Characteristics and Sources of Elements in PM2.5 During Summer for Three Typical Cities in Pingdingshan-Suizhou-Wuhan, Central China

Abstract

This study investigates the elemental characteristics and sources of aerosol fine particulate matter (PM2.5) samples obtained from Pingdingshan, Suizhou, and Wuhan, Central China, in June 2017. Thirteen kinds of elements (Ti, Zn, Cu, Cr, As, Pb, Fe, Ni, Se, V, Sb, Cd, and Co) were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), and three source identification methods-enrichment factor, principle component analysis and multiple linear regression (PCA-MLR), and backward trajectory clustering-were applied. The results showed that Zn was the highest trace element in PM2.5 in samples from Pingdingshan, Suizhou, and Wuhan, and that the concentration of As exceeded the annual limit of Chinese air quality standards (GB 3096-2012). Concentrations of Pb and Cd in PM2.5 in samples from the three cities during the summer were low. The enrichment factor coefficients for Se, Sb, Cd, As, Cu, and Zn exceeded 10, which suggests that summer pollution from human activities was serious, for example, the enrichment factor coefficient for Se was>600. PCA-MLR and backward trajectory clustering analysis results showed that the main pollution sources in Pingdingshan during the summer were industrial fuel oil (57.90% of total), traffic pollution (24.40%), coal combustion (6.10%), and mine soil (11.60%). The main pollution source in Suizhou was fuel, which contributed 54.30% of the total. Wuhan was mainly affected by industrial emissions (60.80% of the total) and motor vehicle pollution (39.20%). Hence, Wuhan and Suizhou were mainly affected by local source emissions, whereas Pingdingshan was jointly affected by local emissions and regional inputs during the summer.