title: Traffic-related air pollution and the development of asthma and allergies during the first 8 years of life.
abstract: BACKGROUND
  The role of air pollution exposure in the development of asthma, allergies, and related symptoms remains unclear, due in part to the limited number of prospective cohort studies with sufficiently long follow-ups addressing this problem.
  
  
  OBJECTIVE
  We studied the association between traffic-related air pollution and the development of asthma, allergy, and related symptoms in a prospective birth cohort study with a unique 8-year follow-up.
  
  
  METHODS
  Annual questionnaire reports of asthma, hay fever, and related symptoms during the first 8 years of life were analyzed for 3,863 children. At age 8, measurements of allergic sensitization and bronchial hyperresponsiveness were performed for subpopulations (n = 1,700 and 936, respectively). Individual exposures to nitrogen dioxide (NO(2)), particulate matter (PM(2.5)), and soot at the birth address were estimated by land-use regression models. Associations between exposure to traffic-related air pollution and repeated measures of health outcomes were assessed by repeated-measures logistic regression analysis. Effects are presented for an interquartile range increase in exposure after adjusting for covariates.
  
  
  RESULTS
  Annual prevalence was 3 to 6% for asthma and 12 to 23% for asthma symptoms. Annual incidence of asthma was 6% at age 1, and 1 to 2% at later ages. PM(2.5) levels were associated with a significant increase in incidence of asthma (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.10-1.49), prevalence of asthma (OR, 1.26; 95% CI, 1.04-1.51), and prevalence of asthma symptoms (OR, 1.15; 95% CI, 1.02-1.28). Findings were similar for NO(2) and soot. Associations were stronger for children who had not moved since birth. Positive associations with hay fever were found in nonmovers only. No associations were found with atopic eczema, allergic sensitization, and bronchial hyperresponsiveness.
  
  
  CONCLUSIONS
  Exposure to traffic-related air pollution may cause asthma in children.
authors: Institute for Risk Assessment Sciences, Utrecht University, The Netherlands. u.gehring@uu.nl
authors: Ulrike
authors: U
authors: Gehring
authors: Alet H
authors: AH
authors: Wijga
authors: Michael
authors: M
authors: Brauer
authors: Paul
authors: P
authors: Fischer
authors: Johan C
authors: JC
authors: de Jongste
authors: Marjan
authors: M
authors: Kerkhof
authors: Marieke
authors: M
authors: Oldenwening
authors: Henriette A
authors: HA
authors: Smit
authors: Bert
authors: B
authors: Brunekreef
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology; D001336:Automobiles; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D011795:Surveys and Questionnaires; D001335:Vehicle Emissions
chemical_list: D001335:Vehicle Emissions