Dataset Information

Childhood Exposure to Ambient Air Pollutants and the Onset of Asthma: An Administrative Cohort Study in Quebec.

ABSTRACT:

Background

Although it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear.

Objective

We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants.

Method

An open cohort of children born in the province of Québec, Canada, was created using linked medical-administrative databases. New cases of asthma were defined as one hospital discharge with a diagnosis of asthma or two physician claims for asthma within a 2 year period. Annual ozone (O3) levels were estimated at the child's residence for all births 1999-2010, and nitrogen dioxide (NO2) levels during 1996-2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (PM2.5) were estimated at a 10 km × 10 km resolution and assigned to residential postal codes throughout the province (1996-2011). Hazard ratios (HRs) were assessed with Cox models for the exposure at the birth address and for the time-dependent exposure. We performed an indirect adjustment for secondhand smoke (SHS).

Results

We followed 1,183,865 children (7,752,083 person-years), of whom 162,752 became asthmatic. After controlling for sex and material and social deprivation, HRs for an interquartile range increase in exposure at the birth address to NO2 (5.45 ppb), O3 (3.22 ppb), and PM2.5 (6.50 ?g/m3) were 1.04 (95% CI: 1.02, 1.05), 1.11 (95% CI: 1.10, 1.12), and 1.31 (95% CI: 1.28, 1.33), respectively. Effects of O3 and PM2.5 estimated with time-varying Cox models were similar to those estimated using exposure at birth, whereas the effect of NO2 was slightly stronger (HR = 1.07; 95% CI: 1.05, 1.09).

Conclusions

Asthma onset in children appears to be associated with residential exposure to PM2.5, O3 and NO2.

Citation

Tétreault LF, Doucet M, Gamache P, Fournier M, Brand A, Kosatsky T, Smargiassi A. 2016. Childhood exposure to ambient air pollutants and the onset of asthma: an administrative cohort study in Québec. Environ Health Perspect 124:1276-1282;?http://dx.doi.org/10.1289/ehp.1509838.

SUBMITTER: Tetreault LF

PROVIDER: S-EPMC4977042 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

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Publications

Childhood Exposure to Ambient Air Pollutants and the Onset of Asthma: An Administrative Cohort Study in Québec.

Tétreault Louis-Francois LF Doucet Marieve M Gamache Philippe P Fournier Michel M Brand Allan A Kosatsky Tom T Smargiassi Audrey A

Environmental health perspectives 20160105 8

<h4>Background</h4>Although it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear.<h4>Objective</h4>We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants.<h4>Method</h4>An open cohort of children born in the province of Québec, Canada, was created using linked medical-administrative databases. New cases of asthma were defined as one hospita ...[more]

PMID: 26731790

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