The toxic and teratogenic effects of selected organophosphorus compounds on the embryos of three species of amphibians.

The toxic and teratogenic effects of 4 organophosphorus compounds (phenyl saliginen cyclic phosphate (PSCP), leptophos-oxon (LPTO), tri-o-tolyl phosphate (TOTP), and paraoxon (PXN] were investigated in the embryos of 3 species of frogs. Developmental abnormalities were observed in surviving embryos of each of the 3 species following exposure to PSCP at concentrations as low as 500 ppb for 24 h. LPTO, while being toxic to gray treefrog embryos at concentrations as low as 2.2 ppm, did not induce developmental abnormalities. TOTP and PXN were neither toxic nor teratogenic at concentrations of 10 ppm and 100 ppm respectively.