title: Spatial analysis of exposure to traffic-related air pollution at birth and childhood atopic asthma in Toronto, Ontario.
abstract: Findings from the Toronto Child Health Evaluation Questionnaire (TCHEQ) study indicate that early childhood exposure to traffic-related air pollution (TRAP) is related to the onset of atopic childhood asthma. To test this hypothesis further, we investigated whether spatial patterns in the birth neighbourhood of TCHEQ subjects with atopic asthma (136 of 909 schoolchildren in grades 1-2) could be explained by TRAP and other risk factors. If a causal relationship exists between early childhood residential exposure to TRAP and the development of atopic asthma, we hypothesise that (1) clusters of current asthma should exist around the place of residence at birth, and (2) accounting for residential concentrations of TRAP at birth should explain some of the autocorrelation. Several high asthma clusters were observed. Adjusting for TRAP completely explained one cluster; elsewhere, clusters were only partially explained by TRAP. Findings suggest that exposure during early childhood to TRAP in Toronto is an important contributor to the development of the atopic asthma phenotype and reveal the likely importance of other risk factors not measured in the fixed effects of the model.
authors.affiliation: Centre for Research on Inner City Health in the Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, 209 Victoria, 3rd floor, Toronto, Ontario, Canada, M5B 1C6; Department of Health Sciences, Wilfrid Laurier University, 75 University Ave W., Waterloo, Ontario, Canada N2L 3C5. Electronic address: kshankardass@wlu.ca.
authors.forename: K
authors.initials: K
authors.lastname: Shankardass
authors.affiliation: Department of Environmental Health Sciences and Center for Occupational and Environmental Health, Fielding School of Public Health, University of California, 650 Charles E. Young Drive S, Rm. 56-070 CHS, Mail Code: 177220, Los Angeles, CA 90095, United States. Electronic address: jerrett@berkeley.edu.
authors.forename: M
authors.initials: M
authors.lastname: Jerrett
authors.affiliation: The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8; Department of Pediatrics, University of Toronto, 563 Spadina Crescent, Toronto, Ontario, Canada M5S 2J7. Electronic address: sharon.dell@sickkids.ca.
authors.forename: S D
authors.initials: SD
authors.lastname: Dell
authors.affiliation: The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8. Electronic address: richard.foty@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Foty
authors.affiliation: Population Studies Division, Health Canada, Address Locator 0900C2, Ottawa, Ontario, Canada K1A 0K9. Electronic address: Dave.Stieb@hc-sc.gc.ca.
authors.forename: D
authors.initials: D
authors.lastname: Stieb
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D001249:Asthma / Q000139:chemically induced*; D002648:Child; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D009864:Ontario; D012111:Residence Characteristics; D012307:Risk Factors; D062206:Spatial Analysis; D001335:Vehicle Emissions
chemical_list: D001335:Vehicle Emissions
keywords: Air pollution; Asthma; Atopy; Spatial epidemiology; Traffic