An Experimental Approach to Comparative Analysis of Toxic Impacts of Three Endocrine Disruptor Chemicals-Atrazine, Benzo (A) Pyrene, and Carbendazim-in Common Carp (Cyprinus carpio).

This study evaluated the effects of atrazine, benzo [a]pyrene, and carbendazim on common carp (Cyprinus carpio). Fish were exposed to nominal concentrations of 5, 15, 25, and 45 ppb (prepared from 5 ppm stock solutions), with HPLC analysis confirming actual levels of 4.90, 14.70, 24.50, and 44.10 ppb (98% recovery) over exposure periods of 5, 15, and 30 days. Genotoxicity was assessed using the comet assay to detect DNA strand breaks and the micronucleus assay to evaluate chromosomal alterations. Blood smears stained with giemsa were examined for red blood cell and nuclear abnormalities. Histopathological changes were analyzed following standard formalin fixation, paraffin embedding, and hematoxylin-eosin staining. Peak DNA damage occurred after 5 days of exposure to 15 ppb benzo[a]pyrene and carbendazim and 25 ppb atrazine (P = 0.001). Both genotoxicity assays revealed concentration and time dependent effects. The micronucleus assay further showed significant increases in chromosomal damage, supported by red blood cell distortions and nuclear abnormalities. Histopathological observations confirmed pronounced tissue alterations, with atrazine producing the most severe toxic effects at equivalent concentrations. Overall, both dose and duration influenced the severity of genotoxic and histopathological impacts, identifying atrazine as the most potent toxicant.