PM - Universidad de Navarra

Levels of particulate matter (PM10) and radionuclides in PM10 and bulk
deposition samples in Cienfuegos (Cuba)
Yasser Morera Gómeza,b; Carlos M. Alonso Hernándeza; Jesús Miguel Santamaría Uleciab; David Elustondo Valenciab; Héctor A. Cartas Águilaa
a Centro
b
de Estudios Ambientales de Cienfuegos, AP 5. Ciudad Nuclear, CP 59350, Cienfuegos, Cuba.
Departamento de Química, Universidad de Navarra, Irunlarrea n°1, Pamplona 31009, Navarra, España.
Cosmic ray
Atmosphere
N
Introduction
O
Knowledge of the levels and behavior of the atmospheric particulate matter (PM) and natural radionuclides like 7Be and 210Pb in the atmospheric PM will
yield insight on the atmospheric processes relevant to air quality and climate [1,2]. The long-term measurements of these radionuclides in aerosols are
capable of providing useful information on transport, removal and residence time of aerosol species. 7Be (half-life: 53.3 days) is a cosmogenic radionuclide
produced in the stratosphere when cosmic rays bombard the nucleus of oxygen, and nitrogen atoms in the atmosphere. The main source of 210Pb (half-life:
22 years) is the radioactive decay of 222Rn (half-live: 3.8 days) emitted to the atmosphere from the earth’s crust. These nuclides are attached to the
aerosols mainly in the accumulation mode (0.07-2.0 m) and subsequently removed from the atmosphere, primarily by precipitation [3].
7Be
Rain
40K
210Pb………..
Aerosols +
210Pb
+
7Be
+
40K
222Rn
In this work, levels of PM10 and the concentration of 7Be, 210Pb and 40K in PM10 and in bulk depositions (wet + dry) samples were determined in
Cienfuegos, Cuba. Moreover, the depositional fluxes of these radionuclides and the 210Pb/7Be ratios were calculated.
+…
Earth surface
Results
Materials and methods
Temporal trend of atmospheric PM10, 210Pb and 7Be in a rural and urban site at Cienfuegos
90
Study area: PM10 and 210Pb, 7Be and 40K activity concentrations were determined in PM10 and
PM10 CEAC (urban site)
PM10 COSTERO (rural site)
80
in bulk deposition samples in Cienfuegos (central- southern zone of Cuba).
70
Annual average
(this study)
24,2
Rural
35,7
Urban
PM10 by NC 1020:
2014 (Cuba)
50
24 h
30
Annual average
PM10 Air Quality
Guidelines (WHO)
50
24 h
20
Annual average
3
PM10 (g/m )
60
50
40
30
20
10
25 Jan
25 Feb
2015
25 Mar
25 Apr
25 May
25 Jun
25 Jul
25 Aug
25 Sep
25 Oct
25 Nov
25 Dec
25 Jan
2016
0,0010
0,010
7
Be at rural site
7
Be at urban site
0,008
210
Pb at rural site
Pb at urban site
0,0008
0,0006
0,004
0,0004
0,002
0,0002
Bq/m
3
0,006
210
PM: 24-h samples of PM10 were collected onto quartz fiber filters every three days from
January 2015 to January 2016 using high-volume samplers MCV-CAV (flow of 30 m3/h) at two
different sites (rural and urban background).
0,0000
0,000
Feb Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
100
Radionuclides: 48-h PM10 samples were fortnightly collected at the two sites and bulk
=
𝑚𝐵𝑞
𝐹𝑖 2
𝑚 𝑑
(𝑃𝑀10)
=
7
3
𝑥1000 (𝐵𝑢𝑙𝑘 𝑑𝑒𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛)
40
10
Feb Mar
0,00
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan 2016
400
2
mBq/m d
Pb
5000
200
2
4
100
0
7
2
1
0,02
60
2
mBq/m d
0
0,50
0,45
7
Be
40
K
0,40
50
y=15,4x - 395,6
2
R =0,88
n=22
6000
Be flux (mBq/m d)
Bq/g
2
210
300
3
70
7000
6000
5000
4000
3000
2000
1000
0
4000
3000
2000
1000
7
Be
0
0
40
mBq/m d
0,25
2
Bq/g
0,30
20
0,20
10
0,15
0,10
0
J
J
A
S
O
N
D
F
M
A
M
M
-1
4
A
M
J
J
A
S
O
N
D
E15
F
M
A
M
J
J
A
S
O
N
D
M
-1
4
A
M
J
J
A
S
O
N
E- D
15
100
150
200
250
300
350
400
2
Pb flux (mBq/m d)
Monthly average Anual deposition (2015)
20
18
16
14
12
10
8
6
4
2
0
mBq/m2d
Bq/m2y
210Pb
143
50
7Be
1954
453
40K
9.8
3.6
TDP
g/m2d
0.047
g/m2y
18
40
K
4
-1
M
0,05
50
210
0,35
30
Saharan air masses. A yellow color in
the filters and high PM10 concentrations
was detected .
Air masses from the north with
high 210Pb concentrations.
Atmospheric depositional fluxes of 210Pb, 7Be and 40K in the rural site at Cienfuegos
Pb
5
TDP (g/m d)
0,05
20
0,08
0,03
Jan 2016
Pb/ Be
50
0,10
210
6
0,04
Dec
7000
Total Deposition Particules
0,05
Nov
0,15
7
0,06
Oct
7
60
Activity concentration of 210Pb, 7Be and 40K in bulk deposition in the rural
site at Cienfuegos
0,07
Sep
70
𝐶, 𝐹, 𝐴 and 𝑚 are the concentration, flux, activity and mass of the sample. 𝑉, 𝑆 and 𝑡 are the
area, volume and time of collection.
0,09
Aug
Pb/ Be
30
0,10
Jul
210
𝑚𝐵𝑞
𝐶𝑖
𝑚3
Jun
0,20
PM10 at urban site
210
𝐵𝑞
𝐴𝑖 𝑔 𝑚 𝑔
𝑆 𝑚2 𝑡𝑚 𝑑í𝑎𝑠
May
Continental air masses from south
210
with high Pb concentrations
80
g/m
𝐵𝑞
𝐴𝑖 𝑔 𝑚 𝑔
𝑉 𝑚3
Apr
0,25
90
deposition samples were monthly collected at the rural site only. Samples were measurement
in a gamma spectrometry system.
Feb Mar
Jan 2016
A
M
J
J
A S
O
N
D -15
E
F
M
A
M
J
J
A S
O
N
D
Discussions and conclusions
•
•
•
Annual mean PM10 levels show a similar evolution pattern (R2= 0.68) in both locations studied here. PM10 annual averages exceed the Air Quality Guidelines by the World Health Organization
(WHO) [4] at the rural and urban site and the Cuban regulations (NC 1020:2014) only at the urban site. The maximum permissible daily concentrations of PM10 in Cuba is exceed 12 and 3
times in the urban and rural site, respectively.
7Be and 210Pb activity concentrations showed a good correlation in bulk deposition samples, indicating a similar behavior in the area. In general, the fluxes of 210Pb and 7Be decreases during
the dry period and increases in the months of high rainfall (during the summer, fundamentally). In the rural site a strong correlation between 210Pb and 7Be deposition fluxes was observed
indicating that the deposition of these radionuclides from the atmosphere is affected by similar factors [5,6].
The obtained results suggest that the 210Pb/7Be ratio could be used to trace the origin of air masses affecting the study area. However, further studies involving meteorological variables are
required to understand the 210Pb/7Be temporal trend.
References
[1] J. Aldabe, D. Elustondo, C. Santamaria, E. Lasheras, M. Pandolfi, A. Alastuey, et al., Atmospheric
Res. 102 (2011) 191–205. doi:10.1016/j.atmosres.2011.07.003.
[2] N. Ali, E.U. Khan, P. Akhter, N.U. Khattak, F. Khan, M.A. Rana, J. Environ. Radioact. 102 (2011) 35–
42.
[3] M. Baskaran, Coleman Charles H., P.H.. Santschi, J. Geophys. Res. 98 (1993) 20555–20571.
[4] WHO. (2005). http://www.who.int/phe/health_topics/outdoorair/outdoorair_aqg/en/ (accessed
March 6, 2016).
[5] C.M. Alonso-Hernández, Y. Morera-Gómez, H. Cartas-Águila, A. Guillén-Arruebarrena, J. Environ.
Radioact. 138 (2014) 149–155. doi:10.1016/j.jenvrad.2014.08.023.
[6] M. Baskaran, P.W. Swarzenski, Mar. Chem. 104 (2007) 27–42.