Air Pollution and Doctorsʹ House Calls: Results from the ERPURS System for Monitoring the Effects of Air Pollution on Public Health in Greater Paris, France, 1991–1995

This study examines short-term relationships between doctorsʹ house calls and urban air pollution in Greater Paris for the period 1991–1995. Poisson regressions using nonparametric smoothing functions controlled for time trend, seasonal patterns, pollen counts, influenza epidemics, and weather. The relationship between asthma visits and air pollution was stronger for children. A relative risk (RRP95/P5) of 1.32 [95% confidence interval (CI) = 1.17–1.47)] was observed for an increase from the 5th to the 95th percentile (7–51 μg/m3) in daily concentrations of black smoke (BS). The risks for 24-hr sulfur dioxide and nitrogen dioxide levels were in the same range. Cardiovascular conditions, considered globally, showed weaker associations than angina pectoris/myocardial infarction, for which RRP95/P5was 1.63 (95% CI = 1.10–2.41) in relation to ozone ambient levels. Eye conditions were exclusively related to ozone (RRP95/P5= 1.17, 95% CI 1.02–1.33). Asthma visits and ozone showed an interaction with minimum temperature: an effect was observed only at 10°C or higher. In two-pollutant models including BS with, successively, SO2, NO2, and O3, only BS and O3effects remained stable. Along with mortality and hospital admissions, house call activity data, available on a regular basis, may be a sensitive indicator for monitoring health effects related to air pollution