Abstract: Objective Dicofol is a new type of persistent organic pollutant added to the Stockholm Convention. Current national and international water quality standards lack established standard value for dicofol. It is urgent to carry out the water quality criteria study for dicofol. Methods In this study, acute toxicity data of dicofol to 26 species of freshwater species of 5 phyla, 19 families, and chronic toxicity data of 11 species of freshwater species of 5 phyla,      9 families were collected. Distribution models such as SGompertz, Sigmoid, SRichards and SWeibull were used to fit the species sensitivity distribution curve. The short-term and long-term water quality reference values of dicofol in freshwater environment were 37.50 μg/L and 0.94 μg/L, respectively, based on optimal functions. Results The ecological risk of dicofol in 11 freshwater bodies in China was assessed by using the quotient method. The results of risk characterization showed that all water bodies were acute and risk-free. 72.7% of water bodies were chronic risk-free and 27.3% were chronic low-risk. Conclusion The water quality criteria value of dicofol in freshwater environment derived from the species sensitivity distribution curve can be used as an important reference basis for the formulation of water quality standards and ecological environment damage identification of dicofol in China.

Key words: dicofol, quality criteria, species sensitivity distribution （SSD）, ecological risk

摘要：  目的 三氯杀螨醇是《斯德哥尔摩公约》新增列的一类持久性有机污染物，目前国内外现有水质标准均缺乏三氯杀螨醇的标准值，开展三氯杀螨醇水质基准研究迫在眉睫。方法 通过整理三氯杀螨醇对5门19科共26种淡水生物的急性毒性数据和5门9科共11种淡水生物的慢性毒性数据，采用SGompertz、Sigmoid、SRichards和SWeibull分布模型拟合了物种敏感度分布曲线，运用最优函数推导出淡水环境中三氯杀螨醇的短期水质基准值和长期水质基准值分别为37.50、0.94 μg/L。结果 利用商值法评估了我国11处淡水水体中三氯杀螨醇的生态风险，风险表征结果显示，全部水体均为急性无风险；72.7%的水体为慢性无风险，27.3%水体为慢性低风险。结论 基于物种敏感度分布曲线推导得出的淡水环境中三氯杀螨醇的水质基准值，可作为我国三氯杀螨醇水质标准制定与生态环境损害鉴定的重要参考依据。

关键词:  , 三氯杀螨醇, 基准值, 物种敏感度分布, 生态风险