Study On The Aquatic Organism Criteria For The Key Pesticide In The Yangtze River Delta Region

Aquatic organism criteria are the foundation and scientific basis of water quality standards. China was a big country of the pesticide production and use. The water environment would be adversely affected by long-term use of pesticides.The Yangtze River Delta Region had developed water system which has a wide variety of aquatic organisms. More importantly, it is not only the area with most concentrated pesticide production enterprises, but also the area with high rates of pesticide use. With pesticide production and use, there has been growing concern about the potential impact of pesticide exposure on the surface water and aquatic organism in this area.Four key pesticides (Chlorpyrifos, Endosulfan, Trifluralin, and Chlorothalonil) used in the Yangtze River Delta Region and15kinds of representative aquatic organisms were selected to conduct the acute and chronic test to obtain the toxicity data, and then Assessment Factor, Species Sensitivity Distribution and Toxicity Percentile Rank method were used to derive the aquatic organism criteria for Chlorpyrifos, Endosulfan, Trifluralin and Chlorothalonil.The results showed that the aquatic organism acute criteria of Chlorpyrifos, Endosulfan, Trifluralin, and Chlorothalonil were0.0125μg/L,0.03μg/L,7.50μg/L and0.065μg/L derived by Assessment Factor method;0.056μg/L,1.15μg/L,20.35μg/L and0.94μg/L derived by Species Sensitivity Distribution method;0.021μg/L,0.36μg/L,71μg/L and0.48μg/L derived by Toxicity Percentile Rank method. The aquatic organism chronic criteria of Chlorpyrifos, Endosulfan, Trifluralin and Chlorothalonil were0.0011μg/L,0.0033μg/L,1.36μg/L and0.0041μg/L derived by Assessment Factor method;0.0048μg/L,0.13μg/L,3.68μg/L and0.06μg/L derived by Species Sensitivity Distribution method;0.0036μg/L,0.079μg/L,26μg/L and0.061μg/L by Toxicity Percentile Rank method.The aquatic organism criteria derived by Toxicity Percentile Rank method was recommended as the aquatic organism criteria for the key pesticide in the Yangtze River Delta Region by comparing and analysing the characteristics of Assessment Factor, Species Sensitivity Distribution and Toxicity Percentile Rank method and the criteria derived by the three methods. The aquatic organism acute criteria of chlorpyrifos, endosulfan, trifluralin and chlorothalonil in the Yangtze River Delta Region were0.021μg/L,0.36μg/L,71μg/L and0.48μg/L, the chronic one were0.0036μg/L,0.079μg/L,26μg/L and0.061μg/L.The result of this study would provide scientific basis for pesticide water quality standards formulation/revision and the aquatic ecological risk assessment in the Yangtze River Delta Region.