
Both the WHO and US EPA have given numerical estimates of the skin cancer risk
from ingestion. The WHO estimate is that a lifetime daily exposure to 200 µg/L of
arsenic in drinking water would lead to a 0.5% lifetime fatality risk. Assuming a linear
dose relationship, then the lifetime risk from 1 µg/day is equivalent to 1.7 x 10-6. The
US EPA estimate is given as a “carcinogenic potency factor” or Cancer Slope Factor
(US EPA 2006). The US EPA lifetime skin cancer fatality risk from a lifetime intake of
1 µg/day is 2 x 10-7. Thus the EPA’s estimate of risk is about 10 times less than that of
the WHO. This value, calculated on the basis of total arsenic concentrations, is used in
the US EPA risk assessment process to estimate cancer risks from arsenic ingestion
from environmental media in general (ie water, soil and sediments).
Limited data indicate that approximately 25% of the arsenic present in food is inorganic,
but this depends largely on the type of food ingested. Inorganic arsenic levels in fish and
shellfish are generally < 1%, with levels in meat, poultry and cereals ranging between
10% and 70%. Recent studies of rice, for example, indicate that this product may
contain significant levels of arsenic, depending on the soil type and soil arsenic
concentration. It has been shown that between 72% and 90% of this arsenic is inorganic
(US NRC 1999, Kohlmeyer et al 2003). Generally a generic value of 10% is assigned to
the inorganic proportion of total arsenic in food products (US FDA 1993, FSANZ 2001).
89
9.0 Risk characterisation for the Ok Tedi-Fly River OTML CHS regional
communities
Tables 28 – 32 detail the calculated total metal, arsenic and selenium intakes for four
age groups, using the exposure factors derived from Tables 23 and 24 and the mean
values found for contaminant metals in each medium in the five OTML CHS regions.
The results are presented as weekly intakes per kilogram body weight to allow
comparison with international guideline values. The tables list conservative estimates
for intake of each of the contaminants through all of the significant routes for both the
impacted and control populations in each region. Dermal exposures for surface waters
and for soil and sediments are only minor pathways and only make significant
contributions to the total weekly intakes for copper (Table 25) and copper, lead and zinc
(Table 26) respectively. Some routes have not been included. For example, weekly
intakes from ambient air (dermal) and ambient air (bioavailable) have been
demonstrated to be insignificant (Table 27).
The community drinking water data were similar between all impact and control
villages. The mean impact and mean control have been used for all regions. For ambient
air inhalation, all derived values have assumed 100% bioavailability and 100% retention
of PM 10 particulates in lung. The bioavailable values for the soil and sediments have
been derived using the oral mean values of Owen (Table 22). The oral exposure
coefficient value for lead in children 1 – 5 years of age has been set at 0.5 to allow for
elevated oral absorption for this group.
Comparing the results between the village soils and natural sediments with the results of
roadside sediments, clearly indicated that there was no need to consider the roadside
sediments in Regions 1 and 2 as a unique group for analysis.
Using these inputs it is possible to derive total exposure to each contaminant using
modelled scenarios for a number of different lifestyles and locations. Hence exposure
can be calculated for an infant who may have exposures to mine-derived sediments and
bathe in mine-impacted surface waters and ingest contaminated sediments. These can be
compared with infants who have been exposed to natural non-impacted soils, sediments
and surface waters, to achieve a worst case comparison. A range of potential scenarios
are discussed in Chapter 10.
90
Table 28: Multicompartment exposure Region 1 by age group (weekly intake μg/kg
bw)
Impact communities
As
Cd
Cu
Ambient air inhalation
0.01
0.11
0.03
Drinking water ingestion
2.43
0.49
3.90
Food ingestion
36.78
3.71
436.03
Recreational water ingestion + dermal
0.30
0.10
0.60
Village/garden soils total + dermal
1.29
0.07
14.53
Village/garden soils bioavailable
1.14
0.00
6.96
Impacted flood plain sediment total + dermal
NS
NS
NS
Impacted flood plain sediment bioavailable
NS
NS
NS
Natural sediment total + dermal
1.10
0.06
12.45
Natural sediment bioavailable
0.96
0.00
5.97
As
Cd
Cu
0.01
0.15
0.03
2.89
0.58
4.62
Food ingestion
28.75
2.58
312.14
0.30
0.10
0.70
0.34
0.02
4.19
0.30
0.00
1.84
NS
NS
NS
NS
NS
NS
0.29
0.02
3.59
0.25
0.00
1.57
Adolescents 11 – 15 years of age
As
Cd
Cu
0.01
0.12
0.03
2.29
0.46
3.66
Food ingestion
32.49
2.51
238.72
0.20
0.00
0.50
0.21
0.01
2.75
0.19
0.00
1.14
NS
NS
NS
NS
NS
NS
0.18
0.01
2.36
0.16
0.00
0.97
Adults 16 + years of age
As
Cd
Cu
0.01
0.10
0.02
1.88
0.38
3.01
Food ingestion
15.13
1.51
173.59
0.10
0.00
0.30
0.07
0.00
1.03
0.06
0.00
0.36
NS
NS
NS
NS
NS
NS
0.06
0.00
0.88
0.05
0.00
0.31
Note: NS: Not Sampled. There are no flood plain sediments in Region 1.
Hg
0.03
1.95
2.72
0.20
0.04
0.01
NS
NS
0.06
0.01
Hg
0.04
2.31
1.79
0.30
0.01
0.00
NS
NS
0.02
0.00
Hg
0.03
1.83
1.74
0.20
0.01
0.00
NS
NS
0.01
0.00
Hg
0.03
1.51
1.05
0.10
0.00
0.00
NS
NS
0.00
0.00
Pb
0.01
0.10
14.43
0.00
2.68
1.34
NS
NS
3.53
1.77
Pb
0.01
0.12
13.48
0.00
0.71
0.07
NS
NS
0.93
0.47
Pb
0.01
0.09
6.62
0.00
0.44
0.04
NS
NS
0.58
0.29
Pb
0.01
0.08
4.96
0.00
0.14
0.01
NS
NS
0.18
0.09
Se
4.87
36.05
0.60
0.49
0.29
NS
NS
0.49
0.29
Se
5.78
22.66
0.60
0.13
0.08
NS
NS
0.13
0.08
Se
4.57
26.88
0.40
0.08
0.05
NS
NS
0.08
0.05
Se
3.76
14.67
0.30
0.03
0.02
NS
NS
0.03
0.02
Zn
0.01
63.30
2247.24
1.20
20.92
10.03
NS
NS
11.86
5.69
Zn
0.01
75.14
1552.51
1.30
6.03
2.64
NS
NS
3.42
1.50
Zn
0.01
59.46
1267.34
0.80
3.96
1.64
NS
NS
2.34
0.93
Zn
0.01
48.92
907.16
0.50
1.48
0.52
NS
NS
0.84
0.29
91
bw) (cont’d)
Control communities
Food ingestion
Flood plain sediment total + dermal
Flood plain sediment bioavailable
Food ingestion
Food ingestion
Food ingestion
As
0.01
2.43
37.97
0.30
1.34
1.18
NS
NS
0.73
0.64
As
0.01
2.89
31.57
0.30
0.35
0.31
NS
NS
0.19
0.17
As
0.01
2.29
37.55
0.20
0.22
0.19
NS
NS
0.12
0.11
As
0.01
1.88
16.93
0.10
0.07
0.06
NS
NS
0.04
0.03
Cd
0.11
0.49
3.15
0.10
0.07
0.00
NS
NS
0.06
0.00
Cd
0.15
0.58
2.17
0.10
0.02
0.00
NS
NS
0.02
0.00
Cd
0.12
0.46
2.24
0.00
0.01
0.00
NS
NS
0.01
0.00
Cd
0.10
0.38
1.37
0.00
0.00
0.00
NS
NS
0.00
0.00
Cu
0.03
5.36
468.51
0.50
10.75
5.15
NS
NS
3.18
1.52
Cu
0.03
6.36
362.62
0.60
3.10
1.36
NS
NS
0.91
0.40
Cu
0.03
5.03
263.87
0.40
2.03
0.84
NS
NS
0.60
0.25
Cu
0.02
4.14
200.33
0.30
0.76
0.27
NS
NS
0.23
0.08
Note: NS: Not Sampled. There are no flood plain sediments in Region 1.
Hg
Pb
0.03
0.01
1.95
0.10
2.86 11.32
0.30
0.00
0.04
3.79
0.01
1.89
NS
NS
NS
NS
0.04
1.46
0.01
0.73
Hg
Pb
0.04
0.01
2.31
0.12
2.26
10.17
0.30
0.00
0.01
1.00
0.00
0.10
NS
NS
NS
NS
0.01
0.39
0.00
0.19
Hg
Pb
0.03
0.01
1.83
0.09
2.29
7.98
0.20
0.00
0.01
0.62
0.00
0.06
NS
NS
NS
NS
0.01
0.24
0.00
0.12
Hg
Pb
0.03
0.01
1.51
0.08
1.28
5.35
0.10
0.00
0.00
0.20
0.00
0.02
NS
NS
NS
NS
0.00
0.08
0.00
0.04
Se
4.87
36.39
0.60
0.49
0.29
NS
NS
0.49
0.29
Se
5.78
24.29
0.60
0.13
0.08
NS
NS
0.13
0.08
Se
4.57
30.38
0.40
0.08
0.05
NS
NS
0.08
0.05
Se
3.76
16.03
0.30
0.03
0.02
NS
NS
0.03
0.02
Zn
0.01
78.40
2654.80
10.30
26.88
12.88
NS
NS
8.76
4.20
Zn
0.01
93.06
2068.08
10.90
7.74
3.40
NS
NS
2.53
1.11
Zn
0.01
73.64
1664.29
6.80
5.09
2.10
NS
NS
1.66
0.69
Zn
0.01
60.59
1201.73
4.30
1.91
0.66
NS
NS
0.62
0.22
92
bw)
Impact communities
Food ingestion
Food ingestion
Food ingestion
Food ingestion
As
0.01
2.43
12.39
0.30
0.88
0.77
2.86
2.52
0.83
0.73
As
0.01
2.89
6.75
0.30
0.23
0.20
0.75
0.66
0.22
0.19
As
0.01
2.29
4.57
0.20
0.14
0.13
0.47
0.41
0.14
0.12
As
0.01
1.88
4.40
0.10
Cd
0.11
0.49
3.36
0.10
0.07
0.00
0.15
0.01
0.05
0.00
Cd
0.15
0.58
1.74
0.10
0.02
0.00
0.04
0.00
0.01
0.00
Cd
0.12
0.46
1.19
0.00
0.01
0.00
0.02
0.00
0.01
0.00
Cd
0.10
0.38
1.13
0.00
Cu
0.03
3.90
498.16
7.50
28.34
13.58
147.91
70.88
19.79
9.48
Cu
0.03
4.62
261.63
8.50
8.16
3.58
42.62
18.70
5.70
2.50
Cu
0.03
3.66
186.56
5.70
5.36
2.22
27.99
11.58
3.74
1.55
Cu
0.02
3.01
172.48
3.80
Hg
0.03
1.95
3.83
0.40
0.09
0.01
0.02
0.00
0.04
0.01
Hg
0.04
2.31
1.64
0.40
0.02
0.00
0.01
0.00
0.01
0.00
Hg
0.03
1.83
1.21
0.30
0.01
0.00
0.00
0.00
0.01
0.00
Hg
0.03
1.51
0.97
0.20
Pb
0.01
0.10
27.94
0.00
4.74
2.37
20.45
9.80
2.84
1.42
Pb
0.01
0.12
16.14
0.00
1.25
0.12
5.89
2.58
0.75
0.37
Pb
0.01
0.09
11.02
0.00
0.77
0.08
3.87
1.60
0.46
0.23
Pb
0.01
0.08
10.46
0.00
Se
4.87
20.41
0.60
0.49
0.29
0.73
0.44
0.49
0.29
Se
5.78
9.68
0.60
0.13
0.08
0.19
0.12
0.13
0.08
Se
4.57
7.50
0.40
0.08
0.05
0.12
0.07
0.08
0.05
Se
3.76
6.25
0.30
Zn
0.01
63.30
1872.63
2.40
18.71
8.97
54.72
26.22
6.86
3.29
Zn
0.01
75.14
868.18
2.60
5.39
2.36
15.77
6.92
1.98
0.87
Zn
0.01
59.46
692.65
1.60
3.54
1.46
10.35
4.28
1.30
0.54
Zn
0.01
48.92
598.54
1.00
0.05
0.00
2.01
0.00
0.24
0.03
1.33
0.04
0.15
0.13
0.04
0.04
0.00
0.01
0.00
0.00
0.00
0.70
10.49
3.65
1.40
0.49
0.00
0.00
0.00
0.00
0.00
0.02
1.45
0.50
0.15
0.07
0.02
0.04
0.02
0.03
0.02
0.46
3.88
1.35
0.49
0.17
93
bw) (cont’d)
Control communities
Food ingestion
Food ingestion
Food ingestion
Food ingestion
As
Cd
0.01 0.11
2.43 0.49
15.34 3.18
0.30 0.10
0.57 0.05
0.50 0.00
0.49 0.05
0.43 0.00
0.54 0.05
0.47 0.00
As
Cd
0.01 0.15
2.89 0.58
7.58 1.58
0.30 0.10
0.15 0.01
0.13 0.00
0.13 0.01
0.11 0.00
0.14 0.01
0.12 0.00
As
Cd
0.01
0.12
2.29
0.46
5.01
1.17
0.20
0.00
0.09
0.01
0.08
0.00
0.08
0.01
0.07
0.00
0.09
0.01
0.08
0.00
As
Cd
0.01
0.10
1.88
0.38
4.44
0.96
0.10
0.00
0.03
0.00
0.03
0.00
0.03
0.00
0.02
0.00
0.03
0.00
0.02
0.00
Cu
0.03
5.36
651.48
0.30
11.69
5.60
8.38
4.02
9.15
4.38
Cu
0.03
6.36
296.32
0.40
3.37
1.48
2.42
1.06
2.63
1.16
Cu
0.03
5.03
208.55
0.30
2.21
0.91
1.59
0.66
1.73
0.72
Cu
0.02
4.14
179.48
0.20
0.83
0.29
0.59
0.21
0.65
0.23
Hg
0.03
1.95
7.49
0.20
0.06
0.01
0.09
0.01
0.05
0.01
Hg
0.04
2.31
2.43
0.30
0.02
0.00
0.02
0.00
0.01
0.00
Hg
0.03
1.83
1.88
0.20
0.01
0.00
0.01
0.00
0.01
0.00
Hg
0.03
1.51
1.18
0.10
0.00
0.00
0.00
0.00
0.00
0.00
Pb
0.01
0.10
20.02
0.00
1.33
0.66
1.69
0.81
1.17
0.58
Pb
0.01
0.12
10.47
0.00
0.35
0.04
0.49
0.21
0.31
0.15
Pb
0.01
0.09
7.50
0.00
0.22
0.02
0.32
0.13
0.19
0.10
Pb
0.01
0.08
6.13
0.00
0.07
0.01
0.12
0.04
0.06
0.03
Se
4.87
24.28
0.60
0.49
0.29
0.49
0.29
0.49
0.29
Se
5.78
9.25
0.60
0.13
0.08
0.13
0.08
0.13
0.08
Se
4.57
7.69
0.40
0.08
0.05
0.08
0.05
0.08
0.05
Se
3.76
5.19
0.30
0.03
0.02
0.03
0.02
0.03
0.02
Zn
0.01
78.40
2108.12
1.20
10.15
4.86
16.89
8.10
9.67
4.63
Zn
0.01
93.06
871.55
1.30
2.92
1.28
4.87
2.14
2.78
1.22
Zn
0.01
73.64
671.89
0.80
1.92
0.79
3.20
1.32
1.83
0.76
Zn
0.01
60.59
539.32
0.50
0.72
0.25
1.20
0.42
0.69
0.24
94
bw)
Impact communities
Food ingestion
Impacted flood plain sediment total +
dermal
Food ingestion
dermal
Food ingestion
dermal
Food ingestion
dermal
As
0.01
2.43
18.54
0.30
0.52
0.46
0.65
Cd
0.11
0.49
3.76
0.10
0.05
0.00
0.05
Cu
0.03
3.90
725.82
1.40
4.41
2.11
15.41
Hg
0.03
1.95
13.11
0.20
0.11
0.02
0.07
Pb
0.01
0.10
37.60
0.00
1.57
0.79
2.64
Se
0.57
0.57
0.50
As
0.01
2.89
10.66
0.30
0.14
0.12
0.17
0.00
0.05
0.00
Cd
0.15
0.58
2.21
0.10
0.01
0.00
0.01
7.38
2.24
1.07
Cu
0.01
4.62
467.65
1.50
1.27
0.56
4.44
0.01
0.04
0.01
Hg
0.04
2.31
8.01
0.20
0.03
0.00
0.02
1.27
1.17
0.58
Pb
0.00
0.12
21.63
0.00
0.41
0.04
0.76
0.29
0.49
0.29
Se
0.15
0.15
0.13
As
0.01
2.29
7.25
0.20
0.09
0.08
0.11
0.00
0.01
0.00
Cd
0.12
0.46
1.51
0.00
0.01
0.00
0.01
1.95
0.64
0.28
Cu
0.00
3.66
354.62
1.00
0.83
0.35
2.92
0.00
0.01
0.00
Hg
0.03
1.83
5.62
0.10
0.02
0.00
0.01
0.33
0.31
0.15
Pb
0.00
0.09
14.64
0.00
0.26
0.03
0.50
0.08
0.13
0.08
Se
0.09
0.09
0.08
As
0.00
1.88
5.32
0.10
0.03
0.02
0.03
0.00
0.01
0.00
Cd
0.10
0.38
1.05
0.00
0.00
0.00
0.00
1.21
0.42
0.18
Cu
0.00
3.01
195.38
0.70
0.31
0.11
1.09
0.00
0.01
0.00
Hg
0.03
1.51
3.76
0.10
0.01
0.00
0.00
0.21
0.19
0.10
Pb
0.00
0.08
10.13
0.00
0.08
0.01
0.19
0.05
0.08
0.05
Se
3.76
42.19
0.30
0.03
0.02
0.03
0.75
0.69
0.29
Zn
0.01
48.92
1694.16
1.00
0.25
0.09
0.68
0.03
0.03
0.03
0.00
0.00
0.00
0.38
0.16
0.06
0.00
0.00
0.00
0.07
0.06
0.03
0.02
0.03
0.02
0.24
0.26
0.09
4.87
153.43
0.60
0.49
0.29
0.49
5.78
92.98
0.60
0.13
0.08
0.13
4.57
63.81
0.40
0.08
0.05
0.08
Zn
0.01
63.30
5718.68
2.40
3.48
1.67
9.53
4.57
3.67
1.76
Zn
0.02
75.14
4323.86
2.60
1.00
0.44
2.74
1.20
1.06
0.46
Zn
0.01
59.46
3313.15
1.60
0.66
0.27
1.80
95
bw) (cont’d)
Control communities
Food ingestion
Food ingestion
Food ingestion
Floodplain sediment total + dermal
Food ingestion
As
0.01
2.43
18.83
0.30
0.52
0.46
0.49
0.43
0.49
0.43
As
0.01
2.89
10.58
0.30
0.14
0.12
0.13
0.11
0.13
0.11
As
0.01
2.29
7.28
0.20
0.09
0.08
0.08
0.07
0.08
0.07
As
0.00
1.88
5.22
0.10
0.03
0.02
0.03
0.02
0.03
0.02
Cd
0.11
0.49
3.85
0.10
0.05
0.00
0.05
0.00
0.05
0.00
Cd
0.15
0.58
2.20
0.10
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.12
0.46
1.52
0.00
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.10
0.38
1.11
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Cu
0.03
5.36
599.12
0.30
5.54
2.65
3.98
1.91
4.12
1.97
Cu
0.01
6.36
375.93
0.40
1.60
0.70
1.15
0.50
1.19
0.52
Cu
0.00
5.03
251.72
0.30
1.05
0.43
0.75
0.31
0.78
0.32
Cu
0.00
4.14
158.28
0.20
0.39
0.14
0.28
0.10
0.29
0.10
Hg
0.03
1.95
72.13
0.20
0.12
0.02
0.09
0.01
0.06
0.01
Hg
0.04
2.31
44.88
0.30
0.03
0.00
0.02
0.00
0.02
0.00
Hg
0.03
1.83
31.74
0.20
0.02
0.00
0.01
0.00
0.01
0.00
Hg
0.03
1.51
20.69
0.10
0.01
0.00
0.00
0.00
0.00
0.00
Pb
0.01
0.10
24.38
0.00
1.83
0.91
1.40
0.67
1.51
0.75
Pb
0.00
0.12
13.20
0.00
0.48
0.05
0.40
0.18
0.40
0.20
Pb
0.00
0.09
9.36
0.00
0.30
0.03
0.26
0.11
0.25
0.12
Pb
0.00
0.08
6.30
0.00
0.09
0.01
0.10
0.03
0.08
0.04
Se
4.87
126.80
0.60
0.49
0.29
0.49
0.29
0.49
0.29
Se
5.78
88.83
0.60
0.13
0.08
0.13
0.08
0.13
0.08
Se
4.57
6.03
0.40
0.08
0.05
0.08
0.05
0.08
0.05
Se
3.76
35.09
0.30
0.03
0.02
0.03
0.02
0.03
0.02
Zn
0.01
78.40
4950.95
19.50
7.25
3.48
5.55
2.66
6.73
3.23
Zn
0.02
93.06
3863.64
20.60
2.09
0.92
1.60
0.70
1.94
0.85
Zn
0.01
73.64
2868.76
12.70
1.37
0.57
1.05
0.43
1.27
0.53
Zn
0.01
60.59
1404.08
8.00
0.51
0.18
0.39
0.14
0.48
0.17
96
bw)
Impact communities
Food ingestion
dermal
Food ingestion
dermal
Food ingestion
dermal
Food ingestion
dermal
As
0.01
2.43
27.13
0.30
0.66
0.58
0.85
Cd
0.11
0.49
4.29
0.10
0.05
0.00
0.05
Cu
0.03
3.90
343.40
0.60
3.71
1.78
5.78
Hg
0.03
1.95
6.31
0.20
0.12
0.02
0.12
Pb
0.01
0.10
20.13
0.00
1.67
0.83
2.35
Se
0.75
1.25
1.10
As
0.01
2.89
12.75
0.30
0.17
0.15
0.22
0.00
0.05
0.00
Cd
0.15
0.58
1.85
0.10
0.01
0.00
0.01
2.77
2.90
1.39
Cu
0.01
4.62
163.57
0.70
1.07
0.47
1.67
0.02
0.02
0.00
Hg
0.04
2.31
2.91
0.30
0.03
0.00
0.03
1.13
1.77
0.88
Pb
0.00
0.12
9.42
0.00
0.44
0.04
0.68
0.29
0.49
0.29
Se
0.20
0.33
0.29
As
0.01
2.29
10.74
0.20
0.11
0.09
0.14
0.00
0.01
0.00
Cd
0.12
0.46
4.68
0.00
0.01
0.00
0.01
0.73
0.83
0.37
Cu
0.00
3.66
239.94
0.50
0.70
0.29
1.09
0.00
0.01
0.00
Hg
0.03
1.83
2.19
0.20
0.02
0.00
0.02
0.30
0.47
0.23
Pb
0.00
0.09
6.34
0.00
0.27
0.03
0.44
0.08
0.13
0.08
Se
0.12
0.20
0.18
As
0.00
1.88
5.36
0.10
0.03
0.03
0.04
0.00
0.01
0.00
Cd
0.10
0.38
1.03
0.00
0.00
0.00
0.00
0.45
0.55
0.23
Cu
0.00
3.01
75.77
0.30
0.26
0.09
0.41
0.00
0.00
0.00
Hg
0.03
1.51
1.27
0.10
0.01
0.00
0.01
0.18
0.29
0.14
Pb
0.00
0.08
3.68
0.00
0.09
0.01
0.17
0.05
0.08
0.05
Se
3.76
6.64
0.30
0.03
0.02
0.03
1.07
1.24
0.52
Zn
0.01
48.92
511.48
1.30
1.10
0.38
0.97
0.04
0.06
0.06
0.00
0.00
0.00
0.14
0.21
0.07
0.00
0.00
0.00
0.06
0.09
0.05
0.02
0.03
0.02
0.34
0.47
0.16
4.87
27.69
0.60
0.49
0.29
0.49
5.78
15.09
0.60
0.13
0.08
0.13
4.57
10.19
0.40
0.08
0.05
0.08
Zn
0.01
63.30
2497.56
3.00
15.46
7.41
13.69
6.56
6.58
3.15
Zn
0.02
75.14
1233.61
3.20
4.45
1.95
3.95
1.73
1.90
0.83
Zn
0.01
59.46
802.43
2.00
2.93
1.21
2.59
97
bw) (cont’d)
Control communities
Food ingestion
Food ingestion
Food ingestion
Food ingestion
As
0.01
2.43
12.60
0.30
0.82
0.72
0.55
0.48
0.65
0.57
As
0.01
2.89
7.13
0.30
0.22
0.19
0.14
0.13
0.17
0.15
As
0.01
2.29
9.74
0.20
0.13
0.12
0.09
0.08
0.11
0.09
As
0.00
1.88
3.06
0.10
0.04
0.04
0.03
0.02
0.03
0.03
Cd
0.11
0.49
2.76
0.10
0.05
0.00
0.05
0.00
0.05
0.00
Cd
0.15
0.58
1.47
0.10
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.12
0.46
4.48
0.00
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.10
0.38
0.87
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Cu
0.03
5.36
402.08
0.30
3.76
1.80
2.92
1.40
1.78
0.85
Cu
0.01
6.36
216.44
0.40
1.08
0.48
0.84
0.37
0.51
0.22
Cu
0.00
5.03
223.38
0.30
0.71
0.29
0.55
0.23
0.34
0.14
Cu
0.00
4.14
88.92
0.20
0.27
0.09
0.21
0.07
0.13
0.04
Hg
0.03
1.95
4.48
0.20
0.12
0.02
0.07
0.01
0.04
0.01
Hg
0.04
2.31
2.42
0.20
0.03
0.00
0.02
0.00
0.01
0.00
Hg
0.03
1.83
2.14
0.10
0.02
0.00
0.01
0.00
0.01
0.00
Hg
0.03
1.51
1.26
0.10
0.01
0.00
0.00
0.00
0.00
0.00
Pb
0.01
0.10
36.30
0.00
1.38
0.69
1.56
0.75
1.47
0.74
Pb
0.00
0.12
16.57
0.00
0.36
0.04
0.45
0.20
0.39
0.19
Pb
0.00
0.09
12.52
0.00
0.22
0.02
0.30
0.12
0.24
0.12
Pb
0.00
0.08
6.39
0.00
0.07
0.01
0.11
0.04
0.08
0.04
Se
4.87
23.27
0.60
0.49
0.29
0.49
0.29
0.49
0.29
Se
5.78
12.35
0.60
0.13
0.08
0.13
0.08
0.13
0.08
Se
4.57
10.59
0.40
0.08
0.05
0.08
0.05
0.08
0.05
Se
3.76
5.68
0.30
0.03
0.02
0.03
0.02
0.03
0.02
Zn
0.01
78.40
3510.43
4.30
2.46
1.18
4.83
2.31
5.69
2.25
Zn
0.02
93.06
1754.17
4.50
0.71
0.31
1.39
0.61
1.35
0.59
Zn
0.01
73.64
1143.01
2.80
0.47
0.19
0.91
0.38
0.89
0.37
Zn
0.01
60.59
693.61
1.80
0.17
0.06
0.34
0.12
0.33
0.12
98
bw)
Impact communities
Food ingestion
dermal
Food ingestion
dermal
Food ingestion
dermal
Food ingestion
dermal
As
0.01
2.43
37.57
0.30
2.08
1.83
3.25
Cd
0.11
0.49
2.61
0.10
0.05
0.00
0.05
Cu
0.03
3.90
347.22
0.70
5.69
2.73
3.02
Hg
0.03
1.95
3.31
0.20
0.12
0.02
0.06
Pb
0.01
0.10
17.88
0.00
2.33
1.16
2.57
Se
2.86
4.41
3.88
As
0.01
2.89
23.90
0.30
0.55
0.48
0.86
0.00
0.05
0.00
Cd
0.15
0.58
1.17
0.10
0.01
0.00
0.01
1.45
2.48
1.19
Cu
0.01
4.62
182.93
0.80
1.64
0.72
0.87
0.01
0.02
0.00
Hg
0.04
2.31
1.73
0.30
0.03
0.00
0.02
1.23
2.71
1.36
Pb
0.00
0.12
7.53
0.00
0.61
0.06
0.74
0.29
0.49
0.29
Se
0.75
1.16
1.02
As
0.01
2.29
18.28
0.20
0.34
0.30
0.53
0.00
0.01
0.00
Cd
0.12
0.46
0.89
0.00
0.01
0.00
0.01
0.38
0.71
0.31
Cu
0.00
3.66
147.77
0.60
1.08
0.45
0.57
0.00
0.01
0.00
Hg
0.03
1.83
1.27
0.20
0.02
0.00
0.01
0.32
0.72
0.36
Pb
0.00
0.09
6.05
0.00
0.38
0.04
0.49
0.08
0.13
0.08
Se
0.47
0.72
0.63
As
0.00
1.88
12.48
0.10
0.11
0.09
0.17
0.00
0.01
0.00
Cd
0.10
0.38
0.60
0.00
0.00
0.00
0.00
0.24
0.47
0.19
Cu
0.00
3.01
95.19
0.40
0.40
0.14
0.21
0.00
0.00
0.00
Hg
0.03
1.51
1.07
0.10
0.01
0.00
0.00
0.20
0.44
0.22
Pb
0.00
0.08
3.83
0.00
0.12
0.01
0.18
0.05
0.08
0.05
Se
3.76
8.76
0.30
0.03
0.02
0.03
1.26
3.06
1.27
Zn
0.01
48.92
548.11
5.00
0.98
0.34
1.14
0.15
0.23
0.20
0.00
0.00
0.00
0.07
0.18
0.06
0.00
0.00
0.00
0.06
0.14
0.07
0.02
0.03
0.02
0.40
1.15
0.40
4.87
24.74
0.60
0.49
0.29
0.49
5.78
15.41
0.60
0.13
0.08
0.13
4.57
11.14
0.40
0.08
0.05
0.08
Zn
0.01
63.30
1756.56
12.20
13.79
6.61
16.04
7.69
16.19
7.76
Zn
0.02
75.14
1038.69
12.80
3.97
1.74
4.62
2.03
4.67
2.05
Zn
0.01
59.46
856.97
8.00
2.61
1.08
3.04
99
bw) (cont’d)
Control communities
Food ingestion
Food ingestion
Food ingestion
Food ingestion
As
0.01
2.43
94.36
0.30
2.12
1.86
3.20
2.82
1.56
1.37
As
0.01
2.89
71.78
0.30
0.56
0.49
0.84
0.74
0.41
0.36
As
0.01
2.29
54.42
0.20
0.35
0.30
0.52
0.46
0.25
0.22
As
0.00
1.88
44.62
0.10
0.11
0.10
0.16
0.15
0.08
0.07
Cd
0.11
0.49
2.71
0.10
0.05
0.00
0.05
0.00
0.05
0.00
Cd
0.15
0.58
1.42
0.10
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.12
0.46
1.17
0.00
0.01
0.00
0.01
0.00
0.01
0.00
Cd
0.10
0.38
0.61
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Cu
0.03
5.36
441.79
1.40
3.68
1.77
2.88
1.38
1.52
0.73
Cu
0.01
6.36
246.54
1.50
1.06
0.47
0.83
0.36
0.44
0.19
Cu
0.00
5.03
215.68
1.00
0.70
0.29
0.55
0.23
0.29
0.12
Cu
0.00
4.14
102.72
0.70
0.26
0.09
0.20
0.07
0.11
0.04
Hg
0.03
1.95
8.84
0.20
0.12
0.02
0.06
0.01
0.05
0.01
Hg
0.04
2.31
6.33
0.30
0.03
0.00
0.02
0.00
0.01
0.00
Hg
0.03
1.83
4.71
0.20
0.02
0.00
0.01
0.00
0.01
0.00
Hg
0.03
1.51
4.20
0.10
0.01
0.00
0.00
0.00
0.00
0.00
Pb
0.01
0.10
17.59
0.00
2.02
1.01
2.54
1.22
1.39
0.69
Pb
0.00
0.12
8.75
0.00
0.53
0.05
0.73
0.32
0.37
0.18
Pb
0.00
0.09
7.22
0.00
0.33
0.03
0.48
0.20
0.23
0.11
Pb
0.00
0.08
4.35
0.00
0.10
0.01
0.18
0.06
0.07
0.04
Se
4.87
25.01
0.60
0.49
0.29
0.49
0.29
0.49
0.29
Se
5.78
16.81
0.60
0.13
0.08
0.13
0.08
0.13
0.08
Se
4.57
13.23
0.40
0.08
0.05
0.08
0.05
0.08
0.05
Se
3.76
7.63
0.30
0.03
0.02
0.03
0.02
0.03
0.02
Zn
0.01
78.40
1887.83
1.20
11.03
5.28
14.06
6.74
8.26
3.96
Zn
0.02
93.06
1291.20
1.30
3.18
1.39
4.05
1.78
2.38
1.04
Zn
0.01
73.64
1164.17
0.80
2.09
0.86
2.66
1.10
1.56
0.65
Zn
0.01
60.59
598.93
0.50
0.78
0.27
1.00
0.35
0.59
0.20
100
10.0 Ok Tedi Fly River community exposure scenarios and risk analysis
10.1 Exposure scenarios for the soil and sediment compartments
There are a very large number of potential scenarios that can be used to describe the
present health risk circumstances for the five geographic regions, using the data
presented in Tables 28 - 32. Scenarios were chosen to illustrate and compare the health
risks for the different regions and age groupings. The aggregate exposure within each
region and control or impact area has been calculated by summing the common intake
from ambient air, drinking water, food and recreational water, and then using the soil or
sediment exposure as the possible activity-related variable to assess total exposure ie:
Total intake
=
(surface waters + air + food + drinking water) +
one of the soil/sediment compartments
Hence, the sensitivity of the total exposure of individuals to exposure to one of village
soils, natural sediments and impacted flood plain sediments has been calculated. It
should also be noted that in the absence of a time-activity study it is not possible to
refine this data further. Thus, individuals are presumed to be exposed to village soils, or
natural sediments or impacted flood plain sediments exclusively. It should also be noted
that the soil/sediment data are presented as both the highly conservative total metal
(including dermal exposure values) and the more realistic bioavailable metal values. An
example of this approach for the Region 2 impact and control communities is shown in
Table 33.
Using this data for all five regions and impact or control communities, provides a
framework for deriving the “most realistic case” and maximum (“worst case”) intake
circumstances for soil and sediment exposures in each area. This is provided for all five
regions for each of the metals of concern in Table 34 for the most sensitive 1 – 5 years
of age group and for adults.
In Table 34 the most realistic scenario has adopted the lowest bioavailable value from
either the village and garden soils or natural sediments for each metal. The maximum
(“worst case”) scenario uses the highest value from all soil and sediment analysis. Note
that in some regions, the data for the impacted flood plain sediments is not the most
important source contributing to the maximum (“worst case”) scenario. For example, in
Region 5 the arsenic in natural sediment exceeds that in the flood plain sediment.
The percentage contribution to the total metal intakes from each of the food and
drinking water, recreational water and soil and sediments compartments for each region
and control or impact area is given in Table 35.
The data presented in Tables 34 and 35 are discussed for both the contaminant and
essential trace metals in Section 10.3 Multicompartment risk analysis.
101
Table 33: Soil exposure scenarios for metal intakes (Region 2) (all values µg/kg
bw/week)
Impact communities
As
Cd
dermal
Impacted flood plain sediment
bioavailable
16.01
15.9
17.99
dermal
bioavailable
Compartment
4.13
4.06
4.21
Cu
Hg
Pb
537.93
6.3
32.79
523.17
6.22
30.42
657.5
6.23
48.5
26.37
26.17
26.61
1957.05
1947.31
1993.06
17.65
4.07
580.47
26.32
1964.56
15.96
15.86
4.11
4.06
26.37
26.17
1945.2
1941.63
10.18
10.15
10.7
2.59
2.57
2.61
16.19
16.14
16.25
951.32
948.29
961.7
10.61
2.57
16.18
952.85
10.17
10.14
2.58
2.57
947.91
946.8
6.21
37.85
529.38
6.25
30.89
519.07
6.22
29.47
282.94
4.41
17.52
278.36
4.39
16.39
317.4
4.4
22.16
293.48
4.39
18.85
Se
Zn
dermal
bioavailable
7.21
7.2
7.54
280.48
4.4
17.02
16.19
277.28
4.39
16.64
16.14
1.78 201.31
3.38
11.89
12.55
1.77 198.17
3.37
11.2
12.52
1.79 223.94
3.37
14.99
12.59
7.48
1.77
207.53
12.72
12.54
758
7.21
7.19
1.78
1.77
12.55
12.52
755.02
754.26
dermal
bioavailable
6.44
6.43
6.54
1.61
1.61
1.62
199.69
3.38
11.58
197.5
3.37
11.35
181.32
2.71
10.79
180.01
2.71
10.57
189.8
2.71
12
10.34
10.33
10.35
649.8
648.93
652.35
6.52
1.61
182.96
2.71
11.05
10.33
649.82
6.43
6.43
1.61
1.61
180.71
179.8
2.71
2.71
10.7
10.62
10.34
10.33
648.96
648.64
3.37
757.26
755.18
764.07
102
Table 33: Soil exposure scenarios for metal intakes (Region 2) (all values µg/kg
bw/week) (cont’d)
Control communities
Compartment
Village/garden soils total +
dermal
Flood plain sediment total +
dermal
Flood plain sediment
bioavailable
As
Cd
18.65
Cu
Hg
Pb
3.93 668.86
9.73
21.46
Se
Zn
30.24
2197.88
18.58
18.57
3.88
3.93
662.77
665.55
9.68
9.76
20.79
21.82
30.04
30.24
2192.59
2204.62
18.51
3.88
661.19
9.68
20.94
30.04
2195.83
18.62
18.55
30.24
30.04
2197.4
2192.36
15.76
968.84
dermal
dermal
bioavailable
10.93
3.93 666.32
9.72
21.3
3.88 661.55
9.68
20.71
2.42 306.48
5.1
10.95
10.91
10.91
2.41
2.42
304.59
305.53
5.08
5.1
10.64
11.09
15.71
15.76
967.2
970.79
10.89
2.41
304.17
5.08
10.81
15.71
968.06
10.92
10.9
15.76
15.71
968.7
967.14
dermal
dermal
bioavailable
7.6
2.42 305.74
5.09
10.91
2.41 304.27
5.08
10.75
1.76 216.12
3.95
7.82
12.74
748.26
7.59
7.59
1.75
1.76
214.82
215.5
3.94
3.95
7.62
7.92
12.71
12.74
747.13
749.54
7.58
1.75
214.57
3.94
7.73
12.71
747.66
7.6
7.59
1.76
1.75
12.74
12.71
748.17
747.1
6.46
215.64
3.95
7.79
214.63
3.94
7.7
1.44 184.67
2.82
6.29
9.28
601.14
6.46
6.46
1.44
1.44
184.13
184.43
2.82
2.82
6.23
6.34
9.27
9.28
600.67
601.62
6.45
1.44
184.05
2.82
6.26
9.27
600.84
6.46
6.45
1.44
1.44
184.49
184.07
2.82
2.82
6.28
6.25
9.28
9.27
601.11
600.66
dermal
dermal
bioavailable
Table 34: Most realistic and maximum intakes by region (all values µg/kg bw/week)
Child
1–5
years
Arsenic (Inorganic)
Most
Maximum
realistic (worst case)
Cadmium
Most
Maximum
realistic (worst case)
Impact
Control
7.38
7.28
7.71
7.98
4.48
3.92
4.41
3.85
Impact
Control
4.7
4.7
6.83
4.84
4.21
3.88
4.06
3.93
Impact
Control
5.05
5.05
5.24
5.14
4.46
4.55
4.51
4.6
Impact
Control
6.03
4.48
6.7
4.82
4.99
3.46
5.04
3.51
Impact
Control
8.33
13.55
10.91
15.38
3.31
3.41
3.36
3.46
Copper
Mercury
Most
Maximum
Most
Maximum
realistic (worst case) realistic (worst case)
Region 1
446.53
455.09
4.96
4.91
475.92
485.15
5.15
5.18
Region 2
519.07
657.5
6.21
6.3
661.19
668.86
9.68
9.76
Region 3
732.22
746.56
15.3
15.4
606.72
610.35
74.32
74.43
Region 4
349.32
353.71
8.49
8.61
408.62
411.53
6.67
6.78
Region 5
353.04
357.54
5.49
5.61
449.31
452.26
11.03
11.14
Adult
Most
realistic
Lead
Maximum
(worst case)
Most
realistic
Zinc
Maximum
(worst case)
15.88
12.16
18.07
15.22
2317.44
2747.71
2332.67
2770.39
29.47
20.71
48.5
21.82
1941.63
2192.36
1993.06
2204.62
38.29
25.16
40.35
26.32
5786.06
5051.52
5793.92
5056.11
21.07
37.10
22.59
37.97
2567.02
3594.32
2579.33
3598.83
19.15
18.39
20.70
20.24
1838.68
1971.40
1848.26
1981.50
2.69
2.92
5.06
5.46
5.23
5.64
956.88
1266.85
958.07
1268.54
2.71
2.82
10.57
6.23
12.00
6.34
648.64
600.66
652.35
601.62
5.41
22.34
10.22
6.39
10.40
6.48
1744.18
1472.82
1744.77
1473.19
2.92
2.91
3.77
6.48
3.93
6.58
561.87
756.07
562.81
756.35
2.72
5.85
3.92
4.44
4.09
4.61
602.38
660.23
603.19
661.03
Region 1
Impact
Control
3.51
3.7
3.6
3.8
1.99
1.85
1.99
1.85
177.23
204.87
Impact
Control
2.47
2.45
2.58
2.46
1.61
1.44
1.62
1.44
179.8
184.05
Impact
Control
2.5
2.5
2.6
2.5
1.53
1.59
1.53
1.59
199.15
162.72
Impact
Control
2.55
2.31
2.58
2.33
1.51
1.35
1.51
1.35
79.15
93.3
Impact
Control
3.32
6.52
3.46
6.6
1.08
1.09
1.08
1.09
98.66
107.6
177.95
2.69
205.55
2.92
Region 2
189.8
2.71
184.67
2.82
Region 3
200.18
5.4
163.01
22.33
Region 4
79.49
2.91
93.53
2.90
Region 5
99
2.71
107.82
5.84
104
Table 35: Percentage contribution of total intakes of metals by compartment and region (Worst case) (all values µg/kg bw/wk)
Compartment
Food and drinking water
Recreational water
Soil and sediments
Region 1
Impact
Control
79.4
79.1
3.9
3.8
16.7
17.0
Recreation water
Soil and sediments
95.2
2.8
1.9
98.0
0.0
1.9
Recreational water
Soil and sediments
96.1
2.2
1.6
95.5
2.6
1.8
Recreational water
Soil and sediments
100
0.0
0.0
100
0.0
0.0
Recreational water
Soil and sediments
96.6
0.1
3.1
97.6
0.1
2.2
Recreational water
Soil and sediments
99.2
0.17
0.58
99.4
0.15
0.37
Arsenic – Children 1 - 5 years
Region 2
Region 3
Region 4
Impact
Control
Impact
Control
Impact
Control
53.7
83.3
81.8
84.5
81.7
81.2
4.3
6.3
5.7
5.8
4.7
6.6
41.8
10.3
12.4
9.6
13.5
12.1
Adult
90.2
94.6
94.8
94.8
94.5
94.4
3.8
4.0
3.9
3.9
3.9
4.3
5.8
1.2
1.1
1.1
1.5
1.2
Cadmium - Children 1 - 5 years
93.9
96.0
96.5
96.6
96.9
95.5
2.4
2.6
2.2
2.2
2.0
2.9
3.6
1.3
1.1
1.1
1.0
1.4
Adults
99.3
100
100
100
100
100
0.0
0.0
0.0
0.0
0.0
0.0
0.6
0.0
0.0
0.0
0.0
0.0
Copper - Children 1 - 5 years
76.3
98.7
97.7
99.3
98.2
99.2
1.1
0.0
0.1
0.0
0.1
0.0
22.5
1.2
2.0
0.6
1.6
0.7
Adults
92.4
99.5
99.1
99.7
99.1
99.5
2.00
0.11
0.35
0.12
0.38
0.21
5.53
0.32
0.54
0.17
0.52
0.22
Region 5
Impact
Control
63.5
77.2
3.0
1.9
33.3
20.8
92.0
2.9
5.0
96.0
1.5
2.4
95.3
3.0
1.5
95.5
2.9
1.4
100
0.0
0.0
100
0.0
0.0
98.9
0.2
0.8
99.0
0.3
0.6
99.3
0.40
0.21
99.1
0.65
0.19
Note: The values highlighted in red clearly show the impact of natural mineralisation for arsenic in Regions 1 and 5 (both impact and control) areas and in Region 2
the impact of the tailing affected active flood plain sediments for each of arsenic, cadmium and copper.
105
Table 35: Percentage contribution of total intakes of metals by compartment and region (Worst case) (all values µg/kg bw/wk)
(cont’d)
Compartment
Recreational water
Soil and sediments
Region 1
Impact
Control
95.11
95.83
4.07
3.68
0.81
0.49
Region 2
Impact
93.23
6.45
0.32
Recreational water
Soil and sediments
96.2
3.7
0.0
96.5
3.4
0.0
92.5
7.4
0.0
Recreational water
Soil and sediments
84.40
0.00
15.60
75.08
0.00
24.92
57.79
0.00
42.21
Recreational water
Soil and sediments
97.30
0.00
2.70
96.45
0.00
3.55
87.91
0.00
12.09
Recreational water
Soil and sediments
99.05
0.05
0.90
98.66
0.37
0.97
97.13
0.12
2.75
Recreational water
Soil and sediments
99.79
0.05
0.15
99.51
0.34
0.15
99.25
0.15
0.59
Mercury – Children 1 – 5 years of age
Region 3
Region 4
Control
Impact
Control
Impact
Control
97.02
98.24
99.61
96.27
95.97
2.06
1.30
0.27
2.33
2.99
0.92
0.46
0.12
1.40
1.04
Adults
96.4
98.1
99.5
96.1
96.5
3.5
1.8
0.4
3.4
3.4
0.0
0.0
0.0
0.0
0.0
Lead - Children 1 - 5 years
92.25
93.46
94.59
89.59
95.89
0.00
0.00
0.00
0.00
0.00
7.75
6.54
5.41
10.41
4.11
Adults
98.10
98.17
98.46
95.67
98.33
0.00
0.00
0.00
0.00
0.00
1.90
1.83
1.54
4.33
1.67
Zinc - Children 1 - 5 years
99.18
99.79
99.50
99.35
99.75
0.05
0.04
0.39
0.12
0.12
0.77
0.16
0.11
0.53
0.13
Adults
99.72
99.90
99.43
99.60
99.72
0.08
0.06
0.54
0.23
0.24
0.20
0.04
0.03
0.17
0.04
Region 5
Impact
Control
95.29
97.65
3.62
1.81
1.09
0.54
96.2
3.7
0.0
98.2
1.7
0.0
87.49
0.00
12.51
87.44
0.00
12.56
95.60
0.00
4.40
96.10
0.00
3.90
98.47
0.66
0.87
99.23
0.06
0.71
98.98
0.83
0.19
99.77
0.08
0.15
Note: The values highlighted in red clearly show the impact of natural mineralisation for lead in Region 1 (both impact and control) areas and in Region 2 the impact
of the tailing affected active flood plain sediments for lead and zinc.
10.2 Single compartment risk analysis
10.2.1 Drinking water
The highly turbid Ok Tedi and Fly River are not used as drinking water sources. Lake
Murray has been reported as an occasional use source (Taufa 1997). Within the OTML
CHS area, there were no significant differences between the mean metal results for all
of the study analytes for the main drinking water sources (tanks, springs, creeks and
Lake Murray) either between regions or in impact and control villages within a single
region. The results indicated that the water supplies had relatively low dissolved
concentrations of the metals of concern. All values were markedly less than the WHO,
Canadian, United States and Australian drinking water guidelines and criteria values
and the Papua New Guinea raw drinking water standards.
10.2.2. Recreational waters
There are no studies of community river-use patterns for any of the five OTML CHS
geographic regions. The present study, of necessity, assumes that for all villages within
a single region, the recreational water-use patterns are identical. The study also assumes,
as part of the worst case approach, that recreational water use occurs on a daily basis at
all regions. Clearly, this significantly exaggerates the situation, particularly in Region 1,
but without time-activity data for the communities, this is the only valid approach.
The mean dissolved metal concentrations for recreational waters for all of the target
contaminants at all monitored impact and control communities within the five
geographic regions were an order of magnitude below the respective WHO Recreational
Water Guideline values.
Total extractable metal concentrations for copper was markedly elevated in the Region
2 riverine impact villages (Ningerum, Ieran) and to a lesser degree in the Regions 3 – 5
impact communities. All other metals analysed, generally were present at or below the
respective analytical detection limits. All total metal concentrations at all locations were
within the limits derived from criteria established in the WHO Recreational Water
Guidelines.
10.2.3 Air
The arsenic concentrations in respirable air particulates at all of the monitored locations
were less than 20% of the WHO Guideline level, while the concentrations for mercury
and lead were generally some two orders of magnitude below the respective WHO
Guideline values.
During analysis no cadmium was detected, confirming that cadmium concentrations in
the air samples were consistently below the detection limit of 35 ng/m3. While the
WHO Guideline value for cadmium is 5 - 20 ng/m3, from the available data there was
no evidence that this had been exceeded. WHO does not give guidance values for
metals in ambient air for copper, zinc or selenium, but the observed values were typical
of background ambient air levels in rural and remote environments in other countries.
The sampling method of the study did not permit direct comparison of the PM 10
respirable particle concentrations with the Australian Standard, which is based on a
107
daily average not to be exceeded for more than five days a year at any site. During the
sampling period, Ningerum, Kiunga and Lake Murray sites did not exceed the NEPM
24-hour value. The control site at Ok Om exceeded the NEPM 24-hour value on
approximately 25% of the monitored occasions, due to local grass fires.
10.2.4 Soil and sediments
The mine-area (impact and control) and Region 2 impact villages indicated some natural
soil enrichment in copper, lead and zinc. This was to be expected from the known
mineralisation in the Mt Fubian area. There was also an apparent natural enrichment of
arsenic at the Region 5 (impact and control) villages. All values were well below the
respective HIL values.
The metal levels in the natural sediments were generally comparable with the
corresponding village and garden soils. Typically, the observed values for Regions 1
and 2 expressed as a percentage of the Australian HIL residential values were: arsenic
4% – 9%; cadmium 2%; copper 2.5% – 10%; mercury 3%; lead 3% – 10% and zinc 1%.
With the exception of arsenic at Region 5 (20% – 25% of the HIL), the levels of metals
in soils and natural sediments in the Regions 3 – 5 villages were consistently less than
5% of the respective HILs.
The metal concentrations in active flood plain sediments were markedly elevated for
arsenic, copper, lead and zinc in samples sourced from the Region 2 impact villages,
with maximum concentrations of arsenic 46%; copper 230%; lead 100% and zinc 16%
of the respective residential HILs.
With the exception of a single sample (Manda) the Regions 3 – 5 metal concentrations
in impacted flood plain sediments were typically between 5% – 10% of the respective
residential HILs. Selenium does not have a soil health investigation level.
10.2.5 Food
The OTML CHS Market Basket Survey (OTML CHS MBS) provided a picture of the
dietary patterns and dietary-contaminant intakes for the people of the regions in the
OTML mine area and along the Ok Tedi-Fly River system to the Fly estuary. The
results showed that there were no substantial differences in contaminant and essential
metal concentrations in individual food products between the control and impact
villages of any single geographic region. Between regions, the mean metal
concentration in food, other than a minor elevation in lead from the Region 2 villages
and mercury at the Middle-Lower Fly River, Fly estuary and Lake Murray were again
similar.
The comparability of the data on the levels of contaminant metals in food both within
and between the five regions, supported a conclusion that the disposal of mine wastes to
the river system from the OTML mine had not impacted on the levels of metals in the
villagers’ diets. The high mercury levels at the Middle-Lower Fly River regions and
Lake Murray are demonstrably not mine related.
108
Those products that were targeted for inclusion on the basis of their known
bioaccumulation of the metals of concern, almost without exception, proved to have
metal concentrations comparable with the corresponding values from the Market Basket
Survey conducted in the Porgera-Lagaip-Strickland Rivers and Lake Murray between
2002 – 2004 (Bentley 2004b). Where there were comparable food commodities, the
results were also similar to those reported in the Australian Market Basket Surveys 1994
- 2000, and the US FDA Total Diet Studies 1991 – 1999.
The OTML CHS data showed that for all age groups in all regions the weekly dietary
intake of the essential metals was generally within recommended dietary reference
guidelines and does not pose a risk of adverse effects through excessive intake.
10.3 Multicompartment risk analysis
10.3.1 Essential trace elements
For copper, with the exception of Region 2 impact, there was little difference between
the most realistic and maximum total intake values for both infants and adults. In
Region 2, the maximum value was markedly impacted by the copper levels in impacted
flood plain sediments, which contributed some 22.5% and 5.5% to the total intakes for
children 1 – 5 years of age and adults respectively. It is notable that the maximum
copper value in Region 2 impact was very similar to that of the most realistic (and
maximum) value in Region 2 control, confirming that while significant, the contribution
from the tailing impacted sediments did not result in unusually elevated total copper
intakes.
Clearly, food was the major source of copper intake (between 76% - 99%) for all age
groups in all regions, both impact and control. The highest food intake was 725 µg/kg
bw/wk (Region 3 impact children 1 – 5 years of age), while the lowest food intake was
76 µg/kg bw/wk (Region 4 impact adults). The corresponding total intakes (ie from all
dietary and environmental compartments) for these groups were 746 µg/kg bw/wk and
79 µg/kg bw/wk. The PTWI for copper is 3500 µg/kg bw/wk (JECFA 1982). All age
groups in the five regions were less than 25% of the WHO PTWI value.
As indicated in Figure 12 for all age groups and all regions, total copper intakes were
well within the intake range recommended by the Institute of Medicine. This range is
shown as LL and UL and represents the Lower Intake Level for nutritional sufficiency
(LL) and the Tolerable Upper Intake Level (UL) above which toxicity may be a concern
(IOM 2001).
109
Figure 12: Total copper intake for children 1 – 5 years of age and adults compared
with dietary reference values (UL represents level above which toxicity may be of
concern and LL represents the level for dietary sufficiency)
Total copper intake (ug/kg bw/wk)
1000
UL
900
800
700
600
500
400
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
300
200
LL
100
0
Child 1 - 5 years
Adult
Age group
The total selenium intake results are illustrated in Figure 13. Food, and particularly fish
and other aquatic food, is the major source of intake, being greater than 95% of total
intake for all age groups in all regions and for both impact and control areas.
The highest food intake was 153 µg/kg bw/wk (Region 3 impact children 1 – 5 years of
age), while the lowest food intake was 5.2 µg/kg bw/wk (Region 2 control adult). The
corresponding total intakes were 160 µg/kg bw/wk and 9.3 µg/kg bw/wk respectively.
The 160 µg/kg bw/wk intake for the children 1 - 5 years of age equates to about 250
µg/day intake of selenium, which exceeds the UL for selenium intake of 150 µg/day
published by the US Institute of Medicine for children 4 - 8 years of age. The 9.3 µg/kg
bw/wk for the adults equates to about 72 µg/day intake of selenium, which is above the
US Institute of Medicine adult RDA of 55 µg/day, but very similar to the value adopted
by the United Kingdom of 60 µg/day and 75 µg/day for adult females and males
respectively (MacPherson et al 1997).
110
Figure 13: Total selenium intake for children 1 – 5 years of age and adults
compared with dietary reference values. (UL represents level above which toxicity
may be of concern and LL represents the level for dietary sufficiency).
180
Selenium intake (ug/kg bw/wk)
160
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
140
120
100
80
60
UL
40
20
LL
0
Child 1 - 5 years
Adult
Age group
Zinc intakes were comparable between Regions 1 and 2 and 4 and 5 with no difference
between the most realistic and maximum intake values. The intakes in Region 3 were
markedly elevated, but this was a consequence of elevated dietary zinc. This elevated
zinc intake was parallelled by an elevated intake of selenium in Region 3, resulting from
the unusually high fish consumption in the Middle Fly and Lake Murray communities.
The intakes of zinc and selenium were well within the respective WHO PTWI values
and of no health consequence.
Food, and to a lesser extent drinking water, together accounted for some 97% - 99% of
zinc intakes in both infants and adults. The highest intakes from these two sources were
about 5718 µg/kg bw/wk (Region 3 impact children 1 – 5 years of age), while the
lowest food and drinking water zinc intake was about 560 µg/kg bw/wk (Region 4
impact adult). The corresponding total intakes for these groups were 5794 µg/kg bw/wk
and 562 µg/kg bw/wk, highlighting the particularly low contribution to total intakes
from the other environmental compartments. All regional total intakes were will within
the WHO PTWI for zinc of 7000 µg/kg bw/wk (JECFA 1982).
The adult intakes approximated the Dietary Reference Intake for zinc. The values above
the RDI in Region 3 were of no health significance. The value of 5794 µg/kg bw/wk for
children 1 – 5 years of age equated to about 9.3 mg/day intake of zinc. As indicated in
Figure 14, this approximated the UL for zinc intake of 7 – 12 mg/day for children 1 – 3
years of age and 4 – 8 years of age respectively published by the US Institute of
Medicine (IOM 2001).
111
The zinc intakes of all populations in all OTML CHS regions appears to be at a level
which is both sufficient for nutrition and non-harmful for health.
Figure 14 Total zinc intake for children 1 – 5 years of age and adults compared
with dietary reference values. (UL represents level above which toxicity may be of
concern and LL represents the level for dietary sufficiency).
7000
Total zinc intake (ug/kg bw/wk)
6000
5000
LL
UL
4000
3000
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
2000
LL
1000
0
Child 1 - 5 years
Adult
Age group
10.3.2 Contaminant metals
The WHO PTWI for arsenic is based on inorganic arsenic. The inorganic arsenic intake
in all regions for children 1 – 5 years of age and adults is summarised in Figure 15. This
figure has been constructed using a value of 100% inorganic arsenic for all
environmental media except food. For food, an inorganic arsenic value of 10% has been
adopted in keeping with a similar approach in calculation of dietary exposures by the
Australian Market Basket Survey (ANZFA 1998).
While the food and drinking water compartment comprised between 53% and 84% of
the total arsenic intakes, there were significant contributions from the soil and sediments
compartment in Region 1 (16.7% – 17.0%), in Region 2 impact (41.8%) and in Region
5 (20.8% - 33.3%). The soil and sediment contribution was a result of natural
mineralisation in Regions 1 and 5 and from tailing impacted flood plain sediments in
Region 2 impact.
A comparison of the most realistic and maximum intakes for arsenic for both children 1
– 5 years of age and adults, showed a close similarity between the observed total intakes
in Regions 2 – 4, the contribution from the impacted flood plain sediments was similar
to that naturally present in the Region 2 control area and Regions 3 and 4. In Regions 1
and 5 the inorganic arsenic intake was elevated to a similar level in both the impact and
the control areas. The arsenic intakes in Regions 1 – 4 were all less than 50% of the
WHO PTWI. The highest intake in Region 5 (control) approximated the WHO PTWI
112
inorganic arsenic value of 15 µg/kg bw/wk for the 1 – 5 years of age group. Chemical
toxicity from arsenic intakes in all communities in all CHS regions is of no health
concern.
The cadmium intake in all regions for children 1 – 5 years of age and adults is
summarised in Figure 16. The WHO PTWI for cadmium is 7 µg/kg bw/wk (JECFA
2001). For cadmium, the most realistic and maximum intakes were similar between all
regions and for impact or control areas.
For both adults and children food was the major contributor to cadmium intake
comprising between 93.9% and 96.6% of total intake. The contribution for the soil and
sediments compartment was between 1.0% and 3.6%, with this latter value being in
Region 2 impact. The apparently elevated contribution from drinking water ingestion
shown in Figure 16 was largely a result of the use of the middle bound value for nondetects with the majority of samples being below the detection limit.
The cadmium results indicated that for all regions and impact and control groups, the
total intakes were between 40% – 70% of the WHO PTWI value and of no health
concern.
The mercury intake in all regions for children 1 – 5 years of age and adults is
summarised in Figure 17. Mercury intake was almost entirely from ingestion, which
contributed 93.2% – 99.6% of total intakes. The close similarity between the most
realistic and maximum intakes was a consequence of the mercury being almost entirely
sourced from the food pathway, primarily from fish and other aquatic foods.
Both the impact and control communities in the Middle-Lower Fly River regional
villages for children 1 – 5 years of age approximated the WHO PTWI. At Lake Murray,
the WHO PTWI was exceeded for all age groups between four- and 15-fold. The level
of exceedance reported was likely an underestimation, since the WHO PTWI is based
on the 1989 JECFA value of 5 µg/kg bw/wk total mercury. As discussed in the report
supplement, the principal source of mercury intake was almost certainly methylmercury
and the JECFA value of 1.6 µg/kg bw/wk for methylmercury would appear to be a more
valid comparison (JECFA 2003). On that basis, the exceedance range was between 12and 45-fold. These results were not surprising, since earlier pre-mining era work,
examining the concentrations of mercury in aquatic foods have shown values
extraordinarily high for the Lake Murray communities (Kyle & Ghani 1982a, 1982b,
Currey et al 1992, Abe et al 1995 and see supplement to this report).
The lead intake in all regions for children 1 – 5 years of age and adults is summarised in
Figure 18. Lead intake from food was elevated in Regions 2 (impact) and 3 (impact) and
Region 4 (control), with the WHO PTWI being exceeded by up to two-fold in these
areas in the children 1 – 5 years of age group. For the adult group, the lead intake
approximated 20% – 40% of the WHO PTWI for all regions and impact and control
villages.
The marked difference between the most realistic and maximum levels in Region 2
(impact) were a consequence of the lead intake from the impacted flood plain sediments.
113
This is illustrated in Figure 19. Considering that this markedly increased the level of
exceedance of the WHO PTWI it is likely that lead in mine-derived sediments will be
the critical concern for the child under 5 years of age group for future mine waste
management controls. Figure 19 clearly demonstrates that for the adults, lead intake is
unlikely to be of any health concern.
114
Figure 15: Total arsenic (inorganic) intakes for children 1 – 5 years of age and
adults
Child
16
Arsenic (inorganic) intake (ug/kg bw/wk)
14
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
12
10
8
6
4
2
0
Food and drinking
water
Recreational water
Soils and sediments
PTWI
Compartment
Adult
16
Arsenic (inorganic) intake (ug/kg bw/wk)
14
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
12
10
8
6
4
2
0
Recreational water
Soils and sediments
Compartment
PTWI
115
Figure 16: Total cadmium intakes for children 1 – 5 years of age and adults
Child
8
Cadmium intake (ug/kg bw/wk)
7
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
6
5
4
3
2
1
0
Drinking water
ingestion
Food ingestion
Recreational water Soils and sediments
PTWI
Compartment
Adult
8
Cadmium intake (ug/kg bw/wk)
7
6
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
5
4
3
2
1
0
Drinking water
ingestion
Food ingestion
Recreational water
Compartment
Soils and
sediments
PTWI
116
Figure 17: Total mercury intakes for children 1 – 5 years of age and adults
Child
80
Mercury intake (ug/kg bw/wk)
70
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
60
50
40
30
20
10
0
Drinking water
ingestion
Food ingestion
Recreational water
Soils and
sediments
PTWI
Compartment
Adult
Mercury intake (ug/kg bw/wk)
25
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
20
15
10
5
0
Drinking water
ingestion
Food ingestion
Recreational water
Compartment
Soils and
sediments
PTWI
117
Figure 18 : Total lead intakes for children 1 – 5 years of age and adults
Child
40
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
Lead intake (ug/kg bw/wk)
35
30
25
20
15
10
5
0
Drinking water
ingestion
Food ingestion
Recreational water
Soils and
sediments
PTWI
Compartment
Adult
30
25
20
Region 1 impact
Region 1 control
Region 2 impact
Region 2 control
Region 3 impact
Region 3 control
Region 4 impact
Region 4 control
Region 5 impact
Region 5 control
15
10
5
0
Drinking water
ingestion
Food ingestion
Recreational water
Compartment
Soils and
sediments
PTWI
118
Figure 19: Lead intakes by compartment for children 1 – 5 years of age and adults
Child
60
Lead intake (ug/kg bw/wk
Soils and sediments
Recreational water
50
40
30
20
10
0
Region 1
Region 2
Region 3
Region 4
Region 5
PTWI
Location
Adult
30
25
Soils and sediments
Recreational water
Food ingestion
20
15
10
5
0
Impact
Control
Region 1
Impact
Control
Region 2
Impact
Control
Region 3
Location
Impact
Control
Region 4
Impact
Control
Region 5
PTWI
119
10.4 Cancer risk from arsenic exposure
The published literature indicates that arsenic exposure induces a range of health effects.
It is clear that the severity of adverse health effects is related to the chemical form of
arsenic, and is also time- and dose-dependent (Tchounwou et al 2004). Arsenic in food
is mainly in the organic form and food regulators such as FSANZ (Australia) and the
US FDA generally assign a value of 10% to the inorganic proportion of total arsenic in
food products. Arsenic in other environmental media is generally accepted as being
100% in the inorganic form.
Both the WHO and US EPA have derived estimates for the expected increased
incidence of lung cancer from life time exposures to 1 µg/m3 total arsenic in air (US
EPA 4.3 x 10-3, WHO 3 x 10-3).
For the OTML CHS villages impacted populations, the lifetime fatality risk from lung
cancer can be regarded as insignificant since the inhalational intake was minuscule.
The WHO and US EPA have also given numerical estimates of the lifetime skin cancer
fatality risk from lifetime ingestion of 1 µg/day of arsenic from drinking water (US EPA
2 x 10-7, WHO 1.7 x 10-6).
The most reliable figures for the OTML CHS communities for skin cancer induction by
arsenic are for adults. There is little point in calculating the risk from total ingestion for
the non-adult groups since the most reliable figures for cancer induction by arsenic are
based on lifetime exposure. Hence daily intakes have been calculated only for adults
and these are compared with the risk point estimates from WHO and the US EPA.
Calculation of total intakes for Regions 1 - 4 and Region 5 (impact) gave exposure
values between 2 - 3 μg/kg bw/week of inorganic arsenic. These values are very similar
to the US EPA oral reference dose of 2.1 μg/kg bw/week (reported as 0.3 μg/kg bw/day)
and considerably less than the WHO numerical estimate of lifetime skin cancer fatality
risk. For Region 5 (control) where there were some naturally elevated arsenic levels in
soil, the intakes of inorganic arsenic was about 6 μg/kg bw/week. While marginally
exceeding the very conservative US EPA RfD (oral) this value is below that the WHO
Guideline. The arsenic intakes in all regions and villages can be considered to be of no
health consequence.
120
11.0 Conclusions of the OTML community health study
For the OTML CHS, the databases for the control and impact communities were
collected simultaneously and a cross-sectional assessment completed. The report
examined data from the food, air, water and soil/sediment compartments that was
generated in the period April 2004 to July 2006.
11.1 Reliability considerations
This discussion aims to present some issues concerning the reliability of the overall
OTML CHS. The health risk assessment provides quantitative estimates of the total
intake of contaminant metals by populations in the mine-area tailing-impacted regions
of the Ok Tedi Fly Rivers system. These estimates have been compared with intakes in
control populations for each region and also to internationally accepted health guideline
values.
In considering the main findings (accepting that these were derived using very
conservative assumptions for each exposure compartment) the overall conclusions were
that:
•
•
•
•
•
total contaminant metal intakes for the drinking water and ambient air
compartments were not appreciably different between potentially impacted
villages and the matched control communities within each of the five
geographic regions and between the five regions;
excluding the unique local circumstances regarding dietary mercury intakes
in the Middle-Lower Fly and Lake Murray (Regions 3 and 4), the lead
intakes in Regions 2 and 3 (impact) and Region 4 (control) and the elevated
arsenic intake in Region 5 (control) total metal intakes were similar within
and between regions;
recreational total copper intakes were elevated in the Region 2 impact
villages of Ieran and Ningerum. There were also minor increased intakes
discernable in the Middle-Lower Fly River impact areas. The metal intakes
in the mine-area Region 1 villages from recreational water were low. The
copper and other metal intakes at all OTML CHS monitored villages were
of no public health significance;
village and garden soil and natural (non-impacted) sediments resulted in
slightly higher copper, lead and zinc intakes in the mine area and Ok Tedi
impact and control villages (Regions 1 and 2) resulting from natural
background mineralisation. For the Fly estuary regional villages (Region 5),
both impact and control, the intakes of arsenic were slightly elevated due to
a natural arsenic geochemical soil signature in this region. All values for the
contaminant metals in village and garden soil and natural (non-impacted)
sediments in all regions were of no health significance;
the intakes from exposure to roadside soils in Regions 1 and 2 were
generally comparable with those from the natural non-impacted sediments
and village soils at the same villages albeit there were two samples that
appeared to be comprised of impacted flood plain sediment-like materials;
121
•
•
•
•
for the flood plain sediments there were marked differences in intakes
between the impact and control villages in Region 2 for copper and lead,
with the impact villages generally some 15 – 20-fold higher;
for each of the five regions and impact or control communities, the metal
intakes from the recreational waters and flood plain sediments were
appreciably less than that from dietary intakes for all population age groups;
the release of mine waste materials from the OTML mine has not had any
discernable impact on the levels of contaminant or essential trace metals in
locally-sourced food; and
in the absence of time-activity data for the different age-sex populations, it
was not possible to accurately quantify total exposures for specific groups.
However, using realistic assumptions, it can be concluded that with the
exceptions noted above, and taking into account the very conservative
assumptions adopted by the OTML CHS for each media compartment, the
total metal intakes in the OTML study population for each of the
contaminant metals are of no health concern.
Many potential confounders normally experienced in HHRA studies are not present in
the OTML CHS because all of the potential exposure media have been directly
measured. In particular there have not been any significant new engineering,
environmental, socio-economic or public health interventions in the 2004 - 2006 period
that could confound either the validity of the sampling program (the data collected and
analysed in the present work) or the potential exposures to the impact and control
village communities.
Limitations to the study are the lack of longitudinal epidemiological studies and the
paucity of robust human biomarker studies conducted since the opening of the OTML
mine. Hence, as is the case for many health risk assessments, the estimation of risks to
health is largely dependent on the environmental and toxicological databases. The
exposure factors used in developing scenarios could not take into account any elevated
prevalence of infectious disease and generally lower health status, particularly
malnutrition in the communities studied. Essential nutrient and trace element
deficiencies could contribute to higher intakes of contaminant metals in all age groups.
In the absence of demonstrated causal linkages between the mine waste in the river
system and health effects in the impact villages, it is not possible to identify any
baseline incidence of disease attributable to the mine activities.
The data clearly show that the food compartment was the major contributor to metal
intake in all of the surveyed villages. Additionally, it was clear that food consumption
and amounts were similar between the impact and control villages within each
geographic region and also, allowing for differences in quantity, remarkably similar
between age groups. The reasons for these similarities have been discussed previously
in Volume 1 of the OTML CHS Food and Nutrition Report. The two primary reasons
were the homogeneity of the circumstances and lifestyles of the surveyed populations
within each geographic region, and the cultural norms involving preparation and
consumption of family meals.
122
The study communities are heterogenous with a diverse range of cultural, linguistic and
religious practices between regions. However, within a single geographic region the
diversity is somewhat reduced, and with the exception of the level of consumption of
store foods, there is a close similarity in food consumption patterns.
The main economic activities of the communities vary from an almost total dependence
on subsistence agriculture and sourcing of bush foods with negligible household income
or employment opportunities, through to the semi-urban population of the mine-area
villagers, who have a significant cash-based economy and substantial intakes of trade
store foods. For this reason, each region needed to be treated as a separate entity and
there was little value in extracting data for the impact and control populations on a study
wide basis.
As stated, the food compartment for most communities is the critical compartment for
this study. The reliability of the OTML CHS rests strongly on field data collected from
the actual impacted and control villages during the Food Frequency Survey, and the
analysis of locally sourced food performed during the OTML CHS MBS. Assumptions
made during the analysis of the food compartment have been conservative and the
conclusions regarding metal intakes from this compartment are regarded as robust.
With regard to the other environmental compartments, the study is fortunate in having
an extensive database of analyses performed on each environmental medium, and much
of this database has been specifically developed to support the OTML CHS. Again,
generally conservative assumptions have been made in deriving estimates of metal
intakes and the conclusions regarding metal intakes from these compartments are also
regarded as robust.
The exposure factors adopted for the present study represent best conservative
approximations for calculating the total metal intakes of the Ok Tedi-Fly River villagers
of different ages under various scenarios of daily life. While it would not be realistic to
expect these values to represent every individual in a population, they are presented as
transparently as possible to permit comparisons with the approaches and factors adopted
by other studies.
Ranges were quoted for some model parameters, however only mean values were used
in the actual models. This was partly because the questions to be answered were limited
to providing the most reliable data to identify whether tailing in the river system had an
impact on the population in each geographic region. Monte-Carlo analysis using ranges
would give distributions of exposures but the “tails” of the distributions where
exceedances of guidance values are likely, are the most uncertain/unlikely parts of the
distribution. The means give a “crude” but highly reliable estimate of the exposure.
The use of detection limits as the default values for non detects did not markedly impact
on the contribution of air, drinking water, recreational waters or soils/sediments to the
exposure assessment calculations. For food a value of 50% of the detection limit was
adopted for modelling purposes, in keeping with the approach adopted by the Australian
Market Basket Survey. However, not all total diet studies adopt the 50% DL value. The
United States Food and Drug Administration, for example adopts a value of 0% of the
123
detection limit. The OTML CHS has developed age adjusted weekly intake values for
each of the 0%, 50% and 100% detection limit levels to allow for alternative exposure
modelling to be carried out if required.
11.2 Conclusions and recommendations relevant to public health
The exposure of the Middle-Lower Fly and Lake Murray regional populations to
mercury is non-mine related. An extended discussion has been developed in the report
supplement. While there have been no reports of mercury intoxication, this may be
attributable to the existing poor health circumstances. There have also been no
behavioural studies conducted on children in these populations. In view of the high
levels of mercury intakes from ingestion of food there would appear to be a need for an
education program that supports behavioural change in these communities towards
consumption of fish species and fish size having lower mercury content.
A time-activity study using observation and questionnaires should be conducted in order
to refine the risks associated with exposure to active flood plain sediments in Region 2.
This would be a cost-effective way of prioritising the possible management options.
12.0 Acknowledgements
The conduct of the OTML CHS Food Frequency and Food Consumption Surveys, the
Ok Tedi–Fly Rivers Market Basket Survey environmental media sampling, with their
broad requirements for data collection, through village implementation of
questionnaires, field sampling, preparation of laboratory samples to compliance with
Codex requirements and chemical analysis would not have been possible without the
assistance of a wide range of individuals and organisations.
The OTML Environment Department Project Co-ordinator Mr Markson Yarrao,
assumed primary responsibility for the on-site management of all activities. Particular
appreciation is expressed to the staff from the Environment Department and the Ok Tedi
Development Foundation.
The Queensland Health Scientific Services Laboratories undertook the soil, sediment
and food metals analysis. The Papua New Guinea National Analytical Laboratory in
Lae provided analytical services for the community drinking water and recreational
(surface) waters.
124
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Geneva, Switzerland
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(21 May 2007)
Dr K W Bentley
Director
Centre for Environmental Health Pty Ltd
PO Box 217
WODEN ACT 2606
AUSTRALIA
email: [email protected]
2
Table of contents
List of tables
3
List of figures
3
Glossary
4
1.0 Introduction
5
1.1 Mercury in hair
5
1.2 Other metals, arsenic and selenium
9
2.0 The OTML Community Health Study
10
2.1 Study design and methods
10
2.2 Results for mercury in the OTML CHS study
12
2.3 Results for other contaminant and essential elements in the OTML CHS
16
2.4 Levels of contaminant metals in human scalp hair samples
by village and regional classification
18
3.0 References
20
Appendix 1: OTML CHS analytical results by location, age and sex
23
3
List of tables
Table number
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Title
Reference ranges for metals in healthy human scalp hair
OTML CHS sample frame by region and village for different
age groups
Mercury in the environment in the Strickland-Fly Rivers and
Lake Murray regions
Mercury in hair samples from the OTML CHS
Arsenic and cadmium in hair samples from the OTML CHS
Lead and mercury in hair samples from the OTML CHS
Copper and zinc in hair samples from the OTML CHS
Selenium in hair samples from the OTML CHS
List of figures
Figure number
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Title
Regional map of the Ok Tedi-Fly Rivers and Lake Murray
areas, showing the hair sampling locations
Levels of mercury in hair from published studies in the Ok
Tedi-Fly Rivers region (1987 – 1999)
Levels of contaminant and essential metals in hair from
published studies in the Ok Tedi-Fly Rivers region (1987 –
1999)
Mercury levels in scalp hair for the OTML CHS communities
by age
Mercury levels in scalp hair for the OTML CHS communities
by sex and region
Consumption frequencies for aquatic foods in the Ok Tedi-Fly
Rivers regions compared with the total mercury
concentrations in scalp hair
Mercury in food products sourced from the Ok Tedi-Fly
Rivers and Lake Murray regions
Contaminant and essential metals in hair for the OTML CHS
4
Glossary
ATSDR
Codex
Control villages
HIL
Impact villages
JECFA
Ok
OTML CHS
PTWI
QHSS
RfD
µg/kg bw/wk
US EPA
US FDA
US NRC
WHO
Agency for Toxic Substances and Disease Registry (United
States)
The FAO/WHO Codex Alimentarius Commission
Control villages are located away from the tailing discharge
zone of the OTML mine operations, generally located on a
control river or other water body
Health Investigation Levels for contaminated land (Australia)
The classification adopted that impact villages may
potentially receive contaminant metal impacts from the
OTML mine operations
WHO/FAO Joint Evaluation Committee for Food Additives
Ok in the local Min language mean river or creek. Ok Tedi
means river Tedi.
The Ok Tedi Mining Limited Community Health Study
The WHO Provisional Tolerable Weekly Intake values
represent permissible human weekly exposure to a
contaminant which has a cumulative effect on the body and is
unavoidably present in otherwise wholesome and nutritious
food
Queensland Health Scientific Services Laboratories, Brisbane
Reference dose (United States EPA)
Microgram per kilogram body weight per week (for human
dietary and environmental metal intake assessment)
United States Environmental Protection Agency
United States Food and Drug Administration
United States National Research Council
World Health Organization
5
1.0 Introduction
The present report extends earlier work on contaminant and essential trace metal
concentrations in human scalp hair. These studies have been conducted in the Western
Province lowlands region in Papua New Guinea since the late 1970s. A number of
studies have reported only mercury in hair (Airey 1983, Suzuki et al 1988, Yok 1989,
Yok and Blomeley 1990, Hongo et al 1994, Abe et al 1995), while others have included
mercury in a broader suite of metals examined (Jones et al 1987, Flew 1999). There
have also been studies of mercury in hair for the Lagaip and Strickland Rivers
communities (Yok 1990, Environment Department PJV 1995).
The regional map of the Ok Tedi Mining Ltd Community Health Study (OTML CHS)
communities is given in Figure 1. This map also identifies the principal Enga, Southern
Highlands and Western Provinces areas in which the previously published human
mercury biological index studies have been conducted.
1.1 Mercury in hair
A summary of the published results for the Western Province regions shown in Figure 1
are detailed in Figure 2.
The results of the studies in the highland (Star Mountains) and the Ok Tedi communities,
indicated that the levels of total mercury in hair were within the normal range for nonexposed populations internationally. The mean levels in the highland Star Mountains
region were within a range of means of 0.55 – 0.95 µg/g (Jones et al 1987). The mean
levels in the Ok Tedi region of 2.9 µg/g, determined in the present work, were
somewhat higher, but were still typical of normal low fish-consuming populations.
The mean levels in the highland Lagaip-Upper Strickland Rivers and the Middle
Strickland River regions show a similar pattern, with mean mercury in hair
concentrations of 0.33 ± 0.19 µg/g and 2.3 µg/g respectively again reflecting the low
levels of consumption of fish and other aquatic foods (Yok 1990, Parametrix 1998).
The results from all studies clearly confirm that the body burdens of mercury in these
communities are unrelated to historical or present mining activities in the upper river
catchments.
Communities residing at Lake Murray have been reported to have some of the highest
concentrations of mercury in scalp hair recorded internationally for people not directly
exposed to anthropogenic mercury contamination (Kyle & Ghani 1982a 1982b, Abe et
al 1995). Typically, the results of mercury in hair analysis at Lake Murray have shown
mean total mercury in hair values between 15 – 28 µg/g (Yok 1990, Abe et al 1995,
Parametrix 1998). The range of individual values were between 3.1 - 71.9 µg/g. A reanalysis of the entire database showed little difference either by age or sex (Bentley
2005).
The levels of mercury in scalp hair at Lake Murray are comparable with the Canadian
Inuit and similar high fish and other aquatic food-consuming communities in the
6
Seychelles and Faroe Islands and in the Brazilian Amazon (Grandjean 1997, Davidson
1998, Vasconcellos et al 1998).
These levels of mercury in human hair, which approximate the US NRC benchmark (12
µg/g) and are significantly above the US EPA RfD (1.2 µg/g) and the WHO PTWI for
methylmercury of 1.6 µg/kg bw/week, place the Lake Murray communities within the
mercury in hair range where childhood neurobehavioural development is potentially
impaired in some individuals, but overt mercury intoxication remains unlikely (US NRC
2000, US EPA 1997, JECFA 2003).
The observed human mercury levels at Lake Murray have long been attributed to
natural ecological processes, which lead to an accumulation in the food chain, in an
environment where mercury concentrations in surface waters and lake bed sediments
are generally low (Smith et al 2002). The lake has the ideal physical and chemical
settings for mercury methylation to occur, ie an extensive shallow water body, with a
maximum depth of approximately 10 metres and a mean depth of 5 metres, with a large
littoral region, surrounding wetlands, frequent wet/dry cycles, slightly acidic waters and
a tropical climate.
The Middle Fly and some parts of the Lower Fly River region, with their numerous offriver water bodies, have a similar physical environment to that of Lake Murray.
7
Figure 1: Regional map of the Ok Tedi-Fly River and Lake Murray areas, showing
the hair sampling locations
8
Figure 2: Levels of mercury in hair from published studies in the Ok Tedi-Fly
River region (1987 – 1999) (all mean values µg/g)
Mercury concentration in hair (ug/g)
40
35
30
25
20
15
10
5
0
Lake
Middle
Ok Tedi Middle
region Fly region Fly region Murray
Yok
Flew
Jones et al Abe et al
(1989,
(1999)
(1995)
(1987)
1990)
Lake Lower Fly
region
Murray
Flew
Abe et al
(1999)
(1995)
Fly
estuary
Abe
(1995)
Fly
estuary
Flew
(1999)
Location
Note:
Data from Abe et al (1995) was from sampling conducted at Fly River and Lake Murray in 1988.
The observed mercury in hair levels have also been attributed to the elevated mercury
concentrations in the local fish, and in particular predatory fish such as barramundi
(Kyle & Ghani 1982b, Curry et al 1992). Elevated mercury in fish is also routinely
reported in the OTML and Porgera Joint Venture Annual Environmental Reports. The
mercury levels in fish tissue at Lake Murray frequently exceed the FAO/WHO
recommended limit for total mercury in fish intended for human consumption
(FAO/WHO Codex 1991).
The Lake Murray villagers and those living in the Middle Fly region are also high fish
consumers, with published data indicating a consumption of approximately 250 - 285
g/day and 300 - 350 g/day respectively (OTML 1987, 1988).
Although there have been intermittent and somewhat limited clinical studies of the local
populations, these have consistently failed to reveal any overt signs of mercury
poisoning, although an early study identified a high prevalence of proteinuria (40%) at
Lake Murray (Kyle and Mackenzie 1982). A more recent study identified proteinuria in
15% - 25% of the communities at Membok and Komovai in the Middle Fly River (Flew
1999).
A study by Japanese researchers in 1994 measuring renal and hepatic competence, using
urinary nitrogen and creatinine levels, also identified a higher prevalence of elevated
values, suggesting some renal and/or hepatic disorders in the Lake Murray communities
(Hongo et al 1994). However, the results of these studies are inevitably confounded by
9
the generally poor health of the population, with a high prevalence of malaria and other
communicable and non-communicable diseases (Taufa 1997).
1.2 Other metals, arsenic and selenium
The value in undertaking analysis of human scalp hair as a monitoring tool for
exposures other than mercury in non-occupational populations is still the subject of
considerable debate. Interpretation of the analytical results is confounded by the use of
medical and cosmetic hair products, local environmental concentrations, particularly in
water and sample preparation and washing methods (eg use of chelating agents and
detergents). Presently, there is no internationally accepted standard practice for sample
preparation (ATSDR 2001).
There is also no uniformly accepted set of reference values for trace elements in hair,
since these ranges for normal populations differ significantly with diet (eg seafood
consumption) sex, age, ethnicity and to some degree the season in which the hair is
sampled. For the present discussion, the values published by WHO (1996),
supplemented by more recent reports, have been used for comparison. These values are
given in Table 1.
Table 1: Reference ranges for metals in healthy human scalp hair (all ranges of
values µg/g)
Element
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
1.
WHO (1996)
0.1 – 0.3
0.25 – 1.0
15 – 25
2 – 20
0.5 – 2.0
(no fish consumption)
0.5 – 1.0
150 – 250
Other authors1
0.02 – 2.70
0.03 – 1.72
0.29 – 280
0.12 – 36.7
1.4 – 11.6
0.05 – 17.5
24 – 477
Data ranges combined for North America, Europe, Japan and New Zealand as summarised by
Senofonte. Mercury data is from Papua New Guinea and is for a range of levels of fish
consumption from very low (1 – 2 times/month) to high (every day) (Airey 1983, Senofonte et al
2000).
However, while comparisons between the OTML CHS data with that from earlier
studies is somewhat confounded by a lack of published detail on sample preparation and
unknown age-sex distribution, the data is from the same population groups. With the
exception of the mine area villagers and their markedly elevated consumption of store
purchased foods, the other groups appear not to have made significant changes to their
diets, nor has the ethnicity of the communities markedly changed. A comparison
between the published data is given in Figure 3.
10
Figure 3: Levels of contaminant and essential metals in hair from published studies
in the Ok Tedi-Fly River region (1987 – 1999) (all values µg/g)
40
Metal concentration (ug/g)
35
Cadmium
30
Copper
Lead
25
Zinc / 5
20
15
10
5
0
OTML Mine area
Jones et al (1987)
Star Mountains
Jones et al (1987)
Middle Fly River
Flew (1999)
Lower Fly River
Flew (1999)
Fly estuary Flew
(1999)
Location
The report by Jones provides data from a medical survey in 1982 – 83 and indicates that
the levels for copper and zinc are well within the respective WHO reference ranges
(Table 1). The range of mean values for cadmium (2.1 – 5.3 µg/g) and lead (18 – 36.3
µg/g) are somewhat higher than the corresponding WHO values, and for cadmium are
outside the reference range.
The 1998 OTML Health Survey undertook the analysis of cadmium, copper, lead and
zinc in hair samples, sourced from the Middle Fly-Fly estuary communities (Flew 1999).
While only mean values are available for this data, there is little difference in the
concentrations of any of the metals between these groups. For copper, the range of mean
values was 9.3 – 12.5 µg/g and for zinc 88 – 131 µg/g, somewhat lower than the values
reported by Jones for the Ok Tedi communities. The values reported for cadmium 0.08
– 0.20 µg/g and lead 3.5 – 5.8 µg/g are markedly below those reported in the earlier
study. All values reported from the 1998 analysis for all groups, are well within the
WHO reference ranges in Table 1.
2.0 The OTML Community Health Study
2.1 Study design and methods
The present study has analysed human scalp hair samples from the Ok Tedi region
(Region 1 control) and Ok Tedi River villagers (Region 2 impact), from communities
resident in the Middle Fly River (Region 3 impact) and from communities living in the
Lower Fly River below the Fly-Strickland confluence at Everill Junction (Region 4
control and impact). The study populations by sex and age, are given in Table 2.
11
Table 2: OTML CHS sample frame by region and village for different age groups
Village
Region
Ok Ma
Gre and Ningerum Tamaro
Bossett, Kaviananga,
Komovai and Kukajaba
Aewa
Sapuka
1C
2I
3I
4C
4I
Sex
Male Female
28
12
26
52
43
56
4
15
All participants
6
15
0-5
7
5
3
1
4
Age group (years)
6 - 10
11 - 15
Adult (16 +)
4
2
27
5
8
60
9
39
48
1
6
1
2
7
18
257
Hair samples were cleaned prior to microwave digestion using high purity nitric acid
and hydrochloric acid. The cleansing process involved the use of 1% Triton X 100
detergent and sonication for 15 minutes, before rinsing with MilliQ water. This
cleansing process was repeated followed by drying in an air oven at 50ºC overnight.
Mercury analysis was conducted using inductively coupled plasma mass spectroscopy,
at the Queensland Health Scientific Services laboratory in Brisbane, Australia (QHSS
2003).
The results of environmental monitoring from the OTML CHS study for the levels of
contaminant and trace metals in drinking and surface water and ambient air throughout
the Ok Tedi-Fly River regions are, with the exception of some naturally-mineralised
environments proximal to the mining operations, broadly comparable with typical
international baseline values. A summary of the published data is given in Table 3.
Table 3: Mercury in the environment in the Strickland-Fly River and Lake
Murray regions
Location
Drinking
water(µg/L)
Hg D
Middle Fly River
villages
Lake Murray NW
Reaches
Fly River estuary
Hg T
Surface
waters
(µg/L)
Air
(ng/m3)
Hg T
Hg T
< 0.2
< 0.2
< 0.2
-
< 0.2
< 0.5
< 0.2
< 10
< 0.2
< 0.2
< 0.2
-
Soil and sediments (mg/kg)
< 0.5
Natural
sediment
< 0.5
Lake/River
sediment
<0.6
0.20
0.20
0.26
0.2 - 1.0
0.2 – 0.4
0.2 - 0.5
Soil
The soils and natural sediments results for mercury are somewhat elevated in the
Middle Fly River flood plain and in the Lake Murray bed sediments when compared
with those observed in the Ok Tedi regions, but not exceptionally so. Copper and zinc
are elevated due to natural mineralisation in the highland soils. There would also appear
to be a geochemical signature for arsenic in samples from the Lower Fly River and the
Fly estuary. All values are consistently less than the Australian Health Investigation
Levels (HILs) for the metals in soils and sediments. For total mercury, all values are
less than 10% of the HIL level of 15 mg/kg (NEPC 1999).
12
The summary results for all analyses are given in Tables 5 – 8. The detailed results by
age, sex and location for all analyses are provided in Appendix 1.
2.2 Results for mercury in the OTML CHS study
The total mercury in scalp hair results of the OTML CHS study are shown in Table 4.
The highland and the Ok Tedi villagers typically have a very low to low consumption of
fish, and the levels of mercury in hair are comparable with results reported in earlier
studies.
In the high fish-consuming Middle Fly River villagers, the mean mercury in hair values
were 15.0 µg/g for females and 17.4 µg/g for males, with some individual values
exceeding 80 µg/g. These results are comparable with those reported in the same region
in 1995 (range of means 14.9 – 30.9 µg/g) and somewhat higher than the mean results
reported in a small survey by Flew in 1999 (8.2 µg/g) (Abe et al 1995, Flew 1999).
Table 4: Mercury in hair samples from the OTML CHS (Results expressed as
mean ± standard deviation (number of samples))
Age (years)
0–5
6 – 10
11 – 15
16+ (Adult)
All ages
Males
Females
Upper Ok Tedi
(Highland)
villages
0.60 ± 0.22 (7)
0.60 ± 0.27 (4)
0.70 ± 0.14 (2)
0.49 ± 0.18 (26)
0.53 ± 0.20 (39)
0.55 ± 0.20 (28)
0.48 ± 0.19 (11)
Lower Ok Tedi
(River) villages
2.99 ± 3.78 (5)
2.15 ± 1.18 (5)
1.67 ± 1.04 (8)
3.20 ± 1.82 (63)
2.94 ± 1.95 (81)
3.38 ± 2.29 (29)
2.75 ± 1.70 (52)
Middle Fly River
villages
Lower Fly River
villages
18.21 ± 8.02 (3)
12.90 ± 4.84 (9)
16.51 ± 7.55 (40)
16.16 ± 15.50 (46)
16.06 ± 11.94 (98)
17.36 ± 16.36 (43)
15.04 ± 6.75 (55)
9.98 ± 2.67 (5)
14.23 ± 6.90 (7)
8.63 ± 3.93 (3)
13.89 ± 5.45 (25)
13.06 ± 5.53 (40)
13.96 ± 6.13 (19)
12.25 ± 4.93 (21)
Note: Ok Tedi highland villages (Ok Ma); Ok Tedi villages (Gre, Ningerum Tamaro); Middle Fly River
above Everill Junction (Bossett. Kaviananga, Komovai, Kukujaba) and Lower Fly River villages
(Aewa, Sapuka).
The Middle Fly villagers have a very similar physical living environment to the
communities at Lake Murray, with the off-river water bodies being equivalent to the
shallow lake for mercury bioaccumulation in the aquatic food chain. The fish
consumption values in the Middle Fly communities are also very similar, as is the level
of mercury in the flesh of the principal diet fish species. Not surprisingly, the levels of
mercury in scalp hair are also similar (see Figure 3).
The study results for the Lower Fly River communities, above the Fly estuary (12.3
µg/g for females and 14.0 µg/g for males) were similar to those in the Middle Fly region.
The difference in mean concentrations between males from the two regions were not
statistically significant (p= 0.12), the differences in mean concentrations between
females were significant (p=0.03) but small enough to have no health significance. The
similarities reflect the similar environments and level of fish consumption in the two
areas. The mean value for mercury in hair reported in the 1999 survey (5.5 µg/g all
ages/sex is lower than, but stll within the range of the OTML CHS study levels with a
mean of 9.17µg/g and a standard deviation of 10.2.
13
Figures 4 and 5 provide the results for the OTML CHS study communities by age and
sex. Two way ANOVAs confirmed that there is no significant difference in the total
mercury in hair levels by age (p = 0.822) or for males and females (p = 0.283.
Figure 4: Mercury levels in scalp hair for the OTML CHS communities by age (all
values µg/g)
20
18
0 – 5 years
Mercury in hair (ug/g)
16
6 – 10 years
14
12
11 – 15 years
10
Adult
8
6
4
2
0
Ok Tedi region
Ok Tedi River
Middle Fly River
Lower Fly River
Location
Figure 5: Mercury levels in scalp hair for the OTML CHS communities by sex and
region (all values µg/g)
25
Mercury in hair (ug/g)
20
15
Males
Females
10
5
0
Ok Tedi region Ok Tedi River
Middle Fly
River
Lower Fly River Lake Murray
(South East)
Lake Murray
(North West)
Location
Note: The data for Lake Murray is from the report by Yok (1990).
The Lake Murray and Middle and Lower Fly River regional communities can be
regarded as a single entity, when undertaking human mercury intake calculations. This
has significant public health implications. The Lake Murray region has a population of
5000 – 6000, whereas the combined regions have a population of approximately 25,000.
In geographic regional terms, the Lower Strickland River is also likely to share the same
14
elevated mercury in fish levels in the off-river water bodies. However, this region has
only a few permanent settlements, with most potential exposures being intermittent and
limited to the temporary sago-gathering camps.
The international literature generally assigns 75% - 80% of the total human intakes of
total metals in non-occupationally-exposed groups to the diet, with the uptake of
mercury, particularly methylmercury being almost exclusively through the consumption
of fresh and marine fish and other aquatic food (ATSDR 1999).
A comparison between the consumption frequencies for fresh fish and molluscs and the
observed total mercury concentrations in scalp hair is shown in Figure 6. There is a
reasonable correlation between these two measures for the present study, but less so
when compared with the mercury in hair data results from the 1999 Fly River Health
Survey (Flew 1999). The apparent marked difference in the Ok Tedi region between
fish consumption and mercury in hair, is largely a consequence of the store purchased
fish that is consumed, which comprises mainly tinned herrings and mackerel, with
relatively low levels of mercury in the product.
Figure 6: Consumption frequencies for aquatic foods in the Ok Tedi-Fly River
regions compared with the total mercury concentrations in scalp hair (values
times/week and µg/g)
20
Food consumption frequency (times/wk)
18
All aquatic foods
16
16.1
Hg in hair (CHS 2006)
14
13.1
Hg in hair (Flew 1999)
12
10
8.2
8
5.5
6
4.6
4
2
2.9
0.5
0
Ok Tedi region
Ok Tedi River
Middle Fly River
Lower Fly River
Fly estuary
Location
Figure 7 provides data on the levels of total mercury in protein-rich (ie mercurybioaccumulator) food products for the study regions. The observed levels at Lake
Murray confirm the earlier market basket results from the Porgera Joint Venture Human
Health Risk Assessment (Bentley 2005).
15
Figure 7: Mercury in food products sourced from the Ok Tedi-Fly River and Lake
Murray regions
0.500
0.450
Chicken
Mercury concentration (ug/g)
0.400
Fish
Mammal flesh wild
0.350
Mudclams
Pork flesh
0.300
Prawns
0.250
0.200
0.150
0.100
0.050
0.000
Ok Tedi River
Middle Fly River
Lake Murray
Lower Fly River
Fly Estuary
Location
A comparison of the results from the present study with the mean levels of mercury
observed in comparable foods analysed in the total diet studies from Australia and the
United States of America indicates that the total mercury levels in fish and pork flesh
are markedly higher than for comparable foods as consumed in Australia and the United
States (FSANZ 2001, 2003 US FDA 2006).
There is no question that these very high total mercury levels in the diet, are the main
contributors to the mercury body-burdens in the Middle-Lower Fly and Lake Murray
communities, as expressed in their elevated mercury in scalp hair levels. This is in
agreement with other published results, which also identify food as the major intake
source in non-occupationally-exposed populations. Results from these studies, indicate
an average daily intake for total mercury in the range 2 - 20 µg/day, but some “high fish
consuming” individuals may exceed 25 µg/day (UNEP 2002). Estimates for the Lake
Murray villagers indicate an average daily intake of 20 – 130 µg/day.
16
2.3 Results for other contaminant and essential elements in the OTML CHS
The results for contaminant and essential metals in hair from the OTML CHS are given
in Tables 5 – 8 and Figure 8. Accepting the reservations discussed earlier in this section,
a comparison between the Region 1 control villagers and the Jones data for the OTML
mine area and remote Star Mountains communities indicates that for copper and zinc
the levels in 2006 are very similar to those recorded in 1987. The 2006 values for
cadmium and lead are less than 10% of the earlier reported values. The reason for this is
unclear, and unlikely to be explained by a change in the level of sensitivity of the
analytical methods.
Comparing the 2006 data for the Middle and Lower Fly River regions with the results of
Flew in 1999, the levels of cadmium, copper and lead are virtually identical in both
studies. The levels of zinc in 2006 in the scalp hair for the Middle Fly villagers is some
40% higher than that reported in the earlier study, but for the Lower Fly villagers, again
the results are very similar.
A two-way ANOVA conducted on the log transformed OTML CHS data revealed
highly significant differences between the 4 regions for all the parameters except lead
and cadmium. There were also significant differences between control and potentially
impacted sites for all the parameters except for cadmium (Table x). In each case the
levels at the impacted sites were, on average, higher than those at the controls. None of
the levels were higher than the ranges normally expected, but there appear to be low
levels of selenium in the scalp hair of the highland communities. It is not possible from
hair data, to establish if these levels are indicative of a selenium deficiency in the
population.
The results of two way ANOVAs to test for differences in mean contaminant
concentrations in scalp hair between regions and between control and potentially
impacted sites. Values below 0.05 a generally considered statistically significant
Contaminant
Cadmium
Zinc
Copper
Selenium
Mercury
Lead
Arsenic
Difference between Regions
(p value)
0.115
< .0.001
0.003
< 0.001
< 0.001
0.969
< 0.001
Difference between Impact and
Control sites (p value)
0.131
0.041
0.006
< 0.001
< 0.001
< 0.001
< 0.001
A comparison of the present study results with the reference ranges provided in Table 1,
indicates that all mean values are well within the reference range values for each
element. For example, the range of mean values for arsenic (< 0.2 µg/g), and lead (3.3 –
6.9 µg/g) falls in the middle of the WHO 1996 range. The range of mean values for
cadmium (0.1 – 2.2 µg/g) is somewhat higher than the WHO range, but well within the
results reported in the literature. For the essential metals, the ranges for copper (12 – 22
µg/g and zinc (125 – 200 µg/g) are within the WHO range for normal populations, as
would be expected from the normal body control on the levels of these elements. The
17
levels of selenium (2 – 12 µg/g) are above the WHO reference values, but within those
reported by other authors.
Figure 8: Contaminant and essential metals in hair for the OTML CHS (all values
µg/g)
60
Arsenic (x 5)
Cadmium
Metal concentration (ug/g)
50
Lead
Selenium (x 10)
40
Copper
Zinc (/5)
30
20
10
0
Zone 1C
Zone 2I
Zone 3I
Location
Zone 4C
Zone 4I
18
2.4 Levels of contaminant metals in human scalp hair samples by village and
regional classification
Table 5: Arsenic and cadmium in hair samples from the OTML CHS (all values
µg/g)
Location
Ok Ma
Gre (Highway)
Ningerum Tamaro
Bosset
Kaviananga
Komovai
Kukujaba
Aewa
Sapuka
1C (Ok Ma)
2I (Gre, Ningerum
Tamaro)
3I (Bossett,
Kaviananga,
Komovai, Kukajaba)
4C (Aewa)
4I (Sapuka)
Arsenic
Cadmium
Median
Range
Mean ± sd
Median
0.05 0.05 – 0.40
0.09 ± 0.06
0.09
0.18 0.18 0 0.40
0.12 ± 0.12
0.09
0.17 0.18 – 1.08
0.35 ± 0.50
0.50
0.10 0.04 – 0.22
0.09 ± 0.08
0.10
0.12 0.05 – 0.30
0.16 ± 0.16
0.13
0.03 0.03 – 0.18
0.10 ± 0.09
0.09
0.05 0.05 – 1.40
0.18 ± 0.17
0.12
0.07 0.05 – 0.12
0.13 ± 0.18
0.08
0.13 0.06 – 0.42
0.19 ± 0.20 0.11
By region (impact and control)
0.07 ± 0.07
0.05 0.05 – 0.40
0.09 ± 0.06
0.09
0.22 ± 0.12
0.18 0.18 – 1.08
2.22 ± 0.36
0.11
Mean ± sd
0.07 ± 0.07
0.20 ± 0.06
0.24 ± 0.17
0.11 ± 0.05
0.12 ± 0.05
0.08 ± 0.03
0.17 ± 0.26
0.08 ± 0.02
0.14 ± 0.07
Range
0.01 – 0.27
0.03 – 0.67
0.05 – 2.65
0.0 – 0.28
0.03 – 0.76
0.02 – 0.38
0.03 – 0.82
0.01 – 0.60
0.01 – 0.86
0.01 – 0.27
0.03 – 2.65
0.13 ± 0.15
0.09
0.03 – 1.40
0.15 ± 0.15
0.10
0.0 – 0.82
0.08 ± 0.02
0.14 ± 0.07
0.07
0.13
0.05 – 0.12
0.06 – 0.42
0.13 ± 0.18
0.19 ± 0.20
0.08
0.11
0.01 – 0.60
0.01 – 0.86
Table 6: Lead and mercury in hair samples from the OTML CHS (all values µg/g)
Location
Ok Ma
Gre (Highway)
Ningerum Tamaro
Bosset
Kaviananga
Komovai
Kukujaba
Aewa
Sapuka
1C (Ok Ma)
2I (Gre (Highway),
Ningerum Tamaro)
3I (Bossett,
Kaviananga,
Komovai, Kukajaba)
4C (Aewa)
4I (Sapuka)
Mean ± sd
3.31 ± 2.98
6.78 ± 4.89
6.28 ± 4.56
7.07 ± 5.10
Lead
Median
2.1
4.0
4.56
6.4
Range
0.4 – 13.1
4.0 – 21.0
4.0 – 21.0
1.1 – 14.8
6.70 ± 4.76
3.96 ± 2.11
9.03 ± 17.1
4.10 ± 3.68
5.15 ± 3.54
Mean ± sd
0.53 ± 0.20
4.16 ± 1.82
1.44 ± 0.53
24.65 ±
29.44
16.32 ± 6.95
18.96 ± 7.02
10.75 ± 4.69
12.51 ± 7.08
13.25 ± 5.04
5.8
2.2 – 28.7
2.1
0.9 – 8.8
4.1
2.1 – 97.2
3.1
0.5 – 12.8
4.0
0.8 – 18.6
3.31 ± 2.98
2.1
0.4 – 13.1
0.53 ± 0.20
6.56 ± 4.72
4.0
4.0 – 21.0
2.94 ± 1.95
Mercury
Median
0.5
4.2
0.5
13.6
Range
0.2 – 1.0
1.2 – 9.8
1.3 – 3.1
6.8 – 87.0
15.2
7.0
9.5
9.5
12.5
3.1 – 33.8
5.2 – 34.6
5.0 – 24.3
4.6 – 27.6
3.8 – 22.2
0.5
2.7
0.2 – 1.0
1.3 – 9.8
6.89 ± 10.26
4.6
0.9 – 97.2
16.06 ±
11.94
13.6
3.1 – 87.0
4.10 ± 3.68
5.15 ± 3.54
3.1
4.0
0.5 – 12.8
0.8 – 18.6
12.51 ± 7.08
13.25 ± 5.04
9.5
12.5
4.6 – 27.6
3.8 – 22.2
19
Table 7: Copper and zinc in hair samples from the OTML CHS (all values µg/g)
Location
Copper
Median
Range
Mean ± sd
12.0
7.0 – 33.0
186.8 ± 61.1
13.0 8.7 – 140.0
170.4 ± 79.5
11.9 10.0 – 58.0
201.7 ± 95.8
14.2 8.76 – 48.8
142.8 ± 56.2
15.9
9.7 – 41.7
127.5 ± 46.7
4.8
6.3 – 22.4
116.1 ± 49.8
14.0
8.0 – 20.0
206.5 ± 61.8
10.0
8.4 – 27.3
136.2 ± 57.1
11.1
7.0 – 49.6
127.2 ± 63.7
14.75 ± 6.74
12.0
7.0 – 33.0
186.8 ± 61.1
21.95 ± 17.40
16.5
8.7 – 140
184.5 ± 88.0
Mean ± sd
14.75 ± 6.74
18.81 ± 20.44
25.80 ± 11.92
18.62 ± 11.34
17,51 ± 6.78
13.5 ± 4.76
13.16 ± 3.17
11.8 ± 5.63
15.16 ± 9.51
Ok Ma
Gre (Highway)
Ningerum Tamaro
Bosset
Kaviananga
Komovai
Kukujaba
Aewa
Sapuka
1C (Ok Ma)
2I (Gre (Highway),
Ningerum Tamaro)
3I (Bossett,
Kaviananga,
Komovai, Kukajaba)
4C (Aewa)
4I (Sapuka)
Zinc
Median
172
150
95
129
122
50
198
128
108
Range
99- 386
99 – 580
79 – 520
98 – 304
73 – 295
39 – 261
68 – 368
75 – 257
66 – 326
172
160
99- 386
79 – 580
15.40 ± 6.51
14.0
6.3 – 48.8
155.3 ± 63.9
137
39 – 368
11.8 ± 5.63
15.16 ± 9.51
10.0
11.1
8.4 – 27.3
7.0 – 49.6
136.2 ± 57.1
127.2 ± 63.7
128
108
75 – 257
66 – 326
Table 8: Selenium in hair samples from the OTML CHS(all values µg/g)
Location
Ok Ma
Gre (Highway)
Ningerum Tamaro
Bosset
Kaviananga
Komovai
Kukujaba
Aewa
Sapuka
By village
Mean ± sd
Median
0.10 ± 0.0
0.1
1.25 ± 0.0
1.25
1.25 ± 0.0
1.25
0.90 ± 0.15
0.93
0.76 ± 0.16
0.7
1.00 ± 0.18
0.2
0.10 ± 0.0
0.1
0.65 ± 0.15
0.6
0.57 ± 0.09
0.6
0.10 ± 0.0
0.1
1.25 ± 0.0
1.25
1C (Ok Ma)
2I (Gre (Highway),
Ningerum Tamaro)
3I (Bossett, Kaviananga,
Komovai, Kukajaba)
4C (Aewa)
4I (Sapuka)
Range
0.1
1.25
1.25
0.7 – 1.1
0.5 – 1.4
0.7 – 1.4
0.1
0.5 – 0.9
0.4 – 0.8
0.1
1.25
0.62 ± 0.39
0.7
0.1 – 1.4
0.65 ± 0.15
0.57 ± 0.09
0.6
0.6
0.5 – 0.9
0.4 – 0.8
Note: For deriving mean values, the medium bound value (50% of the detection limit) was adopted. For
Ok Ma, the detection limit was < 0.2 µg/g and for Gre and Ningerum Tamaro < 2.5 µg/g. The
difference is due to the amount of sample supplied to the laboratory for analysis. It is not
anticipated that using these detection limits will have significant impact on the derivation of the
mean. For arsenic at Ok Ma and Komovai, the detection limit was < 0.1 µg/g and for Gre and
Ningerum Tamaro < 0.35 µg/g and for cadmium the detection limit was < 0.02 µg/g and for Gre
and Ningerum Tamaro < 0.05 µg/g. For Gre and Ningerum Tamaro the detection limit for lead
was < 8.0 µg/g. For mercury at Komovai, the detection limit was < 0.2 µg/g and for Ningerum
Tamaro < 2.5 µg/g.
20
3.0 References
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T (1995) High Hair and Urinary Mercury Levels of Fish Eaters in the Non-polluted
Environment of Papua New Guinea, Arch Environ. Health 50:367 – 373
Airey D (1983) Total Mercury Concentrations in Human Hair from 13 Countries in
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ATSDR (1999) Toxicological Profile for Mercury (update) US Department of Human
Health and Human Services, Agency for Toxic Substances and Disease Control,
Atlanta, USA
ATSDR (2001) Summary Report Hair Analysis Panel Discussion: Exploring the State
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Bentley K W (2005) Porgera-Lagaip-Strickland Lake Murray Health Risk Assessment:
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Australia New Zealand, Canberra, Australia available at
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Zealand Food Authority, Canberra, Australia available at
http://www.foodstandards.gov.au
21
Grandjean P, Weihe P, White R F, Debes F, Araki S, Yokoyama K, Murata K, Sorensen
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Organization, Geneva
Jones G L, Willy D, Lumsden B, Taufa T and Laurie J (1987), Trace Metals in the Hair
of Inhabitant of the Ok Tedi Region, Papua New Guinea Env Pollution 48:101 - 115
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Western Province Papua New Guinea Med J. 25:2 81 – 88
Kyle J H and Ghani N (1982b) Mercury concentrations in Ten Species of Fish from
Lake Murray, Western Province. Sci. New Guinea, 9:48 – 58
Kyle J H and MacKenzie C J G (1982) Albuminuria at Lake Murray due to High
Methylmercury Intake, PNG Med J Vol 25 N0.4 Dec 227 - 229
NEPC (1999) Guidelines on Health-based Investigation Levels National Environmental
Health Forum Monographs Soils Series No 1 3rd Ed July 1999 South Australian Health
Commission Australia
OTML (1987) Six Monthly Biology Review, Ok Tedi Mining Limited Reports Nos
ENV 87-08 and 87-14
OTML (1988) Six Supplemental Agreement Environmental Study (1986 – 1988) Final
Draft Report, Ok Tedi Mining Limited Volume 3 Biology, Laboratory Methods and
Geomorphology, Appendix C: Fish Biology: Dietary Surveys. OTML Pty Ltd
Parametrix (1998) Chemistry Data used in the Strickland River SLRA (1998) Prepared
for PJV by Parametrix Inc Washington, USA
QHSS (2003) Total Metals Standard Operating Practice 18229R1 Pathology and
Scientific Services, Biomedical Technology Services, Queensland Health Scientific
Services, Brisbane, Australia
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Elements in Human Hair of Urban Schoolboys, J Trace Elements Med Biol 14:6 – 13
22
Smith R E W, Markham A J and Apte S C (2002) PJV’s response to the CSIRO’s 48
Recommendations (January 1999) Environment Department PJV and CSIRO 1996
Recommendations - Status of Actions by Porgera Joint Venture
Suzuki T, Watanabe S, Hongo T, Kawabe T, Inaoka T and Akimichi T (1988) Mercury
in Scalp Hair of Papuans in the Fly estuary Papua New Guinea Asia-pacific J Public
Health 2:39 – 47
Taufa T (1997) Baseline Health Survey in Parts of the Lagaip, Strickland Rivers and the
Lake Murray Areas Unisearch PNG Pty Ltd for PJV
US EPA (1997) Mercury Study Report to Congress, Vol IV: An assessment of exposure
to mercury in the United States, EPA-452/R-97-006, US Environmental Protection
Agency, Office of Air Quality Planning and Standards and Office of Research and
Development
UNEP (2002) Global Mercury Assessment Report, UNEP Chemicals, Geneva
US FDA (2006) Total Diet Study Statistics on Element Results US Food and Drug
Administration, Washington, DC
US NRC (2000) Toxicologic Effects of Methylmercury, National Research Council
Washington, DC, National Academy of Sciences
Vasconcellos, M B A, Paletti G, Catharino M G M, Saiki M. Fávaro D I T, Baruzzi R
G, Rodrigues D A, Byrne A R and Fort, M C (1998) Studies on Mercury Exposure of
some Brazilian Population Groups Living in the Amazon Region by Means of Hair
Analysis, Paper Submitted by Brazil in UNEP Global Mercury Assessment 2002,
UNEP Chemicals, Geneva
WHO (1996) Trace Elements in Human Nutrition and Health, World Health
Organization, Geneva, Switzerland
Yok D (1989) Demographic and Subsistence Fish Consumption Investigation within the
Fly Delta: Wapi Village, Purutu Channel (August 1989) Environment Department PJV
Yok D (1990) Subsistence Fisheries and Demographic Investigations Within the Lake
Murray Area, Buseki, Usokof and Kusikina Villages, Environment Department PJV
Yok D and Blomeley A (1990) Demographic and Dietary Investigation Along the
Strickland, Lagaip and Porgera Rivers Environment Department PJV
Appendix 1: OTML CHS analytical results by location, age and sex
OTML CHS metals analysis in human scalp hair (all values mg/kg)
Date
sampled
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
23/01/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
04/02/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
Laboratory
code
SS05TM684
SS05TM685
SS05TM686
SS05TM687
SS05TM688
SS05TM689
SS05TM690
SS05TM691
SS05TM692
SS05TM693
SS05TM670
SS05TM674
SS05TM675
SS05TM676
SS05TM677
SS05TM678
SS05TM679
SS05TM680
SS05TM681
SS05TM682
SS05TM683
SS05TM2144
SS05TM2145
SS05TM2146
SS05TM2147
SS05TM2148
Sex
F
F
M
F
M
F
F
M
F
M
M
M
M
M
M
M
M
M
M
M
M
F
M
F
F
F
Age
45
64
29
12
6
38
2
23
45
16
30
27
16
13
11
12
34
30
30
39
7
33
1
25
49
50
Location
Aewe
Aewe
Aewe
Aewe
Aewe
Aewe
Aewe
Aewe
Aewe
Aewe
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Bosset
Gre
Gre
Gre
Gre
Gre
Arsenic
0.07
0.05
0.06
0.09
0.06
0.12
0.09
0.06
0.09
0.08
0.10
0.13
0.14
0.22
0.10
0.09
0.04
0.11
0.11
0.06
0.08
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
Cadmium
0.11
0.02
0.03
0.03
0.20
0.16
0.08
0.60
0.09
0.01
0.02
0.28
0.13
0.16
0.10
0.04
0.00
0.01
0.12
0.12
0.04
0.4
0.3
0.7
0.1
0.1
Copper
10.4
9.6
10.6
8.4
9.1
11.8
8.6
27.3
13.1
9.3
11.3
48.8
22.7
24.3
11.3
14.0
10.7
8.8
16.4
22.3
14.2
43
140
15
22
15
Lead
3.5
1.4
0.9
7.2
2.7
12.8
0.5
4.9
4.7
2.5
1.5
6.4
11.1
14.8
2.5
11.5
1.1
3.6
13.3
9.4
2.6
< 8.0
8.9
< 8.0
< 8.0
< 8.0
Mercury
8.9
14.7
10.2
4.6
20.6
14.6
6.7
8.3
8.9
27.6
13.6
14.1
7.3
6.8
14.5
9.2
80.7
87.0
15.4
11.5
10.9
4.8
9.8
6.1
4.5
4.3
Selenium
0.59
0.61
0.74
0.58
0.52
0.58
0.64
0.50
0.87
0.82
0.69
1.05
0.96
0.79
0.93
0.98
1.11
0.71
0.80
0.83
1.07
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
Zinc
87.7
143.6
188.4
75.0
85.4
136.6
96.1
257.7
171.7
119.6
148.3
150.9
134.2
98.0
115.0
102.5
139.2
129.1
126.7
304.3
122.2
290
580
220
180
160
24
OTML CHS metals analysis in human scalp hair (all values mg/kg) (cont’d)
Date
sampled
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
Laboratory
code
SS05TM2149
SS05TM2150
SS05TM2151
SS05TM2152
SS05TM2153
SS05TM2154
SS05TM2155
SS05TM2156
SS05TM2157
SS05TM2158
SS05TM2159
SS05TM2160
SS05TM2161
SS05TM2162
SS05TM2163
SS05TM2164
SS05TM2165
SS05TM2166
SS05TM2167
SS05TM2168
SS05TM2169
SS05TM2170
SS05TM2171
SS05TM2172
SS05TM2173
SS05TM2174
SS05TM2175
SS05TM2176
Sex
F
F
F
M
F
M
F
F
F
F
F
M
F
F
F
F
M
F
F
F
F
M
M
M
M
M
F
F
Age
57
46
33
40
36
18
40
42
30
17
28
48
23
15
42
7
53
22
41
33
26
65
66
65
63
71
32
17
Location
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Arsenic
< 0.35
< 0.35
0.37
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
0.39
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
Cadmium
0.1
0.1
0.1
< 0.05
0.2
0.1
0.1
0.2
0.2
0.1
0.2
< 0.05
< 0.05
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.3
0.1
< 0.05
0.1
< 0.05
0.1
Copper
11
20
37
9
14
18
12
17
29
32
11
11
10
15
10
11
16
20
13
10
16
9
9
12
13
9
13
16
Lead
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
14.0
< 8.0
15.0
9.7
8.1
< 8.0
< 8.0
< 8.0
< 8.0
11.0
< 8.0
< 8.0
< 8.0
< 8.0
15.0
18.0
< 8.0
< 8.0
< 8.0
13.0
< 8.0
< 8.0
< 8.0
Mercury
4.2
3.5
< 2.5
5.1
4.7
4.0
2.6
4.1
< 2.5
< 2.5
4.5
3.1
4.5
4.2
< 2.5
3.6
4.6
3.9
7.9
5.4
3.7
5.4
5.9
4.4
6.9
7.0
3.6
2.7
Selenium
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
Zinc
150
310
260
180
100
180
190
170
140
140
99
140
130
120
230
140
180
160
130
110
100
130
140
130
160
160
110
170
25
Date
sampled
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
09/06/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
Laboratory
code
SS05TM2177
SS05TM2178
SS05TM2179
SS05TM2180
SS05TM2181
SS05TM2182
SS05TM2183
SS05TM2184
SS05TM2185
SS05TM2186
SS05TM715
SS05TM716
SS05TM717
SS05TM718
SS05TM719
SS05TM720
SS05TM721
SS05TM722
SS05TM723
SS05TM724
SS05TM725
SS05TM726
SS05TM727
SS05TM728
SS05TM729
SS05TM730
SS05TM731
SS05TM732
SS05TM733
SS05TM734
Sex
M
F
F
F
F
F
F
M
F
M
M
M
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
M
Age
6
22
33
40
36
15
26
22
20
19
13
12
16
13
14
13
15
16
14
13
15
12
13
14
13
12
13
14
16
13
Location
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Gre
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Arsenic
< 0.35
0.40
0.37
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
0.12
0.15
0.17
0.12
0.14
0.07
0.07
0.10
0.07
0.13
0.15
0.30
0.09
0.10
0.05
0.11
0.09
0.11
0.07
0.12
Cadmium
0.1
0.1
0.1
0.3
0.1
0.1
0.1
< 0.05
0.1
0.1
0.27
0.15
0.18
0.23
0.06
0.19
0.10
0.05
0.05
0.13
0.10
0.31
0.06
0.13
0.13
0.11
0.07
0.14
0.24
0.04
Copper
11
14
12
18
12
19
11
13
10
31
23.4
20.1
14.6
23.0
11.6
20.2
18.1
11.7
10.0
10.5
14.1
23.5
10.9
15.9
19.7
14.1
12.3
22.0
29.6
12.0
Lead
21.0
8.1
< 8.0
20.0
9.7
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
7.8
10.3
7.8
7.0
2.3
2.1
6.1
3.3
3.3
6.2
3.4
14.9
5.8
6.7
2.8
4.9
5.4
4.1
7.8
4.9
Mercury
3.3
3.7
2.9
6.2
4.9
< 2.5
3.3
3.8
< 2.5
4.5
22.5
17.8
15.3
23.4
24.7
18.7
11.5
15.4
26.7
12.9
11.4
15.3
12.0
18.7
19.2
14.6
15.2
11.0
15.3
8.3
Selenium
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
0.69
0.95
0.74
0.94
1.05
0.80
0.79
0.80
0.82
0.80
0.73
0.75
0.87
0.85
0.75
0.73
0.65
0.71
0.63
0.74
Zinc
130
110
170
200
130
210
130
150
140
170
295.3
106.9
140.2
121.9
114.1
114.1
76.2
72.5
99.7
136.5
105.0
132.8
146.1
110.2
114.4
121.3
107.1
160.8
215.9
107.5
26
Date
sampled
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
03/02/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
Laboratory
code
SS05TM735
SS05TM736
SS05TM737
SS05TM738
SS05TM739
SS05TM740
SS05TM741
SS05TM742
SS05TM743
SS05TM744
SS05TM745
SS05TM746
SS05TM747
SS05TM748
SS05TM749
SS05TM694
SS05TM695
SS05TM696
SS05TM697
SS05TM698
SS05TM699
SS05TM700
SS05TM701
SS05TM702
SS05TM703
SS05TM704
SS05TM705
SS05TM706
SS05TM707
SS05TM708
Sex
M
M
M
M
M
M
M
F
F
F
F
F
M
M
M
M
F
F
F
F
F
M
F
M
F
M
F
F
M
F
Age
14
16
16
14
15
13
14
15
13
13
14
64
24
10
45
60
25
37
13
57
10
21
38
30
23
11
3
60
30
42
Location
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Kaviananga
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Arsenic
0.16
0.09
0.13
0.15
0.13
0.07
0.09
0.09
0.24
0.16
0.07
0.13
0.24
0.15
0.11
0.09
0.07
0.03
0.07
0.09
0.08
0.10
0.07
0.07
0.05
0.08
0.04
0.06
0.08
0.05
Cadmium
0.25
0.26
0.76
0.15
0.14
0.09
0.07
0.04
0.03
0.03
0.06
0.66
0.08
0.18
0.20
0.02
0.10
0.07
0.08
0.10
0.20
0.06
0.14
0.05
0.07
0.17
0.24
0.11
0.08
0.12
Copper
12.1
22.4
26.6
18.1
14.3
18.8
14.8
10.7
13.6
10.0
9.7
21.9
22.7
18.3
41.7
6.3
8.2
9.9
14.9
14.8
15.9
11.0
19.5
9.2
12.9
20.0
16.2
8.9
19.9
12.5
Lead
5.0
7.7
8.2
9.7
4.7
3.3
3.3
3.2
28.7
12.6
5.1
7.5
7.3
6.2
5.3
2.6
2.1
6.1
3.5
8.8
8.1
2.7
6.6
2.6
5.2
0.9
3.6
3.4
4.5
2.9
Mercury
14.7
14.6
24.9
9.7
10.8
23.6
33.2
20.1
33.8
13.6
11.2
10.2
3.1
10.7
7.1
16.2
25.8
9.7
24.7
28.4
19.4
17.4
24.8
20.9
9.6
34.6
23.7
12.3
11.8
5.2
Selenium
0.73
0.64
0.81
0.68
0.62
0.67
1.40
0.68
0.74
0.67
0.62
0.47
0.88
0.57
0.51
1.11
0.87
0.68
1.13
1.03
1.09
1.39
1.06
0.69
0.91
1.15
1.02
1.09
1.06
0.90
Zinc
247.1
136.9
146.4
105.3
120.7
129.9
115.7
163.5
104.9
135.0
106.2
155.5
137.4
198.6
211.6
77.2
96.8
261.4
109.2
103.0
86.4
92.2
98.7
118.0
139.1
160.6
222.3
72.9
39.5
113.9
27
Date
sampled
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
30/01/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
Laboratory
code
SS05TM709
SS05TM710
SS05TM711
SS05TM712
SS05TM713
SS05TM714
SS06TM1127
SS06TM1128
SS06TM1129
SS06TM1130
SS06TM1131
SS06TM1132
SS06TM1133
SS06TM1134
SS06TM1135
SS06TM1136
SS06TM1137
SS06TM1138
SS06TM1139
SS06TM1140
SS06TM1141
SS06TM1142
SS06TM1143
SS06TM1144
SS06TM1145
SS06TM1146
SS06TM1147
SS06TM1148
SS06TM1149
Sex
M
M
M
F
M
M
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
M
Age
12
7
30
3
10
42
45
42
21
15
27
12
10
7
26
25
23
20
15
48
25
32
19
15
28
16
14
44
51
Location
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Arsenic
0.06
0.09
0.18
0.09
0.15
0.09
0.3
< 0.1
< 0.1
< 0.1
0.3
0.3
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
0.2
< 0.1
< 0.1
0.4
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
1.4
< 0.1
Cadmium
0.38
0.06
0.03
0.06
0.02
0.03
0.19
0.32
0.22
0.06
0.14
0.09
0.09
0.12
0.08
0.1
0.27
0.33
0.82
0.62
0.07
0.12
0.08
0.08
0.2
0.08
0.15
0.07
0.04
Copper
22.4
13.5
7.2
19.5
9.5
11.3
15
16
10
9
14
11
16
15
11
11
20
15
12
13
8
14
8
18
12
10
12
18
8
Lead
1.6
2.8
3.6
3.3
2.1
6.0
21.4
2.5
10.8
4.1
5.6
2.7
97.2
4.1
4.6
2.7
3.6
2.1
2.6
4.5
10.3
13.4
2.5
3.2
4.1
9.4
20.2
7.1
12.1
Mercury
21.8
17.1
19.1
22.0
19.5
14.4
24.3
10.6
23.7
10.1
5
6.3
12.4
8.5
9.4
5
6.6
12.3
7.7
10.1
16.8
8.7
9.5
12
9.5
14.5
17
11.5
10.2
Selenium
0.89
0.72
1.26
0.89
0.97
1.01
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
Zinc
121.6
139.5
90.5
75.1
114.3
105.8
297
220
266
206
68
305
368
198
184
222
175
228
191
214
165
156
339
132
205
148
247
221
154
28
Date
sampled
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
05/12/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
Laboratory
code
SS06TM1150
SS06TM1151
SS06TM1152
SS06TM1153
SS06TM1154
SS06TM1155
SS06TM1156
SS06TM1157
SS05TM2109
SS05TM2110
SS05TM2111
SS05TM2112
SS05TM2113
SS05TM2114
SS05TM2115
SS05TM2116
SS05TM2117
SS05TM2118
SS05TM2119
SS05TM2120
SS05TM2121
SS05TM2122
SS05TM2123
SS05TM2124
SS05TM2125
SS05TM2126
SS05TM2127
SS05TM2128
SS05TM2129
SS05TM2130
Sex
M
M
M
M
M
M
M
M
M
F
F
M
M
M
F
F
F
M
M
F
F
F
F
F
F
F
F
F
F
F
Age
10
4
18
14
10
30
49
20
3.5
3.5
7
3.5
6
3.5
11
10
12
13
15
28
56
41
45
46
46
46
27
38
27
30
Location
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Kukujaba
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Arsenic
Cadmium
0.3
< 0.1
0.4
0.3
0.2
< 0.1
< 0.1
< 0.1
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
0.37
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
0.07
0.03
0.04
0.38
0.22
0.26
0.24
0.11
0.1
0.1
0.2
0.3
0.2
0.4
0.3
0.3
0.3
0.1
0.2
0.1
1.1
0.1
0.2
0.1
0.1
0.1
1.4
0.2
0.2
0.1
Copper
14
12
18
16
14
14
14
10
10
13
29
19
22
23
45
32
52
24
23
14
31
12
29
12
18
14
20
21
31
12
Lead
4.8
2.3
5.6
2.9
3.8
3.3
3.5
3
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
14.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
11.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
< 8.0
Mercury
12.1
9
13.9
8.1
5.5
5.8
7.7
9.4
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
Selenium
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
Zinc
196
173
180
226
219
129
174
195
120
79
130
150
160
370
190
110
160
120
180
120
150
100
180
160
150
120
140
130
190
160
29
Date
sampled
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
26/05/05
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
Laboratory
code
SS05TM2131
SS05TM2132
SS05TM2133
SS05TM2134
SS05TM2135
SS05TM2136
SS05TM2137
SS05TM2138
SS05TM2139
SS05TM2140
SS05TM2141
SS05TM2142
SS05TM2143
SS06TM1066
SS06TM1067
SS06TM1068
SS06TM1069
SS06TM1070
SS06TM1071
SS06TM1072
SS06TM1073
SS06TM1074
SS06TM1075
SS06TM1076
SS06TM1077
SS06TM1078
SS06TM1079
SS06TM1080
SS06TM1081
Sex
F
F
F
F
M
M
M
M
M
M
F
M
F
F
F
F
F
F
F
F
F
F
F
F
F
M
M
M
M
Age
25
36
36
35
57
38
30
54
58
15
13
50
17
40
30
45
30
38
26
18
30
6
5
40
30
36
36
34
30
Location
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ningerum Tamaro
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Arsenic
Cadmium
< 0.35
< 0.35
< 0.35
< 0.35
0.45
1.08
0.56
< 0.35
< 0.35
< 0.35
< 0.35
< 0.35
0.40
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
0.2
< 0.1
< 0.1
< 0.1
< 0.1
0.3
0.4
0.4
0.4
0.1
0.8
0.1
0.2
2.7
0.5
0.2
0.2
0.1
0.05
0.06
0.11
0.18
0.05
0.1
0.24
0.02
0.02
0.09
0.14
0.09
0.07
0.09
0.27
0.06
Copper
16
30
39
58
24
47
23
16
20
26
31
42
25
13
12
13
18
8
11
8
7
8
11
17
12
33
10
24
12
Lead
< 8.0
9.0
8.0
21.0
11.0
20.0
13.0
< 8.0
8.9
< 8.0
< 8.0
< 8.0
< 8.0
0.7
1.8
5.4
2.2
1.2
4.1
2.1
1.5
1.5
1.9
2
2.7
3.8
2.5
13.1
1.8
Mercury
< 2.5
2.8
< 2.5
2.7
< 2.5
< 2.5
3.1
< 2.5
2.9
< 2.5
< 2.5
< 2.5
< 2.5
0.2
0.6
0.6
0.4
0.6
0.3
0.4
0.9
0.5
0.5
0.5
0.3
0.4
0.8
0.4
0.3
Selenium
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 2.5
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
Zinc
200
160
270
210
390
520
250
350
260
250
260
250
320
207
152
240
386
135
167
179
163
130
192
225
223
175
131
147
167
30
Date
sampled
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
19/01/06
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
Laboratory
code
SS06TM1082
SS06TM1083
SS06TM1084
SS06TM1085
SS06TM1086
SS06TM1087
SS06TM1088
SS06TM1089
SS06TM1090
SS06TM1091
SS06TM1092
SS06TM1093
SS06TM1094
SS06TM1095
SS06TM1096
SS06TM1097
SS06TM1098
SS06TM1099
SS06TM1100
SS06TM1122
SS06TM1123
SS06TM1124
SS06TM1125
SS06TM1126
SS05TM750
SS05TM751
SS05TM752
SS05TM753
SS05TM754
Sex
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
F
F
F
M
F
Age
40
18
2
16
14
5
29
19
17
30
5
33
2.5
0.66
6
29
7
6
11
30
16
56
4
34
55
63
21
33
40
Location
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Arsenic
Cadmium
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
0.2
< 0.1
0.4
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1
0.3
0.09
0.10
0.19
0.06
0.06
0.08
0.1
0.04
0.04
0.25
0.06
0.04
0.03
0.04
0.09
0.11
0.09
0.1
0.05
0.13
0.14
0.13
0.07
0.05
0.08
0.13
<0.02
0.13
0.05
0.03
0.02
0.29
0.06
0.13
Copper
11
15
12
17
16
10
17
13
9
10
9
12
21
13
28
11
25
11
8
21
33
12
26
13
8.5
7.0
32.1
10.7
13.0
Lead
6.8
1.3
9.9
1.9
1.1
1.8
4.3
1.7
5.8
1.1
1.6
2.6
8.6
4.6
12.1
0.4
1.4
1.7
2
3.8
1.7
2.5
2.8
2.6
6.0
4.4
8.3
4.6
1.9
Mercury
0.5
0.5
0.3
0.5
0.6
0.7
0.8
0.5
0.6
0.8
0.9
0.6
0.8
0.4
0.4
0.4
0.5
1
0.8
0.3
0.5
0.3
0.6
0.3
11.2
21.3
21.7
11.2
9.3
Selenium
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
< 0.2
0.49
0.68
0.66
0.59
0.59
Zinc
117
116
178
204
190
187
165
117
167
226
202
166
252
149
156
198
176
124
99
260
315
169
169
352
68.9
95.2
326.3
113.4
110.1
31
Date
sampled
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
22/01/05
Laboratory
code
SS05TM755
SS05TM756
SS05TM757
SS05TM758
SS05TM759
SS05TM760
SS05TM761
SS05TM762
SS05TM763
SS05TM764
SS05TM765
SS05TM766
SS05TM767
SS05TM768
SS05TM769
SS05TM770
SS05TM771
SS05TM772
SS05TM773
SS05TM774
SS05TM775
SS05TM776
SS05TM777
SS05TM778
SS05TM779
Sex
M
M
F
F
M
F
F
M
M
F
M
M
M
M
M
F
F
F
M
M
M
M
F
F
F
Age
38
60
9
5
30
6
30
3
62
42
35
31
60
28
6
5
24
7
41
5
6
9
11
13
27
Location
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Arsenic
Cadmium
0.11
0.06
0.10
0.14
0.09
0.13
0.18
0.19
0.15
0.12
0.14
0.19
0.17
0.42
0.20
0.18
0.17
0.11
0.11
0.10
0.20
0.07
0.11
0.16
0.13
0.02
0.19
0.07
0.50
0.08
0.07
0.11
0.07
0.11
0.17
0.12
0.86
0.02
0.36
0.25
0.34
0.05
0.28
0.01
0.70
0.39
0.22
0.16
0.08
0.05
Copper
7.5
7.4
11.2
27.1
12.6
10.6
13.1
11.6
8.6
9.4
8.5
11.0
7.1
49.6
20.6
23.4
9.3
25.3
7.4
22.5
21.2
21.0
18.3
9.6
9.7
Lead
3.5
3.1
2.4
5.1
5.1
0.8
4.1
1.4
3.8
8.6
10.1
5.2
3.5
18.1
3.8
4.5
3.9
2.9
3.6
8.6
9.0
3.4
1.7
2.9
10.4
Mercury
19.7
9.7
13.0
13.6
7.4
22.2
7.4
8.5
12.9
15.9
20.4
16.2
12.6
21.0
19.9
11.6
8.1
8.8
14.3
9.6
3.8
11.3
12.4
8.9
13.4
Selenium
0.68
0.47
0.79
0.57
0.48
0.61
0.59
0.63
0.49
0.67
0.57
0.61
0.66
0.51
0.54
0.55
0.55
0.54
0.57
0.43
0.50
0.39
0.51
0.50
0.63
Zinc
100.0
113.3
97.6
138.0
66.0
107.6
137.4
103.6
110.0
66.1
88.2
130.5
107.5
266.5
87.6
294.3
104.5
82.7
76.1
101.6
194.8
138.4
136.3
128.0
96.2
QHSS quality control March 2005
NOTES:
(1)
Hair samples were cleaned as follows prior to digestion: Hair samples were placed in a 70mL
urine jar and 1% Triton X100 was added. Jars and contents were then placed in an ultrasonic bath
for 15 minutes. The hair was then rinsed with MilliQ water. This cleaning process was repeated
after which the hair was dried in an air oven at 50 degrees overnight.
(2)
All samples were digested by microwave digestion using high purity nitric acid and hydochloric
acid.
(3)
Analyses for trace elements were conducted by ICPMS.
(4)
QC values were calculated from raw data before converting to weight based concentrations.
Spike recovery % (all values mg/kg)
QHSS Lab code
TM675B
TM675B SPK
Difference
% Recovery
TM704A
TM704A SPK
Difference
% recovery
Note:
Copper
43
92
48.4
88
49
98
49
89
Zinc
250
297
46.3
84
384
434
49
90
Arsenic
0.3
5.1
4.8
96
0.2
5.1
4.9
98
Selenium
1.8
6.9
5.0
100
2.5
7.7
5.1
103
Cadmium
0.2
5.1
4.9
98
0.42
5.3
4.9
98
Mercury spikes not carried out due to high levels found in samples.
Mercury
Lead
21
25
4.4
87
2.7
7.5
4.7
95
33
QC NCS DC 73347 (Hair) (all values mg/kg)
QHSS Lab
code
05MS324
05MS325
05MS360
05MS372
05MS396
05MS408
05MS430
05MS442
05MS454
05MS466
05MS478
05MS490
05MS502
05MS514
05MS525
05MS549
05MS561
05MS573
05MS585
05MS597
05MS361
05MS373
05MS397
05MS409
05MS431
05MS443
05MS455
05MS467
05MS479
05MS491
05MS503
05MS515
05MS526
05MS550
05MS562
05MS574
05MS586
05MS598
Mean
sd
RV
Copper
Zinc
Arsenic
Selenium
Cadmium
Mercury
Lead
8.9
9.2
9.1
9.0
8.6
9.1
9.0
9.0
9.3
9.0
9.1
9.2
8.3
9.0
9.1
9.3
9.3
9.0
8.9
9.0
8.9
8.9
8.8
9.7
8.9
8.9
8.9
8.4
9.2
9.6
8.8
9.0
9.0
9.3
9.1
10.4
9.0
9.0
9.1
0.4
10.6±0.7
160
166
174
167
160
167
163
166
161
166
171
174
156
168
176
173
175
169
167
179
167
165
167
167
166
163
164
156
169
180
166
168
180
175
173
170
171
177
169
6
190±5
0.20
0.22
0.21
0.23
0.21
0.22
0.23
0.22
0.21
0.24
0.24
0.23
0.20
0.21
0.22
0.22
0.21
0.22
0.22
0.21
0.23
0.23
0.22
0.22
0.21
0.20
0.23
0.20
0.23
0.25
0.22
0.22
0.23
0.20
0.22
0.22
0.22
0.22
0.22
0.01
0.28±0.04
0.46
0.55
0.54
0.54
0.54
0.67
0.66
0.71
0.58
0.73
0.65
0.67
0.60
0.51
0.48
0.60
0.58
0.66
0.61
0.58
0.70
0.60
0.60
0.64
0.56
0.58
0.64
0.61
0.59
0.66
0.62
0.59
0.52
0.64
0.59
0.68
0.55
0.50
0.60
0.05
0.60±0.03
0.10
0.11
0.11
0.12
0.11
0.11
0.12
0.11
0.14
0.11
0.11
0.12
0.10
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.11
0.12
0.12
0.11
0.11
0.11
0.12
0.11
0.11
0.10
0.11
0.11
0.00
0.11±0.02
0.45
0.45
0.52
0.53
0.47
0.55
0.54
0.56
0.50
0.54
0.55
0.53
0.47
0.50
0.37
0.58
0.53
0.52
0.50
0.52
0.51
0.48
0.51
0.53
0.49
0.51
0.49
0.48
0.52
0.53
0.50
0.52
0.37
0.62
0.52
0.56
0.49
0.49
0.51
0.05
0.36±0.05
11.2
7.9
10.4
8.4
7.0
8.7
9.0
8.6
8.5
9.1
9.1
14.8
8.0
8.1
9.4
10.4
8.1
8.0
8.0
8.6
8.3
9.5
7.5
8.6
7.9
8.4
8.8
7.8
8.9
10.8
8.6
8.1
7.6
8.7
9.1
10.1
8.5
11.9
9.0
1.0
8.8±0.9
34
QHSS quality control 22 August 2005
Aqueous QC samples (all values µg/L)
QHSS Lab code
Copper
Zinc
Arsenic
FWQC
FWQC
FWQCA
FWQC
FWQCB
FWQC
Certified values
10.44
10.44
10.72
10.00
51.88
53.40
54.40
50.00
19.87
19.23
19.51
20.00
FWQC
FWQC
FWQCA
FWQC
FWQCB
FWQC
Certified values
10.36
10.52
10.24
10.00
60.29
62.37
61.21
50.00
19.91
20.15
19.51
20.00
QC23
QC23
QC23A
QC23
QC23B
QC23
Certified values
9.48
9.52
9.40
9.7±1.9
19.49
20.69
21.89
11.1±3.4
7.87
7.83
7.67
8.4±1.6
QC23
QC23
QC23A
QC23
QC23B
QC23
Certified values
9.40
9.48
9.56
9.7±1.9
13.68
14.68
15.28
11.1±3.4
7.79
7.27
6.83
8.4±1.6
Selenium
Run 1
19.84
19.12
19.76
20.00
Run 2
19.98
20.78
19.10
20.00
Run 1
3.50
4.26
3.42
4.2±1.4
Run 2
3.40
3.56
2.68
4.2±1.4
Cadmium
Mercury
Lead
0.51
0.51
0.47
0.50
-0.17
2.79
2.51
***
10.49
12.45
12.81
10.00
0.51
0.51
0.55
0.50
0.14
0.30
0.54
***
10.22
9.58
9.42
10.00
2.51
2.47
2.51
2.6±0.68
0.10
0.14
1.30
****
3.74
3.58
3.38
3.8±0.93
2.47
2.39
2.43
2.6±0.68
-0.13
1.67
1.91
****
3.85
4.49
4.65
3.8±0.93
Spike recovery (all values µg/L)
QHSS Lab code
5TM2121
5TM2121T
% recovery
179693455
179693455SPK
5TM2171
5TM2171T
% recovery
179693956
179693956SPK
Copper
Zinc
Arsenic
251
454
92
1206
1436
105
0.39
20
100
84
296
97
1254
1508
115
0.75
21
103
Selenium Cadmium
Run 1
5.02
9.35
26
29
107
98
Run 2
5.48
3.07
28
23
113
99
Mercury
Lead
7.58
9.62
102
47
66
93
54
57
166
73
102
145
35
Replicates (all values µg/L)
Copper
QHSS Lab code
5TM2116
5TM2116R
5TM2124
5TM2124R
5TM2132
5TM2132R
5TM2139
5TM2139R
5TM2147
5TM2147R
5TM2155
5TM2155R
5TM2163
5TM2163R
5TM2171
5TM2171R
5TM2178
5TM2178R
179693400
179693400R
179693488
179693488R
179693562
179693562R
179693638
179693638R
179693716
179693716R
179693793
179693793R
179693876
179693876R
179693956
179693956R
179694029
179694029R
261
261
100
101
244
231
138
133
185
175
104
102
84
84
84
83
108
108
Zinc
907
907
1320
1310
1295
1223
1806
1738
1509
1437
1668
1635
1869
1843
1254
1268
843
841
Arsenic Selenium Cadmium
Repeats (within run)
0.43
5.46
2.07
0.23
4.62
2.07
-0.37
3.62
0.43
-0.33
3.86
0.47
0.59
5.78
2.87
0.27
5.18
2.71
0.95
9.78
18.43
0.55
7.90
17.67
0.11
7.62
0.75
0.47
8.06
0.67
1.91
4.20
1.11
1.95
4.72
1.11
-0.49
3.16
0.75
-0.49
3.04
0.75
0.75
5.48
3.07
0.71
5.08
3.03
2.35
3.92
0.95
2.31
3.88
0.95
Mercury
Lead
4.9
5.0
8.1
8.2
23
23
20
20
38
36
23
23
18
17
54
54
30
31
46
46
9.30
9.10
92
88
66
64
39
37
28
28
104
103
73
73
75
75
Arsenic Selenium Cadmium
Repeats (between runs)
0.19
2.42
0.35
-0.17
2.30
0.27
0.39
4.62
2.27
0.35
4.94
2.55
0.03
4.02
0.99
-0.09
4.22
0.75
0.99
9.86
3.23
1.99
10.54
3.35
0.91
7.94
1.63
1.67
9.62
2.15
Mercury
Lead
4.58
3.30
3.18
4.22
18
8
30
55
Replicates (all values µg/L)
QHSS Lab code
5TM2109
5TM2109B
5TM2117
5TM2117B
5TM2125
5TM2125B
5TM2133
5TM2133B
5TM2142
5TM2142B
Copper
Zinc
59
42
420
462
166
140
347
353
397
486
736
536
1269
1538
1350
1249
2462
2564
2398
2787
179693331
179693331B
179693411
179693411B
179693499
179693499B
179693571
179693571B
179693660
179693660B
9.78
8.50
9.22
9.94
11.66
14.38
43
65
75
66
38
44
QC NCS DC 73347 (Hair) (all values mg/kg)
QHSS Lab code
QCNCS1 QCNCS
QCNCS2 QCNCS2
QCNCS3 QCNCS3
QCNCS4 QCNCS4
QCNCS5 QCNCS5
QCNCS6 QCNCS6
QCNCS7 QCNCS7
QCNCS8 QCNCS8
Mean
sd
CV (Target)
Copper
10
11
14
16
11
10
10
10
11.26
2.08
10.6±0.7
Zinc
176
190
264
296
208
176
182
182
209.31
42.66
190±5
Arsenic
0.30
0.31
0.46
0.49
0.40
0.23
0.28
0.26
0.34
0.09
0.28±.04
Selenium
0.70
0.46
1.29
1.28
0.81
0.63
0.96
0.78
0.86
0.28
0.60±0.03
Cadmium
0.11
0.12
0.18
0.22
0.13
0.11
0.12
0.12
0.14
0.04
0.11±0.02
Mercury
0.39
0.48
0.78
0.81
0.62
0.65
1.08
0.87
0.71
0.21
0.36±0.05
Lead
7.24
6.28
18
16
7.33
9.33
11
12
10.97
4.05
8.8±0.9
36
QHSS quality control 22 May 2006
Digest Blanks (all values µg/L)
QHSS Lab
code
6TMDIGBLK1
6TMDIGBLK2
6TMDIGBLK3
6TMDIGBLK4
6TMDIGBLK5
6TMDIGBLK6
6TMDIGBLK7
sd
Method DL (3
X SD)
Reporting
Limit (3 X
MDL)
Copper
Zinc
Arsenic
Selenium
Cadmium
Mercury
Lead
0.315
0.322
0.343
0.312
0.314
0.318
0.306
0.011
0.033
-0.169
-0.199
-0.067
0.091
0.100
0.663
0.048
0.267
0.802
0.057
0.107
0.133
0.047
0.054
0.034
0.061
0.033
0.099
0.155
0.189
0.301
0.012
0.113
-0.001
0.205
0.100
0.300
0.053
0.059
0.067
0.044
0.035
0.041
0.046
0.010
0.030
0.158
0.119
0.102
0.084
0.071
0.068
0.063
0.032
0.095
0.029
0.026
0.012
0.015
0.013
0.022
0.014
0.006
0.019
0.099
2.407
0.296
0.899
0.091
0.285
0.058
Analytical blanks (all values µg/L)
QHSS Lab
code
BLK01
BLK02
BLK03
BLK04
BLK05
BLK01B
BLK02B
BLK03B
BLK04B
BLK05B
BLK01C
BLK02C
BLK03C
BLK04C
BLK05C
sd
Method DL
(3 X SD)
Reporting
Limit (3 X
MDL)
sd
Method DL
(3 X SD)
Reporting
Limit (3 X
MDL)
Copper
Zinc
Arsenic
Selenium
Cadmium
Mercury
Lead
0.323
0.324
0.329
0.337
0.317
0.340
0.326
0.321
0.317
0.321
0.400
0.352
0.341
0.331
0.326
0.020
0.060
0.199
0.260
0.174
0.177
-0.258
0.389
0.144
0.059
0.122
0.166
0.275
0.256
0.116
0.145
0.264
0.138
0.414
0.101
0.026
-0.049
0.116
-0.099
0.043
0.100
0.026
-0.081
-0.140
-0.018
0.041
-0.026
0.036
-0.151
0.082
0.247
0.162
0.036
0.135
0.082
0.025
0.048
0.308
0.129
0.044
0.189
0.257
0.173
-0.027
0.138
0.080
0.088
0.263
0.038
0.034
0.039
0.029
0.025
0.022
0.013
0.028
0.022
0.019
0.010
0.019
0.033
0.022
0.005
0.010
0.029
0.058
0.048
0.044
0.038
0.038
1.120
0.746
0.673
0.500
0.403
0.956
0.792
0.683
0.581
0.513
0.208
0.623
0.022
0.012
0.013
0.013
0.011
0.018
0.012
0.016
0.012
0.012
0.019
0.017
0.018
0.015
0.016
0.003
0.010
0.181
1.243
0.741
0.790
0.086
1.868
0.030
Low Hg
0.007
0.022
0.066
37
Method RL Based on 0.05 g sample with 0.1mL final volume (all values mg/kg)
sd
Method
DL (3 X
SD)
Reporting
Limit (3 X
MDL)
Copper
0.0022
0.0066
Zinc
0.0535
0.1604
Arsenic
0.0066
0.0198
Selenium
0.0200
0.0599
Cadmium
0.0020
0.0061
Mercury
0.0063
0.0190
Lead
0.0013
0.0038
0.0198
0.4813
0.0593
0.1798
0.0182
0.0570
0.0115
Reference standards (all values µg/L)
QHSS Lab
code
QCNCS1
QCNCS2
Expected
range
LEVEL19A
LEVEL19B
LEVEL20A
LEVEL20B
FWQC
FWQCA
FWQCB
FWQCC
Expected
range
TM24
TM24A
TM24B
TM24C
Expected
range
Copper
Zinc
Arsenic
Selenium
Cadmium
Mercury
Lead
9.647
8.832
9.4-11.8
212
196
181-199
0.285
0.238
0.23-0.33
0.737
0.659
0.56-0.64
0.129
0.114
0.08-0.14
0.370
0.383
0.28-0.44
9.585
8.851
7.7-9.9
48.0
47.6
9.7
9.8
10.7
8.9
9.4
9.4
10.0
51.3
52.0
10.8
11.0
57.2
47.9
51.4
51.7
50.0
51.3
52.3
10.6
10.6
22.4
19.2
19.8
19.8
20.0
51.2
52.6
10.2
10.3
22.7
19.9
20.3
21.4
20.0
52.1
51.8
10.5
10.5
0.4
0.6
0.5
0.5
0.5
4.8
5.1
1.1
1.4
-0.1
0.3
1.0
1.3
***
53.9
52.9
10.8
10.7
11.1
9.8
10.6
10.5
10.0
8.1
6.7
6.9
6.8
7.3±1.8
25.0
20.2
21.0
20.8
18.7±4.7
5.7
5.1
4.9
4.7
4.9±1.1
3.8
2.7
2.7
3.1
3.2±0.83
4.7
4.0
4.2
4.1
4.1±0.53
-0.1
0.0
0.8
1.0
**nv**
7.0
6.1
6.3
6.3
6.2±1.4
Selenium
Cadmium
Mercury
Lead
<2.0
<2.0
<2.0
<2.0
0.14
0.13
0.06
0.07
0.47
0.47
0.69
0.67
Replicates (all values mg/kg)
QHSS Lab
code
230894346
230894346R
230894453
230894453R
Copper
16.97
11.27
9.68
11.78
Zinc
225.12
173.74
186.72
187.22
Arsenic
<0.2
<0.2
<0.2
<0.2
2.05
2.11
1.82
1.93
Appendix 1
Ok Tedi Community Health Study 2007
QHSS analytical data for drinking water and recreational water
17 May 2007
Date
QHSS Lab
Client Ref
Region
Location
Sample
8/3/06
06NA2650
CHSW234/35
1C
Derengo
Filtered
8/3/06
06NA2652
CHSW236/37
1C
Derengo
Total
8/3/06
06NA2654
CHSW238/39
1C
Derengo
Total
23/3/06
06NA3809/10
CHS W260/61
1C
Derengo
Filtered
23/3/06
06NA3811/12
CHS W262/63
1C
Derengo
Total
23/3/06
06NA3813/14
CHS W264/65
1C
Derengo
Total
8/3/06
06NA2608
CHSW192/93
1C
Ok Ma
Filtered
8/3/06
06NA2610
CHSW194/95
1C
Ok Ma
Total
8/3/06
06NA2612
CHSW196/97
1C
Ok Ma
Total
23/3/06
06NA3807/8
CHS W258-59
1C
Ok Ma
Total
23/3/06
23/3/06
15/12/05
06NA3805/6
06NA3803/4
05NA8359
CHS W256/57
CHS W254/55
CHSW101
1C
1C
1I
OkMa
OkMa
Bultem*
Total
Filtered
Total
15/12/05
15/12/05
05NA8459
05NA8461
CHSW97
CHSW99
1I
1I
Bultem*
Bultem*
Filtered
Total
Sample
Description
Derengo DW
Pipe*
Derengo DW
Pipe*
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Recreational
Water
Tank water
Tank water
Recreational
Water
Tank Water
Tank Water
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
0.021
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.023
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.013
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.014
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.018
<0.005
<0.0002
<0.01
0.61
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.005
<0.005
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
<0.02
<0.02
<0.005
<0.005
<0.001
<0.001
< 0.005
< 0.005
<0.002
<0.002
<0.0002
<0.0002
<0.01
<0.01
<0.02
<0.02
3
Date
QHSS Lab
Client Ref
Region
Location
Sample
8/3/06
06NA2602
CHSW186/87
1I
Bultem*
Filtered
8/3/06
06NA2604
CHSW188/89
1I
Bultem*
Total
8/3/06
06NA2606
CHSW190/91
1I
Bultem*
Total
8/3/06
06NA2596
CHSW180/81
1I
Finalbin
Filtered
8/3/06
06NA2598
CHSW182/83
1I
Finalbin
Total
8/3/06
06NA2600
CHSW184/85
1I
Finalbin
Total
15/12/05
15/12/05
15/12/05
05NA8453
05NA8455
05NA8457
CHSW91
CHSW93
CHSW95
1I
1I
1I
Finalbin*
Finalbin*
Finalbin*
Filtered
Total
Total
8/3/06
06NA2614
CHSW198/99
2C
Songty V
Filtered
8/3/06
06NA2616
CHSW200/201
2C
Songty V
Total
8/3/06
06NA2618
CHSW202/203
2C
Songty V
Total
15/12/05
05NA8350
CHSW03
2C
Filtered
15/12/05
05NA8352
CHSW05
2C
15/12/05
05NA8354
CHSW07
2C
Songty
V*
Songty
V*
Songty
V*
Total
Total
Sample
Description
Bultem
Drinking water
pipe*
Bultem
Drinking
water, pipe*
Recreational
Water
Finalbin
Drinking water
pipe*
Finalbin
Drinking water
pipe*
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.022
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
0.006
<0.005
<0.005
<0.001
<0.001
<0.001
0.07
< 0.005
< 0.005
0.022
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.05
<0.02
<0.02
<0.005
<0.001
0.009
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.01
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
0.03
4
Date
QHSS Lab
Client Ref
Region
Location
23/3/06
06NA3825/26
23/3/06
Sample
CHS W276/77
2C
Songty V
Filtered
06NA3827/28
CHS W278/79
2C
Songty V
Total
23/3/06
06NA3829/30
CHS W280/81
2C
Songty V
Total
8/3/06
8/3/06
8/3/06
06NA2644
06NA2646
06NA2648
CHSW228/29
CHSW230/31
CHSW232/33
2C
2C
2C
Walawam
Walawam
Walawam
Filtered
Total
Total
23/3/06
23/3/06
23/3/06
06NA3815/16
06NA3817/18
06NA3819/20
CHS W266/67
CHS W268/69
CHS W270/71
2C
2C
2C
Walawam
Walawam
Walawam
Filtered
Total
Total
7/3/06
06NA2590
CHSW174/75
2I
Gre
Filtered
7/3/06
06NA2592
CHSW176/77
2I
Gre
Total
7/3/06
06NA2594
CHSW178/79
2I
Gre
Total
24/3/06
06NA3842/43
CHS W294/95
2I
Gre
Filtered
24/3/06
06NA3844/45
CHS W296/97
2I
Gre
Total
24/3/06
06NA3846/47
CHS W298/99
2I
Gre
Total
9/3/06
9/3/06
9/3/06
06NA2656
06NA2658
06NA2660
CHSW240/41
CHSW242/43
CHSW244/45
2I
2I
2I
Ieran
Ieran
Ieran
Filtered
Total
Total
23/3/06
23/3/06
06NA3821/22
06NA3823/24
CHS W272/73
CHS W274/75
2I
2I
Ieran
Ieran
Filtered
Total
Sample
Description
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank water
Tank water
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank water
Tank water
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.04
0.04
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.06
0.05
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.03
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.03
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.06
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.018
0.018
0.023
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.06
0.06
<0.02
<0.005
<0.005
<0.001
<0.001
< 0.005
< 0.005
<0.005
<0.005
<0.0002
<0.0002
<0.01
<0.01
0.03
<0.02
5
Date
QHSS Lab
24/3/06
06NA3848/49
24/3/06
24/3/06
24/3/06
Client Ref
Region
Location
Sample
CHS W300/301
2I
Ieran
Total
06NA3831/32
06NA3833/34
06NA3835/36
CHS W282/83
CHS W284/85
CHS W286/87
2I
2I
2I
Kwilok
Kwilok
Kwilok
Filtered
Total
Total
10/3/06
10/3/06
10/3/06
06NA2664
06NA2666
06NA2668
CHSW248/49
CHSW250/51
CHSW252/53
2I
2I
2I
Kwilok
Kwilok
Kwilok
Filtered
Total
Total
7/3/06
7/3/06
7/3/06
06NA2584
06NA2586
06NA2588
CHSW168/69
CHSW170/71
CHSW172/73
2I
2I
2I
Ningerum
Ningerum
Ningerum
Filtered
Total
Total
24/3/06
24/3/06
24/3/06
06NA3837/38
06NA3839/40
06NA3840/41
CHS W288/89
CHS W290/91
CHS W292/93
2I
2I
2I
Ningerum
Ningerum
Ningerum
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8356
05NA8368
05NA8375
CHSW09
CHSW11
CHSW13
3C
3C
3C
Buseki*
Buseki*
Buseki*
Filtered
Total
Total
8/3/06
8/3/06
8/3/06
06NA2620
06NA2622
06NA2624
CHSW204/205
CHSW206/207
CHSW208/209
3C
3C
3C
Buseki*
Buseki*
Buseki*
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8377
05NA8379
05NA8381
CHSW15
CHSW17
CHSW19
3C
3C
3C
Usokoff*
Usokoff*
Usokoff*
Filtered
Total
Total
Sample
Description
Recreational
Water
Tank water
Tank water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
DW Tank*
DW Tank*
Recreational
Water
Tank water
Tank water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
0.393
0.021
<0.0002
<0.01
0.09
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
0.007
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
<0.02
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
0.02
0.009
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
<0.02
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.036
0.036
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.09
0.09
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.008
0.008
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.09
0.09
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
1.1
1.2
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
1.3
1.3
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.03
0.03
6
Date
QHSS Lab
Client Ref
Region
Location
Sample
8/3/06
8/3/06
8/3/06
06NA2626
06NA2628
06NA2630
CHSW210/11
CHSW212/13
CHSW214/15
3C
3C
3C
Usokoff*
Usokoff*
Usokoff*
Filtered
Total
Total
15/12/05
05NA8391
CHSW29
3I
Filtered
15/12/05
05NA8393
CHSW31
3I
Total
Tank Water
<0.005
<0.001
0.009
<0.002
<0.0002
<0.01
0.14
15/12/05
05NA8395
CHSW33
3I
Total
<0.001
0.009
0.002
<0.0002
<0.01
0.14
06NA2638
CHSW222/23
3I
Filtered
Recreational
Water
Tank Water
<0.005
8/3/06
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.04
8/3/06
06NA2640
CHSW224/25
3I
Total
Tank Water
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
0.04
8/3/06
06NA2642
CHSW226/27
3I
Total
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
05NA8383
05NA8385
05NA8387
CHSW21
CHSW23
CHSW25
3I
3I
3I
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
<0.02
0.02
15/12/05
05NA8389
CHSW27
3I
Manda*
Total
<0.005
<0.001
0.033
0.002
<0.0002
<0.01
<0.02
8/3/06
8/3/06
8/3/06
06NA2632
06NA2634
06NA2636
CHSW216/17
CHSW218/19
CHSW202/21
3I
3I
3I
Manda*
Manda*
Manda*
Filtered
Total
Total
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
0.049
<0.005
<0.005
0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.03
0.03
<0.02
15/12/05
15/12/05
15/12/05
05NA8403
05NA8405
05NA8407
CHSW41
CHSW43
CHSW45
4C
4C
4C
Aewa*
Aewa*
Aewa*
Filtered
Total
Total
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
0.006
0.006
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.07
0.07
13/2/06
13/2/06
06NA2384
06NA2386
CHS W118/9
CHS W120/21
4C
4C
Aewa*
Aewa*
Filtered
Total
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
<0.005
15/12/05
15/12/05
15/12/05
Komovai
*
Komovai
*
Komovai
*
Komovai
*
Komovai
*
Komovai
*
Manda*
Manda*
Manda*
Sample
Description
Tank Water
Tank Water
Recreational
Water
Tank Water
<0.005
<0.005
<0.001
<0.001
0.009
0.009
<0.005
<0.005
<0.0002
<0.0002
<0.01
<0.01
0.09
0.09
Filtered
Total
Total
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.016
0.017
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.08
0.08
<0.02
<0.005
<0.001
0.024
<0.002
<0.0002
<0.01
<0.02
7
Date
QHSS Lab
Client Ref
Region
Location
Sample
15/12/05
06NA2388
CHS W122/23
4C
Aewa*
Total
15/12/05
15/12/05
15/12/05
05NA8397
05NA8399
05NA8401
CHSW35
CHSW37
CHSW39
4C
4C
4C
Kiru*
Kiru*
Kiru*
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8409
05NA8411
05NA8413
CHSW47
CHSW49
CHSW51
4I
4I
4I
Sapuka*
Sapuka*
Sapuka*
Filtered
Total
Total
13/2/06
13/2/06
13/2/06
06NA2390
06NA2392
06NA2394
CHS W124/25
CHS W126/27
CHS W128/29
4I
4I
4I
Sapuka*
Sapuka*
Sapuka*
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8415
05NA8417
05NA8419
CHSW53
CHSW55
CHSW57
4I
4I
4I
Sialowa*
Sialowa*
Sialowa*
Filtered
Total
Filtered
15/12/05
05NA8421
CHSW59
4I
Sialowa*
Total
15/12/05
05NA8423
CHSW61
4I
Sialowa*
Total
13/2/06
13/2/06
13/2/06
06NA2396
06NA2398
06NA2400
CHS W130/31
CHS W132/33
CHS W134/35
4I
4I
4I
Sialowa*
Sialowa*
Sialowa*
Filtered
Total
Filtered
13/2/06
06NA2402
CHS W136/37
4I
Sialowa*
Total
13/2/06
06NA2404
CHS W138/39
4I
Sialowa*
Total
15/12/05
05NA8425
CHSW63
5C
Abam*
Filtered
15/12/05
05NA8427
CHSW65
5C
Abam*
Total
Sample
Description
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Tank Water
Tank Water
Surface Water
(drinking)
Surface Water
(drinking)
Recreational
Water
Surface Water
(drinking)
Surface Water
(drinking)
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.005
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.12
0.12
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.11
0.11
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
0.014
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.05
0.05
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.03
< 0.005
< 0.005
0.007
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.02
0.23
0.23
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
0.03
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
0.03
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.013
0.014
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.24
0.24
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.013
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
0.023
0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.002
<0.0002
<0.01
<0.02
8
Date
QHSS Lab
Client Ref
Region
Location
Sample
13/2/06
06NA2406
CHS W140/41
5C
Abam*
Filtered
13/2/06
06NA2408
CHS W142/43
5C
Abam*
Total
15/12/05
15/12/05
15/12/05
05NA8429
05NA8431
05NA8433
CHSW67
CHSW69
CHSW71
5C
5C
5C
Kadawa*
Kadawa*
Kadawa*
Filtered
Total
Total
13/2/06
13/2/06
06NA2410
06NA2412
CHS W144/45
CHS W146/47
CHS W148/49
5C
5C
5C
Kadawa*
Kadawa*
Kadawa*
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8441
05NA8443
05NA8445
CHSW79
CHSW81
CHSW83
5I
5I
5I
Sagero*
Sagero*
Sagero*
Filtered
Total
Total
13/2/06
13/2/06
13/2/06
06NA2422
06NA2424
06NA2426
CHS W156/57
CHS W158/59
CHS W160/61
5I
5I
5I
Sagero*
Sagero*
Sagero*
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8447
05NA8449
05NA8451
CHSW85
CHSW87
CHSW89
5I
5I
5I
Tapila*
Tapila*
Tapila*
Filtered
Total
Total
13/2/06
13/2/06
13/2/06
06NA2428
06NA2430
06NA2432
CHS W162/63
CHS W164/65
CHS W166/67
5I
5I
5I
Tapila*
Tapila*
Tapila*
Filtered
Total
Total
13/2/06
13/2/06
13/2/06
06NA2416
06NA2418
06NA2420
CHS W150/51
CHS W152/53
CHS W154/55
5I
5I
5I
Wapi
Wapi
Wapi
Filtered
Total
Total
15/12/05
15/12/05
15/12/05
05NA8435
05NA8437
05NA8439
CHSW73
CHSW75
CHSW77
5I
5I
5I
Wapi*
Wapi*
Wapi*
Filtered
Total
Total
Sample
Description
Surface Water
(drinking)
Surface Water
(drinking)
Tank Water
Tank Water
Recreational
Water (sea)
Tank Water
Tank Water
Recreational
water (well)
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water
Tank Water
Tank Water
Recreational
Water (sea)
Tank Water
Tank Water
Recreational
Water
Arsenic
Cadmium
Copper
Lead
Mercury
Selenium
Zinc
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.001
< 0.005
<0.005
<0.0002
<0.01
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
0.064
0.066
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
<0.02
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.012
0.012
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.03
0.03
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
0.012
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.57
0.62
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
0.006
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
1
1
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.006
< 0.005
< 0.005
<0.002
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
<0.02
0.18
0.18
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
0.005
0.005
0.03
<0.005
<0.005
0.007
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.17
0.17
0.03
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
0.005
< 0.005
<0.005
<0.005
<0.005
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.09
0.09
<0.02
<0.005
<0.005
<0.005
<0.001
<0.001
<0.001
< 0.005
< 0.005
< 0.005
<0.005
<0.002
<0.002
<0.0002
<0.0002
<0.0002
<0.01
<0.01
<0.01
0.09
0.29
0.31
Appendix 2
Team Ferrari Ok Tedi Respirable Particle Air Sampling Study
April 2007
10
Respirable Particle Air Sampling
Study
For
Ok Tedi Mining Limited (OTML)
2004-2005
by
Len Ferrari
ENVIRONMENTAL
PO Box 43, South West Rocks NSW 2431
Ph: (02) 6566 5584, Mobile: 0429 929 365, e-mail:
[email protected]
11
EXECUTIVE SUMMARY
Respirable particle (PM10) and fine particle (PM2.5) levels were measured at 3 sites in the Ok
Tedi-Fly River area of PNG over 16 days of during the period December 2004 to December
2005 to determine the air quality impact from the Ok Tedi Mine. The sites selected were
Finalbin, the village closest to the mine pit, Ningerum and Gre, a village close to the Kiunga
port facility.The sites were intended to measure the population exposure to a range of likely air
pollutants from mine operations.
The airborne suspended particle mass concentrations measured as PM10 and PM2.5 did not
exceed the Australia Air Quality Standards at any time. In addition the concentrations of
airborne elemental inorganic contaminants were found to be at acceptable levels at all sites
throughout the sampling period.
Ion Beam analysis for over 20 inorganic elements was conducted on all samples and the
concentrations of the most significant elements: Fluoride, Vanadium, Manganese, Nickel,
Arsenic, Sulfide, Copper, Zinc and Lead, were investigated in detail. The study found the levels
of these elements to be at low to normal levels and well below the appropriate guidelines or
standards.
In summary the air quality study has shown that respirable particle concentrations of
PM10 and PM2.5 and all the elemental inorganics measured in the air in the vicinity of
the mine did not at any time exceed Australian Standards or World Health Organisation
goals. The 16 days of sampling could not be considered as comprehensive but it is
probable that the results found were fairly representative of other nearby villages.
12
TABLE OF CONTENTS
Executive Summary ……………………………………………………………………..……2
Table of Contents ……………………………………………………………………….…….3
List of Tables ………………………………………………………………………………….4
1
BACKGROUND …………………………………………………………………….5
2
2.1
2.2
2.2.1
2.2.2
2.2.3
2.3
2.4
THE STUDY ………………………………………………………………………... 5
Siting ………………………………………………………………………………….6
Instrumentation ………………………………………………………………….……6
Air Samplers …………………………………………………………………….……6
Ion Beam Analysis ……………………………………………………………….…...6
Met Station ……………………………………………………………………………6
Sampling ……………………………………………………………………….…......7
Analysis
……………………………………………………………………….…7
3
3.1
3.2
3.3
3.4
DATA AND RESULTS …..……………………………………………………......9
Fine Particulate Matter of diameter less than 2.5 μm (PM 2.5) ………………....…..9
Respirable Particulate Matter of diameter less than 10 μm (PM10) …………....…...9
Levels of Arsenic, Vanadium, Manganese, Nickel, Fluoride, Lead, Sulfide,
Copper and Zinc ………………………………………………………………..…11
Comparison of Maximum values and Standards/Guidelines ……………………...13
4
CONCLUSION ……………………………………………………………………….….…14
6
REFERENCES ……………………………………………………………….…...….……..15
7
APPENDIX …………………………………………………………………….…………...16
LIST OF TABLES
1
Elements Analysed by Ion Beam Analysis ………………………………………..…7
2
Results from all sites ………………………………………………………………….8
3
Subset of data showing error bars and MDLs ……………………………...……….10
4
Subset of data after adjusting for error bars and MDLs ……….………....…………12
5
Maximum daily concentrations of PM10 and PM2.5 and
elements in PM10 fraction Vs Guidelines/Standards ………………………………..13
13
RESPIRABLE PARTICLES AIR SAMPLING STUDY
Final Report
June 2006
This report provides the results of a study into the concentration and elemental constituents of
PM10 respirable particles (particles less than 10 μm in diameter) and fine PM 2.5 particles
(particles less than 2.5 μm in diameter) suspended in the air in an area impacted by the OTML
mine in PNG. Monitoring sites were selected in villages close to the mine and the port loading
facility. Sampling was carried out on 16 days during the period December 2004 to December
2005.
1. BACKGROUND
OTML operates a large open cut mine in the headwaters of the Ok Tedi in Western PNG. This
respirable particle study is the air component of a more extensive study for the OTML
Environment Department This study provides environmental data on ambient air quality while
other studies will provide data on drinking water, soils, and food.
The study of the air environment involves a survey of the particles suspended in air in areas
potentially impacted by the mine works. Particles less than approximately 10 μm (termed PM
10) and fine particles less than approximately 2.5 μm (PM 2.5) are inhaled by humans and pass
into the lower respiratory tract where they can be retained and affect persons with a disposition
to respiratory disease.
Particles are emitted from mining processes and stockpiles. Airborne dust is particularly
evident when vehicles move over unsealed roads. At elevated concentrations, these particles,
even if inert, can result in acute or chronic effects in humans. Strong winds, particularly when
the land is dry, have the potential to generate elevated levels of dust. However most of the
particles developed at mine sites are most likely to be in the size range greater than 10 μm and
are therefore considered more of a nuisance than a health hazard. Nuisance effects are
experienced when particles deposit on property and cause soiling.
The area where the mine is operating has a high and frequent rainfall. However as a
precautionary measure, OTML decided to investigate the concentration and constituents of
PM10 and PM 2.5 in areas that could potentially be impacted by the mine. Team Ferrari
Environmental was contracted to conduct the ambient air investigation commencing in
December 2004.
2. THE STUDY
2.1 Siting
The samplers operate by drawing air through filters to collect the fine particles and so they
represent the concentrations of suspended particles in the air surrounding them. The movement
of air passing over the sampling head determines the air that is sampled.. Sampling sites are
chosen so that, as far as possible, they are not unduly influenced by nearby extraneous sources.
In this study, sampling sites have been selected by Team Ferrari Environmental and OTML
Environment Department specialists so that they are generally representative of community
exposure to respirable particles. In most cases samples would provide reasonable representation
of the air breathed by persons living within at least 500 metres and probably this an appreciably
larger area.
14
2.2
Instrumentation
2.2.1
Air Samplers
Particles were collected by the ANSTO designed samplers using inlet cyclones to collect only
the particles less than a defined diameter, either 10µm (PM 10) or 2.5 µm (PM2.5). The sample
pump draws air through PTFE filters, contained in filter cassettes, for 24 hour periods at a flow
rate of approximately 22 L/min. measured by mass flow meters. The filter remains in the
cassette during sampling and in transit to prevent contamination. A parallel sampling system
was used to collect PM 10 and PM 10 - PM 2..5 particles.
Samplers were sited according to the Australian Standard AS2922 – Guide for the Siting of
Sampling Units.
2.2.2
Ion Beam Analysis (Cohen et. al 1993)
The samples collected on the PTFE filters were returned to ANSTO at Lucas Heights, Australia
for non-destructive ion beam analysis of elemental composition. The techniques used were:
• particle induced X-ray emission (PIXE) which can provide analysis of elements from
silicon to uranium
• particle induced gamma ray emission (PIGME) which can provide analysis of light
elements such as lithium, boron, fluoride, sodium, magnesium, aluminium and silica
• particle elastic scattering analysis (PESA) which can provide elemental analysis of light
elements such as hydrogen, carbon and nitrogen.
The limits of detection are in the range of 1 – 50 ng/m3 for most elements using a 4-minute
exposure to the ion beam. For the elements of interest in this study the detection limits were
generally in the range 1 – 3 ng/m3.
2.2.3
Met Station
A Davis Weather Monitor 11 meteorological station was used to monitor the meteorological
conditions at each site. The Weather Monitor complied with the specifications in the Australian
Standard AS 2923 – Guide for the Measurement of Horizontal Wind for Air Quality
Applications. The station measured and recorded hourly averages and maxima for : wind speed
and direction, relative humidity, dew point, temperature, rainfall and barometric pressure.
The station was located and operated beside the sampling instruments and stored the data on an
inbuilt data logger from which they were downloaded to a portable computer weekly. The
anemometer was installed on a 10-metre tower. The results from the meteorological station
were typical of that found in tropical areas with frequent rainfall and cool temperatures and
relatively low barometric pressure due to the elevation above sea level.
2.3
Sampling
The air quality study at OTML commenced on 8th December 2004 at Finalbin. The program
involved sampling at 3 sites consecutively for both a PM 10 - PM 2,5 coarse (C) fraction and a
PM 2,5 fine (F) fraction. Sampling equipment required 240-Volt power and was located and
15
operated by OTML personnel. At the Ningerum site there was no reticulated power so a
portable generator was used as a power source. The samplers were intended to operate for over
40 days but due to a number of factors, only 18 days sampling occurred.
The samples of the airborne particles were sent weekly to the Australian Nuclear Science and
Technology Organisation (ANSTO) for the Ion Beam non-destructive analysis.
2.4
Analysis
The samples sent to ANSTO were quantitatively analysed, by ion beam analysis, for 22
elements (Table 1).
TABLE 1. ELEMENTS ANALYSED BY ION BEAM ANALYSIS
Fluoride
Aluminium
Phosphorus
Chlorine
Calcium
Vanadium
Manganese
Cobalt
Copper
Bromine
Carbon
Sodium
Silicon
Sulfur
Potassium
Titanium
Chromium
Iron
Nickel
Zinc
Lead
Arsenic*
*Arsenic was not directly reported as the PIXE emission line lies near to the lead line and for
this study was always at a concentration less than the lead concentration.
. The results and shown in Table 2 below. Cmass represents the concentration of particle mass
collected
16
Of the parameters measured critical contaminants and markers of mine emisiions are
considered to be :
PM 2.5, PM 10, Arsenic, Vanadium,
Manganese, Nickel, Fluoride, Lead, Sulfide, Copper, and Zinc. These parameters are discussed
in more detail below.
3.
DATA AND RESULTS
The results for the critical contaminants in the study are displayed in Table 3 Subset of
Data for the coarse fraction (PM 10 - PM 2.5 ), the fine fraction (PM 2.5 ) and for the full
respirable fraction (PM 10). The total PM 10 fraction is the SUM of the first two
fractions.
Particles less than 2.5 μm in diameter are generally formed by chemical processes, often
combustion, while particles greater than 2.5 μm are commonly formed by mechanical
action such as wind action, vehicle tyre abrasion and associated updraught from mining
operations.
When analysing samples at low concentrations the instrument outputs have to be
adjusted to take account of the error bars on the analysis and the MDLs (minimum
detectible levels) for each individual component under the conditions of test.
3.1
Fine Particulate Matter of diameter less than 2.5 μm (PM 2.5 )
Table 3 displays the PM 2.5 mass concentration of all samples in ng/m 3 .
Note that 1000 ng/m 3 = 1 µg /m3.
The Advisory NEPM Reporting Level is 25 ug/m3 (i.e. 25000 ng/m 3) for a maximum
daily average and 8 ug/m3 for an annual average. This standard is considered by some
commentators to be relatively strict. The number of samples at Ok Tedi is insufficient
for an annual average assessment and therefore only the daily values are used for this
comparison.
Levels measured at all sites Finalbin, Ningerum and Gre did not exceed the Reporting
Level on any day of sampling. All values were less than half the Reporting Level of 25
ug/m3 for a daily maximum.
3.2
Particulate Matter PM 10 (the sum of the Fine and Course fractions)
Table 3 also displays the PM 10 mass concentration of all samples in ng/m 3 .
PM 10 concentrations are calculated by summing the fine and coarse fractions.
17
The NEPM Australian Standard level for PM10 is 50 μg/m3 (i.e. 50000 ng/m 3) for a
daily average not to be exceeded more than 5 days a year at any site. The annual mean
value is 25 µg/m3. The number of samples at Ok Tedi is insufficient for an annual
average assessment and therefore only the daily values are used for this comparison.
Levels measured at all sites Finalbin, Ningerum and Gre did not exceed the NEPM
Standard on any day of sampling. All values were less than half the Standard of 50
ug/m3 for a daily maximum.
3.3 . Levels of Arsenic, Vanadium, Manganese, Nickel, Fluoride, Lead, Sulfide, Copper
and Zinc.
Tables 3 shows the levels of individual results for the Vanadium, Manganese, Nickel,
Fluoride, Lead, Sulfide, Copper and Zinc at all sites together with the error bars and
MDLs. The arsenic readout using the PIXE technique is at the same wavelength as lead
and is masked by it. Arsenic levels are therefore less than the indicated lead levels.
In the majority of cases the levels determined for Vanadium, Manganese, Lead, Arsenic
and Nickel were less than the error bars and MDL ranges.
The Table 4 has been constructed by reporting only those values above the MDL and
error ranges of analysis. Where the reported values were below the MDL and error
ranges of analysis the entry is given as a “<” value. Arsenic levels are shown as less
than the Lead values. The large number of results show a “<” value indicating most
levels measured were very low and below or at the limits of detection.
The only values substantially above the limits of detection were the fluoride, sulfide,
copper and zinc levels, and the nickel levels at Gre.
Table 4 shows the data from Table 3 after adjusting for Errors and MDLs.
18
Table 4. Subset of Data after adjustment for Error bars and MDLs
Site
CMass
Date
Type
F
ng/m3
F
F
F
F
F
F
F
F
N
N
G
G
G
G
G
G
6395
5951
9008
6791
11679
9574
3594
5534
3341
9164
13352
6370
12110
7319
13393
7447
8/12/2004
12/12/2004
15/12/2004
19/12/2004
22/12/2004
26/12/2004
29/12/2004
2/01/2005
25/01/2005
2/02/2005
30/11/2005
4/12/2005
7/12/2005
11/12/2005
14/12/2005
17/12/2005
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
35.4
42.2
37.2
28.5
22.6
32
21.4
58.1
<30
41
22.1
<23
<21
13.2
25.3
<23
V
MN
ng/ ng/m3
m3
<2
<2
<8
1.3
<2
3.4
<2
1.7
<3
3.5
<5
<2
<2
1
<5
1.2
<3
1.7
<3
2.7
<3
1.5
<2
<1
<3
1.4
<3
1.1
<3
3.1
<2
<1
F
F
F
F
F
F
F
F
N
N
G
G
G
G
G
G
6665
5878
7400
7620
11224
6443
3482
4911
2405
5823
7931
5480
7527
8178
10160
5712
8/12/2004
12/12/2004
15/12/2004
19/12/2004
22/12/2004
26/12/2004
29/12/2004
2/01/2005
25/01/2005
2/02/2005
30/11/2005
4/12/2005
7/12/2005
11/12/2005
14/12/2005
17/12/2005
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
28
31.7
26.4
16.7
28.5
19
25.7
76.4
48.9
52.4
26.5
<23
31
25.6
30.9
<23
<2
<2
<2
<9
<3
<2
<2
<3
<2
<2
<3
<7
<2
<4
<7
<2
<2
<1
<2
1.1
<1
<1
<3
0.7
<2
<1
0.9
1.4
<1
1.2
<1
1.2
NI
PB
ng/m3 ng/m3
S
CU
ZN
ng/m3 ng/m3 ng/m3
AS
ng/m3
<2
<2
<2
<2
<2
<2
<1
<2
0.9
<2
3.7
3.8
3.5
4.4
4.4
3.9
<3
<3
<3
<5
<3
<2
<3
<1
<3
<2
<3
<2
<2
<3
<3
<7
57.7
65.7
60.2
94.3
180.5
78.7
48.3
42.2
40.8
39.9
57.1
46.6
76.6
43.3
54.1
39.7
3.6
5.1
5.8
5.1
4.1
2.2
1.9
3.6
0.2
1.1
5.8
6.2
48.4
1.4
10.9
1.1
1.1
1.5
1.1
2.2
4.1
4
1.5
1.4
0.8
1.3
1.2
<0.8
<2
1.1
1.6
0.7
<3
<3
<3
<5
<3
<2
<3
<1
<3
<2
<3
<2
<2
<3
<3
<7
<2
<2
<1
1.1
<2
<1
0.5
0.5
<1
0.7
4
5.3
3.3
6.1
3.8
5.3
<3 249.1
<3 269.9
<4 218.3
<3 506.6
<2 1153.3
<3 331.7
<2 137.2
<1
97.7
<3
136
<3
97.4
<7 104.6
<2 108.2
<2 113.8
<3 108.2
<2 115.3
<4
60.4
1.1
2.1
4.8
2.1
1.5
1
1.1
1.4
0.4
0.6
1.3
1.4
4.2
0.3
1.7
0.3
1.7
1.3
2.4
0.6
1.4
0.8
0.6
1
<0.8
0.9
<0.5
0.7
0.9
<1
1.2
0.5
<3
<3
<4
<3
<2
<3
<2
<1
<3
<3
<7
<2
<2
<3
<2
<4
19
Table 4. Subset of Data after adjustment for Error bars and MDLs (cont’d)
Site
CMass
Date
Type
F
F
F
F
F
F
F
F
N
N
G
G
G
G
G
G
13060
11829
16408
14411
22903
16017
7076
10445
5746
14987
21283
11850
19637
15497
23553
13159
8/12/2004
12/12/2004
15/12/2004
19/12/2004
22/12/2004
26/12/2004
29/12/2004
2/01/2005
25/01/2005
2/02/2005
30/11/2005
4/12/2005
7/12/2005
11/12/2005
14/12/2005
17/12/2005
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
PM10
3.4
F
ng/m3
V
MN
NI
PB
ng/ ng/m3 ng/m3 ng/m3
m3
63.4
<4
73.9 <10
63.6
<4
45.2 <11
51.1
<6
51.0
<7
47.1
<4
134.5
<8
<80
<5
93.4
<6
48.6
<6
<46
<9
<52
<5
38.8
<7
56.2 <10
<46
<4
<4
<3
<6
2.8
<5
<3
<4
1.9
<4
<4
2.4
<3
<3
<3
<4
<2
<4
<4
<3
<3
<4
<3
<2
<3
<2
<3
7.7
9.1
6.8
10.5
8.2
9.2
S
CU
ZN
ng/m3 ng/m3 ng/m3
<6 306.8
<6 335.6
<7 278.5
<8 600.9
<5 1333.8
<4 410.4
<5 185.5
<2 139.9
<6 176.8
<5 137.3
<10 161.7
<4 154.8
<4 190.4
<6 151.5
<5 169.4
<11 100.1
4.7
7.2
10.6
7.2
5.6
3.2
3.0
5.0
0.6
1.7
7.1
7.6
52.6
1.7
12.6
1.4
Comparison of Maximum values with Standards/Guidelines
Table 5 shows the maximum values reported at the three sites at Ok Tedi and the
relevant Australian Standards or WHO Guidelines. In all cases the levels measured are
well below the standards and guidelines.
Table 5. Maximum Daily Concentrations of PM10 and PM 2.5 and Elements in PM 10
fraction Vs Guidelines/Standards
Element
PM10 *
PM 2.5 #
Arsenic
Vanadium
Manganese
Nickel
Fluoride
Lead
Sulfide
Copper
Zinc
Standard /
Guideline
50 ug/m3 *
25 ug/m3 #
1000 ng/m 3
1000 ng/m 3
150 ng/m 3
1000 ng/m 3
1000 ng/m 3
500 ng/m 3
NA
NA
NA
INORGANICS in PM10 *
(ng/m3)
FINALBIN NINGARUM GRE
OTML
MAXIMUM
22.9
15.0 23.6
23.6
11.2
5.8 10.2
11.2
<8
<6
11
< 11
<11
<6
<10
< 11
<6
<4
<4
<6
<4
<3
11
11
135
93
56
135
<8
<6
11
< 11
1334
177
190
1334
11
1.7
53
53
5.5
2.2
2.8
5.5
Note:
Arsenic guideline is for a lifetime average risk of 1.5 deaths in a 1000 (World Health
Organisation - WHO)
2.8
2.8
3.5
2.8
5.5
4.8
2.1
2.4
<2
2.2
<1
<2
<3
<2
2.8
1.2
AS
ng/m3
<6
<6
<7
<8
<5
<4
<5
<2
<6
<5
<10
<4
<4
<6
<5
<11
20
Vanadium guideline is for a maximum daily average (WHO)
Manganese guideline is for an annual average (WHO)
Nickel is for a lifetime average risk of 3.8 deaths in a 10,000 (WHO)
Fluoride level – the WHO advises that this level should be sufficient to protect human health
Lead is for an annual average (NEPM)
* NEPM standard is Daily maximum
# NEPM reporting level is Daily Maximum
The levels of PM10 and PM2.5 measured at all sites were below 50 percent of the
Standard/Guidelines and the maximum inorganic elemental levels in the PM10 fraction
measured are only a small percentage of the level of concern. Levels of Arsenic,
Vanadium, Manganese, Nickel, and Lead were all below 5 percent of the
standard/guideline and only fluoride exceeded 10 percent of the standard/guideline at
13.5%.
These low concentrations indicate it is unlikely the standards/guidelines would be
exceeded for the inorganic elements in the villages at Finalbin, Ningerum and Gre at
any time.
The sulfide, copper and zinc are not of potential air quality concern and were measured
as markers for emissions from mine workings.
21
4
CONCLUSIONS
Fine particle (PM 2.5) and respirable particle (PM10) levels were measured at 3 sites at Ok Tedi
in PNG. Sampling produced 16 days of valid data from three villages – 8 days at Finalbin, 2
days at Ningerum and 6 days at Gre. This is far from a comprehensive data set but the very low
values recorded show the air quality, for the parameters measured, was well within the
appropriate standards/guidelines.
On occasions, particularly in dry and/or windy conditions, it is likely the particle concentrations
could exceed the PM 10 and PM 2.5 levels of concern.
Ion Beam analysis for over 20 elements was conducted on all samples and the concentrations of
the most significant elements Arsenic, Vanadium, Manganese, Nickel, Fluoride and Lead were
found to be at low to normal levels and far below the appropriate guidelines or standards.
These low concentrations make it unlikely the standards/guidelines would be exceeded for the
inorganic elements in the villages at Finalbin, Ningerum and Gre at any time.
6
REFERENCES
Cohen D.D, J.T. Noonman, D.B. Garton, E. Stelser, G.M. Bailey and E.P. Johnson, L.
Ferrari, R. Rothwell, J. Banks, P.T. Crisp, and R. Hyde, Clean Air, 27, 1993, pp15-22,
1993
Cohen D.D., J.L. Gras et al, 1995, Study of Fine Atmospheric Particles and Gases in the
Jakarta Region, Consultants Final Report 3, Physics Division ANSTO, Atmospheric
Research CSIRO, January 1998
22
Appendix 3
QHSS analytical data for village soils and riverine sediments
April 2007
Date
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
10/3/06
8/3/06
Village
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Ok Ma
Bultem
Bultem
Finalbin
Finalbin
Bultem
Bultem
Finalbin
Finalbin
Finalbin
Bultem
Bultem
Bultem
Bultem
Bultem
Finalbin
Finalbin
Finalbin
Finalbin
Songty V
Sample Type
Natural sediment
village soil
village soil
village soil
village soil
Village soil
Village soil
Village soil
village soil
Impact road
Impact road
Impact road
Impact road
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
village soil
village soil
village soil
village soil
Village soil
village soil
village soil
village soil
village soil
Active floodplain
OTML
sample ID
CHSSLSD96
CHSSLSD95
CHSSLSD97
CHSSLSD98
CHSSLSD99
CHSSLSD100
CHSSLSD101
CHSSLSD102
CHSSLSD103
CHSSLSD110
CHSSLSD111
CHSSLSD117
CHSSLSD118
CHSSLSD108
CHSSLSD109
CHSSLSD119
CHSSLSD120
CHSSLSD121
CHSSLSD104
CHSSLSD105
CHSSLSD106
CHSSLSD107
CHSSLSD112
CHSSLSD113
CHSSLSD114
CHSSLSD115
CHSSLSD116
CHSSLSD78
QHSS lab
code
06NA3902
06NA3901
06NA3903
06NA3904
06NA3905
06NA3906
06NA3907
06NA3908
06NA3909
06NA3916
06NA3917
06NA3923
06NA3924
06NA3914
06NA3915
06NA3925
06NA3926
06NA3927
06NA3910
06NA3911
06NA3912
06NA3913
06NA3918
06NA3919
06NA3920
06NA3921
06NA3922
06NA3884
Arsenic
Cadmium
6
10
<4
7
7
23
25
4
8
8
8
<4
<4
11
5
21
<4
<4
38
7
11
13
10
<4
<4
<4
<4
<4
0.5
0.4
< 0.4
0.4
0.6
0.8
1.1
< 0.4
< 0.4
< 0.4
0.5
< 0.4
< 0.4
0.6
0.6
0.4
< 0.4
< 0.4
1.1
0.7
1
0.8
0.5
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
25
38
8
150
120
150
150
19
42
31
28
67
130
100
89
61
110
130
33
140
14
150
23
180
200
110
180
46
Mercury
0.3
0.2
0.2
0.4
<0.2
0.4
0.3
0.3
0.5
0.3
0.2
0.8
0.6
0.4
<0.2
0.4
0.8
0.9
0.4
0.2
0.2
0.5
0.3
0.2
0.2
0.4
0.6
<0.2
Lead
12
27
7
21
30
72
54
17
21
11
17
14
13
54
22
52
8
9
32
22
23
59
15
14
13
9
11
9
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
69
100
33
210
120
330
230
290
380
65
83
23
39
160
65
170
36
36
150
550
110
150
190
100
150
39
43
89
24
Date
11/6/04
11/6/04
8/3/06
8/3/06
20/1/06
20/1/06
8/3/06
8/3/06
8/3/06
11/6/04
11/6/04
25/2/06
25/2/06
20/1/06
20/1/06
20/1/06
20/1/06
20/1/06
11/6/04
11/6/04
11/6/04
11/6/04
11/6/04
25/2/06
25/2/06
25/2/06
25/2/06
25/2/06
9/306
7/3/06
7/3/06
7/3/06
22/6/05
22/6/05
Village
Songty Valley
Songty Valley
Buseki
Buseki
Derengo
Derengo
Songty V
Songty V
Songty V
Songty Valley
Songty Valley
Walawam
Walawam
Derengo
Derengo
Derengo
Derengo
Derengo
Songty Valley
Songty Valley
Songty Valley
Songty Valley
Songty Valley
Walawam
Walawam
Walawam
Walawam
Walawam
Ieran
Ningerum
Ningerum
Ningerum
Gre
Gre
Sample Type
Active floodplain
Active floodplain
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
village soil
village soil
village soil
village soil
village soil
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Impact road
Impact road
OTML
sample ID
SONRS/01
SONRS/02
CHSSLSD82
CHSSLSD83
CHS-SLSD-30
CHS-SLSD-31
CHSSLSD79
CHSSLSD80
CHSSLSD81
SONFS/01
SONFS/02
CHS-SLSD-61
CHS-SLSD-62
CHS-SLSD-25
CHS-SLSD-26
CHS-SLSD-27
CHS-SLSD-28
CHS-SLSD-29
SONGS/01
SONGS/02
SONVS/01
SONVS/02
SONVS/03
CHS-SLSD-56
CHS-SLSD-57
CHS-SLSD-58
CHS-SLSD-59
CHS-SLSD-60
CHSSLSD92
CHSSLSD75
CHSSLSD76
CHSSLSD77
GREVS03
GREVS05
QHSS lab
code
04MG367
04MG368
06NA3888
06NA3889
06NA2348
06NA2349
06NA3885
06NA3886
06NA3887
04MG363
04MG364
06NA2379
06NA2380
06NA2343
06NA2344
06NA2345
06NA2346
06NA2347
04MG365
04MG366
04MG369
04MG370
04MG371
06NA2374
06NA2375
06NA2376
06NA2377
06NA2378
06NA3898
06NA3881
06NA3882
06NA3883
05NA4193
05NA4195
Arsenic
Cadmium
<4
<4
4
<4
<4
<4
<4
<4
<4
<4
<4
<4
8
4
<4
<4
<4
<4
<4
<4
<4
<4
<4
8
6
5
5
7
<4
<4
43
43
<4
<4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
2
2
< 0.4
< 0.4
Copper
78
74
18
21
160
160
49
37
26
73
66
22
55
170
210
140
140
130
65
60
53
52
63
67
69
42
47
72
38
20
2300
2300
11
27
Mercury
<1
<1
<0.2
<0.2
0.4
0.3
<0.2
<0.2
0.2
<1
<1
0.2
<0.2
0.4
0.3
0.4
<0.2
0.5
<1
<1
<1
<1
<1
0.4
0.3
<0.2
<0.2
0.3
<0.2
0.2
<0.2
<0.2
<1.0
<1.0
Lead
17
14
13
12
5
7
11
12
9
13
9
9
11
10
11
9
12
6
11
12
8
9
11
12
14
14
12
13
13
11
310
310
9
17
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<8
<8
<4
<4
Zinc
170
140
19
19
110
64
73
70
70
99
88
39
72
110
110
93
73
80
71
64
62
62
86
73
72
72
110
60
56
27
830
810
32
79
25
Date
7/3/06
7/3/06
7/3/06
16/5/05
16/5/05
7/3/06
7/3/06
7/3/06
22/6/05
7/3/06
9/3//06
7/3/06
7/3/06
7/3/06
7/3/06
22/6/05
22/6/05
22/6/05
22/6/05
22/6/05
9/3/06
9/3/06
9/3/06
9/3/06
9/3/06
9/3/06
9/3/06
16/5/05
16/5/05
16/5/05
7/3/06
Village
Gre
Gre
Gre
Kwiloknae
Kwiloknae
Kwiloknae
Ningerum
Ningerum
Ningerum T
Gre
Ieran
Kwiloknae
Kwiloknae
Ningerum
Ningerum
Gre
Gre
Gre
Gre
Gre
Ieran
Ieran
Ieran
Ieran
Ieran
Ieran
Ieran
Kwiloknae
Kwiloknae
Kwiloknae
Kwiloknae
Sample Type
Impact road
Impact road
Impact road
Impact road
Impact road
Impact road
Impact road
Impact road
Impact road
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
village soil
village soil
Village soil
village soil
village soil
village soil
village soil
village soil
village soil
Village soil
Village soil
Village soil
Village soil
Village soil
OTML
sample ID
CHSSLSD63
CHSSLSD64
CHSSLSD66
KWMP01
KWPG01
CHSSLSD67
CHSSLSD73
CHSSLSD74
NINVS01
CHSSLSD65
CHSSLSD94
CHSSLSD68
CHSSLSD69
CHSSLSD71
CHSSLSD72
GREVS01
GREVS02
GREVS04
GREVS06
GREGS01
CHSSLSD86
CHSSLSD87
CHSSLSD88
CHSSLSD89
CHSSLSD90
CHSSLSD91
CHSSLSD93
KWBB01
KWSC01
KWCG01
CHSSLSD70
QHSS lab
code
06NA3869
06NA3870
06NA3872
05NA4186
05NA4189
06NA3873
06NA3879
06NA3880
05NA4198
06NA3871
06NA3900
06NA3874
06NA3875
06NA3877
06NA3878
05NA4191
05NA4192
05NA4194
05NA4196
05NA4197
06NA3892
06NA3893
06NA3894
06NA3895
06NA3896
06NA3897
06NA3899
05NA4187
05NA4188
05NA4190
06NA3876
Arsenic
Cadmium
6
6
<4
4
5
<4
<4
<4
32
18
<4
<4
7
<4
<4
<4
<4
10
<4
<4
32
7
<4
4
<4
<4
23
<4
5
4
6
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
0.5
0.5
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
2.6
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
1.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
25
560
41
100
52
29
16
16
770
770
54
47
24
7
33
17
19
34
27
55
2000
330
54
120
29
36
1300
38
38
48
21
Mercury
0.2
0.2
<0.2
<1.0
<1.0
0.2
0.2
0.3
<1.0
<0.2
0.2
0.2
<0.2
0.4
0.3
<1.0
<1.0
<1.0
<1.0
<1.0
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
0.3
<1.0
<1.0
<1.0
<0.2
Lead
11
14
12
19
14
10
9
12
160
51
23
13
26
13
14
15
14
32
17
12
220
59
21
31
14
16
170
16
17
20
21
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
27
59
26
71
130
30
27
27
340
200
23
34
25
21
21
35
62
160
56
29
1000
200
71
130
40
100
550
58
100
64
24
26
Date
22/6/05
22/6/05
22/6/05
1/7/04
1/7/04
8/3/06
30/6/04
30/6/04
8/3/06
30/6/04
30/6/04
30/6/04
30/6/04
30/6/04
1/7/04
1/7/04
1/7/04
1/7/04
1/7/04
2/6/04
2/6/04
31/7/05
31/7/05
31/7/05
31/7/05
1/6/04
1/6/04
1/6/04
27/705
27/705
27/705
27/705
Village
Ningerum T
Ningerum T
Ningerum T
Usokof
Usokof
Usokoff
Buseki
Buseki
Usokoff
Buseki
Buseki
Buseki
Buseki
Buseki
Usokof
Usokof
Usokof
Usokof
Usokof
Manda
Manda
Manda
Manda
Manda
Manda
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Komovai
Sample Type
village soil
village soil
village soil
Active floodplain
Active floodplain
Active floodplain
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Natural sediment
OTML
sample ID
NINVS02
NINVS03
NINVS04
USOFS/01
USORS/01
CHSSLSD85
BUSFS/01
BUSRS/01
CHSSLSD84
BUSGS/01
BUSGS/02
BUSVS/02
BUSVS/03
BUSVS/01
USOGS/01
USOGS/02
USOVS/02
USOVS/03
USOVS/01
MANFS/01
MANRS/01
CHS-SLSD-17
CHS-SLSD-22
CHS-SLSD-23
CHS-SLSD-24
KOMFS/01
KOMRS/01
KOMVS/01
CHS-SLSD-14
CHS-SLSD-15
CHS-SLSD-16
CHS-SLSD-09
QHSS lab
code
05NA4199
05NA4200
05NA4201
04MG378
04MG381
06NA3891
04MG310
04MG313
06NA3890
04MG311
04MG312
04MG314
04MG315
04MG316
04MG379
04MG380
04MG382
04MG383
04MG384
04MG337
04MG340
06NA2335
06NA2340
06NA2341
06NA2342
04MG330
04MG333
04MG334
06NA2332
06NA2333
06NA2334
06NA2327
Arsenic
Cadmium
6
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
4
<4
7
<4
<4
<4
<4
<4
<4
20
4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
0.6
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
23
19
31
37
26
31
35
23
65
26
23
34
27
47
41
49
66
69
54
29
1200
20
20
21
18
40
38
21
20
14
14
20
Mercury
<1.0
<1.0
<1.0
<1
<1
0.2
<1
<1
0.2
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
0.3
0.2
0.2
0.3
<1
<1
<1
<0.2
<0.2
<0.2
0.2
Lead
16
16
12
11
11
11
14
11
12
10
8
12
11
16
29
13
14
15
22
10
130
10
7
9
9
13
13
10
10
18
10
9
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
24
32
63
72
30
29
96
35
96
36
14
68
33
58
45
43
55
59
160
26
510
37
30
33
29
24
48
19
14
120
10
12
27
Date
27/705
27/705
27/705
27/705
31/7/05
31/7/05
31/7/05
1/6/04
1/6/04
1/6/04
1/6/04
2/6/04
2/6/04
2/6/04
2/6/04
2/6/04
31/7/05
23/7/05
25/5/04
25/5/04
23/7/05
24/5/04
237/05
22/2/06
22/2/06
245/5/04
23/7/05
23/7/05
23/7/05
23/7/05
22/2/06
22/2/06
23/6/05
Village
Komovai
Komovai
Komovai
Komovai
Manda
Manda
Manda
Komovai
Komovai
Komovai
Komovai
Manda
Manda
Manda
Manda
Manda
Manda
Kiru
Aewe
Aewe
Aewe
Kiru
Kiru
Aewe
Aewe
Kiru
Kiru
Kiru
Kiru
Kiru
Kiru
Kiru
Kiru
Sample Type
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
OTML
sample ID
CHS-SLSD-10
CHS-SLSD-11
CHS-SLSD-12
CHS-SLSD-13
CHS-SLSD-19
CHS-SLSD-20
CHS-SLSD-21
KOMGS/01
KOMGS/02
KOMVS/02
KOMVS/03
MANGS/01
MANGS/02
MANVS/01
MANVS/02
MANVS/03
CHS-SLSD-18
CHS-SLSD-06
AEFS/01
AERS/01
CHS-SLSD-08
KIRFS/01
CHS-SLSD-07
CHS-SLSD-34
CHS-SLSD-35
KIRRS/01
CHS-SLSD-02
CHS-SLSD-03
CHS-SLSD-04
CHS-SLSD-05
CHS-SLSD-32
CHS-SLSD-33
CHS-SLSD-01
QHSS lab
code
06NA2328
06NA2329
06NA2330
06NA2331
06NA2337
06NA2338
06NA2339
04MG331
04MG332
04MG335
04MG336
04MG338
04MG339
04MG341
04MG342
04MG343
06NA2336
06NA2324
04MG303
04MG306
06NA2326
04MG323
06NA2325
06NA2352
06NA2353
04MG326
06NA2320
06NA2321
06NA2322
06NA2323
06NA2350
06NA2351
06NA2433
Arsenic
Cadmium
<4
5
5
6
5
<4
4
<4
<4
<4
<4
4
<4
5
<4
6
4
5
<4
<4
5
<4
5
7
6
<4
<4
<4
<4
12
<4
<4
<4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
20
12
14
12
22
20
23
24
24
20
32
49
39
39
52
46
22
11
23
26
20
23
35
11
10
22
15
11
14
19
13
15
10
Mercury
0.4
0.3
0.3
0.3
0.3
0.3
0.3
<1
<1
<1
<1
<1
<1
<1
<1
<1
<0.2
0.2
<1
<1
0.2
<1
0.2
0.3
0.2
<1
0.2
0.2
0.2
0.2
<0.2
<0.2
<0.2
Lead
9
11
9
8
11
10
9
11
8
9
9
15
14
15
20
18
10
10
16
15
11
11
11
10
6
11
27
9
14
13
8
9
14
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
21
20
27
20
37
36
41
15
21
18
20
34
32
55
21
26
32
7.9
73
35
10
58
44
13
12
51
67
70
22
16
20
46
52
28
Date
25/5/04
25/5/04
25/5/04
25/5/04
25/5/04
24/5/04
24/5/04
24/5/04
24/5/04
24/5/04
19/5/04
19/5/04
16/5/04
16/5/04
22/2/06
22/2/06
22/2/06
22/2/06
19/5/04
19/5/04
19/5/04
19/5/04
19/5/04
16/5/04
16/5/04
16/5/04
16/5/04
16/5/04
25/4//04
23/2/06
22/2/06
22/2/06
22/2/06
Village
Aewe
Aewe
Aewe
Aewe
Aewe
Kiru
Kiru
Kiru
Kiru
Kiru
Sapuka
Sapuka
Sialowa
Sialowa
Sapuka
Sapuka
Sialowa
Sialowa
Sapuka
Sapuka
Sapuka
Sapuka
Sapuka
Sialowa
Sialowa
Sialowa
Sialowa
Sialowa
Abam
Abam
Kadawa
Abam
Abam
Sample Type
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Active floodplain
Active floodplain
Active floodplain
Natural sediment
Natural sediment
OTML
sample ID
AEGS/01
AEGS/02
AEVS/01
AEVS/02
AEVS/03
KIRGS/01
KIRGS/02
KIRVS/01
KIRVS/02
KIRVS/03
SAPFS/01
SAPRS/01
SIAFS/01
SIARS/01
CHS-SLSD-36
CHS-SLSD-37
CHS-SLSD-38
CHS-SLSD-39
SAPGS/01
SAPGS/02
SAPVS/01
SAPVS/02
SAPVS/03
SIAGS/01
SIAGS/02
SIAVS/01
SIAVS/02
SIAVS/03
ABSE/01
CHS-SLSD-52
CHS-SLSD-55
CHS-SLSD-50
CHS-SLSD-51
QHSS lab
code
04MG304
04MG305
04MG307
04MG308
04MG309
04MG324
04MG325
04MG327
04MG328
04MG329
04MG349
04MG352
04MG356
04MG359
06NA2354
06NA2355
06NA2356
06NA2357
04MG350
04MG351
04MG353
04MG354
04MG355
04MG357
04MG358
04MG360
04MG361
04MG362
04MG299
06NA2370
06NA2373
06NA2368
06NA2369
Arsenic
Cadmium
7
7
6
10
10
5
<4
5
9
<4
<4
9
5
10
6
9
12
14
<4
<4
5
6
5
7
<4
9
6
<4
6
8
65
5
5
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
30
33
28
43
43
18
27
20
32
22
24
78
34
46
20
46
11
14
16
16
28
50
18
33
27
33
42
29
20
8
40
5
3
Mercury
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<0.2
<0.2
0.2
<0.2
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<0.2
<0.2
<0.2
<0.2
Lead
9
15
8
16
15
10
8
9
13
10
15
23
23
13
11
23
11
13
7
8
13
18
7
17
14
14
17
22
12
12
36
14
9
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
18
24
15
25
20
29
15
16
21
11
48
100
200
83
58
100
23
26
14
14
68
38
8.8
490
40
44
110
390
58
54
220
29
18
29
Date
Village
Sample Type
27/4/04
22/2/06
22/2/06
25/4//04
25/4//04
25/4//04
25/4//04
25/4//04
28/4//04
28/4/04
28/4/04
28/4/04
28/4/04
7/5/04
22/2/06
13/5/04
22/2/06
22/2/06
22/2/06
22/2/06
22/2/06
22/2/06
22/2/06
22/2/06
22/2/06
7/5/04
7/5/04
7/5/04
7/5/04
13/5/04
13/5/04
13/5/04
13/5/04
13/5/04
Kadawa
Kadawa
Kadawa
Abam
Abam
Abam
Abam
Abam
Kadawa
Kadawa
Kadawa
Kadawa
Kadawa
Sagero-Koa
Sagero-Koa
Tapila
Tapila
Wapi
Wapi
Sagero-Koa
Sagero-Koa
Tapila
Tapila
Wapi
Wapi
Sagero-Koa
Sagero-Koa
Sagero-Koa
Sagero-Koa
Tapila
Tapila
Tapila
Tapila
Tapila
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Active floodplain
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Natural sediment
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
Village soil
OTML
sample ID
KARS/01
CHS-SLSD-53
CHS-SLSD-54
ABGS/01
ABGS/02
ABVS/01
ABVS/02
ABVS/03
KAGS/01
KAGS/02
KAGS/03
KAVS/01
KAVS/02
SAGRS/01
CHS-SLSD-47
TASE/01
CHS-SLSD-42
CHS-SLSD-43
CHS-SLSD-44
CHS-SLSD-48
CHS-SLSD-49
CHS-SLSD-40
CHS-SLSD-41
CHS-SLSD-45
CHS-SLSD-46
SAGGS/01
SAGGS/02
SAGVS/01
SAGVS/02
TAGS/01
TAGS/02
TAVS/01
TAVS/02
TAVS/03
QHSS lab
code
04MG317
06NA2371
06NA2372
04MG297
04MG298
04MG300
04MG301
04MG302
04MG318
04MG319
04MG320
04MG321
04MG322
04MG347
06NA2365
04MG374
06NA2360
06NA2361
06NA2362
06NA2366
06NA2367
06NA2358
06NA2359
06NA2363
06NA2364
04MG344
04MG345
04MG346
04MG348
04MG372
04MG373
04MG375
04MG376
04MG377
Arsenic
Cadmium
34
10
10
7
6
<4
4
<4
6
6
64
66
7
10
45
6
6
49
44
49
51
9
7
49
52
8
7
6
7
6
8
19
7
7
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
27
13
12
17
27
5
16
5
28
26
88
51
27
44
18
24
16
23
18
21
23
15
14
21
23
36
34
36
40
30
59
40
39
23
Mercury
<1
<0.2
<0.2
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
0.2
<1
<0.2
<0.2
0.3
0.2
0.2
<0.2
<0.2
0.2
0.3
<1
<1
<1
<1
<1
<1
<1
<1
<1
Lead
11
13
10
12
12
4
11
5
11
10
51
39
11
15
26
11
15
28
26
29
31
7
9
28
30
13
13
12
14
14
21
10
17
7
Selenium
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
<4
Zinc
79
100
99
20
90
6
48
9.6
78
77
320
130
89
79
160
44
65
250
160
170
160
56
49
170
160
75
65
72
80
140
97
82
98
72
30
Date
5/5/04
5/5/04
5/5/04
5/5/04
5/5/04
Village
Wapi
Wapi
Wapi
Wapi
Wapi
Sample Type
Village soil
Village soil
Village soil
Village soil
Village soil
OTML
sample ID
WAGS/03
WAGS/04
WASE/05
WAVS/01
WAVS/02
QHSS lab
code
04MG385
04MG386
04MG387
04MG388
04MG389
Arsenic
Cadmium
41
30
19
35
39
< 0.4
< 0.4
< 0.4
< 0.4
< 0.4
Copper
62
49
56
59
64
Mercury
<1
<1
<1
<1
<1
Lead
33
23
25
31
34
Selenium
<4
<4
<4
<4
<4
Zinc
160
120
130
150
180

- Ok Tedi Mining Limited

Transcription

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