Long-Term Effect of Outdoor Air Pollution on Mortality and Morbidity: A 12-Year Follow-Up Study for Metropolitan France

Abstract

Background: Short-term effects of air pollution are documented more than long-term effects. Objective: We investigated 12-year impacts of ambient air pollutants on cardiovascular and respiratory morbidity and mortality at the departmental level in metropolitan France. Methods: Daily air pollution data at 2-km resolution, including concentrations of particulate matter of 10 µm or 2.5 µm in diameter or less (PM10 and PM2.5), nitrogen dioxide (NO2), and ozone (O3), were accrued from the CHIMERE database for 1999 and 2000. Simultaneously, morbidity (hospitalizations) and mortality data were collected in 2012 using the ESPS (Enquête Santé et Protection Sociale/Health, Health Care and Insurance Survey) survey data and the CepiDc (Centre d’Épidémiologie sur les Causes Médicales de Décès/French Epidemiology Centre on Medical Causes of Death) database. Based on Poisson regression analyses, the long-term effect was estimated. A higher risk of all-cause mortality was observed using CépiDc database, with a relative risk of 1.024 (95% CI: 1.022, 1.026) and 1.029 (95% CI: 1.027, 1.031) for a 10 µg/m3 increase in PM2.5 and PM10, respectively. Mortality due to cardiovascular and respiratory diseases likewise exhibited long-term associations with both PM2.5 and PM10. Using ESPS survey data, a significant risk was observed for both PM2.5 and PM10 in all-cause mortality and all-cause morbidity. Although a risk for higher all-cause mortality and morbidity was also present for NO2, the cause-specific relative risk due to NO2 was found to be lesser, as compared to PM. Nevertheless, cardiovascular and respiratory morbidity were related to NO2, along with PM2.5 and PM10. However, the health effect of O3 was seen to be substantially lower in comparison to the other pollutants. Conclusion: Our study confirmed that PM has a long-term impact on mortality and morbidity. Exposure to NO2 and O3 could also lead to increased health risks.