Abstract
Objective
To describe the incidence of occupational heat illness in Ontario.
Methods
Heat illness events were identified in two population-based data sources: work-related emergency department (ED) records and lost time claims for the period 2004–2010 in Ontario, Canada. Incidence rates were calculated using denominator estimates from national labour market surveys and estimates were adjusted for workers’ compensation insurance coverage. Proportional morbidity ratios were estimated for industry, occupation and tenure of employment.
Results
There were 785 heat illness events identified in the ED encounter records (incidence rate 1.6 per 1,000,000 full-time equivalent (FTE) months) and 612 heat illness events identified in the lost time claim records (incidence rate 1.7 per 1,000,000 FTE months) in the seven-year observation period with peak incidence observed in the summer months. The risk of heat illness was elevated for men, young workers, manual workers and those with shorter employment tenure. A higher proportion of lost time claims attributed to heat illness were observed in the government services, agriculture and construction sectors relative to all lost time claims.
Conclusions
Occupational heat illnesses are experienced in Ontario’s population and are observed in ED records and lost time claims. The variation of heat illness incidence observed with worker and industry characteristics, and over time, can inform prevention efforts by occupational health services in Ontario.
Key Words: Heat stress disorders, occupational exposure, epidemiology
Résumé
Objectif
Décrire l’incidence des maladies professionnelles liées à la chaleur en Ontario.
Méthode
Les épisodes de maladies liées à la chaleur ont été recensés dans deux sources de données populationnelles: les dossiers des services médicaux d’urgence (SMU) concernant les travailleurs et les réclamations avec interruption de travail pour la période de 2004 à 2010 en Ontario (Canada). Les taux d’incidence ont été calculés à l’aide d’estimations dans le dénominateur tirées d’enquêtes nationales sur le marché du travail, et ces estimations ont été ajustées selon la couverture d’assurance indemnisant contre les accidents du travail. Des ratios proportionnels de morbidité ont été estimés par industrie, par profession et par durée d’emploi.
Résultats
Sur notre période d’observation de sept ans, 785 épisodes de maladies liées à la chaleur ont été recensés dans les dossiers des SMU (taux d’incidence: 1,6 p. 1 000 000 mois équivalents temps plein [ETP]), et 612 épisodes du même type dans les réclamations avec interruption de travail (taux d’incidence: 1,7 p. 1 000 000 mois ETP), avec des pics observés durant les mois d’été. Le risque de maladie liée à la chaleur était élevé chez les hommes, les jeunes travailleurs, les travailleurs manuels et les personnes ayant eu une durée d’emploi plus courte. Une proportion supérieure de réclamations avec interruption de travail imputées aux maladies liées à la chaleur a été observée dans les secteurs des services gouvernementaux, de l’agriculture et du bâtiment comparativement à l’ensemble des réclamations avec interruption de travail.
Conclusions
Il y a des cas de maladies professionnelles liées à la chaleur dans la population ontarienne; ils sont observés dans les dossiers des SMU et dans les réclamations avec interruption de travail. On constate des écarts dans l’incidence des maladies liées à la chaleur selon les caractéristiques des travailleurs et des industries; au fil du temps, ces écarts peuvent éclairer les efforts de prévention des services de santé au travail en Ontario.
Mots Clés: troubles dus à la chaleur, exposition professionnelle, épidémiologie
Footnotes
Sources of Support: Melanie Fortune was funded by a CIHR CGS Scholarship as well as an Ontario Graduate Scholarship as a part of her Master’s work.
Conflict of Interest: None to declare.
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