PM2.5 Emission Inventory of Urban Areas in Nakhonchaiburin Provincial Cluster

Abstract

Background and Objectives: Particulate matter smaller than 2.5 microns (PM_2.5) is a major problem in the country, having adverse effects on public health and causing much concern to all parties. Although some local areas have not yet encountered the problem, as the economy develops, they may eventually face air quality issues. Therefore, building the capacity to cope with the PM_2.5 problem for the public and local agencies, such as municipalities and towns, is important and necessary for their operations and to prevent the problem from increasing in the future. The present research aimed to create an inventory of PM_2.5 sources and emissions of urban areas in the Nakhonchaiburin provincial cluster, namely, Nakhon Ratchasima Municipality, Chaiyaphum Municipality, Buriram Municipality, and Surin Municipality, and to study and compare the proportion of PM_2.5 emissions between sources, as well as spatial analysis by creating PM_2.5 emission maps of the study areas.

Methodology: The methodology consisted of reviewing relevant studies and selecting significant sources, which were divided into 3 main groups: (1) point type, including industrial plants, temples, and large establishments; (2) mobile type, including road transport and rail transport; and (3) area type, including residences and commercial buildings, markets, and agricultural areas. Then, data on sources were collected through field surveys, questionnaire data collection, contacting agencies for information, and traffic volume surveys. Emissions were estimated using the emission factor method, with the base year set to be 2023.

Main Results: Road transport group was the most important source of PM_2.5 emissions in all study areas, accounting for more than half of all sources, or 51-61 percent. The second most significant source in all areas was the residential and commercial group, accounting for 19-33 percent. The third most significant source was the industrial factory group in 3 areas, except for Chaiyaphum Municipality, which is an agricultural area group. The sources that contributed the least to PM_2.5 emissions in all areas were temples, large businesses, rail travel, and markets. When considering the pollutant emission rate per unit area, it was found that Buriram Municipality, which has the smallest area of only 6 sq.km, exhibited the highest pollutant emission rate per area, at 2,384 kg/sq.km/year, while Nakhon Ratchasima Municipality had a slightly lower pollutant emission rate per area at 2,239 kg/sq.km/year. Surin and Chaiyaphum municipalities ranked 3^rd and 4^th with values of 1,725 kg/sq.km/year and 1,004 kg/sq.km/year, respectively. The pollutant emission rate per capita, ranked from the highest to the lowest, was Chaiyaphum, Nakhon Ratchasima, Buriram, and Surin municipalities with values of 0.84, 0.72, 0.61, and 0.53 kg/person/year, respectively.

Conclusions: The main sources of PM_2.5 emission were the road transport group, the residential and commercial group, and the industrial group. The emission rate per unit area was in the range of 1,004 - 2,384 kg/sq.km/year. The emission rate per population was in the range of 0.53 - 0.84 kg/person/year. The results of the spatial emission analysis for large municipalities clearly show that higher emission areas were along the main roads.

Practical Application: Results are useful for the four municipalities, government agencies involved in air quality management, public health agencies, academics, and the general public. Knowing the pollutant main sources and emission rates would lead to effective measures to reduce emissions and solve PM_2.5 problem in the study areas.