Effect of herbicide Atrezine chronic toxicity on bioaccumulation process in fillet of Barbus grypus

Atrazine is one of the most important and effective pollutant in aquatic ecosystems. The largest sugar cane farms of Middle East is located in Khouzestan Province, Iran in which large amounts of Atrezine are being used in farming. The aim of this study was to investigate acute toxicity (LC50 96 h) of atrazine on barbus grypus and the effects of chronic toxicity with sub-lethal concentration of atrazine on bioaccumulation of atrazine in fish fillet. LC50 96 h of atrazine on barbus grypus was measured according to the OECD standard method, 180 barbus grypus were divided into 4 equal groups (in triplicates). Groups 1, 2 and 3 were exposed to 3.25 mg l-1 (5%), 6.5 mg l-1 (10%) and 13 mg l-1 (20%) of LC50 96 h concentrations, respectively. Group 4 exposed to toxin free water as a control group. Experimental exposures did last for 21 days, muscles samples of the large dorsal muscle were taken on days 0, 7, 14 and 21 of experiment. Bioaccumulation of Atrazine was measured in the muscle at days 0, 7, 14 and 21 in all groups. Results indicated that atrazine was toxic for barbus grypus and its toxicity increased not only with increase in atrazine but also with increase in the exposure time. The bioaccumulation of atrazine in fish muscles was increased significantly in groups 2 and 3 in all sampling periods and in groups 1 only in day 21. The results of present study showed that placing barbus grypus in the presence of chronic and sub lethal concentrations of the herbicide Atrazine for three weeks may lead to accumulation of toxins in the fish fillets.