Diverse chemical components of PM10 emitted from different coal combustions resulting in distinct cytotoxicity

Abstract

Inhalable particles (PM10, particulate matters with an aerodynamic diameter < 10 μm) emitted from coal combustions is one of the most significant contributors to air pollution, endangering human health. The compositions of emissions and corresponding health risks of different types of coal sources are currently unclear. To address this, ten distinct types of coal were burnt, and original PM10 samples were collected using dilution channel samplers. Subsequently, we performed a componential analysis on the collected samples and conducted in vitro cytotoxicity tests. Results showed that PM10 from honeycomb, anthracite and industrial coals were dominated by water-soluble ions, while bituminous coal was dominated by carbonaceous components. Although heavy metal contents were lower than other investigated components in these PM10, they were still enriched in Fe, Pb and Zn. The NH4+, Cl- and SO42- account for a large proportion of water-soluble ions. PM10 induced obvious cytotoxicity to human lung cell A549, and the ability of anthracite coal to induce cellular TNF-α production was greater than that of honeycomb and bituminous coal. For IL-6, industrial coal elicited a stronger response than bituminous coal, followed by honeycomb and anthracite coal. Correlation analysis revealed that although heavy metals (Fe, Mn, Co, Ni, Cu) and water-soluble ions (K+, Ca2+, F-) accounted for less particle mass, they were strongly and significantly correlated with oxidative stress and inflammatory damage (r > 0.6, p < 0.05). Considering the actual coal consumption amount, our study identified restricting anthracite coal combustion should be a crucial focus for aerosol pollution control and public health protection policies. The results of the study not only increase the understanding of the chemical composition and cytotoxicity of PM10 from the perspective of source emissions, but also provide targeted advice on the control of coal combustion, which is of great significance in environmental research, public health policy and air pollution control efforts.