Chemical characterization and source apportionment of PM and PM in Tianjin, China: Impacts of biomass burning and primary biogenic sources.

The submicron particulate matter (PM) and fine particulate matter (PM) are very important due to their greater adverse impacts on the natural environment and human health. In this study, the daily PM and PM samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin, China. The collected samples were analyzed for the carbonaceous fractions, inorganic ions, elemental species, and specific marker sugar species. The chemical characterization of PM and PM was based on their concentrations, compositions, and characteristic ratios (PM/PM, AE/CE, NO/SO, OC/EC, SOC/OC, OM/TCA, K+/EC, levoglucosan/K, V/Cu, and V/Ni). The average concentrations of PM and PM were 32.4 µg/m and 53.3 µg/m, and PM constituted 63% of PM on average. The source apportionment of PM and PM by positive matrix factorization (PMF) model indicated the main sources of secondary aerosols (25% and 34%), biomass burning (17% and 20%), traffic emission (20% and 14%), and coal combustion (17% and 14%). The biomass burning factor involved agricultural fertilization and waste incineration. The biomass burning and primary biogenic contributions were determined by specific marker sugar species. The anthropogenic sources (combustion, secondary particle formation, etc) contributed significantly to PM and PM, and the natural sources were more evident in PM. This work significantly contributes to the chemical characterization and source apportionment of PM and PM in near-port cities influenced by the diverse sources.