The assessment of the health impact of air pollution on the Nîmes metropolitan area, presented in this report, was conducted as part of the Languedoc-Roussillon Regional Air Quality Plan. The study was carried out for the Nîmes urban area using a standardized method proposed by the French Institute for Public Health Surveillance. The health impact of air pollution is estimated based on five years of air quality measurements, combined with mortality data from 1999 to 2001 and hospital admissions from 1999 to 2003. The resulting estimates allow for an assessment of the short- and long-term health impacts of urban air pollution. The estimate of the short-term health impact of air pollution compared to a theoretical low-pollution level shows that each year, air pollution is directly responsible for 24 premature deaths in the urban area of Nîmes, including 9 due to cardiovascular causes and 3 due to respiratory causes. The pollution levels observed there also cause 43 hospital admissions annually for cardiovascular reasons, 9 for cardiac reasons, and 10 for respiratory reasons among adults over the age of 15. Calculations of the health benefits associated with various strategies to reduce air pollution show that a 25% reduction in the annual average background pollution level is the most effective public health measure. The figures presented in this study provide an order of magnitude to illustrate the effects of air pollution on a population’s health even when measured concentrations are moderate or even below regulatory thresholds. The estimates obtained show that while relative risks are considered "low" at the individual level, the impact on the entire population is significant due to the large number of people exposed. (R.A.)