Trace elemental composition and source identification of PM2.5 in the metropolitan area of Bangkok, Thailand

¹ Nuclear Technology Research and Development Center, Thailand Institute of Nuclear Technology (Public Organization), Nakhon Nayok, Thailand
² Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
³ Research Center for Circular Products and Energy, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand
⁴ Department of Chemical Engineering, Faculty of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand
⁵ Department of Chemical Engineering, Faculty of Engineering, Srinakharinwirot University, Nakhon Nayok, Thailand

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The trace elements in PM_2.5 samples collected in Pathum Thani province, the metropolitan area of Bangkok were determined and their possible sources were analyzed. PM_2.5 samples were monitored from January to December in 2022. The mass concentration of PM_2.5 ranged from 4.33 to 66.02 μg/m³ with and an average (± std.) value of 24.64 ± 13.97 μg/m³. The concentrations of trace elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Zn, Ni and Cu) were measured using accelerated based ion beam analysis (IBA) methods, particle-induced X-ray emission (PIXE). Elements such as K, Ca, Fe, S, Si and Cr were found to be the dominant elements in PM_2.5 across all seasons. The Pearson correlation coefficients between Fe-Cr, Ni-Cr, Fe-Ni, Mn-Cr, Fe-Mn and Ni-Mn were all above 0.893 with p < 0.01. The enrichment factor indicated that S, Cl, V, Cr, Mn, Fe, Zn, Ni and Cu came mainly from anthropogenic emissions; Ca, Ti and Fe were generated from natural and anthropogenic sources; Na, Mg, Al and Si originated from natural sources. These findings suggested that biomass burning, industrial and soil dust emissions were the major sources of PM_2.5 in the study area.