(HealthDay News) — Long-term exposure to particulate matter is associated with increased risk of acute coronary events, even at levels below the current European limit values, according to a study published online January 21 in BMJ.
Giulia Cesaroni, from Lazio Regional Health Service in Rome, and colleagues examined the effect of long-term exposure to airborne pollutants on the incidence of acute coronary events in 11 European cohorts involving 100,166 people enrolled from 1997 to 2007 and followed for an average of 11.5 years. Based on measurements of air pollution conducted in 2008 to 2012, modeled concentrations of particulate matter <2.5 µm (PM2.5), 2.5 to 10 µm (PMcoarse), and <10 µm (PM10) in aerodynamic diameter, soot (PM2.5 absorbance), nitrogen oxides, and traffic exposure at the home address were determined.
The researchers found that 5,157 individuals experienced incident events during follow-up. Increases of 5 and 10 µg/m³ in estimated annual mean PM2.5 and PM10 correlated with increased risks of coronary events (hazard ratios, 1.13 [95% confidence interval (CI), 0.98 to 1.30] and 1.12 [95% CI, 1.01 to 1.25], respectively). There was no evidence of heterogeneity between the cohorts. There was evidence of positive correlations below the current annual European limits of 25 µg/m³ for PM2.5 (hazard ratio, 1.18 for each 5 µg/m³ increase in PM2.5) and 40 µg/m³ for PM10 (hazard ratio, 1.12 for each 10 µg/m³ increase in PM10). For other pollutants, there were positive but nonsignificant associations.
“Long term exposure to particulate matter is associated with incidence of coronary events, and this association persists at levels of exposure below the current European limit values,” the authors write.