The Seveso Studies on Early and Long-Term Effects of Dioxin Exposure: A Review

• Published in: Environmental health perspectives Vol. 106; no. Suppl 2; pp. 625 - 633
• Main Authors: Bertazzi, Pier A., Bernucci, Ilaria, Brambilla, Gabriella, Consonni, Dario, Pesatori, Angela C.
• Format: Journal Article
• Language: English
• Published: United States National Institute of Environmental Health Sciences. National Institutes of Health. Department of Health, Education and Welfare 01.04.1998
• Subjects: Accidents; Adolescent; Adult; Aged; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - etiology; Chemical hazards; Child; Child, Preschool; Death; Diabetes; Diabetes Mellitus - epidemiology; Diabetes Mellitus - etiology; Dioxins; Dioxins and Furans: Epidemiologic Assessment of Cancer Risks and Other Human Health Effects. Monograph Based on Papers Presented at the International Symposium on Dioxins and Furans: Epidemiologic Assessment of Cancer Risks and Other Human Health Effects held 7-8 November 1996 in Heidelberg, Germany; Environmental Exposure; Epidemiologic Studies; Female; Health benefits; Humans; Infant; Infant, Newborn; Italy - epidemiology; Male; Middle Aged; Mortality; Myocardial ischemia; Neoplasms - epidemiology; Neoplasms - etiology; Polychlorinated Dibenzodioxins - adverse effects; Pulmonary heart disease; Respiratory Tract Diseases - epidemiology; Respiratory Tract Diseases - etiology; Risk Assessment; Soil pollution; Italy
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.98106625

The industrial accident that occurred in the town of Seveso, Italy, in 1976 exposed a large population to substantial amounts of relatively pure 2,3,7,8-tetrachlorodibenzo-p-dioxin. Extensive monitoring of soil levels and measurements of a limited number of human blood samples allowed classification of the exposed population into three categories, A (highest exposure), B (median exposure), and R (lowest exposure). Early health investigations including liver function, immune function, neurologic impairment, and reproductive effects yielded inconclusive results. Chloracne (nearly 200 cases with a definite exposure dependence) was the only effect established with certainty. Long-term studies were conducted using the large population living in the surrounding noncontaminated territory as reference. An excess mortality from cardiovascular and respiratory diseases was uncovered, possibly related to the psychosocial consequences of the accident in addition to the chemical contamination. An excess of diabetes cases was also found. Results of cancer incidence and mortality follow-up showed an increased occurrence of cancer of the gastrointestinal sites and of the lymphatic and hematopoietic tissue. Experimental and epidemiologic data as well as mechanistic knowledge support the hypothesis that the observed cancer excesses are associated with dioxin exposure. Results cannot be viewed as conclusive. The study is continuing in an attempt to overcome the existing limitations (few individual exposure data, short latency period, and small population size for certain cancer types) and to explore new research paths (e.g., differences in individual susceptibility).