Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario L01 1N0, Canada.
Environ Pollut. 2010 Mar;158(3):749-55. doi: 10.1016/j.envpol.2009.10.013. Epub 2009 Nov 11.
The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil-air exchange was examined. The most prominent OCs were the DDTs (Geometric Mean, GM=1.6 ng g(-1)), endosulfans (0.16 ng g(-1)), and toxaphenes (0.64 ng g(-1)). DDTs in soils of southern Mexico showed fresher signatures with higher FDDTe=p,p'-DDT/(p,p'-DDT+p,p'-DDE) and more racemic o,p'-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil-air fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and air showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization.
研究了土壤中有机氯农药（OCs）的空间分布及其向土壤-空气交换的潜力。最突出的 OCs 是滴滴涕（几何平均值，GM=1.6ng g(-1))、硫丹（0.16ng g(-1)) 和毒杀芬（0.64ng g(-1))。墨西哥南部土壤中的滴滴涕具有更新鲜的特征，FDDTe=p,p'-DDT/(p,p'-DDT+p,p'-DDE）更高，对映体 o,p'-DDT 更多，而墨西哥中北部的特征则更表明是陈旧的残留。土壤-空气逸度分数表明，一些土壤是滴滴涕从大气中吸收的净受体，而其他土壤则是净源。土壤和空气中的毒杀芬剖面显示，Parlar 39 和 42 的消耗表明土壤是大气的来源。由于目前仍在使用硫丹，因此大多数地点的硫丹都在进行净沉积。其他 OCs 的逸度变化很大，表明存在净沉积和挥发的混合。
