Emphasizing that for any known teratogen no safe dosage level exists, this case-illustrated review identifies the bases for current concern about the pollution of the environment, reflects on the promise and complexities of the emerging disciplines of behavioral toxicology and behavioral teratology, and describes existing evidence of teratogenic effects of toxic chemicals. Bases of concern include (1) the need for bureaucracies to create environmental limits to toxic concentrations; (2) the tendency for the burden of proof of toxic effect to lie with the afflicted; (3) the concept of a safe dose level; and (4) the influence of politico-economic considerations on decisions to improve environmental control of effluents and industrial emissions. Discussion of the currently available evidence of toxic effects focuses on polychlorinated biphenyls, diethylstilboestrol, vinyl chloride monomer, manganese, mercury, and, extensively, lead. Recommended actions to be taken to adequately protect citizens from chemical assault are offered, and the paper concludes with an account of evidence of nuclear take-up by children living near British nuclear installations and the lack of adequate official response to such evidence. (RH)