Does exposure to air pollution increase the risk of acute care in young children with asthma? An Ontario, Canada study

Teresa To; Jingqin Zhu; Emilie Terebessy; Kimball Zhang; Ivy Fong; Lauren Pinault; Michael Jerrett; Alain Robichaud; Richard Ménard; Aaron van Donkelaar; Randall V Martin; Perry Hystad; Jeffrey R Brook; Sharon Dell; Dave Stieb

doi:10.1016/j.envres.2021.111302

Does exposure to air pollution increase the risk of acute care in young children with asthma? An Ontario, Canada study

Environ Res. 2021 Aug:199:111302. doi: 10.1016/j.envres.2021.111302. Epub 2021 May 19.

Authors

Affiliations

¹ Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada; Dalla Lana School of Public Health, University of Toronto, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada. Electronic address: teresa.to@sickkids.ca.
² Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada.
³ Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada.
⁴ Health Analysis Division, Statistics Canada.
⁵ The University of California, Los Angeles, Fielding School of Public Health, CA, USA.
⁶ Air Quality Research Division, Environment and Climate Change Canada.
⁷ Department of Physics and Atmospheric Science, Dalhousie University, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
⁸ Department of Physics and Atmospheric Science, Dalhousie University, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA; Harvard-Smithsonian Center for Astrophysics, USA.
⁹ College of Public Health and Human Sciences, Oregon State University, USA.
¹⁰ Dalla Lana School of Public Health, University of Toronto, Canada.
¹¹ Department of Pediatrics, Faculty of Medicine, University of British Columbia, Canada; Pediatric Respiratory Medicine, Provincial Health Services Authority, BC Children's Hospital, Canada.
¹² Environmental Health Science and Research Bureau, Health Canada, Canada.

PMID: 34019894
DOI: 10.1016/j.envres.2021.111302

Abstract

Owing to their greater outdoor activity and ongoing lung development, children are particularly vulnerable to the harmful effects of exposure to fine particulate matter (PM_2.5)_. However, the effects of PM_2.5 components are poorly understood. This study aimed to use a longitudinal birth cohort of children with physician-diagnosed incident asthma to investigate the effect of PM_2.5 components at birth on morbidity measured by health services utilization. Of 1277 Toronto Child Health Evaluation Questionnaire (T-CHEQ) participants, the study population included 362 children diagnosed with asthma who were followed for a mean of 13 years from birth until March 31, 2016, or loss-to-follow-up. Concentrations of PM_2.5 and its components were assigned based on participants' postal codes at birth. Study outcomes included counts of asthma, asthma-related, and all-cause health services use. Poisson regression in single-, two-, and multi-pollutant models was used to estimate rate ratios (RR) per interquartile range (IQR) increase of exposures. Covariates were included in all models to further adjust for potential confounding. The adjusted RR for sulfate (SO₄) and all-cause hospitalizations was statistically significant with RR = 2.23 (95% confidence interval [CI]: 1.25-3.96) in a multi-pollutant model with nitrogen dioxide (NO₂) and ozone (O₃). In multi-pollutant models with oxidants, the adjusted RRs for SO₄ of all-cause hospitalizations and emergency department (ED) visits were also statistically significant with RR = 2.31 (95% CI: 1.32-4.03) and RR = 1.39 (95% CI: 1.02-1.90), respectively. While unadjusted single-pollutant RRs for asthma-specific and asthma-related health services use with the SO₄ component of PM_2.5 were above one, none were statistically significant. This study found significant associations with exposure to SO₄ in PM_2.5 and all-cause acute care, chiefly for hospitalizations, in children with asthma.

Keywords: Acute care; Air pollution; Asthma; Early life exposures; Fine particulate matter.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
Air Pollutants* / toxicity
Air Pollution* / adverse effects
Air Pollution* / analysis
Asthma* / chemically induced
Asthma* / epidemiology
Child
Child, Preschool
Environmental Exposure / adverse effects
Environmental Exposure / analysis
Humans
Infant, Newborn
Nitrogen Dioxide / analysis
Nitrogen Dioxide / toxicity
Ontario / epidemiology
Ozone* / analysis
Particulate Matter / analysis
Particulate Matter / toxicity

Substances

Air Pollutants
Particulate Matter
Ozone
Nitrogen Dioxide