title: Exposure to air pollution from traffic and childhood asthma until 12 years of age.
abstract: BACKGROUND
  There are limited prospective data on long-term exposure to air pollution and effects on childhood respiratory morbidity. We investigated the development of asthma and related symptoms longitudinally over the first 12 years of life in relation to air pollution from road traffic.
  
  
  METHODS
  The Swedish birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiological Survey) includes 4089 children who were followed up with repeated questionnaires and blood samples for up to 12 years of age. Residential, daycare, and school addresses, time-activity patterns, emission databases, and dispersion models were used to estimate individual exposure to particulate matter with aerodynamic diameter <10 μm (PM10) and nitrogen oxides (NOx) from traffic.
  
  
  RESULTS
  Overall, the data suggested possible associations between exposure to air pollution during the first year of life and asthma and wheezing in children up to 12 years of age. Asthma risks seemed to be particularly increased in children age 8 to 12 years; the overall odds ratio was 2.0 (95% confidence interval = 1.1-3.5), and for nonallergic asthma, the odds ratio was 3.8 (0.9-16.2) for a 5th to 95th percentile increase in time-weighted average exposure to PM10 (corresponding to 7.2 µg/m). Results were similar using exposure to traffic-NOx.
  
  
  CONCLUSIONS
  We found modest positive associations between air pollution exposure from traffic during infancy and asthma in children during the first 12 years of life, with stronger effects suggested for nonallergic asthma.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. olena.gruzieva@ki.se
authors.forename: Olena
authors.initials: O
authors.lastname: Gruzieva
authors.forename: Anna
authors.initials: A
authors.lastname: Bergström
authors.forename: Olesya
authors.initials: O
authors.lastname: Hulchiy
authors.forename: Inger
authors.initials: I
authors.lastname: Kull
authors.forename: Tomas
authors.initials: T
authors.lastname: Lind
authors.forename: Erik
authors.initials: E
authors.lastname: Melén
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Moskalenko
authors.forename: Göran
authors.initials: G
authors.lastname: Pershagen
authors.forename: Tom
authors.initials: T
authors.lastname: Bellander
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis / Q000706:statistics & numerical data; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008962:Models, Theoretical; D009589:Nitrogen Oxides / Q000032:analysis / Q000633:toxicity*; D016017:Odds Ratio; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions