Temporal variations in health risk indices and combustion-derived components of PM_1.0: Focus on terephthalate and levoglucosan

This study evaluated the health risks and chemical composition of PM_1.0 and PM_2.5 in Incheon, South Korea, emphasizing the critical role of particle size in public health impacts. The average concentrations were 10.89 μg/m³ for PM_2.5 and 8.11 μg/m³ for PM_1.0. PM_1.0 displayed higher proportions of carbonaceous components and water-soluble ions, predominantly formed through photochemical reactions and atmospheric chemistry processes. Health risk assessments, using the Benzo [a]pyrene toxic equivalency factor, mutagenic and carcinogenic potential, risk index, and oxidative potential (DTT-OP), indicated that PM_1.0 poses significantly higher health risks per unit mass compared to PM_2.5. Key components in PM_1.0, such as levoglucosan and terephthalic acid (TPA), indicate significant contributions from combustion sources like biomass burning and plastic incineration, particularly at night. PM_1.0 showed higher carcinogenic and mutagenic risks than PM_2.5. The correlation between levoglucosan, PAHs, and TPA supports common combustion origins. Effective management of combustion-related emissions is crucial for reducing health risks associated with PM_1.0. The overall average risk index for PM_1.0 is 1.30 times higher than PM_2.5, implying that, on average, PM_1.0 poses a 30 % higher health risk across the measured indices compared to PM_2.5. This study emphasizes the need for targeted management of combustion emissions, particularly those from plastic and fuel combustion, to mitigate the health risks posed by PM_1.0. Effective control of the precursors contributing to PM_1.0 formation is crucial for reducing the adverse health impacts of air pollution.