Air pollution and asthma among children in Seoul, Korea

Background. As information about the health risks associated with air pollution has become available, attention has focused increasingly on susceptible persons such as children and persons with preexisting respiratory diseases, such as asthma. Methods. We investigated the association between outdoor air pollution and asthma attacks among children under 15 years of age in Seoul, Korea. We estimated the relative risks of hospitalization associated with an interquartile range (IQR) increase in pollutant concentrations and used time series analysis of the counts by means of the generalized additive Poisson model. Results. The estimated relative risk of hospitalization for asthma was 1.07 (95% confidence interval [CI] = 1.04-1.11) for particulate matters less than or equal to 10 μm in aerodynamic diameter (IQR = 40.4 μg/m³); 1.11 (95% CI = 1.17) for sulfur dioxide (IQR = 4.4 ppb); 1.15 (95% CI = 1.10-1.20) for nitrogen dioxide (IQR = 14.6 ppb); 1.12 (95% CI = 1.07-1.16) for ozone (IQR = 21.7 ppb); and 1.16 (95% CI = 1.10-1.22) for carbon monoxide (IQR = 1.0 ppm). Conclusions. These findings support the hypothesis that air pollution at levels below the current standards of Korea is harmful to sensitive subjects such as asthmatic children.