钱塘江流域沉积物中有机氯农药的对映体选择性残留及生态风险

Enantioselective Residues and Ecological Risks ofOrganochlorine Pesticides in the Sediments of Qiantang River Basin

钱塘江流域作为我国最主要的农业生产基地,历史上曾长期、大量使用有机氯农药(OCPs).文章从手性层面研究了钱塘江流域30个沉积物样品中OCPs的残留和分布状况.结果显示,钱塘江流域沉积物中OCPs的质量分数为2.12~65.96 ng/g,平均值为20.98 ng/g,手性α-HCH、o,p′-DDD和o,p′-DDT的EF值分别为0.306~0.412、0.489~0.63和0.498~0.634.进一步利用组成分分析,研究了钱塘江流域底泥中OCPs的来源,结果表明,有机氯农药HCH和DDT既有历史残留又有新源的输入.生态风险评价表明,钱塘江流域沉积物生态风险毒性处于中等毒性水平.

Historically,Qiantang River Basin was one of the areas where organochlorine pesticides(OCPs)were heavily used owing to the developed agriculture.In the present project,spatial distributions and chiral residues of OCPs in the surface sediments from Qiantang River Basin were investigated.The total OCPs quality score ranged from 2.12 to 65.96 ng/g,with a mean value of 20.98 ng/g.The EF values ofα-HCH,o,p′-DDD and o,p′-DDT were in the range of 0.306-0.412,0.489-0.63 and 0.498-0.634,respectively.Furthermore,using component analysis,the sources recognition of OCPs was investigated in the Qiantang River Basin.As a result,the OCPs pollution was attributable to a mixed usage of fresh and weathered HCH and DDT.The ecological risk assessment showed that an intermediate ranking of sediment toxicity existed in Qiantang River Basin.