Toxicology Effects Of Organic Pesticides On Freshwater Organisms

The extensive use of pesticides has made pesticide pollution become a increasingly serious problem. According to the present situation that the research on the pesticides to ecological criteria of quality standard for water environment were just started, and the long term toxic research on the algae and fish were not much. Under laboratory conditions, using Microcystis aeruginosa and Pelteobagrus fulvidraco which come from different trophic levels as the experiment subject and selecting three common pesticides such as chlorpyrifos, endosulfan, trifluralin, the toxic effects of three kinds of pesticides on Microcystis aeruginosa and Pelteobagrus fulvidraco were investigated. Amied at providing data support to the research on the toxic effects of organic pesticides on Microcystis aeruginosa and Pelteobagrus fulvidraco in the Yangtze River Delta region and providing the basis for further research on toxicity assessment endpoints and the establishment of water quality criteria in China. The main results were as follows:1. Algal toxicity testThe 96h EC50 of chlorpyrifos, endosulfan and trifluralin on Microcystis aeruginosawere 691.50mg/L,5.35mg/L and 79.45mg/L. The toxicity of three pesticides on Microcystis aeruginosa were showed as endosulfan> trifluralin> chlorpyrifos. Under the effect of chlorpyrifos and endosulfan, the content of chlorophyll a of Microcystis aeruginosa was decreased significantly. Under the effect of trifluralin, the content of chlorophyll a was raised significantly. Under the effect of chlorpyrifos,the content of proteinof Microcystis aeruginosa was decreased significantly. Under the effect of trifluralin, the content ofprotein was raised significantly. Under the effect of chlorpyrifos,the avtivity of SODof Microcystis aeruginosa was decreased significantly. Under the effect of endosulfan and trifluralin,the avtivity of SODwas increased first and then decreased. Under the effect of chlorpyrifos,the content of MDAof Microcystis aeruginosa was decreased significantly.Under the effect of trifluralin,the content of MDAwas raised significantly. Under the condition of long-term toxicity stress,the chlorophyll a and SOD of Microcystis aeruginosa were sensitive to the three kinds of pesticides, the protein and MDA were sensitive to the chlorpyrifos and trifluralin. The mentioned above were able to be the effective evaluation of toxicity sensitive index. The effect of protein and MDA of Microcystis aeruginosaon endosulfan were not significant so that the protein could not be the effective evaluation of toxicity sensitive index.2. Fish toxicity testThe 96h LC50 of chlorpyrifos, endosulfan and trifluralin on Pelteobagrus fulvidraco were 0.08mg/L,15.16ug/L and 1.25mg/L. The toxicity of three pesticides on Pelteobagrus fulvidraco were showed as endosulfan> chlorpyrifos> trifluralin. Under the effect of three kinds of pesticides, the avtivity of AChE of Pelteobagrus fulvidracowas raised first and then decreased in the first 20 days. The activity of CAT was raised first and then decreased. The AChE and CAT of Pelteobagrus fulvidraco were sensitive to the three kinds of pesticides which were all changed significantly so that both of them were able to be biological markers to detect the pollution degree of pesticides.