Source analysis of the particle-associated oxidative potential and polycyclic aromatic compounds in Shenyang, China

In this study, a dithiothreitol (DTT) assay was performed to assess the oxidative potential (OP) induced by atmospheric particulate matter in Shenyang, China, in the winter and summer of 2015. OP sources were identified by using the positive matrix factorization (PMF) model, and the relationships between components of the total suspended particulate (TSP), including different types of polycyclic aromatic compounds, and the OP were investigated. The volume-based DTT consumption rate (DTT_v) was used as an OP indicator. During sampling, the average daily TSP concentration and DTT_v in Shenyang City were 142 µg/m³ and 1304 pmol/min/m³, respectively, and they markedly increased in the winter compared with the summer. The PMF model identified the following sources for the OP induced by TSP: automobile exhaust and road dust (5.0%), biomass burning (31.0%), coal combustion (10.6%), soil (21.1%), diesel combustion (13.4%), and secondary pollution (19.0%). Furthermore, the source analysis revealed that biomass burning was the largest source of oxygenated and nitrated polycyclic aromatic hydrocarbons and that coal combustion was the largest source of polycyclic aromatic hydrocarbons.