Air Pollution in Small Urban Settlements Cannot be Ignored: A Case Study of Jimunai, Northwest China

Abstract Air pollution is a widespread issue that poses significant risks to human health and exacerbates climate change. However, research on this issue in small towns across China is limited, and pollution levels are often underestimated. In this study, 242 total suspended particulates (TSP) samples were collected within four years from a representative town (Jimunai) in Xinjiang，a western province of China. We conducted comprehensive analyses of various pollutants, including organic carbon (OC), elemental carbon (EC), 8 water-soluble inorganic ions (WSIIs), 16 polycyclic aromatic hydrocarbons (PAHs), and 15 organic molecular markers. Most of these species—including OC, EC, PAHs, and levoglucosan—exhibited substantially elevated concentrations compared to remote regions, with levels comparable to those observed in some urban areas of eastern China, indicating nonnegligible air pollution in Jimunai. The PMF (Positive Matrix Factorization) source apportionment identified six sources of pollution in both summer semester and winter semester, namely biomass combustion sources (summer: 28.6%; winter: 19%), secondary formation sources (summer: 23.7%; winter:15.8%), coal-natural gas combustion sources (summer: 15.9%; winter: 21.2%), vehicle exhaust sources (summer: 11.9%; winter: 26.5%), air–soil exchange sources (summer: 11.2%; winter: 10.2%), and fungal spore sources (summer: 8.8%; winter: 7.3%). Fossil fuel combustion and biomass burning are the main sources of atmospheric pollutants. The health risk assessment showed that the carcinogenic risk of PAHs fell into the “potential risk category” and the carcinogenic risks for adults and children from EC are 3.71 × 10 –4 and 1.52 × 10 –4 , respectively, which were comparable to those of some urban areas worldwide. It can be concluded that the atmospheric pollution in small towns in western China is more severe than we thought. Therefore, greater attention should be given to these regions in China, where a large number of elderly people and children reside. Graphical Abstract