Atmospheric deposition of 210Po and 210Pb in Malaysian waters during haze events (original) (raw)
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Atmospheric Environment, 2011
The natural radionuclide 210 Pb was analysed in rainwater samples in _ Izmir by radiometric methods. The samples were collected continuously from January 2000 through December 2003 depending on the frequency of rain. The levels of 210 Pb in the samples were found to vary between 9 AE 1 and 198 AE 6 mBq l À1 with an average value of 51 AE 0.5 mBq l À1 . 210 Po activity concentration in total (wet and dry) deposition has also been investigated in the study from November 2001 to April 2003 and the results were found to vary between 2 AE 0.4 and 35 AE 3 mBq l À1 . The average value of 210 Po activity concentration is found as 8 AE 0.5 mBq l À1 . 210 Po/ 210 Pb activity ratios were derived as between 0.03 and 1.09. The annual 210 Po and 210 Pb fluxes were 12 and 48 Bq m À2 y À1 , respectively.
Speciation of 210Po and 210Pb in air particulates determined by sequential extraction
Journal of Environmental Radioactivity, 2006
Speciation of 210 Po and 210 Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble 210 Po and 210 Pb (attached to silica and soluble in mineral
Estuaries and Coasts, 2014
ABSTRACT Surface seawater was collected using a high-volume water pump in Malaysian waters during the first Prime Scientific Sailing Expedition in 2009 to obtain activity levels of lead-210 (210Pb) and polonium-210 (210Po). The 210Pb activity in surface water obtained from this sampling ranged from 0.22 ± 0.06 to 0.96 ± 0.31 mBq/L, averaging 0.58 ± 0.28 mBq/L, whereas the 210Po activity was between 1.52 ± 0.11 and 8.98 ± 0.96 mBq/L, averaging 4.19 ± 0.58 mBq/L. The 210Po/210Pb activity ratios in the surface water at the studied sites were between 3.48 ± 1.06 and 13.08 ± 3.78, with an average of 7.27 ± 3.73, which is distinctly higher than the range of 0.1 to 2.8 in the whole southern South China Sea and western Pacific regions. The relatively high activities of dissolved 210Po in Malaysian waters can be attributed to high depositional fluxes of the radionuclides from enhanced dry precipitations caused by haze events. The higher 210Po fractions found in this study compared with those found in the major oceans were due to terrestrial fires with estimated 210Po residence times between 0.15 and 0.51 years, slightly less than the 0.2- to 0.8-year residence times found in oceans with higher productivities. Higher residence times have also been observed more often offshore than near the shoreline. This phenomenon results in a slower rate of removal of 210Po from offshore surface water.
Activities of 210Po and 210Pb in the water column at Kuala Selangor, Malaysia
Journal of environmental radioactivity, 2005
Natural radionuclides, such as (210)Po and (210)Pb were measured in the water samples collected from six stations at Kuala Selangor, Malaysia. Results for (210)Po and (210)Pb in dissolved and particulate phases have showed the difference in distribution and chemical behavior. The fluctuation activities of (210)Po and (210)Pb depend on wave action, geology and degree of fresh water input occurring at study areas and probably due to different sampling dates. The distribution coefficient, K(d), values of (210)Po and (210)Pb ranged from 2.0 x 10(3)lg(-1) to 265.15 x 10(5)lg(-1), and from 3.0 x 10(3)lg(-1) to 558.16 x 10(5)lg(-1), respectively. High K(d) values of (210)Po and (210)Pb indicated that a strong adsorption of (210)Po and (210)Pb onto suspended particles, and the sinking of both nuclides on the seabed at study locations were controlled by the characteristics of suspended particles.
Geochemical Journal, 1995
Atmospheric bulk deposition and aerosol samples were collected simultaneously in the surface air over the west coast of Japan (38°46' N, 139°44' E), and analyzed for 210Pb. By coupling data with those pre viously reported for 210Po (Suzuki, 1994), the following results have been obtained. (1) The 210po/210Pb activity ratios in aerosols were consistently larger than those in atmospheric depositions, and (2) the activity ratios in April were larger than those in July and October in both aerosol and deposition samples. The results can be variously attributed to the difference of residence time between atmospheric suspending and settling particles, and the difference of contribution from various sources in which 210Pb and 210Po are in over-, under or secular-equilibrium.
Limnology and Oceanography: Methods, 2013
Accurate measurements of particulate 210 Po ( 210 Po p ) and 210 Pb ( 210 Pb p ) are required in the investigation of (i) partitioning of Po and Pb between particulate and dissolved phases and (ii) export estimates of carbon and other key trace metals from the euphotic zone via sinking particulate matter. Based on the intercomparison of different composition of the filter material (QMA, Supor, Millipore, and Pall GN6) and flow rates (2 to 8 L min), we show how these factors affect the measured concentrations of 210 Po p and 210 Pb p and their activity ratios (AR). As such, we recommend using Supor 0.4 µm filter and a flow rate of up to 8 L/min for the measurements of 210 Po p and 210 Pb p . Furthermore, we inter-compared 210 Po p and 210 Pb p obtained by small-volume McLane and large-volume MULVFS pumps. The activities of 210 Po p in MULVFS filter samples are somewhat higher than that of McLane filter samples, whereas the 210 Po/ 210 Pb AR collected by McLane pump is distinctly lower, suggesting some fractionation in the collection process by the pumping systems. Likewise comparison of vertical profiles of 210 Po p and 210 Pb p obtained using McLane pumps by two independent research groups at the two intercalibration stations in the Pacific Ocean show quite similar values except in the mesopelagic waters, suggesting possible uneven loading and presence of larger gelatinous plankton in the filter. Finally, we append a detailed analysis of various correction factors for the accurate calculation of in situ 210 Po and 210 Pb. Presented results are relevant to the worldwide community that uses 210 Po-210 Pb as tracers in aquatic systems.
The sources and fate of 210Po in the urban air: A review
Environment International, 2016
The origin of 210 Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the 210 Po/ 210 Pb and 210 Bi/ 210 Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported 210 Po coming from other sources than 222 Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of 210 Po in the urban air. The average doses of 210 Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from 210 Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure.
Journal of Radioanalytical and Nuclear Chemistry, 2012
The significant differences in the activities of 210 Pb, 210 Bi, 210 Po and cosmogenic 7 Be and 22 Na radionuclides in the urban aerosol samples collected in the summers 2010 and 2011 in the Lodz city of Poland were observed. Simultaneous measurement of these radionuclides, after a simple modification of the one compartment model, allows us to calculate both: the corrected aerosol residence times in the troposphere (1 7 25 days) and in the lower stratosphere (103 7 205 days). The relative input of the additional sources (beside of the 222 Rn decay in the air) to the total activity concentrations of 210 Pb, 210 Bi and 210 Po radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of 210 Po.
Aerosol Science and Technology, 2000
Lead-210 and 210 Po were measured in size-fractionated aerosol samples collected at several sites in North America. Total particulate mass concentrations of the samples were 23-98 m g r r r r r m 3 , with 23-67% of the mass in size ranges below 2 m m. The aerosol mass size distributions below 9 m m were generally bimodal, with a maximum in the coarse-particle range occurring primarily at 3.1 m m and a maximum in the accumulation range occurring at approximately 0.6 m m. Total 210 Pb concentrations were 0.