Abstract

Air pollution in megacities remains a challenge due to its negative effects on human health. This study was conducted to evaluate the concentrations of selected air pollutants and to identify the emission sources of particulate matters (PM) in Ho Chi Minh City using the Positive Matrix Factorization (PMF) model. The target air pollutants included gaseous compounds (i.e., SO₂, HNO₃, HCl, NH₃) and particulate-bound ions (i.e., SO₄^2-, NO₃^-, Cl^-, NH₄⁺, Na⁺, Mg²⁺, K⁺, and Ca²⁺). Data on these substances were retrieved from the Acid Deposition Monitoring Network in East Asia (EANET). The results showed that pollutant concentrations tended to increase and decrease during the dry and rainy seasons, respectively. Among the ions, SO₄^2- and NO₃^- were predominant, primarily originating from fossil fuel combustion and vehicular emission. Additionally, meteorological parameters, such as wind direction, precipitation, humidity, and sunshine duration, exhibited negative correlations with the concentrations of both gaseous pollutants and PM-bound ions. PMF model analysis revealed that secondary aerosol formation might contribute significantly to PM concentrations during the dry season,. Furthermore, transportation activities and fossil fuel combustion were identified as the major sources of PM emission across both seasons. The findings of this study contribute to a better understanding of the current state of PM pollution in Ho Chi Minh City, thereby supporting decision-making related to air pollution mitigation in the region.