摘要:Pesticides formulations are complex mixtures and the toxicity information on active ingredients alone is not sufficient to evaluate the risk of adverse health effects of commercial pesticides. So the present study was designed to investigate the adverse effects of exposure to formulated chlorpyrifos-ethyl (9.60 mg kg-1 b.wt.), chlorpyrifos-methyl (300 mg kg-1 b.wt.) and methomyl (1.70 mg kg-1 b.wt.) on some haematological and biochemical parameters of male rats given repetitive oral doses for 90 consecutive days. There was significant decrease in body weight gain of chlorpyrifos-ethyl, chlorpyrifos-methyl and methomyl and increase in relative liver and kidney weights of chlorpyrifos-ethyl and chlorpyrifos-methyl treated rats. Chlorpyrifos-methyl caused significant decrease in Hb conc. Haematocrit value (PCV, %) and Red Blood Cells (RCBs) counts, while chlorpyrifos-ethyl and methomyl caused significant decrease in PCV% and White Blood Cells (WBCs) counts. All of the tested insecticides increased significantly serum Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) activities and decreased significantly the total protein level. In addition, the tested insecticides caused significant increase in serum uric acid and creatinine. We can conclude that both technical and formulated methomyl and chlorpyrifos-ethyl and its methyl analogues caused significant alteration on hematological and biochemical parameter of mal rats. The effects of commercial form of tested insecticides were more pronounced than its technical form.