Title: Traffic-related air pollution and asthma onset in children: a prospective cohort study with individual exposure measurement.
Authors: Jerrett, Michael; Shankardass, Ketan; Berhane, Kiros; Gauderman, W James; Kunzli, Nino; Avol, Edward; Gilliland, Frank; Lurmann, Fred; Molitor, Jassy N; Molitor, John T; Thomas, Duncan C; Peters, John; McConnell, Rob
Published In Environ Health Perspect, (2008 Oct)
Abstract: The question of whether air pollution contributes to asthma onset remains unresolved.In this study, we assessed the association between asthma onset in children and traffic-related air pollution.We selected a sample of 217 children from participants in the Southern California Children's Health Study, a prospective cohort designed to investigate associations between air pollution and respiratory health in children 10-18 years of age. Individual covariates and new asthma incidence (30 cases) were reported annually through questionnaires during 8 years of follow-up. Children had nitrogen dioxide monitors placed outside their home for 2 weeks in the summer and 2 weeks in the fall-winter season as a marker of traffic-related air pollution. We used multilevel Cox models to test the associations between asthma and air pollution.In models controlling for confounders, incident asthma was positively associated with traffic pollution, with a hazard ratio (HR) of 1.29 [95% confidence interval (CI), 1.07-1.56] across the average within-community interquartile range of 6.2 ppb in annual residential NO2. Using the total interquartile range for all measurements of 28.9 ppb increased the HR to 3.25 (95% CI, 1.35-7.85).In this cohort, markers of traffic-related air pollution were associated with the onset of asthma. The risks observed suggest that air pollution exposure contributes to new-onset asthma.
PubMed ID: 18941591
MeSH Terms: Adolescent; Age of Onset; Air Pollution*; Asthma/etiology*; Asthma/physiopathology; Child; Cohort Studies; Confounding Factors (Epidemiology); Environmental Exposure*; Female; Humans; Male; Models, Statistical; Seasons; Vehicle Emissions