title: Traffic-related air pollution and development of allergic sensitization in children during the first 8 years of life.
abstract: BACKGROUND
  The role of exposure to air pollution in the development of allergic sensitization remains unclear.
  
  
  OBJECTIVE
  We sought to assess the development of sensitization until school age related to longitudinal exposure to air pollution from road traffic.
  
  
  METHODS
  More than 2500 children in the birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiological Survey) from Stockholm, Sweden, were followed with repeated questionnaires and blood sampling until 8 years of age. Outdoor concentrations of nitrogen oxides, as a marker of exhaust particles, and particles with an aerodynamic diameter of less than 10 μm (PM(10)), mainly representing road dust, were assigned to residential, day care, and school addresses by using dispersion models. Time-weighted average exposures were linked to levels of IgE against common inhalant and food allergens at 4 and 8 years of age.
  
  
  RESULTS
  Air pollution exposure during the first year of life was associated with an increased risk of pollen sensitization at 4 years of age (odds ratio, 1.83; 95% confidence interval, 1.02-3.28) for a 5th to 95th difference in exposure to nitrogen oxides. At 8 years, there was no general increase in the risk of sensitization; however, the risk of food sensitization was increased, particularly among children free of sensitization at 4 years of age (odds ratio, 2.30; 95% confidence interval, 1.10-4.82). Results were similar by using PM(10). No associations between air pollution exposure after the first year of life and sensitization were seen.
  
  
  CONCLUSIONS
  Traffic-related air pollution exposure does not seem to increase the overall risk of sensitization to common inhalant and food allergens up to school age, but sensitization to certain allergens might be related to exposure during infancy.
authors: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. olena.gruzieva@ki.se
authors: Olena
authors: O
authors: Gruzieva
authors: Tom
authors: T
authors: Bellander
authors: Kristina
authors: K
authors: Eneroth
authors: Inger
authors: I
authors: Kull
authors: Erik
authors: E
authors: Melén
authors: Emma
authors: E
authors: Nordling
authors: Marianne
authors: M
authors: van Hage
authors: Magnus
authors: M
authors: Wickman
authors: Vitaliy
authors: V
authors: Moskalenko
authors: Olesya
authors: O
authors: Hulchiy
authors: Göran
authors: G
authors: Pershagen
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity; D000397:Air Pollution / Q000009:adverse effects*; D000485:Allergens / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity; D015995:Prevalence; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D000485:Allergens; D052638:Particulate Matter; D001335:Vehicle Emissions; D007073:Immunoglobulin E