Health effects of dioxin exposure: A 20-year mortality study

Follow-up of the population exposed to dioxin after the 1976 accident in Se veso, Italy, was extended to 1996. During the entire observation period, al l-cause and all-cancer mortality did not increase. Fifteen years after the accident, mortality among men in high-exposure zones A (804 inhabitants) an d B (5,941 inhabitants) increased from all cancers (rate ratio (RR) = 1.3, 95% confidence interval (CI): 1.0, 1.7), rectal cancer (RR = 2.4, 95% CI: 1 .2, 4.6), and lung cancer (RR = 1.3, 95% CI: 1.0, 1.7), with no latency-rel ated pattern for rectal or lung cancer. An excess of lymphohemopoietic neop lasms was found in both genders (RR = 1.7, 95% CI: 1.2, 2.5). Hodgkin's dis ease risk was elevated in the first 10-year observation period (RR = 4.9, 9 5% CI, 1.5, 16.4), whereas the highest increase for non-Hodgkin's lymphoma (RR = 2.8, 95% CI: 1.1, 7.0) and myeloid leukemia (RR = 3.8, 95% CI: 1.2, 1 2.5) occurred after 15 years. No soft tissue sarcoma cases were found in th ese zones (0.8 expected). An overall increase in diabetes was reported, not ably among women (RR = 2.4, 95% CI: 1.2, 4.6), Chronic circulatory and resp iratory diseases were moderately increased, suggesting a link with accident -related stressors and chemical exposure. Results support evaluation of dio xin as carcinogenic to humans and corroborate the hypotheses of its associa tion with other health outcomes, including cardiovascular- and endocrine-re lated effects.