Health-risk estimates for 2,3,7,8-tetrachloro-dibenzodioxin: an overview.

As has been abundantly noted by many investigators, the paucity of definitive knowledge of metabolism, pharmacokinetics and pathogenesis of the chlorinated dioxins, principally 2,3,7,8-TCDD, in human populations continues to severely limit our ability to evaluate the scope of the chronic and delayed effects of exposure to these agents. The marked qualitative and quantitative differences in the response of animals to TCDD plus the inability to validate a number of the critical assumptions and mathematical models relative to risk assessment make the extrapolation of data from intact animals to man particularly uncertain. Hence, it is vital to vigorously pursue the elaboration of the mechanism of action of TCDD at the molecular level. This should greatly contribute to our fundamental understanding of this agent and the potential danger that it may pose for man.