Characteristics and health risk assessments of heavy metals in PM2.5 in Taiyuan and Yuci college town, China

To clarify the pollution sources of heavy metals in PM2.5 and the health risks posed by them in heating and non-heating seasons, 42 samples were collected in 2017 and 2018 in Taiyuan and Yuci college town, China. Elemental analysis of the PM2.5 samples through acid-dissolved plasma mass spectrometry was performed to determine the concentrations of 10 elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn). We determined the types of pollution sources by enrichment factor (EF) and principal component analysis (PCA). We performed a health risk assessment based on the US Environmental Protection Agency (EPA) guidelines and the database of the International Agency for Research on Cancer (IARC) to assess both carcinogenic and non-carcinogenic risks of the heavy metals to adults and children. The results indicate that the EF values of all 10 elements were greater than 1, suggesting anthropogenic sources in both heating and non-heating seasons. PCA revealed that the three main components were soot dust, metal smelting emission, and industrial dust. Regarding the health risks caused by the heavy metals, children were more susceptible to non-carcinogenic risks than adults, and people faced higher non-carcinogenic risks during the heating season. For carcinogenic risk, Cr has the highest risk coefficient (1.68 × 10−4), higher than the US EPA’s threshold (1.00 × 10−6). People were exposed to carcinogenic risk. The study explored specific pollution sources and explained their effect on health to assist with the development of prevention and control measures.