A Research Of Aquatic Life Water Quality Criteria For Two Organophosphorus Pesticides

Organophosphorus pesticides(OPs)have a characteristic of the high efficacy,many varieties,wide range and low cost.Therefore,it widely used by farming.These pesticides,act on acetylcholinesterase(AChE),are harmful to aquatic organisms and humans' health.However,the threshold value of some OPs in water quality standard(WQS)in China can not protect the aquatic organisms,and can not meet the demand of pesticide environmental management.Meanwhile,the establishment of water quality criteria(WQC)is restricted.Therefore,this study selected the use of large,and in the water environment detection rate of typical OPs to carry out ecological toxicology research.To provide scientific data support to the establishment of Aquatic Life Criteria(ALC)system in China.Firstly,we collected and screened the toxicity data of native and non-native aquatic organisms.Then,we selected the representative aquatic organisms in China to carry out ecological test,and deduced the ALC by species sensitivity distribution(SSD).Finally,the inhibitory effects of OPs for AChE were analyzed.The sensitivity of AChE inhibition at the molecular level to conventional endpoint was compared.The main results of this thesis are as follows:(1)Eight kinds of organisms were used as a test to the acute toxicity of 4 days and chronic toxicity of 28 days for two organophosphorus pesticides.Results showed that the 96h-LC50 values of dichlorvos for N.denticulate,C.cahayensis,B.gargarizans,L.claparedeianus,P.parva and M.anguillicaudatus were 34.100,36436,15062,494.23,3726.6 and 4902.9 ?g/L,respectively;The 48h-EC50 values of dichlorvos for D.magna was 2.8726 ?g/L.The 48h-LC50 values of dichlorvos for C.plumosus was 33275 ?g/L.The 28 d-NOEC values of dichlorvos for N.denticulate and P.parva were 0.991 and 380 ?g/L,and the 28 d-LOEC values were 1.388 and 570 ?g/L,respectively.The 28 d-EC10 values of dichlorvos for D.magna was 0.1755 ?g/L.The 96h-LC50 values of malathion for N.denticulate,C.cahayensis,B.gargarizans,L.claparedeianus,P.parva,M.anguillicaudatus,G.rarus were 84641,13812,7378.1,41281,12393,18657 and 5559 ?g/L,respectively.The 48h-EC50 values of malathion for D.magna was 12.356 ?g/L.The 48h-LC50 values of malathion for C.plumosus was 22246 ?g/L.The 28 d-NOEC values of malathion for N.denticulate and P.parva were 7.755 and 266 ?g/L;and the 28 d-LOEC values were 15.200 and 400 ?g/L,respectively.The 28 d-EC10 values of malaion for D.magna was 0.3955 ?g/L.(2)The SSD was used to derive the ALC in freshwater of dichlorvos and malathion.The results showed that the criteria mixmum concentrations(CMC)of dichlorvos and malathion were 4.285 ?g/L and 0.368 ?g/L,and the criteria continuous concentrations(CCC)were 0.621 ?g/L and 0.007 ?g/L,respectively.The results show that the water environment quality standards of these organophosphorus pesticides may be "under-developed" the aquatic organisms.There are some differences between native and non-native species sensitivity indexing.Indicating the uncertainty and unreliability of directly applying toxicity data from non-native species in deriving ALC in China.(3)Through comparison between the acute toxicity data and AChE inhibitory effect data.The results showed that the 5% hazard concentration(HC5)of acute toxicity and inhibition effect of dichlorvos were 2.947 ?g/L and 1.53 ?g/L,respectively.The data of OPs to AChE inhibition effect might provide useful reference for deriving the water qulity criteria.