Abstract
OBJECTIVE: Children are recognized to be more susceptible than healthy adults to the effects of air pollution; however, relatively few Canadian studies of children have focused on industrial emissions. We conducted a spatial cross-sectional study to explore associations between emergency department (ED) visits for childhood asthma and residential proximity to two industrial sources of air pollution (coal-fired power plant and petrochemical industry) in Edmonton, Canada.
METHODS: Using administrative health care data for Alberta between 2004 and 2010, we conducted a spatial analysis of disease clusters of count data around these two industrial sources. The distance from children’s place of residence to these industrial sources was determined by using the six-character postal code from the children’s ED visit. Clusters of cases were identified at the census dissemination area. Negative binomial multivariable spatial regression was used to estimate the risks of clusters in relation to the distance to these industrial sources.
RESULTS: The relative risk of ED visits for asthma, calculated using a spatial scan test for events, was 10.4 (p value <0.01) within the power plant area when compared with the outside area. In addition, there was an inverse association of the distance to the power plant (coefficient = −0.01 per km) with asthma visits when multivariable models were used. No asthma clusters were identified around the petrochemical industrial area.
CONCLUSION: Our analyses revealed that there was a cluster of ED visits for asthma among children who lived near the coal-fired power plant just outside Edmonton.
Key words: Air pollution, asthma, disease cluster, industry, Canada
Résumé
OBJECTIF: Il est reconnu que les enfants sont plus sensibles aux effets de la pollution de l’air que les adultes en bonne santé, mais les études canadiennes sur les enfants portant sur les émissions industrielles sont relativement rares. Nous avons mené une étude spatiale transversale pour explorer les associations entre les visites aux services d’urgence (SU) dues à l’asthme chez les enfants et le fait de résider à proximité des deux sources industrielles de pollution de l’air (la centrale thermique au charbon et l’industrie pétrochimique) à Edmonton, au Canada.
MÉTHODE: À l’aide des données administratives sur les soins de santé de l’Alberta de 2004 à 2010, nous avons procédé à l’analyse spatiale de données chiffrées sur les grappes de cas de maladies autour de ces deux sources industrielles. La distance entre le lieu de résidence des enfants et ces sources industrielles a été déterminée à l’aide du code postal de six caractères obtenu lors des visites des enfants aux SU. Les grappes de cas ont été déterminées à l’échelle des aires de diffusion du Recensement. Une régression spatiale multivariée binomiale négative a permis d’estimer les risques de grappes par rapport à la distance des sources industrielles.
RÉSULTATS: Le risque relatif de visites aux SU dues à l’asthme, calculé à l’aide d’une analyse spatiale des événements, était de 10,4 (valeur p <0,01) dans les environs de la centrale comparativement à la zone extérieure. Il y avait en outre une association inverse entre la distance de la centrale (coefficient = −0,01 par km) et les visites dues à l’asthme lorsque nous avons utilisé des modèles multivariés. Aucune grappe de cas d’asthme n’a été repérée dans la zone de l’industrie pétrochimique.
CONCLUSION: Nos analyses ont révélé la présence d’une grappe de visites aux SU dues à l’asthme chez les enfants vivant près de la centrale thermique au charbon située juste en dehors d’Edmonton.
Mots clés: pollution de l’air, asthme, grappe de cas de maladie, industrie, Canada
Footnotes
Funding: The study was supported by the Emergency Medicine Research Croup from the Department of Emergency Medicine, and the Department of Pediatrics, University of Alberta. Dr. Rodriguez-Villamizar was supported by the Colombian Administrative Department for Science and Technology. Dr. Rowe’s research is supported by the Canadian Institutes of Health Research (CIHR) through a Tier I Canada Research Chair in Evidence-based Emergency Medicine from the Government of Canada (Ottawa, Ontario). Dr. Osornio Vargas’s research is supported by a Collaborative Health Research Program CIHR/Natural Sciences and Engineering Research Council grant. The funders do not take responsibility for the design, conduct, results, or interpretations presented here.
Conflict of Interest: Authors do not have a conflict of interest to declare.
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