Contribution of Large-Scale Wildfires to Particulate Matter Concentrations in Agricultural Areas in South Korea

This study quantitatively analyzed the impact of concurrent large-scale wildfires that occurred in Korea in March 2025 on air quality in agricultural regions and identified potential risks to agricultural workers. Analysis of air quality data from eight agricultural sites nationwide revealed that the average concentrations of PM10 and PM2.5 during the wildfire period increased by 47.3% and 24.9%, respectively, compared to non-fire periods. Multiple regression analysis indicated that PM10 concentrations were dominated by physical dispersion and dilution effects driven by variables such as wind speed and distance. In contrast, PM2.5 showed a strong positive correlation with relative humidity, suggesting it is significantly influenced by secondary formation and atmospheric stagnation. Notably, the potential for particulate matter accumulation was confirmed during high-humidity hours when atmospheric inversion layers form, combined with the basin topography characteristic of Korean rural areas. This implies that elderly agricultural workers may be exposed to high concentrations of hazardous substances even when smoke is not visually apparent. Therefore, this study suggests the necessity of establishing specific protective measures for agricultural workers, including the introduction of targeted, site-specific forecasting (“pinpoint forecasts”) for downwind farmlands and restrictions on outdoor work during early morning hours.