DETERMINATION OF AEROSOL MEAN RESIDENCE TIME USING 210Pb AND 7 Be RADIONUCLIDES IN THE ATMOSPHERE OF ISLAMABAD
Abstract
The concentrations of 210Pb, 214Pb and 7 Be radionuclides (having radioactive half lives of 22.3 years, 27 min. and 53.29 days, respectively) in 184 surface level air samples of Islamabad (33.38° N, 73.10° E) were measured using the technique of non-destructive gamma-spectrometry on high purity germanium (HPGe) detector. The mean concentrations of 210Pb, 214Pb and 7 Be in the samples were found to be 0.284 ± 0.012 mBq m-3, 631.06 ± 155.47 mBq m-3 and 3.171 ± 0.084 mBq m-3, respectively. The aerodynamic size distribution of 7 Be in the atmospheric aerosols was also determined, using Anderson 1-ACFM cascade impactors, which resulted in the mean diameter of 7 Be-laden aerosols as 0.79 ± 0.12 µm. The mean residence times (MRT) for 210Pb and 7 Be-laden aerosols, thus obtained, were 5.29 ± 0.91 days and 7.18 ± 0.97 days respectively.References
B.I.B. Wiman, H.M. Unsworth, E.S. Lindberg,
B. Bergkvist, R. Jaenicke and H.C
Hanssan, J. Aerosol Sci. 21 (1990) 313.
A.S. Likuku, The influence of topography and
vegetation canopy on the deposition of
atmospheric particulates studied with 210Pb
and 137Cs soil inventories. Ph.D Thesis,
University of Edinburgh, Scotland (2003).
S. Talpos and V. Cuculeanu, J. Aerosol Sci.
(1997) S577.
R.A. Brost, T. Feichter and M. Heimann, J.
Geophys. Res. 96 (1991) 22423.
D. Lal and B. Peters, In: Cosmic ray
produced radioactivity on the earth: Handbook of Physics (1967) p.551.
S.E. Poet, H.E. Moore and E.A. Martell, J.
Geophys. Res. 77 (1972) 6515.
S.J.S. Anand, C. Rangarajan and U.C.
Mishra, Aerosol residence time calculations
using Bismuth-210/Lead-210 activity ratios of
atmospheric particulates. In: Atmospheric
Aerosols and Nucleation. Springer, Berlin /
Heidelberg (1988) p. 287.
H.W. Gäggler, D.T. Jost, U. Baltensperger,
M. Schwikowski and P. Seibert, Atmos.
Environ. 29 (1995) 607.
A.A. Ahmed, A. Mohamed, A.E. Ali, A.
Barakat, M.A. El-Hadi and A. El-Hussain, J.
Environ. Radioact. 77 (2004) 275.
H.E. Moore, S.E. Poet and E.A. Martell, J.
Geophys. Res. 78 (1973) 7065.
M.B. Gavini, J.N. Beck and P.K. Kuroda, J.
Geophys. Res. 79 (1974) 4447.
C. Ragarajan and C.D. Eapen, Tellus 42B
(1990) 142.
A.E. Nevissi, J. Radioanal. Nucl. Chem. Art.
(1991) 121.
C. Papastefanou and E.A. Bondietti, J.
Aerosol Sci. 22 (1991) 927.
C. Papastefanou, Aerosol Air Qual. Res. 9
(2009) 187.
IAEA, International Atomic Energy Agency,
Measurement of Radionuclides in Food and
the Environment: a Guide Book (IAEA,
Vienna, 1989) Technical Reports Series No.
National Research Council, Airborne
particles, University Park Press, Baltimore,
USA (1979).
P.H. McMurry and J.C. Wilson, Atmos.
Environ. 16 (1982) 121.
W.C. Graustein and K.K Turekian, J.
Geophys. Res. 91 (1986) 14355.
G. Lambert, J. Sanak and G. Polian, Mean
residence time of the sub micrometer
aerosols in the global troposphere. In: H.R.
Pruppacher, R.G. Semonon, W.G.N. Slinn
(Eds.) Precipitation Scavenging, Dry
Deposition and Resuspension. Elsevier, New
York (1983) p. 1353.
