Short-term nitrogen dioxide ambient pollution and emergency hospital admission for heart attack in Kaunas

Abstract

Air pollution is known to be associated with cardiovascular mortality, bur little is known about the short-term nitrogen dioxide (NO2) effects on acute heart attack risk. The objective of the study was to estimate association between NO2 exposure and emergency hospital admission for heart attack in Kaunas within 2005-2006 periods. Associations were assessed using the case-crossover method and multivariate logistic regression. Mean daily levels of NO2 were related to the daily number of hospital admissions for heart attack. The relative risk for increase of heart attack admissions, evaluated at NO2 tertiles of day of admission and 2 days prior to the data of admissions were as follows: 1; 2.22, 95% CI 1.32-3.76; 2.84, 95% CI 1.70-4.77 and 1; 1.74, 95% CI 1.05-2.89; 2.00, 95% CI 1.23-3.26. The hospital admission odds ratios for each intertertile range increase on NO2 was associated with one day increase of 63.5% (OR=1.64, 95% CI 1.28-2.09; p<0.001), and two day increase of 39.4% (OR=1.39, 95% CI 1.10-1.767; p=0.006). These findings suggest that higher ambient NO2 levels might bee associated with increase of heart attack risk.