Toxic elements, sources and health risk assessment of PM 2.5 in an industrial area of Surabaya, Indonesia

A comprehensive study on air quality in the industrial area of Indonesia, which significantly impacts respiratory health and poses breathing hazards, is still lacking. This study aims to uncover the contents of toxic elements, identify potential sources of fine particles, and evaluate their contributions to health risks in Surabaya’s industrial area. The study focuses on identifying chemical composition, sources, and assessing health risks for both children and adults. The PM2.5 concentration from 2021 to 2022 ranged from 3.29 to 27.05 µg m−3, with an average value of 13.63 ± 4.54 µg m−3, exceeding the WHO’s annual standard of 5 µg m−3. Black carbon (BC) accounted for 27% of PM2.5 composition. A seasonal variation was found; the highest PM2.5 and BC were observed during the dry season, with the highest peak in June. The highest concentration of elements in PM2.5 was observed for S, followed by Si, K, Zn, Fe, and Pb, with maximum values of 3.53, 1.16, 1.01, 1.86, 0.29, and 0.37 µg m−3, respectively. Source apportionment using positive matrix factorisation (PMF) revealed eight sources: galvanising industry, ammonium chloride, secondary sulphate, biomass burning emission, soil, steel industry, vehicle emissions, and lead smelting, with metal industries accounting for 37.3%. Investigation into their potential source locations was conducted using the conditional bivariate probability function (CBPF) method. Human health assessment for adults and children indicates carcinogenic risks with a total risk of 9.50 × 10−5 and 2.38 × 10−5, respectively. The results emphasise the significance of managing sources linked to industry and transportation-related sources, crucial in decreasing high PM2.5 levels and several elevated elements and mitigating the health impact in Surabaya’s industrial area, Indonesia.