Stéphane Buteau1, Mariève Doucet2, Louis-François Tétreault3, Philippe Gamache4, Michel Fournier3, Allan Brand4, Tom Kosatsky5, Audrey Smargiassi6. 1. Institut national de sante publique du Quebec (INSPQ), Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada. 2. Institut national de sante publique du Quebec (INSPQ), Montreal, Quebec, Canada; Department of Medicine, Laval University, Quebec, Quebec, Canada. 3. Montreal's Public Health Department, Montreal, Quebec, Canada. 4. Institut national de sante publique du Quebec (INSPQ), Montreal, Quebec, Canada. 5. British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada. 6. Institut national de sante publique du Quebec (INSPQ), Montreal, Quebec, Canada; Department of Environmental and Occupational Health, School of Public Health, University of Montreal, Montreal, Quebec, Canada; University of Montreal, Public Health Research Institute, Montreal, Quebec, Canada. Electronic address: audrey.smargiassi@umontreal.ca.
Abstract
BACKGROUND: Studies of the association between air pollution and asthma onset have mostly focused on urban and traffic-related air pollution. We investigated the associations between exposure to industrial emissions and childhood-onset asthma in a population-based birth cohort in Quebec, Canada, 2002-2011. METHODS: The cohort was built from administrative health databases. We developed separately for PM2.5 and SO2 different metrics representing children's time-varying residential exposure to industrial emissions: 1) yearly number of tons of air pollutant emitted by industries located within 2.5 km of the residence; 2) distance to the nearest "major emitter" (≥100 tons) of either PM2.5 and SO2 within 7.5 km of the residence, and; 3) tons of air pollutant emitted by the nearest "major emitter" within 7.5 km, weighted by the inverse of the distance and the percentage of time that the residence was downwind. To handle the large number of zeros (i.e., children unexposed) we decomposed the exposure variable into two covariates simultaneously included in the regression model: a binary indicator of exposure and a continuous exposure variable centered at the mean value among exposed children. We performed Cox models using age as the time axis, adjusted for gender, material and social deprivation and calendar year. We indirectly adjusted for unmeasured secondhand smoke. RESULTS: The cohort included 722,667 children and 66,559 incident cases of asthma. Across the different exposure metrics, mean percentage changes in the risk of asthma onset in children exposed to the mean relative to those unexposed ranged from 4.5% (95% CI: 2.8, 6.3%) to 10.6% (95% CI: 6.2, 15.2%) for PM2.5 and, from 1.1% (95% CI: -0.1, 3.3%) to 8.9% (95% CI: 7.1, 11.1%) for SO2. Indirect adjustment for secondhand smoke did not substantially affect the associations. In children exposed, the risk of asthma onset increased with the magnitude of the exposure for all metrics, except the distance to the nearest major emitter of SO2. CONCLUSIONS: In this population-based birth cohort, residential exposure to industrial air pollutant emissions was associated with childhood-onset asthma. Additional studies with improved models for estimating exposure to industrial point-sources are needed to further support the observed associations.
BACKGROUND: Studies of the association between air pollution and asthma onset have mostly focused on urban and traffic-related air pollution. We investigated the associations between exposure to industrial emissions and childhood-onset asthma in a population-based birth cohort in Quebec, Canada, 2002-2011. METHODS: The cohort was built from administrative health databases. We developed separately for PM2.5 and SO2 different metrics representing children's time-varying residential exposure to industrial emissions: 1) yearly number of tons of air pollutant emitted by industries located within 2.5 km of the residence; 2) distance to the nearest "major emitter" (≥100 tons) of either PM2.5 and SO2 within 7.5 km of the residence, and; 3) tons of air pollutant emitted by the nearest "major emitter" within 7.5 km, weighted by the inverse of the distance and the percentage of time that the residence was downwind. To handle the large number of zeros (i.e., children unexposed) we decomposed the exposure variable into two covariates simultaneously included in the regression model: a binary indicator of exposure and a continuous exposure variable centered at the mean value among exposed children. We performed Cox models using age as the time axis, adjusted for gender, material and social deprivation and calendar year. We indirectly adjusted for unmeasured secondhand smoke. RESULTS: The cohort included 722,667 children and 66,559 incident cases of asthma. Across the different exposure metrics, mean percentage changes in the risk of asthma onset in children exposed to the mean relative to those unexposed ranged from 4.5% (95% CI: 2.8, 6.3%) to 10.6% (95% CI: 6.2, 15.2%) for PM2.5 and, from 1.1% (95% CI: -0.1, 3.3%) to 8.9% (95% CI: 7.1, 11.1%) for SO2. Indirect adjustment for secondhand smoke did not substantially affect the associations. In children exposed, the risk of asthma onset increased with the magnitude of the exposure for all metrics, except the distance to the nearest major emitter of SO2. CONCLUSIONS: In this population-based birth cohort, residential exposure to industrial air pollutant emissions was associated with childhood-onset asthma. Additional studies with improved models for estimating exposure to industrial point-sources are needed to further support the observed associations.
Authors: Erick Forno; Diego D Brandenburg; Jose A Castro-Rodriguez; Carlos A Celis-Preciado; Fernando Holguin; Christopher Licskai; Stephanie Lovinsky-Desir; Marcia Pizzichini; Alejandro Teper; Connie Yang; Juan C Celedón Journal: Ann Am Thorac Soc Date: 2022-04
Authors: Dhenuka Radhakrishnan; Sarah E Bota; April Price; Alexandra Ouédraogo; Murad Husein; Kristin K Clemens; Salimah Z Shariff Journal: CMAJ Open Date: 2021-05-04
Authors: Rachel D Freid; Ying Shelly Qi; Janice A Espinola; Rebecca E Cash; Zahra Aryan; Ashley F Sullivan; Carlos A Camargo Journal: Int J Environ Res Public Health Date: 2021-04-15 Impact factor: 3.390