Short-term nitrogen dioxide exposure and geomagnetic activity interaction : contribution to emergency hospitalization for acute coronary syndrome

Abstract

We investigated whether extremely geomagnetic activity may modify the association between short-term nitrogen dioxide (NO2) exposure and emergency hospitalization for acute coronary syndrome (ACS). A case-crossover study design was used to analyze ACS in 6,594 hospitalized patients at the Clinic of Kaunas, Lithuania. We evaluated the associations between NO2, geomagnetic activity and the rate of emergency admissions for ACS by logistic regression controlling for seasonal variation, weekdays and meteorological factors. Ambient NO2 pollution interquartile range increase (IQR) on the day of admission and previous day (lag 0–1) in patients below 65 years of age increase the risk of ACS equal to 24% (95% CI 0.96–1.60). Evidence of effect modification by combined NO2 and geomagnetic activity was observed in relation to ACS, adjusted OR was 1.61; 95% CI 1.03–2.53. In conclusion, these findings suggest that geomagnetic activity variations may increase the traffic-related air pollution effect on ACS, and highlight environmental factors associated with ischemic heart disease course.