Loppuraportti - Itä

Transcription

Loppuraportti - Itä

UNIVERSITY OF EASTERN FINLAND
DEPARTMENT OF ENVIRONMENTAL SCIENCE
Fine particle and aerosol technology laboratory
PL 1627 70211 KUOPIO
Physicochemical and toxic properties of
particulate emissions from different
small-scale wood combustion appliances
TEKES Project 40296/07, Final Report
Jarkko Tissari (Ed.)
2/2011
ITÄ-SUOMEN YLIOPISTON YMPÄRISTÖTIETEEN LAITOKSEN JULKAISUSARJA
PUBLICATION SERIES OF DEPARTMENT OF ENVIRONMENTAL SCIENCE
UNIVERSITY OF EASTERN FINLAND
YMPÄRISTÖTIETEEN LAITOS, ITÄ-SUOMEN YLIOPISTO
DEPARTMENT OF ENVIRONMENTAL SCIENCE, UNIVERSITY OF EASTERN FINLAND
PO Box 1627, FI-70211 KUOPIO, FINLAND
ISSN 1799-1676
PREFACE
3
PREFACE
This work is the final report of the research project ”Particle emissions from small-scale
wood combustion appliances: chemical-toxicity model” (Polttotekniikaltaan erilaisten puun
pienpolttolaitteiden hiukkaspäästöt ja terveys: kemia-toksisuusmalli) which is a part of the
“Finnish-Austrian collaborative project on small-scale biomass combustion: physicochemical
and toxic properties of particulate emissions”. The combustion experiments for this study
were done at the University of Eastern Finland (previously University of Kuopio), Department of Environmental Science, Fine Particle and Aerosol Technology Laboratory (FINE), in
Kuopio between the November 2008 and May 2009 in close cooperation with National Institute for Health and Welfare (THL), Department of Environmental Health (Kuopio) and Finnish Meteorological Institute (FMI), Aerosol Research Group (Helsinki).
The research partners in the project and the representatives of the organizations in the management committee were: Prof. Jorma Jokiniemi (responsible leader of the project), Ph.D.
Jarkko Tissari (secretary of the management committee, 1.1.2008-31.8.2008 and 29.8.200930.4.2011) and M.Sc. Kati Nuutinen (secretary of the management committee, 1.9.200828.8.2009), University of Eastern Finland, Prof. Maija-Riitta Hirvonen and Doc. Raimo O.
Salonen, National Institute for Health and Welfare, Prof. Risto Hillamo, Finnish Meteorological Institute, Marjatta Aarniala, The Finnish Funding Agency for Technology and Innovation
(TEKES), Juha Timonen (chair of the management committee), Tulikivi Ltd, Martti Romu,
Wienerberger Ltd, Antti Hirvelä, Bet-Ker Ltd, Johannes Uusitalo, NunnaUuni Ltd, Timo
Määttä, Motiva Ltd, Mervi Sihvonen, Turun Uunisepät Ltd, Jari Valtonen, Narvi Ltd, Leena
Siltaloppi (1.1.2008-31.12.2009) and Kauko Isomöttönen (1.1.2010-30.4.2011), Vapo Ltd, Kauko Janka (1.1.2008-31.12.2009) and Ville Niemelä (1.1.2010-30.4.2011), Dekati Ltd and Katja
Outinen (8.11.2010-30.4.2011), Ministry of the Environment. Finnish-Austrian collaborative
project was executed with Bioenergy2020+ in Graz with Prof. Ingwald Obernberger and Dr.
Thomas Brunner.
Also several scientists contributed to the project: Heikki Lamberg, Olli Sippula, Annika
Hukkanen, Terhi Penttilä, Jarno Ruusunen, Mika Ihalainen, Tommi Karhunen and Pentti
Willman (University of Eastern Finland), Maija Tapanainen, Pasi Jalava, Mikko Happo, Pasi
Hakulinen and Jorma Mäki-Paakkanen (National Institute for Health and Welfare) and Karri
Saarnio, Anna Frey, Kimmo Teinilä and Minna Aurela (Finnish Meteorological Institute).
On behalf of the project group, I am grateful to TEKES and manufacturers the funding of the
project. Also contributions of all project partners, management committee and especially
writers of this report (Heikki Lamberg, Maija Tapanainen, Karri Saarnio and Anna Frey) are
gratefully acknowledged.
Kuopio, June 2011
Jarkko Tissari
CONTENT
5
Content
1
BACKGROUND ................................................................................................. 7
2
PHYSICOCHEMICAL PROPERTIES OF PARTICULATE EMISSIONS ... 9
2.1 EXPERIMENTAL SET-UP ............................................................................................. 10
2.1.1
Combustion appliances, operation and fuels .......................................... 10
2.1.2
Emission measurements ............................................................................ 11
2.1.3
The FMI’s emission measurements .......................................................... 11
2.2 EXPERIMENTAL PERIODS .......................................................................................... 12
2.3 RESULTS OF FINE LABORATORY MEASUREMENTS ..................................................... 13
2.3.1
The gaseous emissions............................................................................... 13
2.3.2
The particle mass emission factors ........................................................... 14
2.3.3
The particle number emission and number size distributions .............. 15
2.3.4
Particle chemical composition .................................................................. 15
2.3.5
The PAH emissions .................................................................................... 16
2.4 RESULTS OF FMI MEASUREMENTS ............................................................................ 18
2.4.1
Particulate mass ......................................................................................... 18
2.4.2
Water-soluble organic carbon........................................................................ 18
2.4.3
Wood combustion tracers .............................................................................. 18
2.4.4
Inorganic ions ............................................................................................... 19
2.4.5
Organic ions ................................................................................................. 19
2.4.6
Size distributions .......................................................................................... 20
3
TOXICOLOGICAL RESPONSES INDUCED BY PARTICLES.................. 21
3.1 INTRODUCTION ........................................................................................................ 21
3.1.1
The role of macrophages and epithelial cells in immune response
against inhaled particles ........................................................................................... 21
3.1.2
Toxicological analysis ................................................................................ 21
3.2 MATERIALS AND METHODS ...................................................................................... 22
3.2.1
Sample preparation.................................................................................... 22
3.2.2
Study design of toxicological analyses ..................................................... 22
3.3 RESULTS ................................................................................................................... 22
3.3.1
Cell death and other changes in the normal cell cycle ............................ 22
3.3.2
Production of the inflammatory mediators (TNF- , MIP-2 and IL-6)... 23
3.3.3
DNA damage.............................................................................................. 23
3.4 DISCUSSION ............................................................................................................. 24
3.4.1
Relative toxicological responses ............................................................... 24
3.4.2
The effect of chemical composition on particle-induced toxicological
properties ................................................................................................................... 26
4
SUMMARY AND CONCLUSIONS .............................................................. 27
LITERATURE ................................................................................................................... 31
APPENDIXES .................................................................................................................... 35
1. BACKGROUND
1
7
BACKGROUND
Fine particles (PM2.5: Particle Mass below aerodynamic size of 2.5 µm) are one of the most
important pollutant in outdoor air (Pope and Dockery, 2006). The impact of airborne particles on health is very varied, ranging from causing mild, short-lived symptoms to contributing to the onset or worsening of chronic conditions and premature death (Dockery et al.,
1993; Kappos et al., 2004; Salonen and Pennanen, 2007). A safe threshold level for fine particle
concentrations in urban air cannot yet be determined (WHO, 1994). Current level of thoracic
(PM10) and fine particles are associated with about 350 000 premature annual deaths in Europe (Directive 2008/50/EC), hospital admission, and restricted activity in tens of millions of
children and subjects with chronic cardiovascular and pulmonary disease (WHO 2003; 2005;
U.S. EPA, 2004).
Residential wood combustion (RWC) for heat production has been assessed to be a major
source of fine particle mass emissions, particulate polyaromatic hydrocarbons (PAHs) and
certain gaseous pollutants such as volatile organic compounds (VOCs) throughout Europe
(e.g. Olsson et al., 1997; Christensen et al., 1998; Salonen and Pennanen, 2007). In Finland, the
main source of fine particles is long-range transport, whereas traffic, energy plants, industrial processes and residential wood combustion (RWC) are the most important stationary
emission sources. A recent study reported that RWC accounted for 25% of the stationary
combustion emissions in Finland in 2000, based on primary PM2.5 (Karvosenoja et al., 2008).
On the other hand, it has been estimated that RWC can produce locally as much as 20–90% of
the wintertime fine particle emissions (Muhlbaler Dasch, 1982; Boman et al., 2003a). According to an EU agreement, the use of renewable energy in Finland has to increase from 28% to
38% by 2020. This also requires an increase in all kinds of wood energy.
The emissions from RWC have been demonstrated to be highly variable (Nussbaumer,
2003; Johansson et al., 2003; 2004; Sippula et al., 2007a; Tissari et al., 2005; 2007a; 2009). In
small combustion units, the local atmosphere and temperature vary considerably depending
on the grate and burner. There are also many different uncontrolled factors that also affect
the combustion conditions. For example, numerous types and models of wood combustion
appliances are in use, and wood fuel can originate from several tree species. The operational
practices (e.g., fuel seasoning, combustion patterns, combustion rates, kindling approaches
etc.) of RWC also vary widely. Based on the several previous studies, primary factors that
affect the emissions are relatively well-known (e.g. Hedberg et al., 2002; Johansson et al., 2004;
Koyuncu and Pinar, 2007; Tissari et al., 2007b; Sippula et al., 2007a). Recent results show that
the poor operational practice (smouldering combustion) increases the fine particle emissions
remarkably (Tissari et al., 2008a; Hytönen et al., 2009). In addition, the portion of organic fraction, emissions of PAH compounds and genotoxicity of particles increases (Tissari et al.,
2008a; Frey et al., 2008; Hytönen et al., 2009; Jalava et al., 2010a). In complete combustion conditions (e.g. pellet boiler) the the fine particles composed mainly of alkali metal compounds.
In modern masonry heaters, fine particles include also organic and elemental carbon, which
are the main compounds in conventional appliances such as sauna stoves (Tissari et al., 2009).
Primarily due to their health effects, there is a need to decrease the particle and gaseous
emissions from wood combustion in small scale appliances. Because the mechanisms of the
health effects are not yet known exactly, studying both fine particle physical and chemical
properties is important (Lightly et al., 2000). These properties (e.g. particle size and morphology, number and mass concentration, chemical composition) are dependent on combustion
conditions. However, there has been lack in the knowledge concerning fine particle emis-
8
Physicochemical and toxic properties of particulate emissions from RWC
sions from masonry heaters and sauna stoves and their composition during different combustion conditions. Especially, the health related emissions (e.g. PAHs) and toxicological
properties of fine particles have not been well-known. In addition, there is need to knowledge of effects of fine ash particles from complete combustion conditions on health. Thus,
there is actual need to get detailed information from the particle and gas emissions and their
connection to health responses from small scale appliances.
In this study, physicochemical and toxicological properties of particulate emissions were
widely studied from RWC appliances. The study concentrated the experiments in different
type of masonry heaters, a sauna stove and a pellet boiler. The measurements were performed extensively from different combustion conditions with taking the samples during
different combustion phases (firing, gasification) as well as during the whole combustion
cycle and continuous, complete combustion (pellet boiler).
2. PHYSICOCHEMICAL PROPERTIES OF PARTICULATE EMISSIONS
2
9
PHYSICOCHEMICAL PROPERTIES OF PARTICULATE EMISSIONS
Heikki Lamberg1, Jarkko Tissari1, Kati Nuutinen1, Annika Hukkanen1, Terhi Penttilä1, Jarno Ruusunen1, Mika Ihalainen1, Tommi Karhunen1, Pentti Willman1, Jorma Jokiniemi1,2
1University of Eastern Finland, Department of Environmental Science, Fine particle and aerosol technology laboratory, Kuopio, Finland
2VTT Technical Research Centre of Finland, Fine Particles, Espoo, Finland
Karri Saarnio, Anna Frey, Kimmo Teinilä, Minna Aurela, Risto Hillamo
Finnish Meteorological Institute, Aerosol Research Group, Helsinki, Finland
The combustion tests for this study were done at the Fine Particle and Aerosol Technology Laboratory, University of Eastern Finland, in Kuopio (previously University of Kuopio).
The measurement campaign was done between the November 2008 and May 2009. In the
following chapters the combustion tests are generally described.
Figure 1. Experimental setup.
10
2.1
EXPERIMENTAL SET-UP
2.1.1 Combustion appliances, operation and fuels
Seven different small-scale combustion appliances that can be used in households were
tested. Combustion appliances tested here can be divided into three appliance categories:
masonry heaters, sauna stoves and pellet boilers. Four of these appliances were conventional
masonry heaters, one modern masonry heater, a sauna stove and a pellet boiler. Modern masonry heater differs from the conventional ones by its air-staging procedure; combustion air
in conventional masonry heaters is led through the grate and through the door in the conventional technology, where as in the modern combustion technology only part of the combustion air is led in through the grate and most of the air is led to the flame above the fuel
bed. The pellet boiler used in the tests also applied air-staging.
Table 1. Description of the combustion situations, appliances, sampling times and fuel. About 200 g
of kindling were used in the ignition in every combustion test. EFC, IBC, CBC1, CBC2, CBC3, IEBC
include cycle with batch additions and ignition phases, which also take place in normal operation.
IBC/34, CBC2/F, CBC3/23 and IEBC/S include specific combustion situations that take place within
the cycles.
EFC
IBC
IBC/34
CBC1
CBC2
CBC2/F
CBC3
CBC3/23
CBC4
IEBC
IEBC/S
Description of
situations
Combustion
appliance
Collection time
Batch and fuel
Experiment 1,
4 tests
Efficient
combustion
Pellet boiler
Continuous combustion,
2–3h
Commercial wood pellet
Experiment 2,
3 tests
Improved batch
combustion
Modern masonry
heater
Experiment 3,
3 tests
Conventional
batch
combustion
Conventional
masonry heater 1
Experiment 4,
3 tests
Conventional
batch
combustion
Conventional
masonry heater 2
Experiment 5,
3 tests
Conventional
batch
combustion
Conventional
masonry heater 3
Experiment 6,
3 tests
Conventional
batch
combustion
Conventional
masonry heater 4
Cycle, 50 min
1 batch 7x1 kg +
5x200g
Experiment 7,
3 tests
Inefficient batch
combustion
Sauna stove
Cycle, 55 min
Ignition batch and 2.
batch, 20–35 min
1. batch 5x0.31 kg,
2. batch 6x0.53 kg,
3. batch 5x0.64 kg
Cycle, 120 min
3. and 4. batch, 50 min
Cycle, 55 min
Cycle, 140 min
Firing phase, beginning of
the 2. batch, 15 min
Cycle, 65 min
2. and 3. batches, 40 min
1. batch 10x400g, other
batches 4x1 kg
1. batch 7x0.23 kg,
other batches 5x0.48 kg
1. batch 3x1 kg, other
batches 3x1.3 kg
1. batch 7x0.43 kg,
other batches 4x0.75 kg
Each of the combustion appliances was used according to manufactures’ operation manual. In every combustion test, the appliances were kept at room temperature and they were
left to cool down after each test. An ignition batch, described in Table 1, was set on the bottom of the appliance’s fire chamber, and 200 g of wood stick and chippings were placed on
top of wood logs as kindling to ensure sufficient start-up. The batch was ignited from top
with matches.
Birch wood was used in all of the log fuelled appliances with varying sizes of log batches,
and commercial wood pellet was used in the pellet boiler. Primary pellet raw material was
pine. Logs were relatively dry since it was stored inside before the tests; the moisture content
was approximately 10-13% and 8% in the pellet fuel.
11
2.1.2 Emission measurements
Each combustion appliance was attached to about 3 m high chimney (Figure 1). Flue gases
were led outside through a hood using a flue gas fan. Gaseous emissions (CO, NOX, OGC,
O2, HxCy, etc.) were measured in the hot flue gas with two gas analyzers: ABB fas analyzer
(Hartman&Braun) and FTIR gas analyzer (Gasmet Oy). Fine particle samples were taken
from a chimney and diluted with three different dilution systems. 1) Particle sample for
chemical (ions, polyaromatic hydrocarbons (PAH)) and toxicological analyzes was diluted
with porous tube diluter (PRD). Sample was collected with a Dekati Gravimetric Impactor
(DGI, Dekati Inc.). Toxicological analyzes were done at the National Institute for Health and
Welfare from this sample. 2) Particle samples for OC/EC analyzes and mass-size distribution
(Dekati Low Pressure Impactor (DLPI), Dekati Oy) were diluted with porous tube diluter
and ejector diluter (PRD+ED). In dilution systems 1 and 2, dilution air was dry and particle
free, and the flow was controlled with a mass flow controller. 3) A heated sample line transported part of the flue gas to a dilution tunnel. Dilution air for dilution tunnel was room air
from the laboratory, which was filtered for particles, OGC and NOX. Dilution ratio (the
amount of dilution) was calculated from the difference of CO2 concentration in raw flue gas
and in diluted sample. Finnish Meteorological Institute made their sampling in the dilution
tunnel. Online particle measurement devices Electrical Low Pressure Impactor (ELPI, Dekati
Oy) and Fast Mobility Particle Sizer (FMPS, TSI Inc.) measured particle number-size distributions in the dilution tunnel. In addition, temperatures of the flue gas and the diluted samples
were measured with type-K thermometer. Because dilution is known to have effects on particle properties, the dilution ratio of dilution system 1) and 2) were kept approximately same
in each test to keep the samples well comparable with each other.
Organic carbon and elemental carbon were analyzed from quartz filter using a Carbon
Aerosol Analyzer from Sun Laboratories Inc. Concentrations of major inorganic ions (Cl-,
NO3-, SO42-, Na+, NH4+, K+, Mg2+, and Ca2+) were analyzed using two Dionex ICS-2000 (Dionex
Corporation, Sunnyvale, CA, USA) ion chromatography systems. Twelve different elements
(Al, As, Cd, Co, Cu, Cr, Pb, Mn, Ni, Fe, Zn and V) were analyzed with an ICP-MS (Perkin
Elmer Sciex Elan 6000, Perkin-Elmer Corp., Waltham, MA, USA). Polyaromatic hydrocarbons (PAH) compounds in particulate matter samples were identified and quantified comparing against a mixture of standard compounds comprising of 30 commercially available
PAHs.
2.1.3 The FMI’s emission measurements
The FMI Aerosol Research group participated in the emission measurements of the pellet
boiler (Experiment 1, Table 1), of the sauna stove (Experiment 7, Table 1) and in those of one
conventional masonry heater (Experiment 5) in the Fine particle and aerosol technology laboratory at the University of Eastern Finland. The emission particle samples were collected
with following methods:
o PM1-sampler that was constructed of a pre-impactor that removed the particles with
aerodynamic diameter greater than 1 µm from the sample flow, followed by a filter
cassette. Polytetrafluoroethylene (PTFE) membrane filters were used as a sampling
material.
o Small deposit area impactor (SDI) was used to segregate the particles into 12 size
classes in the range of 0.04-10 µm. The sampling material used was polycarbonate foil
that was greased with a thin layer of Apiezon L-vacuum grease.
12
o
o
o
o
o
2.2
Gravimetric analysis of particulate mass was made by weighing the PTFE filters before and after PM1 sample collection. The balance was Mettler UMT2 with readability
of 1 µg. The SDI samples were not weighed.
Water-soluble organic carbon (WSOC) was determined extracting one quarter of the
PTFE filters in deionized water and analysing the carbonaceous content of the
aqueous extract with a Shimadzu TOC-VCPH total carbon analysator with a high
sensitive catalyst.
Tracer compounds of incomplete burning of biomass (monosaccharide anhydrides
(MAs), such as levoglucosan, mannosan, and galactosan) were determined from
aqueous extract of one quarter of PTFE filters using a high-performance anionexchange chromatograph coupled to a quadrupole mass spectrometer (HPAEC-MS).
The HPAEC-MS method for determination of MAs was developed during this project
(Saarnio et al., 2010).
Selected water-soluble inorganic anions and cations and organic anions were determined extracting one quarter of PTFE filters in deionized water and analysing with a
Dionex ICS-3000 ion chromatograph coupled to a conductivity cell and a quadrupole
mass spectrometer (IC-MS). The selected ions included: ammonium, potassium, sodium, chloride, nitrate, phosphate, sulphate, methane sulphonate, acetate, formate,
glyoxylate, oxalate, malate, maleate, malonate, succinate, adipate, azelate, pinicate,
and pinonate. The ion determination was made both for the PM1 samples on PTFE filters and for the size-segregated SDI samples.
In part of the emission samples from the sauna stove and the conventional masonry
heater, there were problems with the dissolution with water. On the collected PTFE
filters, a hydrophobic surface had formed of the sample material. Therefore the dissolution had probably not been quantitative. This may have affected the determination
results of the water-soluble compounds. In the case of the pellet boiler samples, no
such problem existed.
EXPERIMENTAL PERIODS
Collection times and batch information are presented in Table 1. It shows the
abbreviations of the different combustion tests, test durations, appliance information and
batch information. Sampling times were selected to represent different kinds of combustion
situations in normal small-scale combustion. Selected combustion situations and their
emissions may not represent typical average emissions from the types of appliances used in
this study, but they represent the average values of emissions from different combustion
situations. Combustion situations are affected by the appliance type, use of the appliance and
fuel properties. Emissions over specific combustion situations can be related to the properties
of the produced particles and their toxicological responses. However, particle number
emissions and gas emissions are described both from the combustion cycle, as well as from
each combustion situations (sampling time for toxicological studies). Sampling and collection
times are divided into different categories according to the individual combustion situation
in the different combustion appliances. The particle samples in EFC were collected from a
small-scale pellet boiler with 25 kW maximum output power, which represented modern
small-scale combustion technology. In CBC1, the sample collection period was 55 minutes
over combustion cycle including the ignition phase and three batches. In CBC2 firing phase
(CBC2/F), the sample time was 15 minutes from the beginning of the second batch to obtain a
13
sample of PM1 from a firing phase in conventional masonry heater. In CBC3 batches 2 and 3
(CBC3/23), the sample time was 40 minutes during second and third batches. It represented
the relatively good combustion conditions in the CBCs. In CBC4, sampling time was 50 min
including one large batch. In IBC batches 3 and 4 (IBC/34), the collection time was 50 minutes
during the third and fourth batches. In IEBC, sampling was conducted during the start
(IEBC/S); ignition and the second batch. In the FMI’s measurements the sampling time in the
pellet boiler measurements was four hours (four samplings in total). The emitted combustion
air was diluted with a dilution ratio of about 100. In the measurements of the sauna stove
and the conventional masonry heater, the samplings included the emissions of the ignition
batch and two addition batches and the sampling duration was either 55 or 65 minutes (six
samplings from the sauna stove, five from the masonry heater). The used dilution ratios
were in the range of 670–1000 for the masonry heater emissions and 1000–2500 for the sauna
stove. a after the dilution tunnel+ED, b after PRD+ED+ED.
Table 2. Combustion and sampling parameters of the measurements.
O2 (%)
EFC
11.9
IBC/34
10.5
DR
PRD+
DGI
Dilution
tunnel
PRD+
ED
13
106
14
26
810
a
790
a
24
Sample temperature ( oC)
Dilution
PRD+
PRD+
DGI
tunnel
ED
24
26
26
27
a
27
a
Flue gas
temperature
(oC)
20
152
27
268
IBC
11.6
CBC1
13.4
16
128
24
19
22
22
222
CBC2/F
8.4
17
280b
35
19
26b
23
88
CBC2
10.3
CBC3/23
12.2
CBC3/23
13.0
CBC4
12.4
IEBC/S
10.9
IEBC
8.1
385b
20
91
24b
20
23
88
140
24
242
25
96
21
25
b
90
20
30
21
19
108
246
b
23
23
276
166
19
311
450
a) after the dilution tunnel+ED, b) after PRD+ED+ED.
2.3
RESULTS OF FINE LABORATORY MEASUREMENTS
Dilution ratios and temperatures were measured during the test periods and average
values are presented in Table 2. The emission factors from continuous measurements are
presented as an average of all measured data during the sampling period (Table 3–7).
2.3.1 The gaseous emissions
Gaseous emission factors and particle number emissions factors during the toxicological
sampling are presented in Table 3 and 4. During the sampling times CO emission factors
varied between 80 mg/MJ (EFC) and 4400 mg/MJ (IEBC/S) and OGC emission factors 0.96
mg/MJ (EFC) and 1050 mg/MJ (IEBC/S).
14
Generally, pellet boiler produced the smallest gaseous emissions and sauna stove the
largest ones. In conventional masonry heaters, CBC3 produced clearly lower emissions compared to CBC1 and CBC2. On the other hand, emissions of CO and OGC were lower from
IBC than from CBCs. This shows that air-staging has decreased the gaseous emissions that
have formed in incomplete combustion. Combustion controlled pellet boiler, which worked
with continuous combustion produced significantly lower gaseous emissions than batch
combustion appliances.
Table 3. Gas emissions (mg/MJ) of different combustion situations. Carbon monoxide (CO), organic
gaseous compounds (OGC) and nitrogen oxide (NOX) were measured with the ABB gas analyzer,
while hydrogen chloride (HCl), methane (CH4) and benzene (C6H6) were measured with the FTIR gas
analyzer.
CO
OGC
NOX
HCl
CH4
C6H6
EFC
80
0.96
49
0.1
0.3
0.9
IBC
390
14
75
n/a
n/a
n/a
IBC/34
580
16
74
n/a
n/a
n/a
CBC1
2700
95
82
1.7
47
7.0
CBC2
2300
250
194
0.8
130
27
CBC2/F
1200
82
76
1.3
84
18
CBC3
830
66
82
0.95
43
5.9
CBC3/23
930
94
88
0.9
55
6.9
CBC4
1470
50
70
0.5
13
2.2
IEBC
6100
1050
540
n/a
n/a
n/a
IEBC/S
4400
830
420
3.2
770
50
Table 4. Emissions of PM1, carbon compounds, number emissions and GMD. PM1, EC, OC, CO3,
mg/MJ; NTot, #/MJ; GMD, nm.
EFC
PM1
EC
OC
CO3
NTot
GMD
19.7
0.1
0.9
1.2
3.5E+13
60
8.4E+13
76
IBC
IBC/34
50.7
24
3.6
2.3
6.8E+13
74
CBC1
81.4
24
11
3.4
1.0E+14
63
1.2E+13
142
136
CBC2
CBC2/F
67
49
19
4.2
1.9E+13
3.1E+13
70
CBC3/23
51.6
28
3.5
5.4
3.4E+13
73
CBC4
127
55
14
10
4.2E+13
104
7.3E+13
107
6.7E+13
105
CBC3
IEBC
IEBC/S
257
130
160
5.9
2.3.2 The particle mass emission factors
Particle emissions (PM1) factors were only collected during the selected combustion situations. The results show that the emissions varied significantly between different combustion
situations. Similarly to the gaseous emissions factors, EFC produced the smallest PM1 emis-
15
sions and IEBC/S the largest emissions. Emissions of organic carbon (OC) and elemental carbon (EC) show that there are basically none of these components from EFC. On the other
hand, when batch combustion is applied, OC and EC are always present. This confirms the
findings from gaseous emissions that there are emissions of incomplete combustion (OC, EC,
CO, OGC) when batch combustion is applied.
2.3.3 The particle number emission and number size distributions
The averaged number emission factors (NTot) and geometric mean diameters (GMD) over
combustion situations are presented in Table 4. GMD values calculated from ELPI data varied between 60 nm and 142 nm. The largest GMD values were measured from CBC2 and the
smallest from EFC. The number emission was smallest in CBC2/F, 1.9E+13 #/MJ and highest
from CBC1, 1.0E+14 #/MJ. The Figure 2 shows bimodal number size distributions in IEBC/S,
CBC4 and CBC2/F. These combustion situations are also those with the most incomplete
combustion, according to the emissions of gases, EC and OC. It has been previously reported
that particle size increases when combustion situation get worse (Tissari et al., 2008a). In
CBC2/F, the low flue gas temperature (Table 2) provides also evidence that the residence
time inside the appliance has been relatively long, giving the particles more time for coagulation or agglomeration, leading to a smaller number concentration and a larger particle size.
1.4E+14
Number dN/dlogDp [#/MJ]
1.2E+14
1.0E+14
J]
M
/
[#
p 8.0E+13
D
g
o
l
d
/
N
d 6.0E+13
r
e
b
m
u
N
4.0E+13
CBC1
CBC4
CBC3/23
CBC2/F
IBC/34
EFC
IEBC/S
2.0E+13
0.0E+00
0.01
0.1
1
10
Particle size (µm)
Figure 2. The average number size distributions from different combustion situations.
2.3.4 Particle chemical composition
Most of the particulate matter consists of inorganic alkali metal components in EFC,
shown in Tables 5 and 6. The most abundant chemical species were K+, SO42-, Cl- and Na+.
These components vaporize in hot flame temperatures from ash forming elements in the fuel.
16
When flue gases cool down, they form particles. The smallest emissions of alkali metals and
metals were seen in CBC2/F. It can be concluded that its combustion temperature was most
likely the lowest of all appliances tested here, since the evaporation of these components is
strongly related to combustion temperature. However, the temperature inside the combustion chamber was not measured. Interestingly, the PM1 chemical properties are similar with
IBC/34 and CBC3/23, even though the air-staging in IBC clearly affected the gas emissions.
This shows that the air-staging in IBC did not affect the oxidation of OC and EC significantly.
Table 5. Emissions of PM1 ion compounds (mg/MJ).
Na
EFC
NH4
3.2
K
8.1E-03
7.2
IBC/34
<DL
<DL
7.0
CBC1
<DL
<DL
9.0
Mg
Ca
<DL
<DL
1.8E-03
<DL
Cl
SO4
2.1
3.1
0.95
<DL
0.11
8.8E-03
0.58
2.3
0.43
9.5E-03
0.098
0.37
8.2E-03
0.049
0.22
0.093
CBC3/23
<DL
0.022
4.0
3.1E-03
0.024
0.67
1.3
CBC4
0.03
0.67
0.079
0.015
CBC2/F
IEBC/S
NO3
<DL
5.4
<DL
<DL
<DL
0.89
<DL
<DL
0.47
0.49
1.3
0.044
0.22
0.24
0.32
0.19
As
Fe
<DL, below detection limit.
Table 6. Emissions of PM1 metal compounds (µg/MJ).
Cd
Co
EFC
0.17
<DL
IBC/34
3.1
14
Cr
Cu
0.4
6.5
<DL
5.5
CBC1
2.2
3.2
1.7
5.9
CBC2/F
1.8
5.5
0.026
1.7
CBC3/23
Ni
20
<DL
Pb
3.9
2.7
0.62
11
7.4
0.81
12
43
V
<DL
0.021
<DL
1.6
2.7
0.11
1.8
1.4
<DL
2.0
1.9
0.7
7.2
0.026
1.9
<DL
1.5
<DL
<DL
<DL
6.3
0.10
IEBC/S
<DL, below detection limit.
2.3.5
Mn
0.045
<DL
1.4
20
Zn
84
1300
<DL
21
630
<DL
160
280
24
730
<DL
970
0.037
<DL
The PAH emissions
Different combustion situations in CBCs are at a similar level in total PAHs, but the differences between IBC/34 and different CBCs were greater than in PM1. In addition, when
comparing PAH contents and PM1 emissions from IBC/34 and EFC, it can be seen that the
difference in PAHs between these two combustion conditions are greater than indicated by
the PM1 emissions. This highlights that the impact of improved combustion technology on
the particulate PAH seem to be more significant than would be predicted from the PM1
emissions, gas emissions or other particle chemical properties. The distributions of the different PAH-species varied with the different combustion situations. In all combustion situations, phenanthrene, fluoranthene and pyrene were the most common PAH compounds,
except in CBC3/23 where cyclopenta[c,d]pyrene was the third most common PAH compound.
17
Table 7. Polycyclic aromatic hydrocarbon (PAH) contents in PM1 samples, total PAHs, genotoxic
PAHs and PAH/PM1. Genotoxic PAH compounds defined on the basis of the WHO/IPCS criteria
(WHO 1998). Determination limit of the method 0.1 ng/mg. <DL, under determination limit.
PAH compounds, ng/mg in
PM1
EFC
IBC/34
CBC1
CBC2/F
CBC3/23
IEBC/S
Naphthalene
0.2
1.0
1.1
<DL
<DL
5.7
Acenaphthylene
<DL
4.5
51.1
129.3
11.9
1517.7
Acenaphthene
<DL
<DL
1.6
3.5
1.4
64.5
Fluorene
<DL
4.9
90.0
333.5
34.6
2928.6
Phenanthrene
0.6
352.5
2317.3
5369.6
1060.8
19381.1
Anthracene
<DL
25.6
483.7
955.7
226.5
4611.7
1-Methylphenanthrene
0.1
15.7
148.0
122.9
81.8
788.4
Fluoranthene
1.7
412.1
2834.9
3475.9
2187.4
11264.9
Pyrene
2.1
371.2
2742.1
3199.8
2578.2
12045.6
Benzo[c]phenanthrene
0.1
31.9
29.9
361.2
248.8
875.8
Benzo[a]anthracene
0.1
46.1
1004.3
1396.5
1051.8
3005.7
Cyclopenta[c,d]pyrene
0.2
<DL
2150.1
1991.1
1954.2
6576.1
Triphenylene
0.1
5.3
127.7
187.2
85.6
366.0
Chrysene
0.1
19.1
907.0
1201.9
908.7
2493.0
5-Methylchrysene
<DL
0.7
7.4
7.3
4.5
18.5
Benzo[b]fluoranthene
0.1
47.7
783.2
1208.4
859.7
1748.1
Benzo[k]fluoranthene
<DL
5.0
1120.5
868.0
656.8
4497.0
Benzo[j]fluoranthene
0.1
19.3
365.9
881.3
626.4
927.5
Benzo[e]pyrene
0.2
31.2
524.8
801.3
600.3
1234.2
Benzo[a]pyrene
0.1
32.6
1149.0
2001.9
1628.4
3245.0
Perylene
<DL
4.2
152.9
255.4
216.8
438.8
Indeno[1,2,3-cd]pyrene
<DL
11.5
506.9
924.1
703.7
1305.5
Dibenzo[a,h]anthracene
<DL
1.7
49.5
156.3
122.2
210.2
Benzo[g,h,i]perylene
0.2
16.1
669.4
1051.2
924.6
1672.8
Anthanthrene
<DL
2.3
307.9
549.7
473.0
1006.9
Dibenzo[a,l]pyrene
<DL
<DL
4.0
26.0
11.9
13.0
Dibenzo[a,e]pyrene
<DL
<DL
63.3
190.5
93.4
208.8
Coronene
<DL
1.5
421.8
419.3
245.3
971.0
Dibenzo[a,i]pyrene
<DL
<DL
<DL
53.1
21.1
<DL
Dibenzo[a,h]pyrene
<DL
<DL
12.2
92.6
26.8
19.7
Total PAHs
5.96
1464
19027
28215
17647
83442
Total genotoxic PAHs
2.62
650
10400
14070
10273
33241
6.0E-04
0.15
1.9
1.8
2.8
8.3
0.439
0.444
0.547
0.499
0.582
0.398
PAH/PM1 (%)
Proportion of genotoxic
PAHs from the sum
of all PAHS
18
2.4
RESULTS OF FMI MEASUREMENTS
2.4.1 Particulate mass
The fine particle emissions (Figure 3) differed remarkably between the different combustion appliances. The clearly highest particulate mass concentrations were measured for sauna
stove emissions. The fine particle emissions from the sauna stove were eight times higher
than from the conventional masonry heater and 16 times higher than from the pellet boiler
(concentration ratios 16:2:1, sauna stove/masonry heater/pellet boiler).
Figure 3. Particulate mass concentrations of the combustion appliances.
2.4.2 Water-soluble organic carbon
In this project, one main object of FMI Aerosol Research group was to study the watersoluble content of the particulate matter. The water-solubility of the particulate matter was
very different in the emissions from the pellet boiler compared to those from the sauna stove
and the conventional masonry heater. In the pellet boiler emissions, the particulate matter
consisted mostly of water-soluble material (mainly ash-forming ions) whereas more than
90% of particulate emissions from the sauna stove and the masonry heater were waterinsoluble (presumably mainly elemental carbon and water-insoluble organic compounds
that could not have been measured from these samples). The ratios of the WSOC concentrations of the fine particle emissions (concentration ratios 15:1:1, sauna stove/masonry heater/pellet boiler) were almost similar to those of particulate mass concentrations. It was expected that from the pellet boiler emissions, only low concentration of WSOC would be
measured. Contrary to the expectations, WSOC were on the same concentration level as from
the conventional masonry heater. However, this could be due to the inaccuracy of the determination method with the low concentration samples and other methodological reasons.
2.4.3 Wood combustion tracers
High concentrations of MAs in particulate emissions are a signal of incomplete combustion of biomass. In the experiments of PUPO-poltto project, the clearly highest concentrations
of MAs were determined in samples of the sauna stove. The MAs’ concentrations were remarkable also in samples from masonry heater, whereas in the samples from the pellet boiler, the MAs’ concentrations were close to the detection limit of these compounds in the
HPAEC-MS method. The MAs’ emissions from pellet boiler were almost negligible compared to those of the other two combustion appliances. The ratios of MAs between the ap-
19
pliances were 320:140:1. The contribution of MAs to WSOC was high in PM1 samples from
the conventional masonry heater (39%) and from the sauna stove (10%) while from pellet
boiler it was only 0.25%. It can be stated that the combustion in the pellet boiler was of good
quality whereas in the other two appliances the combustion was more or less incomplete.
Figure 4. Chemical mass closures of the particulate emissions from pellet boiler (a), sauna stove (b),
and masonry heater (c).
2.4.4 Inorganic ions
The fine particle emissions from the pellet boiler were mainly composed of inorganic ash
forming components (i.e., inorganic ions). Compared to the ion emissions from the pellet
boiler, the ion emissions from the conventional masonry heater and the sauna stove were
minor. The ratios of the mass concentration sums of the selected ions were 2:3:13 (sauna
stove/masonry heater/pellet boiler) between the combustion appliances, respectively. The
main ions in the pellet boiler emissions were potassium, sulphate, sodium, and chloride,
whereas in the particulate emissions of the sauna stove and the conventional masonry heater,
the main ions were potassium, sulphate, chloride, and nitrate.
2.4.5 Organic ions
The concentrations of organic ions were significantly lower than those of inorganic ions:
in the PM1 emissions from the pellet boiler there were 125 times more inorganic ions than
organic ions, from the sauna stove 20 times more, and from the conventional masonry heater
13 times more. The concentration of oxalate is commonly used as a tracer for biomass burn-
20
ing in ambient air samples. However, the concentrations of primary oxalate were minor in
this study compared to other biomass burning tracers, such as potassium and levoglucosan
(MAs). The results of this study showed that organic ions are probably formed in particles
when the combustion emissions are mixed with the ambient air (secondary formation). In
this study, the sample collections were made directly from the primary emissions of the
combustion.
2.4.6 Size distributions
In the size-distributions of inorganic and organic ions, it was noted that the particulate
emissions of these compounds from the pellet boiler were concentrated nearly totally in the
particles smaller that 500 nm. The ion emissions of the conventional masonry heater and,
especially, those of the sauna stove were distributed in a wider size-range, however, concentrating in the particles smaller than 1 µm.
Figure 5. Mass size distributions of inorganic ions (a) and organic ions (b).
3. TOXICOLOGICAL RESPONSES INDUCED BY PARTICLES
3
21
TOXICOLOGICAL RESPONSES INDUCED BY PARTICLES
Maija Tapanainen1, Pasi I. Jalava2, Mikko S. Happo2, Pasi Hakulinen1, Raimo O. Salonen1, Jorma
Mäki-Paakkanen1 ja Maija-Riitta Hirvonen1,2
1National Institute for Health and Welfare (THL), Department of Environmental Health, Kuopio, Finland
2University of Eastern Finland, Department of Environmental Science, Kuopio, Finland
3.1
INTRODUCTION
3.1.1 The role of macrophages and epithelial cells in immune response against
inhaled particles
Macrophages are white blood cells of the innate immune system which encounter inhaled
particles in the respiratory system. They have a special ability to uptake large particles and
destroy or clear them from the respiratory system. Furthermore, they also stimulate lymphocytes and other immune cells to respond to the pathogen by producing inflammatory
mediators. If the size of the particles is very small i.e. ultrafine particles, the role of macrophages is diminished and the particles can pass on the bloodstream via lung epithelial cells.
Bronchial epithelial cells line the bronchi and they also take part in host defense reactions
against inhaled particles.
3.1.2 Toxicological analysis
Cell death and other changes in the normal cell cycle
Cell death can be mediated by intra - or extracellular signals. Generally, cells have two
different mechanisms for dying. In acute cell death, damaged cells dissolve and release their
contents to the intermediate state of the cells. Usually acute cell death is followed by secondary inflammatory reactions. The other mechanism is programmed cell death, which is a
protective mechanism to remove damaged cells and it does not cause massive tissue damage around the single damaged cell. Some intracellular signals, e.g. damaged DNA, are able
to arrest a normal progress of the cell cycle. The cell can initiate a normal proliferation cycle
after the damage has been repaired. Extensive cell death of macrophages might lead to impaired immune system and increase susceptibility to infections.
Production of the inflammatory mediators (TNF- , MIP-2 and IL-6)
Inflammation is a protective response against inhaled particles, microbes, pathogens and
other harmful agents. Inflammatory mediators are small proteins which regulate these inflammatory processes. Tumor necrosis factor alpha (TNF- ) and macrophage inflammatory
protein 2 (MIP-2) participate in responses against inhaled particles. Macrophages produce
TNF- in the early phase of the inflammation to stimulate other white blood cells to produce inflammatory mediators and to increase the uptake of the particles. Furthermore, TNFstimulates epithelial cells and recruits inflammatory cells to site of inflammation. MIP-2
functions also in recruitment of other cells. Interleukine 6 (IL-6) contributes to the initiation
and extension of the inflammatory process. Chronic inflammation can lead to exacerbation
of diseases or even onset of a tumor or disease.
22
DNA damage
DNA contains all the information needed in development and function of living organisms. DNA damage and increased cell proliferation might lead to development of cancer
within time. Wood combustion particles contain several potential carcinogenic compounds
such as polycyclic aromatic hydrocarbons (PAHs) which are able to damage DNA directly
or indirectly via inflammation or oxidative stress.
3.2
MATERIALS AND METHODS
3.2.1 Sample preparation
The particles with aerodynamic diameter less than 1 µm (PM1) were collected from diluted flue gas with Dekati gravimetric impactor (DGI) in Fine Particle and Aerosol Technology Laboratory in University of Eastern Finland (Figure 1). Sample substrates from each impaction stage were washed with methanol and weighed before and after the sampling. The
collected material was extracted from the substrates with methanol in a water-bath sonicator
and the extracts were concentrated using a rotary evaporator. The remaining particle suspension was dispensed into glass tubes on a mass basis and the samples were dried under
nitrogen flow, and stored in -20 °C. For the toxicological experiments, the PM1 samples were
suspended into a small amount of DMSO and sterile water. The suspension was sonicated in
a water bath right before the cell exposures. Blank control substrates were collected from all
the sampling campaigns and treated similarly as the other substrates.
3.2.2 Study design of toxicological analyses
Toxicological analyses were performed in a time point of 24 hours and with 3-4 different
particulate doses that were chosen according to previous in vitro studies in PUPO project
(Jalava et al., 2010a). The mouse macrophages were exposed to particulate doses of 15, 50, 150
and 300 µg/ml. The doses vary between 7.5 and 300 µg/ml in the measurement of DNA
damage in human bronchial epithelial cells according to cytotoxicity of the sample. After the
exposure, acute cell death was measured from the cell suspension of macrophages with MTT
test. Programmed cell death and the phases of the cell cycle were determined from the permeabilized macrophages using flow cytometric DNA content analysis. The production of the
inflammatory mediators was performed later from the cell culture medium with ELISA immunoassay. Induced DNA damage was measured from the both cell lines with Comet assay.
3.3
RESULTS
3.3.1 Cell death and other changes in the normal cell cycle
All the studied particulate samples induced a dose dependent decrease in cell viability of
mouse macrophages (Figure 6A). The incomplete combustion sample from the sauna stove
induced more acute cell death than the other studied samples. The largest dose of the sauna
stove derived particles (300 µg/ml) decreased cell viability down to 7%. The same dose of
masonry heater samples sustained the cell viability levels at approximately 50%. There were
more differences in measured programmed cell death between the combustion situations.
However, these detected responses were quite similar as in measurements of acute cell
death. The sauna stove derived sample was the most potent inducer of programmed cell
23
death (Figure 6B). It initiated the programmed cell death in 22% of macrophages at a dose of
150 µg/ml, whereas the same dose from continuous combustion in a pellet boiler induced
programmed cell death only in 9% of macrophages.
Figure 6. A) Acute and B) programmed cell death induced by small-scale wood combustion particles
at dose 15-300 µg/ml in mouse macrophages. The bars represent the mean response ± SEM (standard
error).
3.3.2 Production of the inflammatory mediators (TNF- , MIP-2 and IL-6)
Exposure to wood combustion particles triggered a dose-dependent production of the inflammatory mediators in mouse macrophages (Figure 7A and B). However, the doses used
in this study were not optimal in all cases. Due to extensive cell death, no production of the
inflammatory mediators was detected at the largest dose of sauna stove derived sample.
None of the particulate samples induced production of IL-6 in mouse macrophages. In general, the wood combustion particles induced only moderate inflammatory responses compared to those detected after exposure to particles derived from urban air or traffic (Jalava et
al. 2007; 2010; Kocbach et al., 2008). Furthermore, no clear differences between the inflammatory responses induced by different heating appliance samples were detected on mass dose
basis.
3.3.3 DNA damage
All the wood combustion particles, except those emitted from the pellet boiler, caused
DNA damage in mouse macrophages (Figure 3A) and human bronchial epithelial cells (Figure 8). Overall, the DNA damage was greater in human bronchial epithelial cells, which also
expressed as larger differences between the combustion situations. Human bronchial epithelial cells were more prone to genotoxic effects induced by the combustion particles than
mouse macrophages, and their responses were stronger even at lowest dose of the combustion particles. In the basis of present results, the most potent inducers of DNA damage in
human bronchial epithelial cells were the sauna stove derived particles and those from the
firing phase of the conventional masonry heater. In contrast, the reliable analysis of macrophages exposed to the dose of 300 µg/ml of the particles emitted from the sauna stove could
not be performed due to extensive cell death.
24
Figure 7. The production of A) TNF- and B) MIP-2 presented as fold changes in mouse macrophages
after exposure to wood combustion particles (doses 15-300 µg/ml). The bars represent the mean response ± SEM. Control level is 1.
Figure 8. DNA damage measured as Olive Tail Moment in A) mouse macrophages B) human bronchial epithelial cells after exposure to wood combustion particles (doses 50 and 150µg/ml). The bars
represent the mean response ± SEM.
3.4
DISCUSSION
3.4.1 Relative toxicological responses
Tables 8 and 9 present the toxicological responses to particle dose of 150 µg/ml on mass
dose basis (per mg) and the corresponding relative responses adjusted by the emission factor
(per MJ). These relative responses make a link to real-life situation and indicate the healthdamaging potency of these particles in the atmosphere. The differences in toxicological responses between the combustion situations were enhanced, when the particulate mass emissions were taken into account. These relative responses indicated clearly that the most potential inducers of cell death and DNA damage were particles from incomplete combustion of
wood in the sauna stove. Also the firing phase of the masonry heater was associated with the
25
increased toxic activities. The sauna stove sample had also the highest potency of inducing
inflammatory responses.
Table 8. Cell death and production of the inflammatory mediators after exposure to particle dose of
150 µg/ml on mass dose basis (per mg) and adjusted by the emission factor (per MJ) of each studied
wood combustion appliance in mouse macrophages. The value 1.0 has been set to the responses induced by particles emitted from the pellet boiler. The highest and lowest values are printed in bold.
per mg
Pellet boiler
Modern masonry heater
Masonry heater (cycle)
Masonry heater (batch 2,3)
Masonry heater (firing)
Sauna stove
Acute
1.0
1.1
0.8
1.0
0.7
1.4
per MJ
Pellet boiler
Sauna stove
1.0
4.8
2.7
3.7
5.3
26.4
Cell death
Programmed
1.0
1.4
2.5
1.7
1.5
3.4
1.0
6.0
7.9
6.7
12.2
65.4
Inflammation
TNFMIP-2
1.0
1.0
1.1
1.2
1.1
1.1
1.0
0.8
0.7
0.9
0.7
2.8
1.0
4.7
3.5
4.0
7.3
13.6
1.0
5.1
3.5
3.2
5.6
53.4
Table 9. DNA damage after exposure to particle dose of 150µg/ml on mass dose basis (per mg) and
adjusted by the emission factor (per MJ) of each studied wood combustion appliance in mouse
RAW264.7 macrophage and human BEAS-2B bronchial epithelial cell lines. The value 1.0 has been set
to the responses induced by particles emitted from the pellet boiler. The highest and lowest values are
printed in bold.
RAW 264.7
BEAS-2B
per mg Pellet boiler
1.0
1.0
2.0
3.7
3.6
6.6
2.5
5.5
14.0
3.0
Sauna stove
3.5
per MJ
Pellet boiler
Sauna stove
1.0
8.4
11.6
9.8
23.9
67.7
1.0
16.0
21.1
21.7
112.5
-
26
3.4.2 The effect of chemical composition on particle-induced toxicological properties
The particles emitted from incomplete wood combustion (e.g. the sauna stove and the firing phase of the masonry heater) were the most potent inducers of DNA damage and cell
death in this study. They also contained the highest amounts of organic carbon and PAHs
(Table 7). These compounds may cause immunomodulation in the cells and thus, prevent the
normal inflammatory cascade. The most complete combustion processes in the pellet boiler
and modern masonry heater produced particles that contained mostly inorganic ash compounds and elements. Among this material were compounds, such as metals, which in previous studies are associated with cell death and inflammation in small amounts when dominant organics are absent. Interestingly, the wood combustion particles induced quite similar
inflammatory responses, although the chemical composition of the particles was significantly
different.
4. SUMMARY AND CONCLUSIONS
4
27
SUMMARY AND CONCLUSIONS
Physicochemical and toxicological properties of particulate emissions were studied from
different type of RWC appliances with several methods. The study concentrated the experiments in different type of masonry heaters, a sauna stove and a pellet boiler at the Fine Particle and Aerosol Technology Laboratory at the University of Eastern Finland. In addition,
toxicological studies from appliances typical in Central-Europe were performed at the Graz
University of Technology, Austria. The extensive measurements were performed from different combustion conditions with taking the samples during different combustion phases
(firing, gasification) as well as during the whole combustion cycle and continuous, complete
combustion. Toxicological analyses were done at the Department of Environmental Health,
National Institute for Health and Welfare in Kuopio, Finland.
Emissions and physicochemical properties
o This study shows that the combustion conditions have major role on the emission factors
and the chemical composition of emissions. The combustion conditions vary widely in
RWC and are dependent for example on combustion phase, appliance type, fuel and operational practices. In incomplete combustion conditions (e.g. sauna stoves, old wood
log boilers) the emission factors were high (CO ~6000-13000 mg/MJ, OGC ~600-1200
mg/MJ) and fine particles composed mainly of organic matter and elemental carbon, Also PAH emissions were very high (up to 83 µg/mg in PM1). The poor combustion conditions were due to technical constraints of the appliance (poor heat-storing capacity,
small firebox, insufficient combustion air supply, poor mixing of pyrolysis gases and
combustion air).
o In good combustion conditions, as in pellet boilers in this study, emission factors of gaseous pollutants were very low (CO ~50-80 mg/MJ, OGC ~1-3 mg/MJ) and also fine particle mass (PM1) emissions were clearly lower than in batch combustion appliances. Fine
particles composed mainly of potassium sulphates. PAH emissions were very low (to as
low as 6 ng/mg up to 1.2 µg/mg in PM1).
o In masonry heaters and stoves the emissions were clearly higher than in pellet combustion, but also clearly lower than in the poor combustion conditions. CO emissions in
conventional appliances were 2000-3000 mg/MJ, OGC emissions 100-200 mg/MJ and total PAH emissions 15-35 µg/mg in PM1). In modern appliances, the gaseous emissions
were lower and PAH emissions clearly lower than in conventional appliances although
the PM1 emissions were almost similar.
o The emissions of organic acids (e.g. oxalate) were relatively low in these measurements.
However, oxalate is one of the wood combustion markers of RWC in the air quality studies, and it is probable that oxalate forms only just in atmosphere. Also levoglucosane,
that is marker of incomplete combustion of wood, have been found to correlate with
PAH compound in wood combustion areas.
o The particle number emissions were high in all combustion situations and it did not correlate with the completition of combustion. Typically the particle number size distributions were unimodal (GMD ~60-70 nm), but in incomplete combustion conditions the
bimodal distribution (additional mode in ~250 nm) formed.
28
Toxicological properties of fine particles
o Toxicological results of this study shows that overall, particles from incomplete wood
combustion processes seemed to be potential inducers of programmed cell death and
DNA damage in both of the used cell lines. Moreover, these responses were associated
with the concentration of PAHs and other organic compounds in the particles. In contrast, the studied particles triggered only moderate inflammatory responses, which may
depend on their relatively high cytotoxic effects. In conclusion, by using appropriate
combustion appliances, the particulate emissions and subsequently the particle-induced
toxicological responses can be reduced.
o Human epithelial cells were good cell line for the definition of genotoxicity. Instead of
this, mouse macrophage cell line was better cell line to define cell death and production
of inflammatory mediators.
Correlations
o The combustion related variables and the particle physicochemical and toxicological parameters were tested widely with simple and complex statistical analyses. However,
simple correlations were not found. The parameters, which had the statistical significance in many studied cases, were total PAH, Mn, Ca, Cd, Zn, CO and NOx. However,
the most of parameters gave positive effect of one marker, but negative effect of other
marker.
o The fine particle mass emission, alhough measured with correct sampling and dilution
technique, do not tell enough the harmfulness of emission in “normal” combustion conditions. Also gaseous emissions are not good marker of fine particle emissions or harmfulness of emissions in “normal” combustion conditions. This mean that the particle and
gaseous emissions do not interrelated well (it is not universal) and not correlated with
toxicological markers, when the PM1 emission factor is lower than ~80 mg/MJ
(=”normal” conditions). However, almost all emission compounds correlates well and
also particle toxicity is higher with high emission factors in clearly incomplete combustion conditions.
Conclusions
o This study showed that with the good/modern combustion appliances and correct operational practices it is possible to decrease the emissions and the harmful properties of
fine particles substantially.
o In the group of numerous health related physicochemical compounds, the PAH emissions (in particle phase) seems to be the best-connected to the combustion technology
and combustion conditions. PAH emission seems to be the most sensitive marker of
quality of combustion. In future, PAHs might be a potential parameter to classify the
combustion appliances.
o The harmful of emissions in modern technology appliances were generally lower than in
conventional appliances. Thus, the development of appliances is worthwhile for the
health related problems from RWC appliances.
o Emissions and toxicological results were well line both in Finnish appliances and those
tested in Austria.
4. SUMMARY AND CONCLUSIONS
29
Recommendations and open questions
o More care should be taken in the design of combustion appliances, and improving combustion technology in small-scale batch combustion appliances (as for example the development of gasified combustion in pellet burner).
o A wider set of chemical analyses is recommended to be performed in order to provide
more specific data to aid in the evaluation of health effects attributable to small-scale
combustion of wood.
o For limiting of health related problems it should pay attention to the emissions of old
technology appliances. In the worst appliances, as a first step, this succeeds with the limiting of gaseous emission (CO or OGC). Also there should be ways to limit the emissions from old technology existing appliances if needed (e.g. in densely populated areas).
When increasing the wood combustion, it has to do with the modern technology appliances.
o Only minor change in combustion conditions can affect remarkably to the toxicological
responses of particles. In the different situations, responses can affect via different mechanism. It is also typical that there is found unexpected results between different combustion conditions. Thus, it is important to test toxicologically also the future combustion
appliances and fuels will be used in RWC.
o The most harmful chemical composition seems to be connected to the carboneous or organic constituents, but in future, it is very important to study also harmfulness of single
specific compound occurred in real combustion as a pure compound.
LITERATURE
31
LITERATURE
Amann, C.A., Siegla, D.C. (1982) Diesel particulates–what they are and why. Aerosol Sci. Technol. 1, 73–
101.
Boman B.C., Forsberg, A.B., Järvholm, B.G. (2003a) Adverse health effects from ambient air pollution
in relation to residential wood combustion in modern society. Scand. J. Work Environ. Health 29,
251–260.
Boman, C., Nordin, A., Thaning, L. (2003b) Effects of increased biomass pellet combustion on ambient
air quality in residential areas—a parametric dispersion modelling study. Biomass Bioenergy 24,
465–474.
Boman, C., Nordin, A., Bostrom, D., Ohman, M. (2004) Characterization of inorganic particulate matter
from residential combustion of pelletized biomass fuels. Energy Fuels 18, 338–348.
Christensen, K.A., Stenholm, M., Livjberg, H. (1998) The formation of submicron aerosol particles, HCl
and SO2 in straw-fired boilers. J. Aerosol Sci. 29, 421–444.
Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 Ambient air quality and cleaner air for Europe. Official Journal L152/1, 21/05/2008.
Donahue, N. M., Robinson, A. L., and Pandis, S. N. (2009) Atmospheric organic particulate matter:
From smoke to secondary organic aerosol. Atmos. Environ. 43, 94-106.
Dockery, D.W., Pope, C.A. 3rd, Xu, X., Spengler, J.D., Ware, J.H., Fay, M.E., Ferris, B.G. Jr, Speizer, F.E.
(1993) An association between air pollution and mortality in six U.S. cities. N. Engl. J. Med. 329,
1753–1759.
Fine, P.M., Cass, G.R., Simoneit, B.R.T. (2001) Chemical characterization of fine particle emissions from
fireplace combustion of woods grown in the Northeastern United States. Environ. Sci. Technol. 35,
2665–2675.
Frey, A.K., Tissari, J., Saarnio, K., Timonen, H.J., Tolonen-Kivimäki, O., Aurela, M.A., Saarikoski, S.K.,
Makkonen, U., Hytönen, K., Jokiniemi, J., Salonen, R.O., Hillamo, R.E.J. (2008). Chemical composition and mass size distribution of fine particulate matter emitted by a small masonry heater.
Accepted to Boreal Environ. Res.
Hedberg, E., Kristensson, A., Ohlsson, M., Johansson, C., Johansson, P., Swietlicki, E., Vesely, V., Wideqvist, U., Westerholm, R. (2002) Chemical and physical characterization of emissions from
birch wood combustion in a wood stove. Atmos. Environ. 36, 4823–4837.
Hueglin, C.H., Gaegauf, C.H., Burtscher, H. (1997) Characterization of wood combustion particles:
morphology, mobility, and photoelectric activity. Environ. Sci. Technol. 31, 3439–3447.
Hytönen, K., Yli-Pirilä, P., Tissari, J., Gröhn, A., Riipinen, I., Lehtinen, K. E. J., Jokiniemi, J. (2009) GasParticle Distribution of PAHs in Wood Combustion Emission Determined with Annular Denuders, Filter, and Polyurethane Foam Adsorbent. Aerosol Sci.Technol., 43, 442–454.
Jalava, P.I., Salonen, R.O., Hälinen, A.I., Penttinen, P., Pennanen, A.S., Sillanpää, M., Sandell, E., Hillamo, R., Hirvonen, M-R. (2006) In vitro inflammatory and cytotoxic effects of size-segregated
particulatesamples collected during long-range transport of wildfire smoke to Helsinki. Toxicol.
Appl. Pharmacol. 215, 341–353.
Jalava, P.I., Salonen, R.O., Pennanen, A.S., Sillanpää, M., Hälinen, A.I., Happo, M.S., Hillamo, R., Brunekreef, B., Katsouyanni, K., Sunyer, J., Hirvonen, M-R. (2007) Heterogeneities in inflammatory
and cytotoxic responses of RAW 264.7 macrophage cell line to urban air coarse, fine and ultrafine
particles from six European sampling campaigns. Inhal Toxicol. 19, 213–225.
Jalava, P.I., Salonen, R.O., Nuutinen, K., Pennanen, A.S., Happo, M.S., Penttinen, P., Tissari, J., Frey,
A., Hillamo, R., Jokiniemi, J,, and Hirvonen, M-R. (2010a). Effect of combustion condition on cytotoxic and inflammatory activity of residential wood combustion particles. Atmos. Environ. 44,
1691–1698.
32
Jalava, P.I., Tapanainen, M., Kuuspalo, K., Markkanen, A., Hakulinen, P., Happo, M.S., Pennanen,
A.S., Ihalainen, M., Yli-Pirilä, P., Makkonen, U., Teinilä, K., Mäki-Paakkanen, J., Salonen, R.O., Jokiniemi, J. and Hirvonen, M-R. (2010b). Toxicological effects of emission particles from fossil- and
biodiesel-fueled diesel engine with and without DOC/POC catalytic converter. Inhal. Toxicol. 22,
48–58.
Johansson, L.S., Leckner, B., Gustavsson, L., Cooper, D., Tullin, C., Potter, A. (2004). Emission characteristics of modern and old-type residential boilers fired with wood logs and wood pellets. Atmos.
Environ. 38, 4183–4195.
Johansson, L., Tullin, C., Leckner, B., Sjövall, P. (2003) Particle Emissions from biomass combustion in
small combustors. Biomass Bioenergy 25, 435–446.
Jordan, T.B., Seen, A.J. (2005) Effect of airflow setting on the organic composition of woodheater emissions. Environ. Sci. Technol. 39, 3601–3610.
Kappos, A.D., Bruckmann, P., Eikmann, T., Englert, N., Heinrich, U., Höppe, P., Koch, E., Krause,
G.H.M., Kreyling, W.G., Rauchfuss, K., Rombout, P., Schulz-Klemp, V., Thiel, W.R., Wichmann,
H.-E. (2004) Health effects of particles in ambient air. Int. J. Hyg. Environ. Health 207, 399–407.
Karvosenoja N., Tainio M., Kupiainen K., Tuomisto J.T., Kukkonen J., Johansson M. (2008) Evaluation
of the emissions and uncertainties of PM2.5 originated from vehicular traffic and domestic wood
combustion in Finland. Boreal Environ. Res. 13, 465–474.
Koyuncu, T., Pinar, Y. (2007) The emissions from a space-heating biomass stove. Biomass Bioenergy
31,73–79.
Kocbach, A., Herseth, J.I., Lag, M., Refsnes, M. and Schwarze, P.E. (2008) Particles from wood smoke
and traffic induce differential pro-inflammatory response patterns in co-cultures. Toxicol Appl
Pharmacol 232, 317–326.
Lamberg, H., Nuutinen, K., Tissari, J., Ruusunen, J., Yli-Pirilä, P., Sippula, O., Tapanainen, M., Jalava,
P.I., Makkonen, U., Teinilä, K., Saarnio, K., Hillamo, R., Hirvonen, M-R., Jokiniemi, J. (2011) Physichochemical characterization of fine particles from small scale wood combustion. Atmos. Environ. In Press
Launhardt, T., Thoma, H. (2000) Investigation on organic pollutants from a domestic heating system
using various solid biofuels. Chemosphere 40, 1149–1157.
Lipsky, E.M., Robinson, A.L. (2006) Effects of dilution on fine particle mass and partitioning of semivolatile organics in diesel exhaust and wood smoke. Environ. Sci. Technol. 40, 155–162.
Lighty, J.S., Veranth, J.M., Sarofim, A.F. (2000) Combustion aerosols: factors governing their size and
composition and implications to human health. J. Air & Waste Manag. Assoc. 50, 1565–1618.
Muhlbaler Dasch, J. (1982) Particulate and gaseous emissions from wood-burning fireplaces. Environ.
Sci. Technol. 16, 636–645.
Nussbaumer, T. (2003) Combustion and co-combustion of biomass: fundamentals, technologies, and
primary measures for emission reduction. Energy Fuels 17, 1510–1521.
Olsson, J.G., Jäglig, U., Pettersson, J.B.C. (1997) Alkali metal emission during pyrolysis of biomass.
Energy Fuels 11, 779–784.
Pope, C.A. 3rd, Burnett, R.T., Thun, M.J., Calle, E.E., Krewski, D., Ito, K., Thurston, G.D. (2002) Lung
cancer, cardiopulmonary mortality and long-term exposure to fine particulate air pollution. J.
Am. Med. Assoc. 287, 1132–1141.
Pope 3rd, C.A., Dockery, D. W. (2006) Health effects of fine particulate air pollution: lines that connect.
J. Air & Waste manag. Assoc. 56, 709–742.
Purvis, C.R., McCrillis, R.C., Kariher, P.H. (2000) Fine particulate matter (PM) and organic speciation
of fireplace emissions. Environ. Sci. Technol. 34, 1653–1658.
Robinson, A.L., Donahue, N.M., Shrivastava, M.K., Weitkamp, E.A., Sage, A.M., Grieshop, A.P., Lane,
T.E., Pierce, J.R., Pandis, S.N. (2007) Rethinking organic aerosols: semivolatile emissions and photochemical aging. Science 315, 1259–1262.
Rogge, W.F., Hildemann, L.M., Mazurek, M.A., Cass, G.R. (1998) Sources of fine organic aerosol. 9.
pine, oak, and synthetic log combustion in residential fireplaces. Environ. Sci. Technol. 32, 13–22.
LITERATURE
33
Saarnio, K., Teinilä, K., Aurela, M., Timonen, H., Hillamo, R. (2010) High-performance anion-exchange
chromatography-mass spectrometry method for determination of levoglucosan, mannosan, and
galactosan in atmospheric fine particulate matter. Anal. Bioanal. Chem. 39 ,2253–2264.
Salonen, R.O. (2004) Puun pienpolton terveyshaitat. Ympäristö ja Terveys 35, 4–9.
Salonen, R.O., Pennanen, A. (2007) The Impact of Fine Particles on Health Views and Conclusions
from the FINE Particles – Technology, Environment and Health Technology Programme Edited
by Peter Herring. Original Finnish version by Timo Paukku. Tekes, Helsinki.
Sippula, O., Hytönen, K., Tissari, J., Raunemaa, T., Jokiniemi, J. (2007a) Effect of wood fuel on the
emissions from a top-feed pellet stove. Energy Fuels 21, 1151–1160.
Sippula, O., Hokkinen, J., Puustinen, H., Yli-Pirilä P., Jokiniemi, J. (2007b) Fine particle emissions from
biomass and heavy fuel oil combustion without effective filtration (BIOPOR). VTT Working Papers 72, VTT, Espoo.
Sippula, O., Lind, T., Jokiniemi, J. (2008) Effects of chlorine and sulphur on particle formation in wood
combustion performed in a laboratory scale reactor. Fuel. 87, 2425–2436.
Tapanainen, M., Jalava P.I., Mäki-Paakkanen, J., Hakulinen, P., Happo, M.S., Lamberg, H., Ruusunen,
J., Tissari, J., Nuutinen, K., Yli-Pirilä, P., Hillamo, R., Salonen, R.O., Jokiniemi, J., and Hirvonen,
M-R. (2011). In vitro immunotoxic and genotoxic activities of fine particles emitted from two different small-scale wood combustion appliances. In press
Tissari, J. (edit.), Raunemaa, T., Jokiniemi, J., Sippula, O., Hytönen, K., Linna, V., Oravainen, H., Pyykönen, J., Tuomi, S., Vesterinen, R., Taipale, R., Kolsi, A., Nuutinen, I., Kouki, J., Vuorio, K. (2005)
Puun polton pienhiukkaspäästöt. Loppuraportti. Kuopion yliopiston ympäristötieteiden laitosten
monistesarja, 2/2005. Kuopion yliopisto, Pienhiukkas- ja aerosolitekniikan laboratorio, 2005.
Tissari J, Salonen, R.O., Vesterinen, R., Jokiniemi, J. (toim). (2007a) Puun pienpolton päästöt, ilmanlaatu ja terveys. Kuopion yliopiston ympäristötieteen laitoksen monistesarja 2/2007. 138 s + 1 liite.
Tissari, J., Hytönen, K., Lyyranen, J., and Jokiniemi, J. (2007b). A novel field measurement method for
determining fine particle and gas emissions from residential wood combustion. Atmos. Environ.
41, 8330–8344.
Tissari, J., Lyyränen, J., Hytönen, K., Sippula, O., Tapper, U., Frey, A., Saarnio, K., Pennanen, A.S.,
Hillamo, R., Salonen, R.O., Hirvonen, M.-R., Jokiniemi, J. (2008a). Fine particle and gaseous emissions from normal and smouldering wood combustion in a conventional masonry heater. Atmos.
Environ. 42, 7862–7873.
Tissari, J., Sippula, O., Kouki, J., Vuorio, K., Jokiniemi, J. (2008b) Fine particle and gas emissions from
the combustion of agricultural fuels fired in a 20 kW burner. Energy Fuels 22, 2033–2042.
Tissari, J., Hytönen, K., Sippula, O., Jokiniemi, J. (2009) The effects of operating conditions on emissions from masonry heaters and sauna stoves. Biomass Bioenergy 33, 513–520.
United States Environmental Protection Agency (USEPA) (2004) Air quality criteria for particulate
matter. Publication EPA/600/P-99/002aF. Research Triangle Park, NC: USEPA Office of Research
and Development, National Center for Environmental Assessment – RTP Office.
World Health Organization (WHO) (1994) Update and revision of the air quality guidelines for Europe. Report EUR/ICP/EHAZ 94 05/PB01 of working group on “classical” air pollutants, 11-14 October 1994, Bilthoven, NL. Copenhagen, Denmark: WHO Regional Office for Europe, 1995
(EUR/HFA target 21).
World Health Organization (WHO) (2003) Review of health aspects of air pollution with particulate
matter, ozone and nitrogen dioxide. Report EUR/03/5042688 of working group, Bonn, Germany,
13-15 January 2003. Copenhagen, Denmark: WHO Regional Office for Europe.
World Health Organization (WHO) (2005) WHO air quality guidelines global update 2005. Report
WHOLIS E87950 of Working Group Meeting, Bonn, Germany, 18-20 October 2005. Copenhagen,
Denmark:
WHO
Regional
Office
for
Europe,
2005.
Internet:
http://www.euro.who.int/Document/E87950.pdf
APPENDIXES
35
APPENDIX I. PUBLICATIONS IN PUPO-POLTTO PROJECT
1) Scientific refereed articles
Lamberg, H., Nuutinen, K., Tissari, J., Ruusunen, J., Yli-Pirilä, P., Sippula, O., Tapanainen, M., Jalava, P.I.,
Makkonen, U., Teinilä, K., Saarnio, K., Hillamo, R., Hirvonen, M-R., Jokiniemi, J. (2011) Physichochemical characterization of fine particles from small scale wood combustion. Atmos. Environ. In Press.
Saarnio, K., Teinilä, K., Aurela, M., Timonen, H., Hillamo, R. (2010) High-performance anion-exchange chromatography-mass spectrometry method for determination of levoglucosan, mannosan, and galactosan in atmospheric fine particulate matter. Anal. Bioanal. Chem. 39 ,2253-2264.
Tapanainen, M., Jalava P.I., Mäki-Paakkanen, J., Hakulinen, P., Happo, M.S., Lamberg, H., Ruusunen, J., Tissari, J., Nuutinen, K., Yli-Pirilä, P., Hillamo, R., Salonen, R.O., Jokiniemi, J., and Hirvonen, M-R. (2011). In vitro
immunotoxic and genotoxic activities of fine particles emitted from two different small-scale wood combustion
appliances. Atmos. Environ. In Press.
2) Scientific articles, submitted
Ruusunen, J., Tapanainen, M., Sippula, O., Jalava, P.I., Lamberg, H., Nuutinen, K., Tissari, J., Ihalainen, M.,
Kuuspalo, K., Mäki-Paakkanen, J., Hakulinen, P., Pennanen, A., Salonen, R.O., Hillamo, R., Teinilä, K., Makkonen, U., Hirvonen, M-R.H., Jokiniemi, J. (2011) A novel particle sampling system for physico-chemical and toxicological characterization of emissions. Submitted to Analytical and Bioanalytical Chemistry.
Saarnio, K., Niemi, J.V., Saarikoski, S., Aurela, M., Timonen, H., Teinilä, K., Myllynen, M., Frey, A., Lamberg,
H., Jokiniemi, J., Hillamo, R. (2011) Fine particles from wood combustion in the Helsinki Metropolitan Area.
Submitted to Boreal Environment Research.
3) Scientific articles, manuscripts
Frey, A., et al. Optical properties of wood combustion emissions in different combustion conditions and appliances.
Tapanainen et al. Toxicological properties of particles emitted from different log wood heating appliances.
4) Conference papers
Frey, A., Saarnio, K., Lamberg, H., Tissari, J., Jokiniemi, J., Hillamo, R. (2010). Optical properties of PM1 emissions originated from wood combustion. International Aerosol Conference 2010, Helsinki, Finland.
Lamberg, H., Nuutinen, K., Tissari, J., Ruusunen, J., Tapanainen, M., Jalava, P.I., Makkonen, U., Hillamo, R.,
Hirvonen, M.-R. and Jokiniemi, J. (2010) Physico-chemical characterisation of fine particles from small scale
wood combustion for toxicological studies. American Association for Aerosol Research (AAAR): Air pollution
and health, March 22-26 2010, San Diego, USA.
Lamberg, H., Nuutinen, K., Tissari, J., Ruusunen, J., Tapanainen, M., Jalava, P.I., Yli-Pirilä, P., Makkonen, U.,
Teinilä, K., Hillamo, R., Hirvonen, M-R., Jokiniemi, J. (2010). Physicochemical characterization of fine particles
from small scale wood combustion. International Aerosol Conference 2010, Helsinki, Finland.
Nuutinen, K., Tissari, J., Sippula, O., Lamberg, H., Ruusunen, J., Suonmaa, V., Jokiniemi, J. (2010) Combination
of porous tube diluter and ejector diluter in small-scale combustion emission measurement. Expert Conference
"Dust measuring procedures", Leipzig, Germany.
J. Ruusunen, H. Lamberg, M. Tapanainen, K. Hytönen, O. Sippula, J. Tissari, M. Ihalainen, T. Karhunen, A.S.
Pennanen, P. Willman, M-R. Hirvonen, R.O. Salonen and J. Jokiniemi (2009). A novel particle sampling system
for toxicological characterization of emissions, European Aerosol Conference 2009, Karlsruhe, Abstract
T150A30.
36
Saarnio, K., Teinilä, K., Aurela, M., Frey, A., Timonen, H., Lamberg, H., Jokiniemi, J., Hillamo, R. (2010) Determination of biomass burning tracers in aerosols with a high-performance anion-exchange chromatographymass spectrometry (HPAEC/ESI-MS) method. International Aerosol Conference 2010, Helsinki, Finland.
Tapanainen, M., Jalava, P.I., Happo, M., Mäki-Paakkanen, J., Salonen, R.O., Lamberg, H., Ruusunen, J., Tissari,
J., Yli-Pirilä, P., Nuutinen, K., Jokiniemi, J., Hirvonen, M-R. (2010). Immunotoxic and genotoxic responses induced by emission particles from pellet boiler and conventional masonry heater in RAW264.7 macrophages.
American Association for Aerosol Research (AAAR): Air pollution and health, March 22-26 2010, San Diego,
USA.
Tapanainen, M., Jalava, P.I., Happo, M., Mäki-Paakkanen, J., Hakulinen, P., Salonen, R.O., Lamberg, H., Tissari,
J., Yli-Pirilä, P., Nuutinen, K., Jokiniemi, J., Hirvonen, M-R. (2010). Immunotoxic and genotoxic effects of particles emitted from small-scale wood combustion. International Aerosol Conference 2010, Helsinki, Finland.
Tapanainen, M., Mäki-Paakkanen, J., Hakulinen, P., Jalava, P.I., Lamberg, H., Ruusunen, J., Tissari, J., Yli-Pirilä,
P., Nuutinen, K., Jokiniemi, J., Hirvonen, M-R. (2010). Effect of wood combustion conditions on particleinduced DNA damage In Vitro. Ympäristöterveyden tutkijakoulun vuosiseminaari 2010.
Tapanainen, M., Jalava, P.I., Happo, M., Mäki-Paakkanen, J., Hakulinen, P., Salonen, R.O., Lamberg, H., Ruusunen, J., Tissari, J., Yli-Pirilä, P., Nuutinen, K., Jokiniemi, J., Hirvonen, M-R. (2011). Appliance technology and
combustion condition affect the genotoxic potential of fine particle emission from small-scale wood combustion. Central European Biomass Conference 2011, January 26-29 2011, Graz, Austria.
Tapanainen, M., Jalava, P.I., Lamberg, H., Hakulinen, P., Yli-Pirilä, P., Ruusunen, J., Mäki-Paakkanen, J., Hillamo, R., Jokiniemi, J., Hirvonen, M-R. (2011). Combustion conditions affect toxicological and chemical properties of wood combustion particles. Society of Toxicology Annual Meeting 2011 & ToxExpo March 2011, Washington.
J. Tissari, V. Suonmaa, J. Sutinen, P. Horttanainen and J. Jokiniemi (2009). Effect of air staging on emissions
from masonry heaters, European Aerosol Conference 2009, Karlsruhe, Abstract T083A18.
Tissari, J., Sippula, O., Hytönen, K., Lamberg, H., Hukkanen, A., Penttilä, T., Nuutinen, I., Jokiniemi, J. (2010).
Correlations between PM1 and other emission components in small-scale wood combustion. International
Aerosol Conference 2010, Helsinki, Finland.
APPENDIXES
37
APPENDIX II: SHORT SUMMARIES OF THE UEF, THL AND FMI REPORTS IN FINNISH.
PIENHIUKKAS- JA AEROSOLITEKNIIKAN LABORATORION PÄÄSTÖTUTKIMUKSET
Jarkko Tissari, Heikki Lamberg, Kati Nuutinen, Jarno Ruusunen, Terhi Penttilä, Annika Hukkanen, Jorma Jokiniemi*.
Itä-Suomen yliopisto, Ympäristötieteen laitos, Pienhiukkas- ja aerosolitekniikan laboratorio
*Lisäksi: VTT Pienhiukkaset, Espoo.
Tutkimus tehtiin osana PUPO-poltto projektia, jossa oli tarkoituksena määrittää erilaisista polttotilanteista syntyvien pienhiukkasten ominaisuuksia sekä niiden terveysvaikutuksia. Tutkimuksen kokeellinen osuus tehtiin kahdessa osassa: marraskuussa 2008 ja helmi-toukokuussa 2009. Polttokokeet tehtiin Kuopion yliopiston (Itä-Suomen
yliopiston) Pienhiukkas- ja aerosolitekniikan laboratorion tiloissa Kuopiossa.
Tutkimuksessa käytettiin tutkimuslaboratoriossa olevaa mittauslaitteistoa, jota voidaan käyttää erilaisten polttolaitteiden hiukkas- ja kaasupäästöjen mittaamiseen. Hiukkaspäästöjen mittaamiseksi käytettiin kolme erilaisten
laimennuslaitteistoa. Kuuma hiukkasnäyte täytyy laimentaa ja jäähdyttää mittalaitteita varten. Lisäksi laimentamisen yhteydessä tapahtuu aineensiirtoa kaasumaisten yhdisteiden ja hiukkasten välillä. Hiukkasnäytteenotossa
käytettiin yhteensä kolmea erilaista laimennuslaitteistoa: 1) Huokoisen putken laimentimella laimennettiin näyte
kerättäväksi toksikologisia ja kemiallisia analyysejä varten. Keräyksessä käytettiin impaktoria, joka koostui neljästä
impaktoritasosta ja pohjasuodattimesta (DGI=Dekati Gravimetric Impactor, Dekati Oy). DGI:llä kerätyistä hiukkasista analysoitiin myös polyaromaattisen hiilivedyt (PAH=polyaromatic hydrocarbons) sekä tehtiin toksilogiset
analyysit Terveyden ja Hyvinvoinnin laitoksella (THL). 2) Huokoisen putken laimenninta ja ejektorilaimenninta
käytettiin laimentamaan näyte suodatinkeräyksiä ja massakokojakauman mittaamista varten. Suodatinkeräysten
avulla selvitettiin PM1-päästö sekä analysoitiin epäorgaanisen ja orgaanisen hiilen (OC/EC, organic carbon/elemental carbon) osuus hiukkasnäytteessä. Massa-kokojakauma mitattiin käyttämällä 13-tasoista alipaineimpaktoria (Dekati Low-Pressure Impactor=DLPI). 3) Savupiipusta näyte johdettiin lämmitettyä linjaa pitkin laimennustunneliin, josta mitattiin hiukkasten lukumäärä-kokojaukaumaa jatkuvatoimisesti sähköisillä liikkuvuusanalysaattoreilla (ELPI=Electrical Low-Pressure Impactor, Dekati Oy; FMPS=Fast Mobility Particle Sizer, TSI
Inc.). Laimennustunnelista tehtiin myös Ilmatieteen laitoksen hiukkasanalyysit, jotka on esitetty toisessa kappaleessa.
Taulukko 1. Palamistilanteiden ja polttolaitteiden kuvaus.
Polttotilanne
Pelletti,
hyvä palaminen
Hyvä
panospoltto
Takka,
sykli
Takka,
kaasutus
Takka,
2. ja 3. panos
Takka,
1 panos
Kiuas,
huono palaminen
Combustion phase
Complete
combustion (CC)
Advanced batch
combustion (ABC)
Conventional batch
combustion, cycle (CBC/C)
Conventional batch
combustion, firing (CBC/F)
Conventional batch
combustion (CBC)
Conventional batch
combustion
Incomplete
combustion (IC)
Laitetyyppi
Pellettikattila, jatkuva
palaminen
Moderni tulisija
(ilmanjaolla)
Perinteinen tulisija
Kiuas
Keräysaika
2-3 tuntia
Panostiedot
3. ja 4. panos,
50 min
Koko poltto,
55 min
15 min 2. panoksen alusta
2. ja 3. panos,
40 min
1. panos
1. panos: 10x400g,
muut: 4x1kg
1. panos 1x1,7 kg,
muut: 2,7 kg
1. panos: 3x1kg + 5x200g,
muut: 3x1330kg
1. panos: 7x430g,
muut: 4x750g
5x200 g + 7x1 kg
1. ja 2. panos,
20-35 min
1 panos: 5x310g, 2. panos:
6x530g, 3. panos 5x640g
Laimennuksessa käytettävät laimennusilma oli paineilmaverkosta otettua ilmaa joka oli kuivattu ja suodatettu.
Laimennustunnelin johdettava laimennusilma oli suodatettua mittaustilan ilmaa. Jokaisen laimennusjärjestelmän
jälkeen laimennuskerroin (DR) määritettiin mittaamalla CO2-pitoisuus sekä raa’assa savukaasussa että laimenne-
38
tussa näytteessä. Lisäksi mitattiin sekä laimennetun näytekaasun lämpötila näytelinjasta että kuuman savukaasun
lämpötila savupiipusta. Koska laimennusjärjestelmien 1 ja 2 tulokset haluttiin olevan vertailukelpoisia keskenään,
pyrittiin näiden laimennusjärjestelmien laimennuskertoimet pitämään samana, koska laimennuksen on todettu
vaikuttavan hiukkasten ominaisuuksiin.
Panospolttolaitteilla käytettiin polttoaineena ylivuotista koivuklapia. Polttopuut säilytettiin ennen polttokokeita
sisätiloissa, mikä laski niiden kosteuspitoisuutta. Samasta polttoaineesta tehtiin myös sytytyksessä käytetyt tikut.
Pellettikattilassa käytettiin polttoaineena kaupallista pellettiä, jonka oli valmistanut Vapo Oy.
Polttolaitteet ja -tilanteet
Polttokokeet tehtiin yhteensä seitsemällä erilaisella polttolaitteella. Neljä polttolaitetta edusti perinteistä panospolttoa (varaavia tulisijoja), yksi moderni ilmajaolla varustettu tulisija, saunan kiuas sekä moderni pellettikattila,
jossa oli integroitu pellettipoltin ja kattila-lämmönvaihdin osa. Jokaisesta polttolaitteesta mitattiin jatkuvatoimisilla
mittalaitteilla hiukkas- ja kaasupäästöt koko polttojakson ajan. Suodatinkeräykset kemiallisia ja toksikologisia analyysejä varten tehtiin valituista palamistilanteista. Näiden palamistilanteiden tarkoitus oli edustaa tavallisissa polttolaitteissa tapahtuvia erilaisia palamistilanteita, joista haluttiin selvittää hiukkasten ominaisuudet ja toksikologiset
ominaisuudet kyseissä tilanteissa. Palamistilanteiden kuvaukset on tiivistetty taulukkoon 1. Tämän raportin tulososassa käsitellään näytteenkeräyksen aikana mitattuja päästöjä.
Taulukko 2. Tuloskoonti eri palamistilanteista.
Polttotilanne
Pelletti,
hyvä palaminen
Hyvä
panospoltto
Takka,
sykli
Takka,
kaasutus
Takka,
2. ja 3. panos
Takka,
1 panos
Kiuas, huono
palaminen
PM1päästö,
mg/MJ
19.7
CO-päästö,
mg/MJ
Lukumäästäpäästö,
1/MJ
Kokonais-PAH,
ng/MJ
O2 (%)
80
OGCpäästö,
mg/MJ
0.96
3.5E+13
5.96
11.9
50.7
580
16
6.8E+13
1464
10.5
81.4
2700
95
8.3E+13
19027
13.4
67
1200
82
1.9E+13
28215
8.4
51.6
930
94
3.4E+13
17647
12.2
127
1470
50
4.2E+13
-
12.4
257
4400
830
6.7E+13
83442
10.9
Tulokset
Sekä hiukkaspäästöjen että kaasumaisten päästöjen osalta havaittiin selviä eroja eri palamistilanteiden ja polttolaitteiden välillä. Yleistäen, suurimmat päästöt mitattiin tilanteessa ”kiuas, huono palaminen” ja pienimmät päästöt
tilanteessa ”pellettikattila, hyvä palaminen”. Nämä kaksi ääripäätä erottuivat häkä- (CO), orgaanisten hiilivetyjen
(OGC), PM1- sekä hiukkasten lukumääräpäästöissä. Lisäksi orgaanisen hiilen ja epäorgaanisen hiilen osuudet olivat suurimmat ”kiuas, huono palaminen” ja pienimmät ”pellettikattila, hyvä palaminen” tilanteissa.
Tuloksista voidaan päätellä selviä eroja päästöissä eri palamistilanteiden välillä, mutta eri hiukkas- ja kaasupäästöjen välillä nähdä suoria korrelaatioita. Esimerkiksi ”hyvä panospoltto” tilanteen PM1-päästön ovat hyvin
lähellä ”takka, 2. ja 3. panos” päästöä, mutta selvä ero nähdään CO-päästössä ja hiukkasissa analysoiduissa kokonais-PAH:ssa. Tämä osoittaa, ettei ilmanjaolla panospoltossa ole suurta vaikutusta PM1-päästöön, mutta sen
havaittiin vaikuttavan moniin muihin päästöihin. Pellettikattilan pienistä päästöistä havaitaan että jatkuva palaminen sekä polttoaineen ja palamisilman tarkka ohjaus vaikuttaa päästöihin selvästi. ”Hyvä panospoltto” osoittaa
myös että polttotekniikan kehittämisellä voidaan laskea päästöjä huomattavasti myös panospolttolaitteissa. Perinteisistä takoista mitatut päästöt olivat jokseenkin samalla tasolla, vaikka palamistilanteissa oli selviä eroja. Hiukkasten lukumääräpäästö ei korreloi palamistilanteiden tai muiden mitattujen päästöjen kanssa.
APPENDIXES
39
Julkaisu
Lamberg, H., Nuutinen, K., Tissari, J., Ruusunen, J., Yli-Pirilä, P., Sippula, O., Tapanainen, M., Jalava, P.I., Makkonen, U., Teinilä, K., Saarnio, K., Hillamo, R., Hirvonen, M-R., Jokiniemi, J. (2011) Physichochemical characterization
of fine particles from small scale wood combustion. Atmos. Environ. In Press.
ILMATIETEEN LAITOKSEN PÄÄSTÖTUTKIMUKSET
Karri Saarnio, Anna Frey, Kimmo Teinilä, Minna Aurela, Risto Hillamo
Ilmatieteen laitos, Ilmanlaadun tutkimus, Aerosolitutkimus
Ilmatieteen laitoksen Aerosolitutkimus-ryhmän tavoitteena oli selvittää pellettikattilan, perinteisen varaavan
takan ja saunakiukaan pienhiukkaspäästöjen kemiallinen koostumus. Tietoa kemiallisesta koostumuksesta voidaan
käyttää tukena samoista näytteistä saatujen toksisuustietojen tulkinnassa sekä yleisesti ulkoilmanäytteiden lähdeanalyysissa.
Menetelmät
Ilmatieteen laitoksen Aerosolitutkimus-ryhmä osallistui Itä-Suomen yliopiston Pienhiukkas- ja aerosolitekniikan laboratoriossa suoritettuihin pellettikattilan, saunakiukaan ja yhden perinteisen varaavan takan päästömittauksiin. Pellettikattilassa poltettiin havupellettejä, saunakiukaassa ja varaavassa takassa koivuklapeja. Näytteiden
keräysaika pellettikattilan kohdalla oli neljä tuntia (neljä näytettä). Näytteet otettiin jatkuvakäyttöisen pellettikattilan päästövirtauksesta. Palon päästövirtausta laimennettiin käyttäen laimennussuhdetta n. 100. Saunakiukaan ja
perinteisen varaavan takan mittauksissa näytteet kerättiin siten, että ne sisälsivät sekä alkupanoksen että kahden
lisäpanoksen päästöt. Keräysaika näiden kohdalla oli joko 55 tai 65 minuuttia (kuusi keräystä saunakiukaasta ja
viisi takasta). Polttolaitteiden annettiin jäähtyä kunkin mittauskerran välillä. Käytetyt laimennussuhteet olivat 670–
1000 perinteisen varaavan takan päästöille ja 1000–2500 saunakiukaalle.
Pienhiukkasnäytteitä kemiallisia analyysejä varten kerättiin seuraavilla menetelmillä:
PM1-keräin, joka koostui esi-impaktorista, joka poistaa näytevirtauksesta halkaisijaltaan yli yhden µm:n
hiukkaset, ja suodatinkotelosta. Suodattimena käytettiin polytetrafluoroetyleenistä (PTFE) valmistettuja
membraanisuodattimia.
Moniasteimpaktori (small deposit area impactor, SDI), joka jakaa hiukkaset 12 kokoluokkaan hiukkaskokoalueella 0,04-10 µm. Näytealustoina käytettiin ohuelti Apiezon L-vakuumirasvalla pinnoitettuja polykarbonaattikalvoja.
Näytteet analysoitiin Ilmatieteen laitoksen laboratoriossa.
Näytteiden kokonaismassapitoisuus määritettiin punnitsemalla PTFE-suodattimet ennen ja jälkeen näytteenkeruun. Punnitsemiseen käytettiin Mettler UMT2-vaakaa, jonka tarkkuus on 1 µg. SDI-näytteitä ei
punnittu.
Vesiliukoisen orgaanisen hiilen (WSOC) massakonsentraatio määritettiin liuottamalla kerätty suodatinneljännes ionivaihdettuun veteen ja analysoimalla vesiliuoksesta siihen liuenneen orgaanisen aineksen määrä
käyttäen Shimadzu TOC-VCPH-kokonaishiilianalysaattoria.
Biomassan epätäydellisen palamisen merkkiaineita (monosakkaridianhydridit (MA), kuten levoglukosaani, mannosaani ja galaktosaani) määritettiin PTFE-suodatinneljänneksen vesiliuoksesta käyttäen Dionexin
korkean erotuskyvyn anioninvaihtokromatografia, joka oli liitetty kvadrupolimassaspektrometriin
(HPAEC-MS). Analyysimenetelmä MA-yhdisteiden määrittämiseksi tällä laitteistolla kehitettiin PUPOpoltto-projektin aikana.
40
Valikoima vesiliukoisia epäorgaanisia anioneja ja kationeja sekä orgaanisia anioneja määritettiin yhdestä
PTFE-suodattimen neljänneksestä liuottamalla ionivaihdetulla vedellä ja analysoimalla liuos käyttäen Dionex ICS-3000 -ionikromatografia, joka oli liitetty kvadrupolimassaspektrometriin (IC-MS). Ionivalikoimaan
kuuluivat: ammonium, kalium, natrium, kloridi, nitraatti, fosfaatti, sulfaatti, metaanisulfonaatti, asetaatti,
formaatti, glyoksylaatti, oksalaatti, malaatti, maleaatti, malonaatti, sukkinaatti, adipaatti, atselaatti, pinikaatti ja pinonaatti. Ionimääritys tehtiin sekä PM1-näytteille että kokolajitelluille SDI-näytteille.
Osassa saunakiukaan ja varaavan perinteisen takan päästönäytteiden vesiliuotuksessa oli ongelmia, sillä
PTFE-suodattimien pinnalle oli muodostunut kerätystä näyteaineksesta vettä hylkivä kalvo, joten vesiliuotus ei todennäköisesti ole ollut kvantitatiivinen. Tämä lienee osaltaan vaikuttanut vesiliukoisten yhdisteiden määritystuloksiin. Pellettikattilan päästönäytteiden kohdalla tällaista ongelmaa ei ollut.
Tuloksia
Eri polttolaitteiden pienhiukkaspäästöt poikkesivat merkittävästi toisistaan. Selkeästi suurimmat massapitoisuudet määritettiin saunakiukaan päästöille. Saunakiukaan pienhiukkaspäästöt olivat kahdeksan kertaa suuremmat kuin varaavan takan pienhiukkaspäästöt ja 16 kertaa suuremmat kuin pellettikattilan pienhiukkaspäästöt.
Suhteet massapitoisuudelle saunakiukaan, varaavan takan ja pellettikattilan välillä olivat 16:2:1.
Tässä projektissa yhtenä Ilmatieteen laitoksen Aerosolitutkimus-ryhmän tavoitteena oli tutkia hiukkaspäästöjen
vesiliukoista koostumusta. Pellettikattilan pienhiukkaspäästöt poikkesivat selkeästi saunakiukaan ja perinteisen
varaavan takan hiukkaspäästöistä vesiliukoisuuden perusteella. Pellettikattilan pienhiukkaspäästöt muodostuivat
pääosin vesiliukoisesta aineksesta (pääasiassa tuhkaa muodostavia komponentteja), kun taas saunakiukaan ja perinteisen varaavan takan pienhiukkaspäästöt olivat yli 90 %:sesti veteen liukenematonta (luultavasti alkuainehiiltä
ja veteen liukenemattomia orgaanisia yhdisteitä, joita ei näistä näytteistä kyetty määrittämään). WSOCmassapitoisuuksien suhteet olivat samansuuntaiset kuin kokonaismassan: saunakiuas >> takka ~ pelletti (15:1:1).
Pellettikattilan pienhiukkaspäästöistä ei odotettu löytyvän juurikaan vesiliukoisia hiiliyhdisteitä. Kuitenkin vastoin
odotuksia pellettikattilan pienhiukkaspäästöissä oli likimain saman verran vesiliukoista hiiltä kuin perinteisen
varaavan takan pienhiukkaspäästöissä. Tämä saattoi johtua WSOC-määritysmenetelmän epätarkkuudesta pienissä
pitoisuuksissa sekä muista metodologisista syistä.
Korkeat MA-pitoisuudet hiukkasnäytteissä ovat merkkinä biomassan epätäydellisestä palamisesta. PUPOpoltto-projektin mittauksissa selkeästi korkeimmat MA-pitoisuudet havaittiin saunakiukaalle, mutta myös varaavassa takassa MA-pitoisuudet olivat merkittävät. Näihin verrattuna pellettikattilapäästöjen MA-pitoisuudet olivat
todella pienet (lähellä HPAEC-MS-menetelmän havaintorajaa). MA-pitoisuuksien suhteet polttolaitteiden välillä
olivat 320:140:1. MA-yhdisteiden osuus vesiliukoisten hiiliyhdisteiden kokonaismäärästä oli korkea perinteisen
varaavan takan (39 %) ja saunakiukaan (10 %) pienhiukkasnäytteissä. Pellettikattilan pienhiukkasnäytteissä osuus
oli vain 0,25 %. MA-pitoisuuksien perusteella voidaan todeta, että palamisen laatu pellettikattilassa oli hyvä, kun
taas kahden muun polttolaitteen tapauksessa palaminen on ollut jossain määrin epätäydellistä.
Pellettikattilan pienhiukkaspäästöt koostuivat pääosin epäorgaanisista tuhkaa muodostavista komponenteista
(esim. epäorgaanisia ioneja). Pellettikattilan pienhiukkaspäästöjen tuhkakomponenttien pitoisuuksiin verrattuna
perinteisen varaavan takan ja saunakiukaan vastaavat pitoisuudet olivat vähäisiä. Ionien massapitoisuussuhteet
polttolaitteiden välillä olivat 2:3:13. Pellettikattilan näytteissä pääionit olivat kalium, sulfaatti, natrium ja kloridi,
sauna- ja takkanäytteissä kalium, sulfaatti, kloridi ja nitraatti.
Orgaanisten ionien pitoisuudet olivat merkittävästi alhaisemmat kuin epäorgaanisten ionien: pellettikattilan
pienhiukkaspäästöissä oli 125 kertaa enemmän epäorgaanisia ioneja kuin orgaanisia ioneja, saunakiukaan pienhiukkaspäästöissä 20 kertaa enemmän ja perinteisen varaavan takan pienhiukkaspäästöissä 13 kertaa enemmän.
Oksalaatin esiintymistä ilmakehän pienhiukkasissa pidetään yleisesti biomassan palamisen merkkinä. Tämän projektin polttokokeiden mittauksissa oksalaatin pitoisuudet pienhiukkasissa olivat kuitenkin vähäiset verrattuna
muihin biomassan palamisen merkkiaineisiin, kuten kaliumiin ja levoglukosaaniin (MA-yhdisteet). Tulokset osoittavat, että orgaaniset ionit muodostuvat hiukkasiin todennäköisesti vasta palamisen päästöjen sekoittuessa ilmakehään (sekundaarinen muodostuminen). Tässä projektissa näytteet otettiin kuitenkin suoraan palamisen suorista
päästöistä.
APPENDIXES
41
Epäorgaanisten ja orgaanisten ionien kokojakaumista havaittiin, että pellettikattilan päästöt keskittyivät näiden
komponenttien osalta lähes täysin alle 500 nm:n hiukkasiin. Perinteisen varaavan takan ja erityisesti saunakiukaan
ionipäästöt olivat jakautuneet laajemmalle kokoalueelle keskittyen kuitenkin alle 1 µm hiukkasiin.
Yhteenveto
PUPO-poltto-projektissa määritettiin kolmen hyvin erilaisen biopolttolaitteen hiukkaspäästöjä useilla eri menetelmillä. Selkeästi korkeimmat pienhiukkasten kokonaispitoisuudet mitattiin saunakiukaan päästöistä. Havaittiin
myös, että eri polttolaitteiden hiukkaspäästöjen kemiallinen koostumus ja optiset ominaisuudet poikkesivat toisistaan selkeästi. Määritettyjen hiukkasominaisuuksien perusteella voidaan päätellä, että pellettikattilassa palaminen
on tehokasta eikä epätäydellisen palamisen merkkiaineita (levoglukosaania) juurikaan synny. Sen sijaan saunakiukaassa ja varaavassa takassa palaminen on jokseenkin epätäydellistä, jolloin levoglukosaanin ja muiden orgaanisten yhdisteiden pitoisuudet ovat korkeat. Mittausten perusteella saunakiukaassa palaminen on huonolaatuisinta, mikä johtunee polttolaitteen teknisistä rajoitteista (huono lämmönvarauskyky, pieni palotila, huono hapensyöttö).
Tuloksia voidaan käyttää muun muassa arvioitaessa puun pienpolton vaikutusta ulkoilman pienhiukkaspitoisuuksiin. Tuloksia tullaan hyödyntämään erilaisissa biomassan palamiseen liittyvissä tutkimuksissa, joiden tuloksia julkaistaan kansainvälisissä tieteellisissä lehdissä.
Julkaisut
Saarnio, K., Teinilä, K., Aurela, M., Timonen, H., Hillamo, R. (2010) High-performance anion-exchange chromatography–mass spectrometry method for determination of levoglucosan, mannosan, and galactosan in atmospheric
fine particulate matter. Anal. Bioanal. Chem. 398, 2253-2264. doi:10.1007/s00216-010-4151-4
Saarnio, K., Niemi, J.V., Saarikoski, S., Aurela, M., Timonen, H., Teinilä, K., Myllynen, M., Frey, A., Lamberg, H.,
Jokiniemi, J., Hillamo, R. (2011) Fine particles from wood combustion in the Helsinki Metropolitan Area. Submitted
to Boreal Environment Research.
PUUN PIENPOLTON PÄÄSTÖHIUKKASTEN TOKSISUUSTUTKIMUKSET
Maija Tapanainen1, Pasi Jalava1,2, Pasi Hakulinen1, Mikko Happo2, Raimo Salonen1, Jorma Mäki-Paakkanen1 ja Maija-Riitta
Hirvonen1,2
1 Terveyden ja hyvinvoinnin laitos (THL), Ympäristöterveyden osasto, Kuopio
2 Itä-Suomen yliopisto, Ympäristötieteen laitos, Kuopio
Toksikologisten solukokeiden avulla saadaan tärkeää tietoa savukaasualtistumisen käynnistämistä mekanismeista ihmiselimistössä. Tässä tutkimuksessa altistettiin kahta nisäkässolulinjaa, hiiren makrofageja ja ihmisen
keuhkoepiteelisoluja, puunpolton päästöhiukkasille. Päästöhiukkaset oli kerätty eri polttotilanteista ja eri puun
pienpolttolaitteilla Itä-Suomen yliopiston Pienhiukkas – ja aerosolitekniikan laboratoriossa. Makrofagit ovat immuunipuolustusjärjestelmän valkosoluja, jotka ovat ensimmäisten joukossa keuhkoissa taistelemassa vierasaineita
vastaan. Niillä on erityinen kyky syödä ja tuhota suuria partikkeleita. Keuhkoepiteelisolut suojaavat keuhkoputkia
reunustamalla niiden sisäpintaa. Valkosolujen tavoin keuhkoepiteelisolut kykenevät erittämään joitakin immuunipuolustusjärjestelmän välittäjäaineita. Vuorokauden kestävän hiukkasaltistuksen jälkeen tutkittiin soluissa käynnistyviä mekanismeja, jotka voivat olla sairauksien pahenemisen ja keuhkosyövän taustalla:
1) Makrofagien elinkierron eli solusyklin vaiheet ja solukuolema
2) Tulehdusvälittäjäainetuotanto
3) Perimävauriot
42
Päästöhiukkasnäytteiden valmistaminen
Päästöhiukkaset kerättiin toksisuustutkimuksiin Dekatin gravimetrisellä impaktorilla (DGI) teflonsuodattimille
kolmesta perinteisestä ja yhdestä modernista varaavasta tulisijasta, kiukaasta sekä pellettikattilasta (prof. Jokiniemi). Suodattimet punnittiin ennen ja jälkeen keräyksen PM1 hiukkasmassan määrittämiseksi. Hiukkaset uutettiin
suodattimilta metanoliin ultraäänivesihauteessa ja uutos jaettiin lasiputkiin massaperusteisesti. Ylimääräinen metanoli haihdutettiin hiukkasnäytteistä pois typpivirrassa. Näytteet säilytettiin -20 °C:ssa toksisuuskokeita ja kemiallisia analyysejä varten. Ennen varsinaisia toksisuuskokeita PM1 hiukkasnäytteet liuotettiin pieneen määrään
DMSO:ta ja steriiliä vettä. Näytteitä sonikoitiin ultraäänivesihauteessa 30 minuuttia ennen solujen altistamista.
Toksikologiset kokeet
Toksikologiset määritykset tehtiin 24 tunnin aikapisteessä 3-4 eri päästöhiukkasannoksella. Annokset oli valittu
aikaisemman PUPO projektin kokeiden perusteella (Jalava ym., 2010). Hiiren makrofageja altistettiin annoksille 15,
50, 150 ja 300 µg/ml. Ihmisen keuhkoepiteelisoluilla tehdyissä kokeissa annokset vaihtelivat 7,5-300 µg/ml välillä
riippuen päästöhiukkasten toksisuudesta. Altistuksen jälkeen mitattiin solususpensiosta akuuttia solukuolemaa
MTT-testillä ja DNA-vaurioita komeettatestillä. Solusyklin vaiheet ja ohjelmoitu solukuolema määritettiin virtaussytometrilla fiksatuista soluista. Tulehdusvälittäjäainetuotanto mitattiin myöhemmin pakastetuista kasvatusmediumeista ELISA-menetelmällä.
1. Solukuolema
Kaikki tutkitut päästöhiukkaset aiheuttivat solukuolemaa annosvasteisesti hiiren makrofageissa, mutta vasteiden voimakkuuksissa oli eroja.
Kuva 1. Puunpolton päästöhiukkasten aiheuttama a) akuutti ja B) ohjelmoitu solukuolema hiiren RAW264.7 makrofageissa
hiukkasannoksilla 15-300 µg/ml.
Kiukaasta kerätyt huonon palamisen hiukkaset aiheuttivat selvästi eniten akuuttia solukuolemaa makrofageissa
(Kuva 1A). Korkeimmalla hiukkasannoksella (300 µg/ml) soluista kuoli jopa 93±2%. Sen sijaan varaavista tulisijoista kerättyjen hiukkasten sama annos nosti solukuoleman noin 50%:iin. Akuuttia solukuolemaa ei mitattu ihmisen
keuhkoepiteelisoluista. Virtaussytometrilla määritetyssä ohjelmoidussa solukuolemassa havaittiin enemmän eroja
polttotilanteiden ja – laitteiden välillä. Vasteiden suunta oli kuitenkin hyvin samankaltainen kuin akuutin solukuoleman mittauksissa. Myös tässä määrityksessä huonon palamisen hiukkaset aiheuttivat eniten ohjelmoitua
solukuolemaa (Kuva 1B). Kiukaan päästöhiukkaset käynnistivät ohjelmoidun solukuoleman 22±1 %:ssa makrofageja 150 µg/ml annoksella, kun taas pellettikattilan hyvästä palamisesta kerätyt hiukkaset aiheuttivat ohjelmoitua
solukuolemaa samalla annoksella vain 9±1 %:ssa makrofageja. Makrofagien solukuolema saattaa heikentää immuunipuolustusjärjestelmää ja lisätä mm. mikrobien aiheuttamia infektioita keuhkoissa.
APPENDIXES
43
2. Tulehdusvälittäjäainetuotanto
Hiiren makrofagit tuottivat tulehdusvälittäjäaineita annosvasteisesti altistuessaan puupolton hiukkasille (Kuva
2A ja B). Tulehdusvälittäjäainetuotanto saattoi laskea tapauksissa, joissa korkein hiukkasannos (300 µg/ml) aiheutti
laajaa solukuolemaa (esim. huono palaminen kiukaassa). Tämä johtui siitä, että solukuoleman vuoksi määrityksessä ei ollut tarpeeksi soluja tuottamaan kyseisiä välittäjäaineita. Yleisesti ottaen päästöhiukkasten aiheuttamat tulehdusvasteet olivat matalia verrattuna esimerkiksi kaupunki-ilman hiukkasten käynnistämiin vasteisiin (Jalava
ym., 2007).
Kuva 2. Hiiren RAW264.7 makrofagien tuottama A) TNF- ja B) MIP-2 kertaluokkina puupolton päästöhiukkasille (annokset 15-300 µg/ml) altistumisen jälkeen. Kontrollitaso vastaa kertaluokkaa yksi.
Kuva 3. Päästöhiukkasten (annokset 7,5-300 µg/ml) aiheuttamat perimävauriot yksikössä Olive Tail Moment A) hiiren
RAW264.7 makrofageissa B) ihmisen BEAS-2B keuhkoepiteelisoluissa.
3. Perimävauriot
Pellettikattilan hyvän palamisen hiukkasia lukuun ottamatta kaikki tutkitut puunpolton päästöhiukkaset aiheuttivat perimävaurioita komeettatestillä mitattuna. Kyseiset vasteet olivat kuitenkin voimakkaampia ihmisen
keuhkoepiteelisoluissa (Kuva 3B) kuin hiiren makrofageissa (Kuva 3A). Kiukaasta kerätyt huonon palamisen hiukkasten annos 300 µg/ml oli niin toksinen makrofageille, ettei DNA-vaurioiden määrää pystytty luotettavasti määrittämään. Ihmisen keuhkoepiteelisoluissa saman näytteen korkeimmaksi määritettävä annos oli 75 µg/ml. Eri polttotilanteiden vaikutus perimävaurioiden syntymiseen näkyi varaavien tulisijojen näytteissä. Korjaamaton DNA-
44
vaurio voi käynnistää syöpäkasvaimeen johtavan reaktion soluissa. Siksi soluilla on kyky korjata DNA:ssa tapahtuvia vaurioita ja tarvittaessa laukaista ohjelmoituun solukuolemaan johtavan tapahtumaketjun. Näin ollen ohjelmoidun solukuoleman määrityksessä havaitut vasteet olivat hyvin linjassa perimävaurioita mittaavan komeettatestin tulosten kanssa.
Yhteenveto
Tutkimuksen tulokset osoittivat selkeästi, että huonon palamisen päästöhiukkaset aiheuttavat enemmän ohjelmoitua solukuolemaa ja perimävaurioita solumalleissa kuin hyvän palamisen päästöhiukkaset. Sen sijaan päästöhiukkasten aiheuttamat tulehdusvasteet olivat heikkoja, mikä viittaa siihen että savukaasulle altistumisesta aiheutuvien akuuttien terveyshaittojen taustalla ei välttämättä ole välittömiä tulehdusreaktiota. Koska tulehdusreaktio
voi kuitenkin käynnistyä välittömän solukuoleman seurauksena, on todennäköitä, että ne hiukkaset jotka aiheuttavat välittömän solukuoleman, aiheuttavat myös tulehdusta. Ihmisen keuhkoepiteelisolut olivat hyvä solumalli
perimävaurioiden määrittämiseen. Sen sijaan hiiren makrofagit olivat parempi solumalli määritettäessä solukuolemaa ja tulehdusvälittäjäainetuotantoa. Tämä tutkimus osoitti, että hyvällä polttolaitteella ja oikealla käyttötavalla voidaan puun pienpolttolaitteen päästöjä ja niiden terveydelle vaarallisia ominaisuuksia vähentää merkittävästi.
Referenssit
Jalava P.I., Salonen R.O., Pennanen A.S., Sillanpää M., Hälinen A.I., Happo M.S., Hillamo R., Brunekreef B., Katsoyanni K., Sunyer J., Hirvonen M.-R. (2007) Heterogeneities in inflammatory and cytotoxic responses of
RAW264.7 macrophage cell line to urban air coarse, fine and ultrafine particles from six European sampling campaigns. Inhalation Toxicology 19, 213 225.
Jalava P.I., Salonen R.O., Nuutinen K., Pennanen A.S., Happo M.S., Tissari J., Frey A., Hillamo R., Jokiniemi J., Hirvonen M.-R. (2010). Effect of combustion condition on cytotoxic and inflammatory activity of residential wood
combustion particles. Atmospheric Environment 44, 1691 1698.
Julkaisu
Tapanainen, M., Jalava P.I., Mäki-Paakkanen, J., Hakulinen, P., Happo, M.S., Lamberg, H., Ruusunen, J., Tissari, J.,
Nuutinen, K., Yli-Pirilä, P., Hillamo, R., Salonen, R.O., Jokiniemi, J., and Hirvonen, M-R. (2011) In vitro immunotoxic and genotoxic activities of fine particles emitted from two different small-scale wood combustion appliances.
Atmos. Environ. In Press.
APPENDIXES
45
APPENDIX III: DETAILED DESCIPTION OF SOME OF MEASUREMENT AND ANALYSES METHODS USED IN THIS STUDY
DGI. Dekati Gravimetric Impactor is a cascade impactor that can be used to collect particles on 47 mm collection
substrates. It classifies particles into five size fractions with stage cutoffs between 2.5 µm and 0.2 µm. The nominal
sample flow rate is 70 lpm. DGI is suited for collecting particles for toxicological analyses from combustion flue
gases.
DLPI. Dekati Low Pressure Impactor, similar to ELPI, classifies particles in 13 different size fractions by their aerodynamic diameter in a size range of 7 nm to 10 µm. In DLPI, particles are collected to collection substrates made of
aluminum foil, which can be later analyzed gravimetrically for determining particle mass-size distribution.
ELPI. Electrical Low Pressure Impactor is a real-time analyzer for particle size distribution and concentration
which classifies particles according to their aerodynamic diameter in 13 different size fractions. ELPI measures
particles in a size range of 7 nm to 10 µm.
FMPS. Fast Mobility Particle Sizer classifies particles real-time in 32 channels between a size range of 5.6 nm and
560 nm for particle size distribution and concentration. FMPS classifies particles by their electrical mobility.
FTIR. Fourier Transform Infrared Spectroscopy. Multicomponent analyser which can be used for the realtime
analysis of several flue gas components simultaneously (CO, CO2, O2, SO2, NO, NO2, N2O, HCl, HF, H2O…).
IC, Ion Cromatography. Technique that allows the separation of ions and polar molecules based on the charge
properties of the molecules. It can be used quantify the amount of almost any kind of charged molecule from sample solutions.
ICP-MS, Inductively coupled plasma mass spectrometry. ICP-MS is a type of mass spectrometry that is highly
sensitive and capable of the determination of a range of metals and several non-metals at concentrations below one
part in 1012. It is based on coupling together inductively coupled plasma as a method of producing ions with a mass
spectrometer as a method of separating and detecting the ions.
OC/EC. OC/EC method can be used to analyze different fractions of carbonate, elemental carbon and organic carbon from quartz-filter samples by a thermal optical method.
Toxicology analyses, Proinflammatory cytokines and chemokines (e.g. TNF , IL-6, MIP-2) are measured with multilabel counter (PerkinElmer Victor3) with spectrophotometric method. Enzyme linked immunosorbent assay
(ELISA) kits are used in determination of the protein concentration in the cell culture mediums after exposures to
the biomass combustion particulate samples. Production of nitric oxide is determined with Griess-method from the
cell culture medium. Absorbances are spectrophotometrically measured with the multilabel counter (PerkinElmer
Victor3). MTT-test is used in determination of the total acute cytotoxicity after exposure to the biomass combustion
particulate samples. Absorbances are spectrophotometrically measured with the multilabel counter (PerkinElmer
Victor3). The cell cycles of the exposed cells are measured with flow cytometer (CyAN ADP, Beckman Coulter)
after propidium iodide staining of the permeabilized cells. The cells are fixed after the exposures to the biomass
combustion particulate samples for the analysis. Programmed cell death (apoptosis) can be gained simultaneously
from cell cycle analysis (CyAN ADP, Beckman Coulter). Uncontrolled cell death necrosis is measured with flow
cytometer (CyAN ADP, Beckman Coulter) after propidium iodide staining of the fresh cell cultures. Oxidative
stress is measured from the cell cultures, exposed to the biomass combustion particulate samples with flow cytometric (CyAN ADP, Beckman Coulter) method detecting intracellular oxidants (e.g. H 2O2, ONOO-) by using 2’,7’dichlorofluorescein diacetate (DCF). Genotoxicity in the cells, exposed to the biomass combustion particulate samples is measured with single cell gel electrophoresis (Comet assay).

Loppuraportti - Itä

Transcription

Similar documents

M7T 234

Tekniikan Englantia

höyrystin