中文摘要：

基于太湖梅梁湾、贡湖湾和胥口湾水体∑PAH8的等效浓度和ΣPAH8对水生生物的无观察效应浓度（NOECs）,分别采用商值法、概率密度函数重叠面积法、安全阈值法和商值概率分布法评价水体∑PAH8对水生生物的生态风险,同时进行方法学比较.商值法评价结果表明∑PAH8对水生生物的生态风险表现为大型蚤（Daphina magna）〉小球藻（Psedokircheriella subcapitata）〉斑马鱼（Danil rerio）〉摇蚊虫（Chironomus riparius）;概率密度函数重叠面积法表明∑PAH8对太湖的生态风险为0.061;安全阈值法表明太湖水体∑PAHs8超过影响10%物种的概率为12.92%;商值概率分布法表明太湖水体∑PAH8对水生生物的风险商值超过临界值（0.3）的概率为29.12%.各种评价方法均表明∑PAH8对梅梁湾的风险最大,贡湖次之,胥口湾的生态风险最小;其中安全阈值法和商值概率分布法的评价结果具有确切的概率意义,更适合太湖水体∑PAH8的生态风险评价.

英文摘要：

Based on the equivalent concentrations of ∑PAH8 and chronic toxicity data of PAHs,ecological risk assessment approaches including quotient method,overlapping areas of probability density curves,margin of safety and probability distribution of quotients,were applied to assess ecological risks of ∑PAH8 to the aquatic organisms in Meiliang Bay,Gonghu Bay,and Xukou Bay of Taihu Lake.The result from the quotient method indicated that ecological risk of ∑PAH8 to aquatic organism was in the order of Daphina magna Psedokircheriella subcapitata Danil rerioChironomus riparius.The result from the overlapping areas of probability density curves suggested that ecological risk of ∑PAH8 was 0.061 in Taihu Lake.The probability of exceeding the 10% value for all tropic groups in Taihu Lake was 12.92% calculated using margin of safety assessment,and the probability of quotient exceeding 0.3 was 29.12% in Taihu Lake based on the results of probability distribution of quotients.Low to high ecological risk for all the aquatic organisms from ∑PAH8 exposure was reported in Meiliang Bay,Gonghu Bay and Xukou Bay.Furthermore,compared with hazard quotient and overlapping areas of probability density curves,the margin of safety and probability distribution of quotients provided the results with probabilistic significance,which were relatively appropriate methods for risk characterization of ∑PAH8 in Taihu Lake.