Derivation Of Aquatic Organism Criteria For Three Pesticides (Triazophos, Malathion And Carbendazim) In The Yangtze River Delta Region

China is a country with agriculture as the foundation of the national economy.The considerable production and use of pesticide has already caused serious pollution to water,leading to serious damages to aquatic organisms and aquatic ecosystem.Water quality standard play an important role in environmental management,while water quality criteria can provide scientific basis for water quality standard formulation.Aquatic Organism Criteria is an important part of the water quality standard.However,researches of Aquatic Organism Criteria are still quite limited in China,especially the research of water quality criteria for pesticides.Each watershed is different from the other in terms of the sensitivity of aquatic organism to pesticide.Aquatic organism criteria for pesticide should be based on toxicity data of the representative aquatic species in a particular watershed.The Yangtze River Delta Region is one of the regions with the maximum usage and production of pesticide in China.The point-source emissions of wastewater during production and the non-point source emissions during using pesticides posed serious hazardous to aquatic ecological system in this area.The Yangtze River Delta Region was selected as the target basin and triazophos,malathion and carbendazim were selected to conduct criteria derivation.The results are as follows:?1?This study selected 14 representative native species as test species,using the national standard or the internationally recommended toxicity test methods to carry out an acute toxicity of Triazophos and other two kinds of pesticides on 14 species,and obtained aquatic acute toxicity data of three pesticides value.?2?The chronic toxic effects of three kinds of pesticides were studied by some samples in these 14 species based on the corresponding chronic toxicity data being obtained during the research.?3?Based on the data of acute and chronic toxicity of three pesticides to aquatic organisms,the acute and chronic criteria of three kinds of pesticides were derived by Species Sensitivity Distributions and Toxicity Percentile Rank respectively.The acute criteria of triazophos,malathion and carbendazim derived by species sensitivity distribution method were 0.1223?g·L^-1,2.7995?g·L^-1 and 4.0957?g·L^-1,respectively;The chronic criteria were 0.0022?g·L^-1,0.1176?g·L^-1 and 0.0131?g·L^-1,respectively.?4?It is shown from the comparison results that when derived the criteria of different kinds of pesticides,Species Sensitivity Distributions and Toxicity Percentile Rank shows their advantages,disadvantages and applicability.Therefore,in order to get more accurate criteria value of pesticide,two methods should be adopted and combined with a variety of factors in the derivation of pesticide aquatic criteria.The final criteria value is proposed after comprehensive analysis and comparison.The criteria obtained by the Species Sensitivity Distribution and the Toxicity Percentile Rank were compared.Afterward,the final criteria of the three pesticides were proposed,that is,the acute and chronic criteria of triazophos were 0.0172?g·L^-1 and 0.0006?g·L^-1,respectively;the acute and chronic criteria of malathion were 0.3114?g·L^-1 and 0.0262?g·L^-1,respectively;the acute and chronic criteria of carbendazim were 0.0262?g·L^-1 and 0.013 I?g·L^-1,respectively.