STUDIES ON THE TERATOGENIC EFFECTS OF DELTAMETHRIN IN RATS

Deltamethrin is a pyrethroid insecticide used to eradicate external pa rasites on farm animals. Residues of this pesticide were shown to be p resent in food from animal origin which encouraged us to investigate t he effects of deltamethrin on foetuses of pregnant rats. Literature se arch shows that previous research was focused on organochlorine and or ganophosphate pesticides whereas little attention was given to the new er pyrethroid insecticides. Four groups of pregnant rats (20 rats each ) were given either the vehicle (control) or doses of 1, 2.5 or 5 mg/k g b. w. of deltamethrin orally from day 6 to day 15 of pregnancy which was terminated by killing the animals on the 19th day for foetal exam inations. The incidence of early embryonic deaths was higher in deltam ethrin-treated rats than in control females. Deltamethrin caused retar dation of growth, hypoplasia of the lungs, dilatation of the renal pel vis and increase in placental weight. No skeletal changes were observe d in foetuses recovered from deltamethrin-treated females. Although de ltamethrin is relatively safe, however its effects on the foetus shoul d be considered when used on pregnant animals or in environments where pregnant animals and women live.