The quantitative relationships of particulate matter (PM10 and PM2.5) in each region and season

Abstract

Particulate matter (PM) is the most air pollutant problem in urban areas. The objectives of this research were to determine the quantitative relationships of particles less than or equal to 10 microns (PM10) and 2.5 microns (PM2.5) in urban areas in all regions of Thailand. This research used secondary data from both types of particulate matter measurements during 2014–2018 from eight Air Quality Monitoring Stations of the Pollution Control Department (PCD), located in the Northern, North-eastern, Central, Eastern and Southern regions of Thailand. The results showed that the PM10 and PM2.5 concentrations were within the ambient air quality standard. The concentrations being higher in the dry season than in the rainy season. As a result of a relationship analysis, the concentrations of both PM2.5 and PM10 particles were interrelated. The relationship being higher during the dry season than during the rainy season. The PM2.5/PM10 ratios in the North, the Northeast, the East, the Central, and the South were 0.67, 0.65, 0.64, 0.59 and 0.45, respectively. Regarding regional PM2.5/PM10 ratios comparison, the ratio for the South was different from those for other regions; and the North’s ratio was different from the East. As for seasonal PM2.5/PM10 ratios, they were different in the dry and rainy seasons. During the dry season, the ratio for the South was different from other regions, while the rainy season, only the ratio for the East was not different from those in other regions.