Temporal variations in health risk indices and combustion-derived components of PM1.0: Focus on terephthalate and levoglucosan

This study evaluated the health risks and chemical composition of PM1.0 and PM2.5 in Incheon, South Korea, emphasizing the critical role of particle size in public health impacts. The average concentrations were 10.89 μg/m³ for PM2.5 and 8.11 μg/m³ for PM1.0. PM1.0 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 PM1.0 poses significantly higher health risks per unit mass compared to PM2.5. Key components in PM1.0, such as levoglucosan and terephthalic acid (TPA), indicate significant contributions from combustion sources like biomass burning and plastic incineration, particularly at night. PM1.0 showed higher carcinogenic and mutagenic risks than PM2.5. 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 PM1.0. The overall average risk index for PM1.0 is 1.30 times higher than PM2.5, implying that, on average, PM1.0 poses a 30 % higher health risk across the measured indices compared to PM2.5. 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 PM1.0. Effective control of the precursors contributing to PM1.0 formation is crucial for reducing the adverse health impacts of air pollution. •PM1.0 contains higher proportions of carbonaceous components than PM2.5.•PM1.0 has a greater carcinogenic and mutagenic risk than PM2.5.•Nighttime combustion increases levoglucosan and terephthalate levels in PM1.0.