Restructuring the workday to reduce occupational exposure to solar ultraviolet radiation (UVR)

Abstract

BACKGROUND AND AIM: Messaging about sun avoidance strategies is often not practical for outdoor workers. The objective of this study was to use personal monitoring data to determine when peak UVR exposure occurs for outdoor workers, estimate how much UVR could be reduced by altering the timing of shady tasks or breaks during peak exposure times, and compare these to peak periods of ambient UVR. The aim was to provide evidence-based sun avoidance recommendations for outdoor workers in British Columbia, Canada. METHODS: UVR exposure data [standard erythemal dose (SED)] were collected during the 2013 summer months in Vancouver, using personal electronic dosimeters. Mixed-effect models were used to estimate the 60-, 30-, and 15-min time intervals at which maximum exposure occurred for the months of July and August. Ambient UVR was also collected using data from the nearest Brewer spectrophotometer station and parallel analyses were conducted. RESULTS:There were 73 workers and 321 participant-days available for analysis. Models indicated that periods of maximum exposure for 15-, 30-, and 60-min intervals began at 12:28 pm, 12:17 pm, and 11:52 am, respectively, for sunny days in July. These periods were similar in August. The median exposure during these time periods and the potential for reducing UVR was 0.03 SED (2.8% potential daily exposure reduction), 0.09 SED (7.1%), and 0.18 SED (15.9%), respectively. However, there was a large range in exposure estimates as some workers experienced up to 84.8% of their exposure in the peak 60-min interval. CONCLUSIONS:Skin cancer prevention messaging does not include practical messages for outdoor workers. Providing workers with information on the timing of peak UVR can help to modify work tasks for the the greatest reductions in exposure. Prevention measures including shady breaks, increased sun protection, and task reorganization during these peak times are recommended to reduce UVR exposure among those at highest risk. KEYWORDS: Occupational exposure, solar radiation, outdoor workers, ultraviolet radiation, prevention