This project, implemented under collaboration between developing (Vietnam and Thailand) and developed (Korea) country partners, aims to develop and apply an integrated approach of in-situ measurement, modeling techniques, and advanced satellite remote sensing for mapping and quantifying separately contribution of local and regional biomass burning sources to air pollution in Vietnam and Thailand. For this purpose, one-year field measurement campaigns will be conducted concurrently in studied areas in Vietnam and Thailand. Chemical analysis will be performed for PM2.5 samples to determine concentration of PM2.5 and water soluble ions, elements, and carbonaceous species to provide insights on air quality measured in studied areas during biomass and non-biomass burning periods, and to provide inputs for positive matrix factorization (PMF) receptor model. Results from PMF derived source apportionment and air mass backward trajectory modeling combined with analysis of MODIS satellite observation data for fire activities, for the first time, will help to map and quantify separately contribution of local and regional open biomass burning sources from different regions/cities in Thailand or Vietnam, and other SEA countries to fine particle PM2.5 pollution in studied areas, which will provide a better platform for evidence-based policy making and identifying prioritized areas and actions for reducing open biomass burning and associated air pollution.