Fresh and aged PM2.5 and their ion composition in rural and urban atmospheres of Northern Thailand in relation to source identification

This study aims to investigate ion composition of PM2.5 in various sites and seasons identify the main sources on spatial temporal basis. compositions two urban rural areas Northern Thailand 2019 were investigated distinguish traffic open burning sources. During season, average concentrations (104 ± 45 ?g m?3) slightly higher than those (94 39 m?3). Source identification by cluster analysis during season one site revealed mixed aged aerosols from biomass burning, transboundary pollution, characterized (NH4)2SO4 KNO3. Only area (Chiang Dao), where intense activities observed, contained significant KCl level addition other compounds. is being used as a tracer for fresh opposes KNO3 aerosols. It was found that proportion total ions increased with both areas, indicating prominent influences regional scale. more distinguishable between varied depending local emissions. Urban secondary inorganic gas conversion contrast which mainly burning.