Climate, traffic-related air pollutants, and asthma prevalence in middle-school children in Taiwan

This study compared the prevalence of asthma with climate and air pollutant data to determine the relationship between asthma prevalence and these fac tors. We conducted a nationwide survey of respiratory illness and symptoms in middle-school students in Taiwan. Lifetime prevalences of physician-diag nosed asthma and of typical symptoms of asthma were compared to air monitor ing station data for temperature, relative humidity, sulfur dioxide, nitrog en oxides, ozone, carbon monoxide, and particulate matter with aerodynamic diameter less than or equal to 10 pm (PM10) A total of 331,686 nonsmoking c hildren attended schools located within 2 km of 55 stations. Asthma prevale nce races adjusted for age, history of atopic eczema, and parental educatio n were associated with nonsummer (June-August) temperature, winter (January -March) humidity, and traffic-related air pollution, especially carbon mono xide and nitrogen oxides, for both girls and boys. Nonsummer temperature, w inter humidity, and traffic-related air pollution, especially carbon monoxi de and nitrogen oxides, were positively associated with the prevalence of a sthma in middle-school students in Taiwan.