Abstract

This study aimed to determine the concentrationof PM<sub style="text-wrap: wrap;">2.5</sub> (particulate matter less than 2.5 μm in size) and PM₁₀(particulate matter less than 10 μm in size) from traffic exhaustaround bus stations in Uthai Tani Province, Thailand, and toassess the inhalation exposure of people to PM_2.5 and PM₁₀around these bus stations. The PM<sub style="text-wrap: wrap;">2.5</sub> and PM10 concentrationsat three stations in the city of Uthai Tani were evaluated usingair quality detectors (model PMS5003) between January andMay 2022. The PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> exposure of the people nearthose stations was evaluated, and the health risk wasdetermined based on the hazard quotient (HQ). The resultsindicated that the highest daily PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> concentrationswere detected at main road in front of the Central Stadium,with PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> concentrations of 58.40 and 64.13 μg/m<sup style="text-wrap: wrap;">3</sup>,respectively. The lowest daily PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> concentrationswere found at the main bus station in Uthai Tani Province, withPM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> concentrations of 51.41 and 58.01 μg/m<sup style="text-wrap: wrap;">3</sup>,respectively. In addition, during rush hour (7:00 to 8:00 a.m.),the PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> concentrations reached the peak values of75.25 and 81.07 μg/m³, respectively. From the exposureassessment, the highest intake of PM<sub style="text-wrap: wrap;">2.5</sub> and PM<sub style="text-wrap: wrap;">10</sub> for peoplenearby were 29.32×10⁻³ mg/kg-day and 30.96×10^-3 mg/kg-day,respectively at 8:00 a.m. The HQ values from PM2.5 and PM₁₀exposure were both greater than 1.