Cytogenotoxic effects of cypermethrin, deltamethrin, lambdacyhalothrin and endosulfan pesticides on Allium cepa root cells

Increased pesticides application in agriculture and public health has contributed to the pollution of the environment. This study evaluates the cytogenotoxic effects of emulsifiable concentrate of cypermethrin, deltamethrin, lambdacyhalothrin and endosulfan on Allium cepa root cells. Five concentrations (1.0, 5.0, 10.0, 20.0 and 40.0 ppm) of each pesticide were used for microscopic (48 h) and macroscopic (72 h) evaluations with distilled water as the control. Data were analyzed by Student's ttest. A dose dependent reduction in A. cepa root length was observed for the pesticides. Significant reduction in treated root length was observed at 10.0 ppm of deltamethrin, cypermethrin and lambdacyhalothrin, and at 20.0 and 40.0 ppm of all the pesticides compared to the control (P<0.05). The EC50 values showed growth inhibition in the order of lambdacyhalothrin > cypermethrin > deltamethrin > endosulfan, while that of total aberrant cells was cypermethrin > lambdacyhalothrin > deltamethrin > endosulfan. Microscopic aberrations observed in the pesticide-treated onions include sticky chromosomes, disturbed spindle and chromosome bridges. Dose dependent reduction was observed in the total mitotic dividing cells and mitotic index of the pesticide-treated A. cepa, except for 5.0 ppm of endosulfan. The pesticides induced growth inhibition and caused cytogenotoxic effects on the meristematic cells of Allium cepa. The data herein provide more information on the pesticides of which exposure to substantial concentration might constitute health risk to non-target organisms.Keywords: Pesticides, mitotic aberration, pyrethroid, organochlorine, growth.African Journal of Biotechnology Vol. 12(41), pp. 6000-600