Quantifying the Contribution of Road Traffic to Total Suspended Particle Pollution in Dong Thap Province, Vietnam

Total suspended particles (TSP) from transportation sources pose a growing environmental and public health concern in rapidly developing regions like Vietnam's Mekong Delta. This study investigated TSP emissions and dispersion patterns in Dong Thap province, an area undergoing significant economic transformation. Using the AERMOD air quality model integrated with R-LINE, we simulated TSP dispersion from 43 major roads divided into 88 segments. The model incorporated high-resolution ERA5 meteorological data from 2021-2023, Vietnam-specific emission factors, and detailed traffic data for eight vehicle categories. The results revealed significant spatial and temporal variations in TSP concentrations. In extreme scenarios, TSP levels in urban centers like Cao Lanh city reached up to 1,100 μg m-³ for 1-hour averages and 350 μg m-³ for 24-hour averages, substantially exceeding national standards. Annual average TSP concentrations in urban areas approached or potentially exceeded the 100 μg m-³ national standard, even when considering only transportation sources. The region's flat terrain facilitated long-range TSP transport, with concentrations up to 100 μg m-³ detected beyond provincial borders under extreme scenarios. Atmospheric stability strongly influenced TSP dispersion, with very stable conditions contributing to elevated TSP levels. The study highlights the critical need for targeted air quality management in Dong Thap, particularly in urban areas and along major transportation routes.