title: Summer outdoor temperature and occupational heat-related illnesses in Quebec (Canada).
abstract: BACKGROUND
  Predicted rise in global mean temperature and intensification of heat waves associated with climate change present an increasing challenge for occupational health and safety. Although important scientific knowledge has been gathered on the health effects of heat, very few studies have focused on quantifying the association between outdoor heat and mortality or morbidity among workers.
  
  
  OBJECTIVE
  To quantify the association between occupational heat-related illnesses and exposure to summer outdoor temperatures.
  
  
  METHODS
  We modeled 259 heat-related illnesses compensated by the Workers׳ Compensation Board of Quebec between May and September, from 1998 to 2010, with maximum daily summer outdoor temperatures in 16 health regions of Quebec (Canada) using generalized linear models with negative binomial distributions, and estimated the pooled effect sizes for all regions combined, by sex and age groups, and for different time lags with random-effect models for meta-analyses.
  
  
  RESULTS
  The mean daily compensation count was 0.13 for all regions of Quebec combined. The relationship between daily counts of compensations and maximum daily temperatures was log-linear; the pooled incidence rate ratio (IRR) of daily heat-related compensations per 1 °C increase in daily maximum temperatures was 1.419 (95% CI 1.326 to 1.520). Associations were similar for men and women and by age groups. Increases in daily maximum temperatures at lags 1 and 2 and for two and three-day lag averages were also associated with increases in daily counts of compensations (IRRs of 1.206 to 1.471 for every 1 °C increase in temperature).
  
  
  CONCLUSIONS
  This study is the first to quantify the association between occupational heat-related illnesses and exposure to summer temperatures in Canada. The model (risk function) developed in this study could be useful to improve the assessment of future impacts of predicted summer outdoor temperatures on workers and vulnerable groups, particularly in colder temperate zones.
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC, Canada.
authors.forename: Ariane
authors.initials: A
authors.lastname: Adam-Poupart
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC, Canada; Institut national de santé publique du Québec (INSPQ), Montreal, QC, Canada.
authors.forename: Audrey
authors.initials: A
authors.lastname: Smargiassi
authors.affiliation: Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC, Canada.
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Busque
authors.affiliation: Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC, Canada.
authors.forename: Patrice
authors.initials: P
authors.lastname: Duguay
authors.affiliation: Direction de santé publique, Agence de la santé et des services sociaux de Montréal, Montreal, QC, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Fournier
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC, Canada; Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC, Canada.
authors.forename: Joseph
authors.initials: J
authors.lastname: Zayed
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC, Canada; Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC, Canada. Electronic address: labreche.france@irsst.qc.ca.
authors.forename: France
authors.initials: F
authors.lastname: Labrèche
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D018882:Heat Stress Disorders / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology*; D011792:Quebec / Q000453:epidemiology; D013696:Temperature
keywords: Ambient temperature; Climate change; Compensation data; Heat-related illnesses; Workers