广州不同季风期近地面大气气溶胶中~7Be与持久性有机污染物的同步观测  

Seasonal variations of beryllium-7 and typical POPs in aerosols from near-surface atmosphere in Guangzhou,China

作　　者：杨永亮[1,2] 史敬磊[3] 张干[2] 朱晓华[1] 李勇[4] 于寒青[4] 

机构地区：[1]国家地质实验测试中心中国地质科学院生态地球化学重点开放实验室,北京100037 [2]中国科学院广州地球化学研究所有机地球化学国家重点实验室,广东广州510640 [3]青岛大学化学化工与环境学院,山东青岛266071 [4]中国农业科学研究院农业环境与可持续发展研究所,北京100012

出　　处：《地球化学》2011年第1期72-82,共11页Geochimica

基　　金：国家自然科学基金(40773010);有机地球化学国家重点实验室开放基金(OGL-200404);广东省自然科学基金(04002144)

摘　　要：2006年8月—2007年7月,在广州市天河区以每周采集2～3天的采样频率连续12个月采集近地面大气气溶胶样品,同步测定近地面气溶胶中7Be和有机氯农药(OCPs)、多氯联苯(PCBs)、多溴联苯醚(PBDEs)等持久性有机污染物的浓度值。7Be浓度全年平均值为2.59 mBq/m3,最高值出现在5月(8.5 mBq/m3),最低值出现在8月底—9月初(0.07 mBq/m3)。冬季和春季为7Be浓度值较高的季节,夏季和秋季浓度值较低。在2月份—4月份期间,7Be可能受到"春季泄漏"现象的影响。∑OCPs、∑33PCBs和∑31PBDEs年平均浓度分别为345.6 pg/m3、317.6 pg/m3和609.0 pg/m3。广州市近地面大气气溶胶中7Be与POPs随时间变化的趋势既有共性部分又存在差异。在夏季、秋季和初冬季7Be与∑PCBs和∑PBDEs的相关性则较好,相关系数r分别为0.9784和0.9006(p=0.01)。OCPs与PCBs和PBDEs的时间变化曲线完全不同,可能是OCPs与PCBs和PBDEs的来源不同以及物理化学性质差异较大,受大气气团的影响不同所致。Near-surface atmospheric aerosol samples were collected at sampling frequencies of 2 3 d per week for one year from August 2006 to August 2007 at a low latitude station in Tianhe District, Guangzhou, Guangdong Province of southern China. The samples were analyzed for cosmogenic nuclide ^7Be and persistent organic pollutants organochlorine pesticides （∑CPs）, polychlorinated biphenyls （PCBs）, and polybrominated diphenyl ethers （PBDEs）. The annual average ^7Be concentration was 2.59 mBq/m3, with the maximum occurred in May （8.5 mBq/m3） and minimum in late August and early September （0.07 mBq/m3）. Winter and Spring were the seasons in which the ^7Be concentrations were higher while summer and autumn were the lower ^7Be seasons. Spring peaks in ^7Be in the near-surface atmospheric aerosols may have associated with the ＂spring discharge＂ episode. The annual average ∑OCPs concentration was 345.6 pg/m3, ∑33PCBs 317.6 pg/m3 and ∑31PBDEs 609.0 pg/m3. The variation trends in the time-series of ^7Be, OCPs, PCBs, and PBDEs in near-surface atmospheric aerosols showed both common features and differences. Significant correlations （r 0.9784 or 0.9006. respectively, p0.01） were observed between the monthly average ^7Be concentrations and those of ∑PCBs and ~PBDEs in summer, autumn, and early winter. The difference between the seasonal variation features of OCPs and PCBs （and PBDEs） could be attributed to the different source functions and physical-chemical properties which could control the behaviors of these compounds in air-aerosol partitions as well as atmospheric transportation.

关 键 词：7Be 大气气溶胶 持久性有机污染物 东亚季风 广州市 

分 类 号：P593[天文地球—地球化学]