Commentary on 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD)

There is deep concern about the long term health effects of exposure to phenoxy herbicides and the contaminant TCDD; however, there is considerable scientific and medical uncertainty regarding the health effects from exposure to these chemicals. There are at least ten ongoing studies on reproduction, morbidity and mortality as well as studies of tissue concentrations of TCDD that are attempting to determine the health effects of these chemicals (see Table 2). Appropriate efforts should be made to prevent human and environmental exposure and to decontaminate the environment while awaiting the results of these investigations. Animal toxicity studies show such wide variations that extrapolations from a different species to humans are tenuous. Human studies on exposed workers and nonoccupational exposures are difficult to interpret because the exposure has not been quantified and because workers were exposed to mixtures of chemicals. Chloracne appears to be an important specific clinical marker of TCDD exposure, however, it can be caused by structurally similar compounds. Many of the past studies on human health effects of 2,4,5-T and TCDD are controversial. Since the scientific data are not firm, no specific statements can be made regarding the long term health effects at this time. Any individual who has had a significant exposure to TCDD should see his/her physician and have appropriate consultation. Long term follow up will be required. Physicians should be instructed regarding the possible manifestations of TCDD exposure to look for chloracne, soft tissue masses, muscle pain, fatigue, peripheral neuropathy, tender hepatic enlargement, enlargement, elevated liver enzymes, elevated lipids, prolonged prothrombin time, hemorrhagic cystitis and hirsutism.(ABSTRACT TRUNCATED AT 250 WORDS)