Air pollution and emergency department visits for chest pain and weakness in Edmonton, Canada

Objectives: Chest pain or weakness can be first signal of health problems. Many studies demonstrate that these conditions can be related to air pollution. This work uses time-series data to investigate the association. Material and Methods: This is a study of 68 714 emergency department (ED) visits for chest pain (ICD-9: 786) and of 66 092 ED visits for weakness (ICD-9: 780). The hierarchical method was applied to analyse the associations between daily counts of ED visits for chest pain and weakness (separately) and the levels of the air pollutants and meteorological variables. The counts of visits for all patients, males and females were analysed separately by whole period (I-XII), warm (IV-IX) and cold (X-III). Results: The results are presented in the form of the excess risks associated with an increase in the interquartile range (IQR) for the pollutant. Chest pain: 2.4% (95% CI: 1.0-3.9) for CO, females, I-XII; 3.8% (95% CI: 0.0-7.8) for NO2, males, IV-IX; 4.5% (95% CI: 0.9-8.3) for O3 (1-day lagged), males, IV-IX; 2.8% (95% CI: 0.5-5.2), for PM10, males, X-III; 2.0% (95% CI: 0.0-4.0), for SO2, females, X-III; 2.1% (95% CI: 0.2-4.0) for PM2.5, all, X-III. Weakness: 2.1% (95% CI: 0.4-3.7) for CO (2-day lagged), males, X-III; 3.4% (95% CI: 1.0-5.9) for NO2 (2-day lagged), males, X-III; 2.4% (95% CI: 0.9-3.9) for SO2, females, I-XII; 4.6% (95% CI: 1.0-8.2) for O3 (1-day lagged), females, IV-IX. Conclusions: Obtained findings provide support for the hypothesis that ED visits for chest pain and weakness are associated with exposure to ambient air pollution.