太湖水体中5种有机磷农药混合物生态风险评价

Ecological Risk Assessment of Five Organophosphorus Pesticides Mixture in Taihu Lake

有机磷农药是一类广泛分布于我国水环境中的污染物,即使在水体中的污染水平处于规定"安全标准"之下,其联合暴露产生的风险仍有可能威胁水生生态安全。采用基于浓度加和模型与生物敏感度分布曲线的混合物风险商法,评价了太湖水体中敌敌畏、对硫磷、甲基对硫磷、马拉硫磷和乐果5种有机磷农药混合物产生的生态风险。结果表明:2003～2004年期间3个不同时期太湖水体中5种有机磷农药的混合物生态风险商(RQ m)均大于1,有机磷农药混合物在2003～2004年期间对太湖水生生物构成了一定威胁。

Organophosphorus （OP） pesticides are widely distributed in the aquatic environment in China. Even ff the levels of single OP pesticides in water are lower than the safety criteria, the ecological risk of pesticide con- currently exposed as the mixture may threaten aquatic ecosystem. In this study, the method of risk quotient （RQ） for mixtures which was based on the concentration addition model and the species sensitivity distribution curve was applied to assess the ecological risk of five OP pesticides mixture including dichlorvos, parathion, methyl parathion, malathion and dimethoate in Taihu Lake. The results indicated that the risk quotients of OP pesticide mixtures （RQm） were greater than 1 in the three different periods from 2003 to 2004, demonstrating that the OP pesticide mixtures in Taihu Lake had posed a certain ecological risk for the aquatic organisms.