Altitude distribution of fine particulate matters PM₁ PM₂.₅ and PM₁₀ in Bangkok

Fine particulate matter particles with a diameter less than 1 micron (PM1), less than 2.5 micron (PM₂.₅) and less than 10 micron (PM₂.₅) have been measured in different height 1.5 m, 25 m and 75 m respectively. The sampling sites were located at Mahamakhut Sci0025 Building Faculty of Science Chulalongkorn University. The particulate matters were sampling from January to March 2020. PM₁₀-₂.₅ and PM₂.₅ were collected using personal modular impactor with filters pack attached and air pump sampler flowrate 3 L/min for 8 hours on both weekend and weekdays. PM₁concentrations were determined by Dust Track with self reading sensor. The highest concentration of PM₂.₅ and PM₁₀-₂.₅ were found at the fifth floor 25 m height with average concentration 62.33 ± 3.04 and 64.42 ± 5.16 μg/m³ respectively. The highest concentration of PM₁ was found at the fifthteen floor 75 m height with average concentration 66.33 ± 31.72 μg/m³. This 5th floor has many teaching activities. There are many students using this area. The results show that the PM levels in the ground area, 1.5 m is much lower than in the aerosol suspended in the high altitude. The SCI 025 building is far from the main road about 300 m. So the traffic emission should have some impact on the ambient PM concentration. This study illustrated the variability of PM distribution with altitude and high-risk locations. These results could be used for the decision of living in high altitude in urban area.