Multi-pollutant air quality in Thailand: A regional to urban perspective

The blooming of the economy in Thailand and the Southeast Asian region has resulted in a dramatic increase of energy usage. The atmospheric pollutants emitted from economic activities such as transportation, and industry cause severe air pollution problems for urban residents. The growing problem of biomass burning in Southeast Asia contributes significantly to the increase of atmospheric pollution in the region. These large contributions of emissions from cities and biomass burning, has resulted in pollution problems at scales ranging from urban to regional. The different air pollution problems at the various scales inspired this investigation of multi-pollutant air quality in Thailand.; Air Pollution during the period of March--Apr 2001 is analyzed as the dry season (Dec--Apr) is the period with the highest pollution levels, and to take advantage of the available data on the larger scale provided by the NASA TRACE-P experiment. Three domains are chosen to analyze the atmospheric impacts of emission on regional, country, and urban scales (i.e., Southeast Asian countries, Thailand, and Bangkok Metropolitan and neighbor provinces, respectively). The Chemical Transport Model, STEM2K1, is used as a tool to evaluate the emission inventories and the impact of these emissions on human health and ecosystems.; Results from a series of simulations designed to isolate specific contributor are analyzed and discussed. It is found that: (1) Current emission estimated of biomass burning are significantly underestimated (factor of 5--10). (2) Emissions from biomass burning dominate the air quality of the northern region of Thailand and Southeast Asia. (3) Anthropogenic emissions from Thailand play a key role in the region, especially for SO2. (4) Air Quality in the region can be improve by policies designed to reduce biomass burning emissions, and by further reductions in SO2 emissions from point sources associated with power generating and industries. (5) The ozone production in the Bangkok area is VOC-limited area, thus the reduction of ozone in suburban areas requires by reductions of VOC emissions. (6) Air Quality in Bangkok will require multiple strategies, with ozone improvement requiring a reduction in emission from transportation sector.