Short-Term Effects of Air Pollution on Coronary Events in Strasbourg, France—Importance of Seasonal Variations

The aim of this study, is to investigate the effects of a short-term exposure to air pollutants, as assessed by Nitrogen dioxide (NO2), Particulate Matter PM2,5 and PM10 concentrations, on coronary event onsets in Strasbourg, France. An observational, analytical, retrospective, epidemiological study was conducted in Strasbourg between 1 January 2012 and 31 December 2014. Higher daily coronary events rates were evidenced when NO2 concentrations were measured above 40 µg/m3 (1.258 (95% CI 1.142–1.374) vs. 1.110 (95% CI 1.033–1.186); p = 0.015). The NO2 concentration was higher than 30 µg/m3 for 677 days (61.8%). Higher daily coronary events rates were evidenced when NO2 concentrations were measured above 30 µg/m3 (1.208 (95% CI 1.128–1.289) vs. 1.067 (95% CI 0.961–1.172) p = 0.009). A marked seasonality of NO2, PM2.5, and PM10 concentrations characterized by an increase during winter and a decrease during the summer could be established. The seasonality of coronary events was evidenced simultaneously. After adjustments were made to account for the time and the month, no independent impact of NO2, PM2.5 or PM10 on daily coronary events could be demonstrated.