Comparison of toxicity of four organophosphorous:Trichlorophon, Diazinon, Malathion and Chlorpyrifos in Barbus grypus
Subject Areas : New Technologies in Aquaculture Development
Keywords: LC50, Barbus grypus, Keywords: Organophosphates pesticides, acute poisoning,
Abstract :
Abstract Organophosphorous pesticides are of the most widely used pesticides in all over the world. The main environmental effect of these pesticides is their effects on the non-target organisms. Aquatic organisms, especially fish are more affected to pesticide intoxication than others. In this research, the acute toxicity of four widely used organophosphate pesticides including Diazinon, Malathion, Chlorpyrifos, and Thrichlorophon were evaluated and compared in the native fish Barbus grypus. For this purpose, the OECD method was used to determine the acute toxicity of these pesticides in B.grypus. In case of any pesticide, 8 increasing concentrations were considered in 3 triplicates in similar tanks and 10 fish were added to each tank. Mortality were recorded daily until 96 hours, and results were analyzed by Probit software. Finally LC50 was determined for each pesticide after 24, 48, 72 and 96 hours. Then the maximum acceptable concentration (MAC) of each pesticide was calculated. The results showed that the toxicity of evaluated pesticides in B.grypus were different (P<0.05) as LC50 96 h for Diazinon, Malathion, Trichlorophon and Chlorpyrifos in native fish B.grypus were 6.698, 0.314, 16.75, and 0.052, respectively. Trichlorofon has the lowest toxicity among the four studied pesticides found in B.grypus and its MAC were 1.675ppm, while the highest toxicity belong to Chlorpyrifos, and its MAC was 0.0052ppm. In case of all Organophosphorous in pesticides used, increase in toxin concentration caused fish mortality and increasing duration of exposure to pesticides resulted in increasing mortality in B.grypus. As a general conclusion it can be stated that the use of Trichlorophone is the best organophosphorous pesticide which can be used in B.grypus. However, due to the high toxicity of Malathion and Chlorpyrifos, these two Organophosphorous pesticides should not be used not only in aquaculture, but also in agriculture. We propose the use of other pesticides such as Diazinon in agriculture as an alternative.
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