Concentrations, Sources, and Correlation Analysis of Polycyclic Aromatic Hydrocarbons in Atmospheric Particulate Matter and Organic Film from Shanghai, China

To understand the enrichment concentrations, compositional characteristics, and sources of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matter (PM) and organic film, PM_2.5, PM₁₀, and organic film on glass surfaces were collected from eight sampling sites in central urban, suburban, and rural Shanghai. Sixteen priority-controlled PAHs were investigated using gas chromatography-mass spectrometry, and mass concentrations, compositional differences, and pollution sources of PAHs in PM and organic film were analyzed. The results indicate that under good air conditions, 2.5-10 μm particles are relatively abundant in the atmosphere; during haze periods, PM is generally less than 2.5 μm. Furthermore, PAHs tend to adsorb on PM less than 2.5 μm. Except at Shengang (SG), 4-ring PAHs are particularly abundant in PM, while 2-and 3-ring PAHs are particularly abundant in organic film. The K_FA of low molecular weight PAHs is higher than the K_OA, indicating that these monomer PAHs have achieved dynamic equilibrium between the organic film and the atmosphere. Source identification results show that PAHs in PM and organic film are generated by vehicle exhaust, domestic exhaust gas, and ground dust.