Short-term effects of air pollution on hospitalization for acute myocardial infarction: age effect on lag pattern.

The aim of the present study is to analyse the age effect on the lag patterns of relative risk of hospitalization for acute myocardial infarction and NO2, PM10 and O3. Daily hospitalizations for AMI during the period 2008-2011 were extracted from administrative data. Analyses were performed using the quasi-Poisson regression model adjusted for seasonality, long-term trend, day of the week and temperature. We observed very different patterns depending on age. For NO2 and PM10, the younger group (25-54 years) shows a more delayed effect in comparison with the two older age groups (55-64 and ≥ 65 years). Overall, the associations between NO2 and AMI are higher compared to PM10. There are no associations between O3 and AMI. This study indicates that age plays a major role in the lag pattern. Younger people have delayed effects, but they are nevertheless sensitive to air pollution.