Toxic Effects Of Organophosphorus Pesticides On Corophium Acherusicum (Crustacea: Amphipoda)

The birth of organophosphorus pesticides makes our country crop yields greatly improved, but the environmental problem caused by organophosphorus pesticide overcommitted can't be non-negligible. Recent studies show that organophosphorus pesticides can not only pollute soil, atmosphere and water of inland, a great deal of organophosphorus pesticides can also be found in sea water of some river estuaries and coastal areas. In this study, three kinds of organophosphorus pesticides:Methyl parathion, Malathion and Monocrotophos are chosen as the pollutants. Corophium acherusicums is selected as testing species. The purpose is to study the toxic effects of the three pesticides on C. acherusicums and to provide scientific basis for offshore marine environment protection and monitoring work. The main research contents and results are listed as follows:1. By means of acute test, make sure the NOEC, LOEC and LC50 of Methyl parathion, Malathion and Monocrotophos on C. acherusicums and compare the acute toxicity of C. acherusicums to the three kinds of organophosphorus pesticides. The results show that the LC50 of Methyl parathion, Malathion and Monocrotophos on C. acherusicums are 1.4μg·L-1,2.9μgL-1,20.8μg·L-1. Methyl parathion is the most toxic pesticide followed by Malathion and Monocrotophos is the weakest pesticide by comparing the physical and chemical parameters and the experimental results.2. The chronic test is used to study the influences of Methyl parathion, Malathion and Monocrotophos on the activity of antioxidant enzymes SOD and CAT and the content of GSH. The results show that in the same condition of exposed density SOD activity, CAT activity and GSH content are increased at first and decreased with the prolonged time. The SOD activity is restrained on the seventh day exposed in Methyl parathion with the concentration of 1.5μg·L-1 and other groups are not inhibited. The SOD activity, CAT activity and GSH content of all concentrations of Malathion and Monocrotophos are also in induction state.3. The single-celled gel electrophoresis experiment is carried out in order to measure DNA damage of C. acherusicums caused by Methyl parathion, Malathion and Monocrotophos. The results show that with the concentrations of the three organophosphorus pesticides increase, the number of DNA damaged cells is increasing all the time. Cell damage rates of Methyl parathion with the concentration of 1.5μg·L-1 is 100%, cell damage rates of Malathion with the concentration of 3μg·L-1 is 72%, cell damage rates of Monocrotophos with the concentration of 20μg·L-1 is 67%.