15 / 2023-04-12 14:24:03

Chemical and physical characteristics and health risks induced by particulate matter in metro stations: a field study

oxidative stress,particulate matter,transition metals,metro station

Particulate matter (PM) from different sources exhibits diverse chemical and physical characteristics, and it is an essential carrier of toxic chemicals. However, the contributions of PM properties to its toxicity remain unclear. Ignoring the PM properties when developing processes for indoor air quality (IAQ) control may be inappropriate for places with internal sources, such as metro stations. This study evaluated the health risks induced by chemical components and the oxidative potential of the PM in the Tianjinzhan metro station. A principal component analysis (PCA) of the chemical compositions showed that the PM in the platform had little risk of spillover when exhaust fans provided ventilation. However, underlying adverse health effects of the PM on the platform was noticeable. The PM samples from metro stations were rich in metals, including Sb, Fe, Cu, and Mo, generated by internal sources, especially metro train mechanical processes. An in-depth toxicology analysis was suggested for the high Ba, Al, and Mn concentrations. The risk from Cr caused a concern over the potential for carcinogenicity. The DTT activity of the platform was 3.3–5.4 times that of the ventilation shafts. An air purification process was required for the platform. The health effects of PM should be evaluated in their entirety. This study considered oxidative potential as a scaling factor for health risks caused by PM. The DTT assay evaluated the general adverse health effects caused by the PM characteristics, including the chemical composition, size distribution, and mass concentration. A limit of 0.038 mg/m³ was recommended for oxidative potential control at the metro station platform. This study provides a step forward in combining IAQ control directly with human health.