[Effect of wolfram, molybdenum, copper and arsenic on intrauterine fetal development].

Experients showed tungsten, molibdenum, copper and arsenic employed in doses producing no general toxic effect on the organism with their prolonged introduction to act adversely on the embryogenesis. Tungsten copper and arsenic were found to increase the embryonal lethality and tungsten and molebdenum to inhibit the processes of bones ossification in fetuses. The authors presume that the embryotoxic effect of the study elements is due to their direct action on the developing organism. Tungsten molibdenum and copper amass in the organism of test fetuses without being arrested in the placenta. A possible embryotoxic effect should be taken account of in chosing biogenic doses of trace elements.