[Dioxins and furans: origins and risks].

A bibliographic review is presented with the objective of describing the origin and the risks to the public health of dioxins and furans and getting familiar with some research areas about these compounds. The review has considered 16 selected references covering a period of approximately twelve years (1986 to 1997). The main conclusions were: a) These compounds are from nonnatural origin, considered highly toxic, extremely persistent in the environment, and they have been detected in all environmental matrices like: soil, sediments, air, water, animals and plants; b) emissions of these compounds to the atmosphere come primarily from combustion processes; c) atmospheric dispersion, deposition and subsequent accumulation in the food chain seem to be the major exposure pathway to the general population; d) due to their lipophilic characteristic and persistence in the environment, these compounds accumulate in adipose tissues, being food of animal origin those which present higher concentrations; e) in Brazil, the few studies conducted, with the measurement of concentrations of these compounds in the environment have showed levels comparable to those obtained in Germany. The authors recommend the development of further studies about these compounds in Brazil, specially about their accumulation in food and in human tissue