Metallic source analysis of PM2.5 and its pollution source identification based on spectral analysis method and time series analysis method

In order to investigate the pollution characteristics and sources of metallic elements in atmospheric fine particulate matter (PM2.5) in a region, the atmospheric PM2.5 in the region was sampled continuously at fixed points from 2019 to 2023. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of the target elements, the median (interquartile spacing) was applied to characterize the temporal variations of the elements, and the enrichment factor, principal component analysis and absolute principal component score-multiple linear regression (APCS-MLR)were used for an in-depth exploration of the sources of the elements. The results showed that the PM2.5 content in the study area showed a decreasing trend from 2019-2023, decreasing from 67.05 μg/m³ to 4.88 μg/m³. Sb, As, Cd, Pb, Se, and Tl were mainly originated from anthropogenic pollution, Mn and Ni had both natural and anthropogenic sources, and the main sources of Al and Cr were natural sources. The main sources of pollution in areas A, C, and the overall were coal combustion sources, and the main source of pollution in Area B is coal combustion sources, followed by industrial process sources and dust sources. This study provides an intuitive understanding of PM2.5 in a particular area and provides clues to alleviate air pollution in the area.