Short-Term Assessment of PM2.5 Physico-Chemical Characteristics at Three Different Sites in Indonesia and Their Potential Association with Respiratory Diseases

In this study, the physicochemical characteristics of PM2.5 at three different locations in Indonesia were compared during a short-term sampling period, and their association with respiratory diseases was also investigated by analysing aerosol optical thickness (AOT) data from Himawari satellite observations due to the limitation of the PM2.5 field sampling. Bandung city in West Java province, Serpong in Banten province, and Ogan Komering Ilir in South Sumatra province were selected as the study locations, each with distinct characteristics. PM2.5 sampling was conducted for 24 hours in Bandung (1-7 November 2021), 12 hours in OKI (4-7 October 2021), and also 12 hours in Serpong (25-29 July 2022). Morphology and elemental analysis for PM2.5 particle characterization were conducted by using a Scanning Electron Microscope (SEM) with an Energy Dispersive X-Ray Spectrometer (EDS). The water-soluble ion composition was analysed using Ion Chromatography to determine the anion (sulfate, nitrate, chloride) and cation (potassium, calcium, magnesium, sodium, ammonium) concentrations. To identify the potential source regions contributing to PM2.5 pollution at the sampling site, trajectory analysis using the HySplit model from NOAA was conducted. The average concentration of PM2.5 at Bandung was 87.98 μg/m³ (24 hours), at OKI was 36.31 μg/m³ (12 hours), and at Serpong was 23.53 μg/m³ (12 hours). The morphology analysis revealed spherical, regular, and irregular particles in Bandung, and some soot particles were found in OKI, with a dominance in Serpong. The elements of Mg, Si, S, K, Ca, Cu, and Pb were detected in Bandung, whereas in OKI, the Ca element was not detected. Si, S, Mg, and K were also detected in Serpong. Sulphate, nitrate, and ammonium (SNA) are the most abundant ions found in almost every location. Trajectory analysis revealed that local sources of pollutants dominated Bandung and OKI, while Serpong experienced some long-range transport from other locations.