Effect of bendiocarb on development of the chick embryo.

Agrochemicals, including pesticides, are being used in increasing amounts in agriculture and are therefore potential environmental contaminants which may affect a variety of biological systems. The pesticide residues directly affect the embryos, disturbing their normal development and causing pathophysiological and morphological changes. We have observed embryotoxicity of cholinesterase inhibitor bendiocarb in the chick embryo. The pesticide dissolved in 10% acetone in water for injection was applied in a volume of 200 microl over the embryo through membrana papyracea at embryonic days (ED) 2, 3, 4, 5 and 10. The toxicity of bendiocarb was rather low, and lethal dose (LD(50)) decreased with advancing development from 0.97 mg per egg at ED 2 to 28.6 mg on ED 5. The malformations in surviving embryos were observed rarely (<2%) and occurred in both control and experimental groups. In the treatment at ED 5 and 10 there was a statistically significant reduction in body weight, but the maximum difference from controls was below 14%. In treated chick embryos on ED 3 and 4 was observed a small but not significant increase in number of dead cells using supravital staining. We conclude that bendiocarb possesses no significant toxicity in the avian embryo. Our analysis of bendiocarb embryotoxic potential in the chick embryo supports the earlier observations in other animal models, testifying to the relative safety of bendiocarb for the embryo or fetus.