Health impact assessment of PM10 exposure in the city of Caen, France.
Résumé
Air pollution in Caen, a city in northwestern France, comes mainly from motor vehicles. The aim of this study was to assess the public health impact of both acute (with immediate or short-term effects) and chronic (with long-term effects) exposure to PM10 (particulate matter <10 microm). The standard World Health Organization (WHO) methodology for a health impact assessment (HIA) was used to calculate the attributable deaths and hospital admissions. Population exposure was estimated from PM10 concentrations collected by the local air quality measurement network. The relative risks were modeled with exposure-risk functions established in epidemiologic studies in the general population. The APHEA-2 program, which combines European time-series studies, was used to assess effects from acute exposures and a meta-risk was calculated from cohort studies to assess the effects of chronic exposure. The health impact of chronic exposure from 1998 through 2002 was estimated at 168 (101-238) deaths. Acute exposure (relative to a baseline level of 10 microg/m3) led to 26 (17-35) deaths and 43 (22-67) hospital admissions during this period. A 10% daily decrease in pollution would reduce the number of expected deaths from short-term exposure by 19%, while achieving compliance with European Union regulations (daily mean in 2010: 50 microg/m3) would reduce them by less than 3%. Because the health impact of the pollution in Caen is due mainly to relatively moderate levels, reducing everyday pollution levels through long-term regulation would be more beneficial than avoiding pollution peaks.