[Characteristics, Sources, and Health Risks of Elements in PM_2.5 in Shanxi University Town]

In order to investigate the pollution characteristics and sources of elements in PM_2.5 in the Shanxi University Town in 2017, an energy dispersive X-ray fluorescence spectrometer (ED-XRF) was used to analyze 21 kinds of elements in PM_2.5 samples. A health risk assessment was conducted for Mn, Zn, Cu, Sb, Pb, Cr, Co, and Ni. The main sources of elements were identified by the principal component analysis (PCA) and positive matrix factorization (PMF). The results found that, among the 21 kinds of elements in PM_2.5 in Shanxi University Town, the mass concentration of Ca was the highest, followed by Si, Fe, Al, S, K, and Cl. These seven elements accounted for 95.71% of the total element concentrations. The concentration of Cr exceeded the annual average concentration limit of ambient air quality standards in China by 104 times. The concentration of Ca in PM_2.5 was the highest in spring, summer, and winter, while in autumn the concentration of S was the highest. Mn was the element that had non-carcinogenic risks to the three population types, and the level of risks were in the order of children > adult men > adult women. Cr and Co had tolerable carcinogenic risks, and the risk levels were in the order of adult men > adult women > children. The main sources of elements in PM_2.5 in Shanxi University Town in 2017 were natural mineral dust, urban dust, coal combustion, and traffic.