千岛湖表层沉积物中有机氯农药的残留特征及生态风险评价

Residue characteristics and ecological risk assessment of organochlorine pesticide( OCPs) in the surface sediments of Lake Qiandao

对千岛湖表层沉积物中21种有机氯农药（OCPs）的残留现状进行调查，明确HCHs与DDTs的组成特征及源解析，并评估其生态风险．结果表明，千岛湖表层沉积物中共检出12种OCPs，各采样点位OCPs总量的浓度范围在0．43～12．70ng／g之间，平均值为5．28±4．84ng／g，处于低残留水平，其中DDTs是主要的残留物，街口、大坝前点位样品出现OCPs高残留．工业DDTs的历史使用是千岛湖表层沉积物DDTs残留的主要来源，仅街口点位样品存在林丹的污染并有新的DDTs输入，应引起重视．利用沉积物质量基准法、沉积物质量标准法分别对千岛湖表层沉积物中OCPs的生态风险进行评价，结果表明部分点位样品中OCPs的残留现状对该区生物可能存在生态风险．

A survey was conducted on twenty-one kinds of organochlorine pesticide （OCPs） residue in the surface sediments of Lake Qiandao. The component characteristics and source apportionment of HCHs and DDTs were confirmed, and the ecological risk assessment was evaluated. The main results were as follows ： twelve kinds of OCPs were detected, total concentrations of OCPs in the surface sediments of the studied area ranged from 0.43 to 12.70 ng,/g, with an average of 5.28 ±4.84 ng,/g, belonging to low residue level. DDTs were the main residues, and high OCPs residue level was found in Jiekou and Dabaqian. The application of industrial DDTs was the main source apportionment of DDTs residue in the surface sediments. Lindane and DDTs in the surface sediment of Jiekou were input recently, which should be paid more attention. In addition, the ecological risk of OCPs in the surface sediment of Lake Qiandao was assessed with the methods of sediment quality guidelines and sediment quality standards, and the results indicated that OCPs residue in some samoling sites may still have potential ecological risk on the investigated area.