Atmospheric organochlorine pesticides in the western Canadian Arctic: Evidence of transpacific transport
Atmospheric organochlorine pesticides in the western Canadian Arctic: Evidence of transpacific transport
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DOI：
10.1029/1999jd901180
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发表时间：
2000-05-16
影响因子：
4.4
通讯作者：
Muir, DCG
中科院分区：
文献类型：
--
作者：
Bailey, R;Barrie, LA;Muir, DCG
1992年12月至1995年1月期间，每周在加拿大塔吉什育空地区的环境空气样本中测量六氯环己烷（HCHs）、滴滴涕（DDT）的浓度。在冬季，塔吉什的空气中六氯环己烷、滴滴涕和氯丹的浓度异常高，主要是受到来自东亚的跨太平洋远距离大气传输的影响，这种传输一般在5天内发生。六氯环己烷和七氯环氧化物的浓度与空气在到达塔吉什之前在东亚上空停留的时间有关。氯丹和滴滴涕也随着跨太平洋迁移而增加，但并未显示出与包括亚洲在内的上风空气区的时间相关，因为这些农药在大气中的成分受到使用模式、施用方法、土壤中母体农药和代谢物的可变成分以及挥发率的影响。当5天逆风气流范围包括美国西部时，源自北美的气团中六氯环己烷和氯丹的浓度最高。在加拿大，六氯环己烷的浓度也可能受到林丹使用的影响。
Concentrations of hexachlorocyclohexanes (HCHs), chlordane, and dichlorodiphenyltrichloroethane (DDT) were measured in ambient air samples on a weekly basis between December 1992 and January 1995 at Tagish Yukon, Canada. In winter, unusually high air concentrations of HCHs, DDT, and chlordanes at Tagish were predominantly influenced by transpacific long-range atmospheric transport from eastern Asia that generally occurred within 5 days. HCH and heptachlor epoxide concentrations were correlated with the time that air spent over eastern Asia prior to arrival at Tagish. Chlordane and DDT, which also increase with transpacific transport, do not show a correlation with the time the upwind airshed included Asia as the composition of these pesticides in the atmosphere is affected by differences in usage patterns, application methods, variable composition of parent pesticides and metabolites in the soil, and rates of volatilization. Air masses originating from North America had the highest concentrations of HCHs and chlordanes when the 5-day upwind airshed included the western United States. Concentrations of HCHs may also be influenced by lindane usage in Canada.