Final Report on ”A Study on Urban Air Pollution Improvement in Asia”

This study investigates urban air pollution in Asia, focusing on particulate matter (PM) levels, acid deposition, and emission sources in the Bangkok Metropolitan Region (BMR). Conducted between March 2015 and December 2017, the research was a collaboration between the Asian Institute of Technology (AIT), the Japan International Cooperation Agency (JICA), and other partners. The study involved extensive air quality monitoring at two sites—AIT (Pathumthani) and the Pollution Control Department (PCD) in Bangkok. Key findings indicate that PM2.5 levels were generally higher in the dry season due to increased biomass burning and stagnant air masses, with major sources including diesel vehicle emissions and open burning. Acid deposition analysis revealed that wet deposition played a crucial role in removing sulfur and nitrogen species from the atmosphere, with measured pH levels indicating occasional acid rain events. An emission inventory identified on-road transport as the primary contributor to pollutants like NOx and PM2.5, while industrial sources dominated SO2 emissions. Air quality modeling using the WRF-CAMx system highlighted traffic emissions as a major contributor to PM2.5, particularly in urban centers. The study underscores the need for long-term air quality monitoring and improved emission reduction strategies to mitigate urban pollution and its environmental and health impacts in the region.