Evaluating the Safety of Wildfire Evacuation Sites from the Perspective of PM2.5 Exposure

Abstract

This study analyzed changes in outdoor PM2.5 concentrations at 140 evacuation sites across five municipalities during the first 8 h period after the first evacuation alert was issued in each region following the March 2025 Gyeongbuk wildfire in Uiseong. Hourly spatial distributions of PM2.5 were estimated using inverse distance weighting (IDW) interpolation, and concentrations at each evacuation site were assessed according to the U.S. EPA Air Quality Index (AQI) criteria. The timing of peak PM2.5 concentrations varied among municipalities. Analysis of evacuation site-hour observations showed that Uiseong recorded the highest number of hazardous-category AQI readings (55), indicating repeated periods of elevated smoke exposure during the later stages of the observation period. These findings suggest that the current evacuation framework, centered on firefront arrival time, may not fully capture the temporal variability and overall level of PM2.5 exposure., and underscore the importance of incorporating smoke exposure into wildfire evacuation planning and associated public health guidance.