[Seveso. Dioxin: an example of environmental medicine. Epidemiologic data as guidelines for health programming]

The 1976 dioxin accident in Seveso, Italy, represented a major environmental health problem for the population of the surrounding territory and a challenge for the entire regional area and the health and scientific institutions. The role of occupational health and of epidemiology in the incident investigation and management is discussed. Of major relevance was the consideration of all the different component factors of the interested environment, from chemical pollution to cultural attitudes and psycho-social stressors. Scientific research was helpful in elucidating the incompletely known toxic effects of dioxin and the complex mechanism of cancer induction by this widespread pollutant of our industrialized environments. The experience gained in Seveso was also useful in prompting national and international legislation concerning major industrial accidents, and the lessons learned contributed to the content of this legislation. Preparedness to these events requires mapping of the potential sources of these accidental occurrences and the monitoring of the social and health characteristics of the possibly affected populations. In the Lombardy Region, the numerous epidemiological investigations performed and the expertise implemented for the study and the control of the accident consequences, formed the basis on which the Regional Epidemiology Surveillance System established.