This research investigated the PM2.5 concentrations and chemical compositions – black carbon, ionic species, and elements – in urban and industrial areas of Nakhon Ratchasima city. For each area, 41 samples were collected consecutively from its sampling location for 4 months (Nov. 2016 – Feb. 2017). Results show that the mean value of the 24-hr average PM2.5 concentration in the industrial area was significantly higher than the urban area, with a 95% confidence level. In contrast, the mean value of black carbon concentration in the urban area was higher. Analyses of 7 ionic species and 20 elements revealed that the mean values of 3 ionic species – Cl-, NO3-, and K+ – and 9 elements – Ag, Al, Cd, Fe, Mn, Ni, Tl, V, and Zn – were higher in the industrial area. In addition, the proportions of the chemical composition of dust in decreasing order were anions, cations, black carbon, and elements for the urban area; and anions, cations, elements, and black carbon for the industrial area. Results of Nakhon Ratchasima city study are comparable to those of other cities and useful for future modeling analysis to identify air pollution sources.
Keywords
air pollution, dust, PM2.5, chemical composition, Nakhon Ratchasima