[Uncertainty, expertise and decision making: the lessons from the Montchanin landfill]

Three epidemiological studies were conducted at the urgent request of the administrative authority of the French department of Saône-et-Loire, in order to assess the health impact of volatile emissions from an industrial wastes dump situated in the vicinity of dwellings in the city of Montchanin, France (6,000 inhabitants). These studies were implemented in the context of deep concern within the local population. Two dealt with the diagnosed morbidity before (retrospective follow-up study), or after (case-control study) the closure of the site. The third one dealt with mortality, for several causes of death liable to be related to the gazes emitted by the landfill (SMR analysis). Due to the small size of the population, these studies had limited statistical power. Despite these uncertainties, the authors claim that the decision to close the site was based on sound health considerations and recommend that the site be cleaned up. This experience illustrates the usefulness and the limitations of field epidemiological evaluations of environmental nuisances.