Jin Meiqing, Fu Jie, Xue Bin, Zhou Shanshan, Zhang Lina, Li An
College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, PR China.
College of Environment, Zhejiang University of Technology, Hangzhou, PR China.
Environ Pollut. 2017 Mar;222:109-117. doi: 10.1016/j.envpol.2016.12.075. Epub 2017 Jan 6.
The spatial distribution, compositional profiles, and enantiomer fractions (EFs) of organochlorine pesticides (OCPs), including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and chlordanes (CHLs), in the surface sediments in the Bering Sea, Chukchi Sea and adjacent areas were investigated. The total concentrations of DDTs, HCHs and CHLs varied from 0.64 to 3.17 ng/g dw, 0.19-0.65 ng/g dw, and 0.03-0.16 ng/g dw, respectively. No significant difference was observed between the Bering Sea and Chukchi Sea for most pollutants except for trans-CHL, ΣCHLs (sum of trans- and cis-chlordane) and p,p'-DDD. Concentration ratios (e.g., α-HCH/γ-HCH, o,p'-DDT/p,p'-DDT) indicated that the contamination in the studied areas may result from inputs from multiple sources (e.g., historical usage of technical HCHs as well as new input of dicofol). Chiral analysis showed great variation in the enantioselective degradation of OCPs, resulting in excess of (+)-enantiomer for α-HCH in thirty of the 32 detectable samples, preferential depletion of (-)-enantiomer for o,p'-DDT in nineteen of the 35 detectable samples, and nonracemic in most samples for trans- and cis-chlordane. The ecological risks of the individual OCPs as well as the mixture were assessed based on the calculation of toxic units (TUs), and the results showed the predominance of DDT and γ-HCH in the mixture toxicity of the sediment. Overall, the TUs of OCPs in sediments from both the Bering and Chukchi Seas are less than one, indicating low ecological risk potential.
对白令海、楚科奇海及邻近区域表层沉积物中有机氯农药（OCPs），包括六氯环己烷（HCHs）、滴滴涕（DDTs）和氯丹（CHLs）的空间分布、成分剖面及对映体分数（EFs）进行了研究。DDTs、HCHs和CHLs的总浓度分别在0.64至3.17 ng/g干重、0.19 - 0.65 ng/g干重和0.03 - 0.16 ng/g干重之间变化。除反式氯丹、ΣCHLs（反式和顺式氯丹之和）和p,p'-滴滴滴外，白令海和楚科奇海的大多数污染物之间未观察到显著差异。浓度比（如α-HCH/γ-HCH、o,p'-DDT/p,p'-DDT）表明，研究区域的污染可能源于多种来源的输入（如工业用HCHs的历史使用以及三氯杀螨醇的新输入）。手性分析表明，OCPs的对映体选择性降解存在很大差异，导致32个可检测样品中有30个样品的α-HCH出现（+）-对映体过量，35个可检测样品中有19个样品的o,p'-DDT优先消耗（-）-对映体，并且大多数样品中反式和顺式氯丹均为非外消旋体。基于毒性单位（TUs）的计算评估了单个OCPs以及混合物的生态风险，结果表明沉积物混合毒性中DDT和γ-HCH占主导。总体而言，白令海和楚科奇海沉积物中OCPs的TUs均小于1，表明生态风险潜力较低。
