Wildfire smoke-related PM2.5 concentration measurements, perceived indoor air quality, and health symptoms among Southern California residents during the 2025 Los Angeles wildfires: A latent class mediation approach

Indoor exposure may be an important mechanism by which people are exposed to wildfire smoke, which can cause adverse health symptoms. While outdoor PM_2.5 concentration is commonly used in wildfire exposure research, our findings suggest that perceived indoor air quality provides additional explanatory information about who experiences more severe symptom profiles, particularly for wildland-urban interface fires where many residents are sheltering in place. Protective behaviors and interventions to maintain clean indoor air during WUI fire events should be promoted.