Climate, traf c-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan

Climate, trafŽ c-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan. Y-L. Lee, C-K. Shaw, H-J. Su, J-S. Lai, Y-C. Ko, S-L. Huang, F-C. Sung, Y.L. Guo. #ERS Journals Ltd 2003. ABSTRACT: The prevalence of allergic rhinitis, a common respiratory disorder, may be rapidly increasing. Epidemiological studies, however, indicate little about its association with climatic factors and air pollution. The relationship between trafŽ crelated air pollutants and allergic rhinitis in middle-school students was therefore investigated. In a nationwide survey of middle-school students in Taiwan conducted in 1995/1996, the lifetime prevalence of physician-diagnosedallergic rhinitis and typical symptoms of allergic rhinitis were compared with air-monitoring station data on temperature, relative humidity, sulphur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), carbon monoxide (CO) and particulate matter with a 50% cut-off aerodynamic diameter of 10 mm (PM10). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Mean (range) annual exposures were: CO 853 (381–1,610) parts per billion (ppb), NOx 35.1 (10.2–72.4) ppb, SO2 7.57 (0.88–21.2) ppb, PM10 69.2 (40.1–116.2) mg?m, O3 21.3 (12.4–34.1) ppb, temperature 22.9 (19.6–25.1)°C, and relative humidity 76.2 (64.8–86.2)%. The prevalence of physician-diagnosedallergic rhinitis was 28.6 and 19.5% in males and females, respectively, with prevalence of questionnaire-determined allergic rhinitis 42.4 and 34.0%. After adjustment for age, parental education and history of atopic eczema, physician-diagnosed allergic rhinitis was found to be associated with higher nonsummer (September–May) warmth and trafŽ c-related air pollutants, including CO, NOx and O3. Questionnaire-determined allergic rhinitis correlated only with trafŽ c-related air pollutants. Nonsummer warmth and trafŽ c-related air pollution, probably mediated through exposure to common allergens such as dust mites, are possible risk factors for allergic rhinitis in middle-school-aged children. Eur Respir J 2003; 21: 964–970. Depts of *Environmental and Occupational Health and Internal Medicine, Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Dept of Public Health, Tzu-Chi University, Hua-lien, Dept of Occupational Safety and Health, China Medical College, Taichung, Dept of Public Health, Kaohsiung Medical University, Kaohsiung, **Institute of Environmental Health Sciences, NationalYang-MingUniversity, and Institute of Environmental Health, National Taiwan University, Taipei, Taiwan.