The Air and Health Surveillance Program (PSAS), coordinated by the French Institute for Public Health Surveillance (InVS)—a public institution under the authority of the Ministry of Health—was launched in 1997 with the aim of characterizing the health risks associated with the French population’s exposure to air pollution. The PSAS is based on a network comprising InVS epidemiologists from the Department of Environmental Health (DSE) and the Interregional Epidemiology Units (CIRE) located in the regions, the Regional Health Observatories (ORS), and the Accredited Air Quality Monitoring Associations (AASQA). Since its inception, the program has collaborated closely with the AASQAs primarily on: - characterizing exposure to air pollution within the framework of epidemiological studies on short- and long-term health effects; - rapidly assessing the health impact associated with increased levels of air pollution during alerts triggered by specific events (recent examples: the ash cloud following the eruption of the Icelandic volcano Eyjafjöll in April 2010, the forest fires in Marseille in July 2009) through the establishment of collaborations at the local or national level; - communication regarding health risks linked to air pollution; - exchanges of general knowledge, particularly through participation in joint expert assessments. (R.A)