Environmental exposure to asbestos, long overshadowed by the issue of occupational exposure, has a health impact that is still difficult to quantify but very real. The French Institute for Public Health Surveillance (InVS) has conducted several studies to assess the risk and help policymakers manage it. Asbestos is a natural fibrous material that was widely used, particularly in the construction, automotive, textile, and plastics industries, until it was banned on January 1, 1997. Since this general ban, more specific decrees and regulations have been enacted to protect workers and the public from the health risks posed by asbestos already in place, mainly in buildings. Even today, due to the very long latency period before cancer associated with asbestos exposure manifests, exposure to asbestos remains, by far, the leading cause of occupational cancers. It was known as early as the beginning of the 20th century that occupational exposure led to pulmonary fibrosis or asbestosis. Subsequently, the role of asbestos in various diseases was established: lung cancer and pleural cancer (mesothelioma), pleural plaques, and pleural thickening; other cancer sites are also suspected. Public health issues related to the impact of environmental exposure are much more recent. Unlike lung cancer, mesothelioma is a very specific disease: no risk factors other than asbestos exposure are known. This is why it is used to assess the health impact of asbestos exposure. This impact is not limited to mesothelioma: today, it is estimated that 5 to 15% of lung cancers in men in France are linked to asbestos. In the vast majority of mesothelioma cases, occupational exposure is identified (see box opposite). For the remaining cases, no occupational explanation could be provided. This leads us to hypothesize that other forms of asbestos exposure were responsible for these cases. What is the health impact of all these forms of exposure? To answer this question, this summary presents the various studies conducted by the InVS. (R.A.)