Characteristics of U-pattern distribution of high-concentration ^(210)Pb in surface air at central Guizhou,China  

作　　者：WAN Guojiang YANG Wei WANG Shilu WAN Enyuan WU Fengchang S.N.LEE WANG Changsheng HUANG Ronggui 

机构地区：[1]State Key Laboratory of Environmental Geochemistry, ChineseAcademy of Sciences, Guiyang 550002, China [2]Environmental Measurements Laboratory, Department of Homeland Security, NY 10014-4811, USA

出　　处：《Chinese Science Bulletin》2005年第16期1750-1755,共6页

基　　金：This work was supported by the National N atural Science Foundation of China(Grant No.40373038);the National Key Project for Basic Research(Grant No.2002CB4 12300).

摘　　要：A better understanding of the variation of 210Pb concentrations in the surface air is the key to trace lake sedimentation and catchment erosion, to establish and vali-date the global diffusion model of contaminants, and to as-sess the impact of natural radiation on the ecological system. Basing on the study progresses of the sedimentation, the at-mospheric model and the unique environmental background in the Yunnan-Guizhou Plateau, and starting from December 20, 2001, we made use of a 500 NE Type aerosol sampler to collect filter samples, once a week in the past consecutive two years, in the surface air at Mt. Guanfeng, Guiyang City, China. Synchronous detailed γ -energy spectrometric obser-vations of 210Pb concentrations at both Chinese and U.S. laboratories have shown that the average monthly 210Pb concentration displays a regular U-patterns distribution of annual variations, with high values appearing in winter and low values in late spring and summer. The average annual 210Pb concentrations are estimated to be 2.77±0.63 mBq/m3, about 4 times the average maximum concentrations reported from quite a number of monitoring stations throughout the world. The possible factors affecting the sources of 210Pb in the surface air in the central part of Guizhou Province are: Release of 222Rn from the U-Ra series enriched in the soils; chemical weathering of carbonate rocks; the exploitation, processing and utilization of coal and phosphorous resources. The principal factor controlling the high 210Pb concentrations in the surface air in the central Guizhou and their annual U-pattern distribution is the release of 222Rn. The average monthly 210Pb concentrations show a good negative power- function relationship with increasing precipitation and also show a good negative linear-function relationship with the rise of air temperature in month grouping. Group No.1 (June to November) reflects a relatively low release of 222Rn from soils in relatively high temperature seasons; Group No.2 (December to May) mirrors a relatively hiAbstract A better understanding of the variation of ^210pb concentrations in the surface air is the key to trace lake sedimentation and catchment erosion, to establish and validate the global diffusion model of contaminants, and to assess the impact of natural radiation on the ecological system. Basing on the study progresses of the sedimentation, the atmospheric model and the unique environmental background in the Yunnan-Guizhou Plateau, and starting from December 20, 2001, we made use of a 500 NE Type aerosol sampler to collect filter samples, once a week in the past consecutive two years, in the surface air at Mt. Guanfeng, Guiyang City, China. Synchronous detailed γ-energy spectrometric observations of ^210pb concentrations at both Chinese and U.S. laboratories have shown that the average monthly ^210pb concentration displays a regular U-patterns distribution of annual variations, with high values appearing in winter and low values in late spring and summer. The average annual ^210pb concentrations are estimated to be 2.77±0.63 mBq/m^3, about 4 times the average maximum concentrations reported from quite a number of monitoring stations throughout the world. The possible factors affecting the sources of ^210pb in the surface air in the central part of Guizhou Province are： Release of ^222Rn from the U-Ra series enriched in the soils; chemical weathering of carbonate rocks; the exploitation, processing and utilization of coal and phosphorous resources. The principal factor controlling the high ^210pb concentrations in the surface air in the central Guizhou and their annual U-pattern distribution is the release of ^222Rn. The average monthly ^210pb concentrations show a good negative powerfunction relationship with increasing precipitation and also show a good negative linear-function relationship with the rise of air temperature in month grouping. Group No.1 （June to November） reflects a relatively low release of ^222Rn from soils in relatively high temperature seasons; Group No.2 （December to May）

关 键 词：表面空气 铅浓度 U模式分布 中国 贵州 

分 类 号：P404[天文地球—大气科学及气象学]