370 Can compensation statistics detect the impact of summer outdoor temperatures on workers’ health and safety? Preliminary results in Quebec (Canada)

Abstract

Objectives Increased temperatures associated with climate change are likely to have impacts on occupational health and safety all over the world. We aimed to explore potential relationships between summer outdoor temperatures and occupational compensation statistics for heat-related morbidity and mortality. Methods Daily compensation counts in the region of Montreal for heat-related health outcomes (such as heat strain, heatstroke, loss of consciousness) were obtained from the workers' compensation board of Quebec for the months of May to September over the period 2000-2010. Daily summer outdoor temperatures for the study period were obtained from Environment Canada. Associations between daily compensation counts and temperatures were analysed with regular Poisson and negative binomial regression models. Results There were 35 compensations for heat-related health outcomes during the 11-year period (for a working population of approximately 1.85 million). Incidence rate ratio (IRR) obtained from preliminary Poisson regression analyses was 1.76 (95% CI: 1.55-2.00) per 1 o C temperature increase. This large IRR translates into a small increase in compensations, given the low compensation base rate (0.002 compensation per day for heat-related health problems) at the average temperature of 18.4 o C. Virtually identical results were obtained with a negative binomial regression. Analyses will be carried out for other regions of Quebec and for indirect impacts of heat (e.g. accidents/injuries related to fatigue and lack of vigilance), with various metrics of temperature (e.g. maximum and minimum, Wet Bulb globe Index), and will be stratified by industrial sectors, age and sex when possible. Conclusions These preliminary results suggest that the effect of increases in summer temperatures can be detected in compensation statistics. The results of this work could prove useful for the surveillance of current and future occupational health and safety risks associated with outdoor temperatures and to orient interventions.