Workplace Exposures May Mask Wildfire Smoke-Related Exposure Inequities and Mortality

High Resolution Image Download MS PowerPoint Slide Millions of outdoor workers cannot avoid wildfire smoke, likely leading to inequalities in exposure and health risk, but we lack a comprehensive understanding of how many outdoor workers are exposed to wildfire smoke in the United States (US). We first characterized work-related exposure to wildfire PM 2.5 for 3,108 contiguous US counties during 2006–2019 by integrating data on wildfire smoke-specific PM 2.5, workplace activities, and employment counts. We then compared the racial and ethnic composition of each county with the person-days exposed to ambient and work-related wildfire smoke to investigate whether certain racial and ethnic groups experience differential exposure to wildfire smoke at home and at work. Lastly, we replicated a previous analysis of ambient wildfire smoke impacts on all-cause mortality and stratified it by work-related exposure to understand differential mortality effects of ambient wildfire PM 2.5 . Despite experiencing less ambient exposure to wildfire PM 2.5, counties with higher portions of non-Hispanic Black and Hispanic Americans experienced higher work-related exposures. We also find suggestive evidence that the effect of ambient smoke fine particulate matter (PM 2.5 ) concentrations on all-cause mortality may differ by workplace exposure. These findings suggest that workplace exposures should be considered in wildfire smoke-adaptation measures.