VOL.: 30 (1983) (p. 131)
Methyl parathion, administered intraperitoneally at maternally lethal doses, was teratogenic to mice. In rats, decreased viability and body weight were seen in the progeny of treated animals, but no teratogenicity was observed.
Methyl parathion was weakly or not mutagenic in bacterial systems and in Drosophila melanogaster, but it was mutagenic in yeasts. In mammalian cells, sister chromatid exchange and presumed gene mutations were induced, but neither chromosomal aberration nor unscheduled DNA synthesis was elicited. Chromosomal aberrations and dominant lethal mutations were not increased in mice treated with methyl parathion. There is sufficient evidence that methyl parathion is mutagenic in a variety of cellular systems, but insufficient evidence that it is mutagenic in mammals.
No data were available to evaluate the teratogenic effects of methyl parathion in humans. The available data were insufficient to evaluate the chromosomal effects of methyl parathion in humans.
No case report or epidemiological study of the carcinogenicity of methyl parathion alone was available to the Working Group. (See, however, the section 'Cancer Epidemiology of Pesticide Manufacturers, Formulators and Users', in this volume.)
The available data provide no evidence that methyl parathion is likely to present a carcinogenic risk to humans.
Subsequent evaluation: Suppl. 7 (1987)
See Also: Toxicological Abbreviations Methyl parathion (EHC 145, 1992) Methyl parathion (HSG 75, 1992) Methyl parathion (ICSC) Methyl Parathion (FAO Meeting Report PL/1965/10/1) Methyl Parathion (IARC Summary & Evaluation, Supplement7, 1987)