Background: The role of traffic-related air pollution (TRAP) exposure in the development of allergic sensitization in children is unclear, and few birth cohort studies have incorporated spatiotemporal exposure assessment.
Objectives: We aimed to examine the association between TRAP and atopy in 1-year-old children from an ongoing national birth cohort study in four Canadian cities.
Methods: We identified 2,477 children of approximately 1 year of age with assessment of atopy for inhalant (Alternaria, Der p, Der f, cat, dog, cockroach) and food-related (milk, eggs, peanuts, soy) allergens. Exposure to nitrogen dioxide (NO2) was estimated from city-specific land use regression models accounting for residential mobility and temporal variability in ambient concentrations. We used mixed models to examine associations between atopy and exposure during pregnancy and the first year of life, including adjustment for covariates (maternal atopy, socioeconomic status, pets, mold, nutrition). We also conducted analyses stratified by time-location patterns, daycare attendance, and modeled home ventilation.
Results: Following spatiotemporal adjustment, TRAP exposure after birth increased the risk for development of atopy to any allergens [adjusted odds ratio (aOR) per 10 μg/m3 NO2 = 1.16; 95% CI: 1.00, 1.41], but not during pregnancy (aOR = 1.02; 95% CI: 0.86, 1.22). This association was stronger among children not attending daycare (aOR = 1.61; 95% CI: 1.28, 2.01) compared with daycare attendees (aOR = 1.05; 95% CI: 0.81, 1.28). Trends to increased risk were also found for food (aOR = 1.17; 95% CI: 0.95, 1.47) and inhalant allergens (aOR = 1.28; 95% CI: 0.93, 1.76).
Conclusion: Using refined exposure estimates that incorporated temporal variability and residential mobility, we found that traffic-related air pollution during the first year of life was associated with atopy.
1School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada; 2Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada; 3Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; 4Air Quality Research Division, Environment Canada, Toronto, Ontario, Canada; 5Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; 6Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; 7Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada; 8Hospital for Sick Children, Department of Paediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; 9BC Children’s Hospital and Child and Family Research Institute, Department of Paediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
Recommended Citation:
Hind Sbihi,1 Ryan W. Allen,2 Allan Becker,et al. Perinatal Exposure to Traffic-Related Air Pollution and Atopy at 1 Year of Age in a Multi-Center Canadian Birth Cohort Study[J]. Environmental Health Perspectives,2015-01-01,Volume 123(Issue 9):902