Environmental Research 104 (2007) 402–409 Air pollution, weather, and associated risk factors related to asthma prevalence and attack rate Wen-Chao Ho a,b,Ã , William R. Hartley b , Leann Myers c , Meng-Hung Lin a , Yu-Sheng Lin d , Chih-Hui Lien a , Ruey-Shiung Lin e a Graduate Institute of Environmental Medicine, China Medical University, 91 Hsueh-Shih Road, Taichung, Taiwan 40402, ROC b Department of Environmental Health Sciences, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA 70112, USA c Department of Biostatistics, Tulane University, 1440 Canal Street, Room 2031, New Orleans, LA 70112, USA d Department of Environmental and Occupational Health, University of North Texas, Health Science Center, Fort Worth, TX 76107, USA e Institute of Preventive Medicine, National Taiwan University, 5Fl. No. 17, Hsu Chow Road, Taipei, Taiwan 100, ROC Received 14 August 2006; received in revised form 29 December 2006; accepted 17 January 2007 Available online 21 February 2007 Abstract Asthma is an important public health challenge. The objective of this research was to investigate the relationship of air pollution and weather to adolescent asthma prevalence and attack rate. A 6-month mass screening asthma study was conducted from October 1995 to March 1996 in Taiwan. The study population included junior high school students from throughout the country (1,139,452 students). Eighty-nine percent of students completed questionnaires (International Study of Asthma and Allergies in Childhood—ISAAC and New England Core Questionnaires) and passed a logical screening error program. Lung function data was collected to assist in the diagnosis of asthma status. From the students screened during this mass survey, a stratified random sample of 64,660 students was analyzed for asthma prevalence and attack rate. Using a regression model to compare the USEPA National Ambient Air Quality Standards 2000 (NAAQS, 2000) to asthma prevalence, this investigation found that the standards may not provide enough protection for adolescents after controlling for age, rhinitis, eczema, urban birth location, parental education level, exercise, cigarette smoking, environmental tobacco smoking, alcohol beverage consumption and weather factors. The general estimating equations (GEE) model, a repeated measurement regression model, was used to examine the relationship between the monthly asthma attack rate among asthma patients and air pollution (nitrogen oxides; nitrogen dioxide; nitric oxide; Ozone; PM 10 ) while controlling for household smoking. The GEE model demonstrated that air pollution is related to asthma attack rate. Air pollution factors also interacted with weather parameters when related to asthma attack rate. r 2007 Elsevier Inc. All rights reserved. Keywords: Air pollution; Weather; Asthma; Prevalence; Attack rate 1. Introduction The objective of this research was to investigate the relationship of air pollution and weather to adolescent asthma prevalence and attack rate after adjusting the effects of notable personal risk factors. In the International Study of Asthma and Allergies in Childhood (ISAAC) research report, the highest asthma prevalence occurred in industrialized and westernized countries. The highest 12- month asthma prevalence rates were in the United King- dom, New Zealand, Australia, and the Republic of Ireland, followed by North, Central, and South America. The highest adolescent asthma prevalence was 36.8% in UK (ISAAC Steering Committee, 1998). A community-based epidemiological study of asthma incidence rates in the USA from 1964 to 1983 showed that the rise in asthma incidence was entirely accounted for by the increased incidence rates in the age range of 1–14 years (Yunginger et al., 1992). Hospital admission rates for asthma have also increased ARTICLE IN PRESS www.elsevier.com/locate/envres 0013-9351/$ - see front matter r 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2007.01.007 Ã Corresponding author. Graduate Institute of Environmental Medi- cine, China Medical University, 91 Hsueh-Shih Road, Taichung, Taiwan 40402, ROC. Fax: +886 4 2201 9901. E-mail address: whocmu@gmail.com (W.-C. Ho).