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

Abstract

Wildfire smoke is an increasingly recognized health risk worldwide. This study investigates the short-term health impacts of acute wildfire smoke exposure among active-duty military personnel stationed at Joint Base Lewis-McChord (JBLM), Washington, USA, from 2018 to 2024. Using two PM₂.₅ thresholds (≥35.4 µg/m³, corresponding to the EPA’s “Unhealthy for Sensitive Groups,” and ≥20.4 µg/m³, based on previous studies), we assessed emergency department (ED) visits for respiratory, cardiovascular, and behavioral health outcomes. We employed conditional logistic regression models adjusting for daily average temperature and examined lag effects from 0 to 7 days prior to ED visits.Our findings reveal that even moderate PM₂.₅ levels were associated with increased odds of respiratory and behavioral health ED visits. For respiratory visits adverse effects emerged after a lag period (e.g., lag 4). Behavioral health outcomes including anxiety, mood disorders, and depression, were significantly elevated several days post-exposure. This outcome underscores the potential mental health burden of wildfire smoke. While asthma and angina visits showed no consistent patterns, these analyses were limited by smaller sample sizes. The results highlight the vulnerability of even a relatively healthy military population to wildfire smoke, with implications for broader public health. Future research should examine the role of preexisting conditions, additional pollutants, and exposures at other military installations. Mitigation strategies, such as an “air category” system, may help safeguard both military readiness and civilian well-being in an era of increasing wildfire frequency and intensity.