Malathion-induced teratisms in the developing chick

Abstract

Malathion is one of the organophosphorous insecticides least toxic to mammals. The toxicity of this compound in chick embryos is known; however, its teratogenic nature has not been recorded. Concentrations of 3.99 and 6.42 milligrams of malathion were injected into the yolk sacs of 4- and 5-day-old incubated eggs respectively. This procedure consistently produced deformed chicks with a combination of sparse plumage, micromelia, overall growth retardation, and beak defects.