title: Association between traffic-related air pollution and development of asthma in school children: cohort study in Japan.
abstract: Air pollution is widely understood to be capable of exacerbating asthma symptoms. Here we examined the association between traffic-related air pollution and development of asthma in school children. Subjects were 10,069 school children in their first through third years of compulsory education (6-9-year old). The main outcome was incidence of asthma as determined from the questionnaire. Follow-up surveys were conducted every year up to 4 years after the end of the study. To evaluate individual level of exposure to traffic-related air pollution, we used a simulation model that accounted for exposure level both at home and at school. As surrogates of traffic-related air pollution, the estimation target was the annual average individual exposure of automobile exhaust-originating nitrogen oxides (NOx) and elemental carbon (EC). Confounding factors were adjusted using a discrete-time logistic regression model. We found a positive association between exposure to EC and incidence of asthma. The odds ratio (OR) (95% confidence interval) for asthma incidence was 1.07 (1.01-1.14) for each 0.1 μg/m(3) EC and 1.01 (0.99-1.03) for each 1 p.p.b. NOx. Traffic-related air pollution is associated with development of asthma in school children.
authors.affiliation: Department of Healthcare Epidemiology, Kyoto University School of Public Health, Kyoto, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Yamazaki
authors.affiliation: Department of Public Health, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shima
authors.affiliation: Department of Hygiene, Showa University, Tokyo, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Nakadate
authors.affiliation: Center for Regional Environmental Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Ohara
authors.affiliation: Faculty of Culture and Information Science, Doshisha University, Kyoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Omori
authors.affiliation: Center for Environmental Health Sciences, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Masaji
authors.initials: M
authors.lastname: Ono
authors.affiliation: Department of Biostatistics, Kyoto University School of Public Health, Kyoto, Japan.
authors.forename: Tosiya
authors.initials: T
authors.lastname: Sato
authors.affiliation: Center for Environmental Health Sciences, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nitta
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D004781:Environmental Exposure; D006801:Humans; D007564:Japan / Q000453:epidemiology; D011446:Prospective Studies; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions