Health Impacts of Acute Wildfire Smoke Exposure on the Active-Duty Military Population at Joint Base Lewis-McChord, Washington, USA

Objective: To examine the acute health effects of wildfire smoke exposure on active-duty military personnel at Joint Base Lewis-McChord (JBLM). Methods: We conducted a time-stratified case-crossover study (2018–2024) using conditional logistic regression to compare emergency department (ED) visits on wildfire smoke versus non-smoke days. Two PM2.5 thresholds were used (≥ 35.4 and ≥ 20.4 µg/m^3). Analyses were adjusted for daily average temperature and lagged exposures (lag 0–7). Results: Both high and moderate PM2.5 exposures are linked with increased odds of respiratory and behavioral health ED visits at specific lags. Even exposures within the moderate range were associated with increased odds of adverse health events. Conclusions: Acute wildfire smoke exposure raises concern for increases in ED visits among an otherwise healthy military population, highlighting the need for on-base air quality monitoring and targeted risk mitigation.