The proportion of PM10 and PM2.5 by AERMOD model in Pathumwan District, Bangkok

Abstract

This study evaluates the proportions of PM₁₀ and PM_2.5 particulate matter resulting from vehicular fuel combustion in urban areas, with a focus on Pathumwan District, Bangkok, a location characterized by high traffic density and consistently elevated levels of PM₁₀ and PM_2.5 that frequently exceed air quality standards. Using the AERMOD mathematical model, this research examines the impacts of particulate matter on air quality to provide a basis for mitigating public health risks. Meteorological data from 2018 to 2020, surface characteristics, and monitoring points in the study area were utilized in the analysis. The Gaussian Plume equation was applied to estimate the dispersion of particulate matter along roadways within the district. The model's results indicated an average PM₁₀ concentration of 83.52 µg/m³ and a maximum average PM_2.5 concentration of 80.28 µg/m³, particularly in the southern area of Pathumwan District. These modeled values were consistent with maximum observed levels recorded at the nearest air quality monitoring station located at Chulalongkorn Hospital (82 µg/m³). The PM_2.5:PM₁₀ ratio was calculated at 0.96, highlighting that vehicular emissions predominantly contribute to PM_2.5 particulate matter. The AERMOD model proved effective in estimating PM₁₀ and PM_2.5 emissions from vehicular sources, with results closely aligned with real-world measurements. Additionally, the model provided valuable insights into the proportions of PM₁₀ and PM_2.5 during periods when particulate levels exceeded air quality standards, facilitating the development of effective air quality management strategies to mitigate health impacts on the population.