Prevalence of exposure to solar ultraviolet radiation (UVR) on the job in Canada.

Objective: Over one third of all newly diagnosed cancers in Canada in 2010 were skin cancer, despite the fact that skin cancer is largely preventable by limiting ultraviolet radiation (UVR) exposure. Outdoor workers are at risk of exposure to UVR, yet the prevalence of exposure in Canada is unknown. The objective of this study was to estimate the number of outdoor workers in Canada.

Methods: Building on CAREX Canada methods, we used a combination of data in the original Finnish CAREX, an Australian skin cancer prevention workbook, career-selection websites, and published studies to flag jobs at high risk of exposure. We also created a category for moderate exposure, where workers were unlikely to spend their whole day outside. Adjustments were made for industry-driven exposure, and prevalence of exposure was assigned for all jobs. Prevalence data were linked to census data to derive the number of workers exposed to solar UVR.

Results: Over 1.5 million Canadian workers are exposed to solar UV at work, and approximately 897,000 of these were flagged as "high exposed" (outdoors > or =75% of the workday). The largest occupational groups were farmers, construction labourers, and landscapers. Proportions of the workforce exposed ranged by province, with 6.9% of workers exposed in Ontario, and up to 17.3% in Prince Edward Island.

Conclusions: Information on solar UVR exposure prevalence is needed for primary skin cancer prevention with regard to targeting of high-risk groups, priority setting, and better risk assessment. This study showed that solar UVR exposure is occurring on a large scale in Canada.