The link between air pollution and mortality is now widely accepted, with a level of causality that allows for health impact assessments such as the one presented in this study for nine French cities participating in the Apheis program, focusing on particulate matter. This health impact assessment is based on the methodology developed by the WHO. The number of preventable deaths ranges from 2.0 to 4.3, 4.0 to 8.9, and 15.0 to 31.5 per 100,000 inhabitants for very short-term, short-term, and long-term effects, respectively. Two scenarios for reducing particulate matter concentrations—one lowering daily levels exceeding 20 μg/m³ to this threshold value, and the other systematically reducing daily levels by 5 μg/m³—are similar for very short-term and short-term effects. The reduction strategy to 20 μg/m³ proves more favorable for long-term effects. This strategy therefore confirms the merit of the recommendation formulated at the national level. (R.A.)