Introduction Butachlor (2-chloro- 2, 6-diethyl-N-butoxymethylacetanilide)the isselective, systemic chloroacetamide herbicide which used extensively as pre-emergent and early post-emergent herbicide in Africa, South America, Asia and Iranespecially in Northern Province.Butachlor remains in soil and absorbs in ground waters and affect aquatics, animals and humans. Butachlor has toxic effect on different organs. In this research we evaluated chronic exposure to butachlor toxin and to observe histological changes of kidney and liver in rats. Method and Material A total of 16 male Wight Wistar rats, having almost similar age (about 10–12 weeks) and weighted 150-200 kg were divided randomly in two groups, each 8 rats. The control group consumed normal regime and water. The case group was administered with sublethal dosebutachlor 72.2 mg/kg equivalent ¼ LD50 for 3 months. After 12 weeks, the specimen of kidney and liver tissue was prepared and examined under lighten microscope. Conclusion Single cell necrosis, lobular hepatitis, interface hepatitis and bile duct proliferation were the histopathological changes in rats liver chronic exposure of butachlor and tubular necrosis and cast formation were the changes in kidney.

Butachlor, histopathology, kidney, liver