Dioxins and furans: epidemiologic assessment of cancer risks and other human health effects.

Within the last two decades tremendous efforts have been made to uncover the potential risks to human health associated with exposure to polychlorinated dibenzop-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), especially for the general population exposed at background levels. Very few other chemicals have been investigated as intensively as these substances, in particular, the most toxic congener within this group, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Public concern with regard to the potential adverse health effects of this chemical, especially the risk for cancer, was generated by the accident in Seveso, Italy, in 1976. Other major environmental or occupational exposures have also occurred, for example, in accidents in chemical factories such as the BASF in Germany in 1953 and during the Vietnam war. Risk assessment for dioxins is an interdisciplinary effort. It is self-evident that disentangling this puzzle requires the integration of research results from various scientific disciplines such as toxicology, molecular biology, biochemistry, medicine, and epidemiology. Epidemiology plays a central role, as there are a number of dioxin-exposed human cohorts worldwide. These have received much attention by scientists, public health professionals, and most importantly by the general population, as dioxins and furans are ubiquituous