Integrated source analysis of particulate and gaseous pollutants: Seoul as an urban case study

Various air pollutants, including fine particulate matter (PM 2.5 , referring to particles smaller than 2.5 μm), volatile organic compounds (VOCs), nitrogen dioxide (NO 2 ), ozone (O 3 ), sulfur dioxide (SO 2 ), among others, can induce or exacerbate diseases. Despite being simultaneously emitted from anthropogenic sources like vehicle exhaust and solvents, source analyses often treat particulate and gaseous pollutants separately. This study investigated the characteristics and sources of PM 2.5 and gaseous pollutants in Jongno, Seoul, from August 2020 to July 2023. PM 2.5 components (ions, carbons, trace elements) and 56 VOCs, NO 2 , SO 2 , CO, and O 3 were measured. Correlation analysis showed a low correlation between road dust, soil ions, and VOCs, while secondary inorganic aerosols and vehicle-related trace elements exhibited strong correlations with VOCs, indicating mobile sources of pollutants. Principal component analysis (PCA) identified nine key factors affecting urban air quality, including traffic emissions, fossil fuel combustion, and diesel exhaust. Vehicle exhaust sources were found to significantly influence both PM 2.5 and VOC levels, highlighting the need for integrated pollutant source analysis. This comprehensive approach provides insights into urban pollution and can inform effective mitigation strategies.