中文摘要：

分析了巢湖流域和太湖流域表层沉积物中苄氯菊酯和高效氰戊菊酯,并结合毒性单元法（Toxic Unit,TU）和物种敏感性分布法（Species Sensitivity Distributions,SSD）评价了两种拟除虫菊酯的生态风险.结果显示,两大流域沉积物中均广泛检测出两类污染物.总体而言,巢湖流域苄氯菊酯含量较高,而太湖流域高效氰戊菊酯含量较高.同时,两种污染物在巢湖流域呈现显著的正相关,但太湖流域二者之间没有相关关系.3种风险评价方法（TU法、沉积物SSD法、水体SSD法）均揭示苄氯菊酯对巢湖流域水生环境影响较大,而高效氰戊菊酯对两个流域影响均较大.因此,需要加强对流域高效氰戊菊酯污染的关注.其中,TU法预测的风险最小,沉积物SSD法预测的风险最大,主要原因在于TU法采用的毒性数据为LC50,而SSD法则选用了NOEC/LOEC,同时沉积物SSD法是出于保护大部分底栖生物为目的的方法.各种方法对于评价沉积物毒害污染物的生态风险均存在不足,尽管沉积物SSD法最为合理,但由于其毒性数据较少,最终预测结果存在一定的不确定性.因此,需要进一步加强对底栖生物毒性的研究和数据积累.

英文摘要：

In the present study permethrin and esfenvalerate in the surface sediments from Chaohu Lake and Taihu Lake watersheds were determined,and ecological risks of two pyrethroids were evaluated using toxic unit（ TU） and species sensitivity distribution（ SSD） models.The results indicate widespread occurrences of two target synthetic pyrethroids.Totally,higher concentration of sediment-associated permethrin was observed in Chaohu Lake watershed,while higher residue of esfenvalerate was investigated in Taihu Lake watershed. Furthermore,permethrin tended to positively correlate against esfenvalerate in Chaohu Lake watershed,but the concentrations of two contaminants were independent in Taihu Lake watershed. Chaohu Lake watershed was exposed high ecological risks to both insecticides,and Taihu Lake watersheds was exposed higher ecological risk to esfenvalerate than to permethrin evaluated by three models. The lowest risks were predicted by TU,because only LC50 was applied in this method. The highest risks were predicted by SSD for benthic habitats,which was explained in part by the model being developed to protect the large proportion of benthic species. The three models for the evaluation of ecological risk to sediment-associated contaminants are not perfect. Despite SSD for benthic habitats is more suitable,there are many uncertainties in final results due to lack of enough benthic organisms associated toxic data. Therefore,further research need to be carried out on the toxicological studies ofbenthic organisms.