氟乐灵对淡水生物的毒性特征及水生生物基准研究

通过毒性试验，得出氟乐灵对15种代表性水生生物的毒性数据，分别采用目前国际上常用的三种基准推导方法，推导氟乐灵的水生生物基准值。结果显示：评价因子法、物种敏感度分布法和毒性百分数排序法得出的基准值分别为0.007 5、0.075、0.071 mg·L-1。评价因子法得出的基准值较低，原因在于该方法主要依赖敏感物种的毒性值推导基准值，有时会造成过保护。物种敏感度分布法和毒性百分数排序法得到的基准值比较接近，大于评价因子法得到的基准值，而且这两种方法基准值的推导都需要较多的水生生物毒性数据，得出的基准值可以保护绝大多数水生生物。研究得到的氟乐灵水生生物基准值将为农药水质标准的制订及农药水生生态风险评价提供科学依据。

Toxicity Characteristic of Trifluralin to Freshwater Biota and Its Aquatic Organism Criteria

The toxicity data of 15 representative aquatic organisms was obtained through the toxicity tests. The aquatic organism criteria of trifluralin derived by assessment factor, species sensitivity distributions and toxicity percentile rank were 0.007 5 mg·L-1, 0.075 mg·L-1 and 0.071 mg·L-1 respectively. The criterion derived by assessment factor was lower, because it mainly based on toxicity data of the most sensitive species, which might result in over protection for aquatic organism. The criteria derived by species sensitivity distributions and toxicity percentile rank were close to each other, both of them were greater than the criterion derived by assessment factor. The latter two methodologies required more toxicity data to derive the criteria, which could protect majority of aquatic organisms. The results of this study will provide scientific basis for pesticide water quality standard development and aquatic ecological risk assessment.