淀山湖表层水、沉积物和鱼体中有机氯农药的时空变化及人体暴露风险

Spatial and temporal variations of organochlorine pesticides in surface water, sediments and fishes collected from Dianshan Lake and the associated human health risk

有机氯农药(organochlorine pesticides,OCPs)是一类持久性有机污染物,研究它们在城市近郊湖泊的污染状况,有助于更好地了解其对湖泊水环境的影响.研究了上海近郊淀山湖表层水、沉积物和鱼体中的OCPs污染状况及人体暴露的健康风险.结果表明,六六六(hexachlorocyclohexanes,HCHs)和滴滴涕(dichlorodiphenyltrichloroethanes,DDTs)分别是表层水和沉积物中的主要OCPs污染物,OCPs在淀山湖野生鱼体中也有检出.淀山湖中HCHs和DDTs的来源主要是历史残留.沉积物中的OCPs浓度相对比较稳定,但表层水中的浓度随采样时间有一定变化,即丰水期浓度高于枯水期.淀山湖进水区域的污染程度普遍高于出水区域.考察了饮食摄入(食鱼和饮水)、呼吸和皮肤渗透(游泳)3种途径对人体暴露量的影响,发现饮食摄入是DDTs和HCHs的主要暴露源.淀山湖水环境已受到OCPs的影响,但污染水平不高且不会产生健康风险.

Organochlorine pesticides （OCPs） are persistent organic pollutants. It can provide fundamental data to help researchers comprehensively understand the influence of contaminants inalake aquatic environment, investigate contamination levels and distribu- tion characteristics of 0CPs. The results showed that hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and its metabolites were the main OCPs in sur- face water and sediments, respectively. Accumulation of OCPs in wild fishes was observed. DDTs and HCHs in the lake were mainly historical residues. OCPs＇ concentrations in sediments were stable, while those in surface water varied during the sampling period. Concentrations of contaminants in surface water were higher in wet season than in dry season. The contaminant levels in the inlet area were higher than in the effluent area. Dietary intake of fishes and water was the main exposure sources of DDTs and HCHs, but the contamination level was low, and it did not lead to significant health risks.