Early Life Exposure to Air Pollution and Incidence of Childhood Asthma, Allergic Rhinitis and Eczema
- Teresa To1,2,3⇑,
- Jingqin Zhu1,3,
- Dave Stieb4,
- Natasha Gray1,
- Ivy Fong1,
- Lauren Pinault5,
- Michael Jerrett6,
- Alain Robichaud7,
- Richard Ménard7,
- Aaron van Donkelaar8,9,
- Randall V. Martin8,9,10,
- Perry Hystad11,
- Jeffrey R. Brook2 and
- Sharon Dell1,2
- 1Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children
- 2Dalla Lana School of Public Health, University of Toronto
- 3Institute for Clinical Evaluative Sciences, Ontario, Canada
- 4Environmental Health Science and Research Bureau, Health Canada
- 5Analytical Studies Branch, Statistics Canada
- 6The University of California, Fielding School of Public Health, Los Angeles, California, USA
- 7Air Quality Research Division, Environment and Climate Change Canada
- 8Department of Physics and Atmospheric Science, Dalhousie University
- 9Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States
- 10Harvard-Smithsonian Center for Astrophysics
- 11College of Public Health and Human Sciences, Oregon State University
- Teresa To at The Hospital for Sick Children, Child Health Evaluative Sciences, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada. E-mail: teresa.to{at}sickkids.ca
Abstract
Rationale There is growing evidence that air pollution may contribute to the development of childhood asthma and other allergic diseases. In this follow-up of the Toronto Child Health Evaluation Questionnaire (T-CHEQ) study, we examined associations between early life exposures to air pollution and incidence of asthma, allergic rhinitis and eczema from birth through adolescence.
Methods 1286 T-CHEQ participants were followed from birth until outcome, March 31, 2016, or loss-to-follow-up with a mean of 17 years of follow-up. Concentrations of NO2, O3 and PM2.5 from January 1, 1999, to December 31, 2012 were assigned to participants based on their postal codes at birth using ground observations, chemical/meteorological models, remote sensing and land use regression (LUR) models. Study outcomes included incidence of physician-diagnosed asthma, allergic rhinitis and eczema. Cox proportional hazard regression models were used to estimate hazard ratios (HR) per interquartile range of exposures and outcomes, adjusting for potential confounders.
Results HRs of 1.17 (95%CI: 1.05, 1.31) for asthma and 1.07 (95%CI: 0.99, 1.15) for eczema were observed for total oxidants (O3 and NO2) at birth. No significant increase in risk was found for PM2.5.
Conclusion Exposures to oxidant air pollutants (O3 and NO2), but not PM2.5 were associated with an increased risk of incident asthma and eczema in children. This suggests that improving air quality may contribute to the prevention of asthma and other allergic disease in childhood and adolescence.
Footnotes
This manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.
Conflict of interest: Dr. To has nothing to disclose.
Conflict of interest: Ms. Zhu has nothing to disclose.
Conflict of interest: Dr. Stieb has nothing to disclose.
Conflict of interest: Ms. Gray has nothing to disclose.
Conflict of interest: Ms. Fong has nothing to disclose.
Conflict of interest: Dr. Pinault has nothing to disclose.
Conflict of interest: Dr. Jerrett reports grants from Health Canada, during the conduct of the study.
Conflict of interest: Dr. Robichaud has nothing to disclose.
Conflict of interest: Dr. Ménard has nothing to disclose.
Conflict of interest: Dr. van Donkelaar has nothing to disclose.
Conflict of interest: Dr. Martin reports grants from Health Canada, during the conduct of the study.
Conflict of interest: Dr. Hystad has nothing to disclose.
Conflict of interest: Dr. Brook has nothing to disclose.
Conflict of interest: Dr. Dell has nothing to disclose.
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- Received May 7, 2019.
- Accepted November 7, 2019.
- Copyright ©ERS 2019