Annie Doubleday



Project title: Mortality associated with wildfire smoke exposure in Washington State, 2006-2017

Degree: MPH | Program: Environmental and Occupational Health (EOH) | Project type: Thesis/Dissertation
Completed in: 2019 | Faculty advisor: Tania M Busch Isaksen

Abstract:

Wildfire events are increasing in prevalence in the western United States. Research has found mixed results on the degree to which exposure to wildfire smoke increases the risk of mortality. A time-stratified case crossover study was employed to examine the odds of non-traumatic mortality on wildfire smoke days compared to non-wildfire smoke days in Washington State. Wildfire smoke exposure is characterized by daily average PM2.5 concentrations on wildfire smoke days, from June 1 through September 30, for 2006-2017. Monitoring data was obtained from the Washington State Department of Ecology’s monitoring network, and mortality data was obtained from the Washington State Department of Health. After adjusting for humidex, the odds of same-day non-traumatic mortality across the entire population was 1.0% (95% CI: 0.99 - 1.04) greater on wildfire smoke days compared to non-wildfire smoke days. Among adults ages 65-84, we estimated a 2.0% (95% CI: 0.98, 1.06) increase in the odds of same-day non-traumatic mortality, and an 8.0% (95% CI: 0.96, 1.21) increase in the odds of same-day respiratory mortality on wildfire smoke days compared to non-wildfire smoke days in this age group. Among all ages, we estimated a 1.3% (95% CI: 1.00, 1.02) increase in the odds of next-day non-traumatic mortality on wildfire smoke days compared to non-wildfire smoke days. This study is the first to examine wildfire smoke and mortality in Washington State, and its findings are consistent with other research on wildfire smoke and mortality. This study lays the groundwork for estimating the risk associated with exposure to wildfire smoke in Washington, and will help inform local and state risk communication efforts and decision-making during future wildfire smoke events. URI http://hdl.handle.net/1773/44208