Spatio-temporal modelling and related factors analysis of PM2.5 pollution: A case study of Ho Chi Minh city, Vietnam

• Published in: Physics and chemistry of the earth. Parts A/B/C Vol. 131; p. 103417
• Main Authors: Bui, Long Ta, Hoang Nguyen, Phong, Chau My Nguyen, Duyen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2023
• Subjects: Meteorological conditions; PM2.5 pollution; Precursor emissions; Uncertain factors; WRF/CMAQ; WRF/CMAQ; PM2.5 pollution; Precursor emissions; Uncertain factors; Meteorological conditions
• ISSN: 1474-7065; 1873-5193
• DOI: 10.1016/j.pce.2023.103417

Outdoor PM2.5 pollution issues have significantly impacted public health in megalopolis areas of Vietnam, especially in Ho Chi Minh City (HCMC). In this area, rapid urbanisation and industrialisation in recent years have been one of the main reasons for the rise in PM2.5-related emission precursors. Thus, clarifying the effects of anthropogenic and natural activities contributing to spatiotemporal PM2.5 concentration distribution in HCMC is necessary to propose emission reduction solutions and develop a clean air action plan. The inventory datasets of anthropogenic and biological (natural) emissions from the emissions of atmospheric compounds were applied to estimate the outdoor PM2.5 pollution level in HCMC and clarify the influence of PM2.5 precursor emissions on pollution contribution. Simultaneously, the study area was divided into five subdivisions (from SG1 to SG5) to analyse the role of the emission contribution in each subdivision. A coupled Weather Research and Forecasting Model/Community Multiscale Air Quality Model (WRF/CMAQ) and multiple linear regression models were also used to determine the dependence of PM2.5/pollution levels on meteorological conditions and precursor emissions. The modelling outcomes in 2018 reported that the annual mean PM2.5 concentration across the city ranged between 55.82 and 65.25 μg/m3. These values were 2.3–2.47 times higher than the National Ambient Air Quality Standards (NAAQS), in which the high PM2.5 pollution mainly occurred in subdivisions SG4, SG3, and a part of subdivision SG5. In addition, six PM2.5 precursor emissions, including SO2, NOx, NMVOCs, BC, OC, and CO, from three sectors of industrial processes, road transportation, and residential areas were found to contribute to PM2.5 in each subdivision of HCMC. Meanwhile, wind direction (Wd) and temperature (T) at 2 m above the surface were the meteorological factors that affected PM2.5 concentration changes in subdivisions SG1, SG2, and SG4. The study results would support the authorities and policymakers of HCMC to build suitable PM2.5 control solutions and develop medium- (2020–2025) and long-term (2025–2030) strategies for the clean air action plan in HCMC.
•The PM2.5 pollution assessment framework using WRF-CMAQ models was developed.•Assessment of one-year PM2.5 pollution in Ho Chi Minh city (HCMC) have done.•The PM2.5 concentration in dry and wet seasons are 69.594 and 44.58 μg/m3.•The meteorological and precursor factors affecting PM2.5 pollution were analysed.•The group of industries contributing to PM2.5 pollution was indicated.