American Journal of Epidemiology Advance Access published online on January 10, 2008
American Journal of Epidemiology, doi:10.1093/aje/kwm371
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Original Contribution |
Mortality in a Population Exposed to Dioxin after the Seveso, Italy, Accident in 1976: 25 Years of Follow-Up
1 Unit of Epidemiology, Department of Preventive Medicine, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy
2 EPOCA Research Center, Department of Occupational and Environmental Health, University of Milan, Milan, Italy
3 Regional Epidemiological Office, Health Directorate, Lombardy Region, Milan, Italy
4 Section of Epidemiology, ASL Milano 3, Monza, Italy
Correspondence to Prof. Pier Alberto Bertazzi, EPOCA Research Center, Department of Occupational and Environmental Health, University of Milan, Via San Barnaba, 8, 20122 Milano, Italy (e-mail: Pieralberto.Bertazzi{at}unimi.it).
Received for publication August 13, 2007. Accepted for publication November 29, 2007.
The Seveso accident in 1976 caused a large, populated area north of Milan, Italy, to be contaminated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this study, the authors followed up the exposed population for chronic effects; this paper reports the results of the mortality follow-up extension for 1997–2001. The study cohort includes 278,108 subjects resident at the time of the accident or immigrating/born in the 10 years thereafter in three contaminated zones with decreasing TCDD soil levels (zone A, very high; zone B, high; zone R, low) and in a reference territory comprising surrounding, noncontaminated municipalities. Vital status and cause-of-death ascertainment were 99% complete. Adjusted rate ratios and 95% confidence intervals were calculated by using Poisson regression. Results confirmed previous findings of excesses of lymphatic and hematopoietic tissue neoplasms in zones A (six deaths; rate ratio = 2.23, 95% confidence interval: 1.00, 4.97) and B (28 deaths; rate ratio = 1.59, 95% confidence interval: 1.09, 2.33). These zones also showed increased mortality from circulatory diseases in the first years after the accident, from chronic obstructive pulmonary disease, and from diabetes mellitus among females. A toxic and carcinogenic risk to humans after high TCDD exposure is supported by the results of this study.
accidents, occupational; carcinogens, environmental; chemical industry; cohort studies; mortality; tetrachlorodibenzodioxin
Abbreviations: CI, confidence interval; RR, rate ratio; TCDD, 2,3,7,8-tetrachlorodibenzo-p-dioxin