A relationship between urban green space and PM2.5 levels in urban and suburban areas of Bangkok

Abstract

Abstract Bangkok, Thailand's densely populated capital, faces critical air pollution due to overpopulation, traffic, industry, and biomass burning. Of particular concern is the escalating PM2.5 pollution, which poses significant risks to both public health and the environment. This research investigates the relationship between Bangkok's urban green spaces (UGS) and PM2.5 levels by comparing the concentrations of PM2.5 in non-green areas (on roads) and green areas (city parks) in both urban (Ratchathewi) and suburban (Lat Krabang) locations. The methodology in this study involves data collection from secondary sources and statistical analysis using ANOVA, T-tests, and the Mann-Kendall test with Sen's slope. The findings indicate a consistent expansion of UGS within the study areas, while levels of air pollution exhibit discernible seasonal fluctuations. Notably, concentrations of PM2.5 near roads were significantly higher than those of nearby parks, with 43% and 38% higher levels at Ratchathewi and Lat Krabang, respectively. Several factors contribute to this discrepancy, encompassing the proximity to pollution sources, the processes of dispersion and dilution, the presence of vegetation and green spaces, and the role of physical barriers. Based on the research findings, recommendations propose to improve air quality through UGS initiatives and collaboration with relevant stakeholders.