The objective of this study is to analyze the relationship between the incidence of cancer in adults and exposure to air emissions from municipal waste incineration plants. It focused on liver, lung, and breast cancers, leukemias, multiple myeloma, non-Hodgkin’s malignant lymphomas, and soft tissue sarcomas, all diagnosed in the Haut-Rhin, Bas-Rhin, Isère, and Tarn departments between 1990 and 1999. Nearly 135,000 cancer cases were recorded over approximately 25 million person-years. The exposure of statistical units (Iris, or clusters grouped for statistical purposes) during the 1970s and 1980s was quantified by modeling the accumulated surface deposition of dioxins emitted by 16 incinerators. The risks of cancer occurrence in IRIS with high exposure to incinerators were compared to the risks observed in IRIS with low exposure. A statistically significant association was found in women between exposure to incinerators and the incidence of all cancers combined, breast cancer, and non-Hodgkin’s lymphomas. A significant link was also found for non-Hodgkin’s lymphomas in both sexes combined and for multiple myeloma in men only. This ecological-geographic study does not establish causality for the observed associations, but it provides compelling evidence to the body of epidemiological arguments highlighting the impact of incinerator emissions on health. As it pertains to a past situation, its results cannot be applied to the present day. (R.A.)