Pollution characteristics and source apportionment of Polycyclic Aromatic Hydrocarbons in atmospheric PM2.5 in Jinchang City

Abstract Polycyclic aromatic hydrocarbons (PAHs) are typical persistent organic pollutants with persistence, long-distance migration, bioaccumulation, and high toxicity. Due to their adverse effects on human health and the environment, they have been listed as a priority to be monitored and controlled. To explore the pollution characteristics and sources of polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 in Jinchang City, the mass concentrations of PM2.5 and 16 types of priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS). The HYSPLIT model was used to simulate the backward trajectory of the air masses, and the potential source contribution factor (PSCF) and the characteristic ratio methods were used to analyze the pollution characteristics and the source of PAHs respectively. The results indicated that ρ(PAHs) in atmospheric PM2.5 was in the order Winter [(86.40 ± 12.55) ng∙m− 3] > Spring [(71.82 ± 18.60) ng∙m− 3] > Autumn [(61.54 ± 17.48) ng∙m− 3] > Summer [(31.86 ± 7.64) ng∙m− 3]. Correlation analysis showed that the concentration of PAHs was highly significantly negatively correlated with temperature and humidity, but was significantly positively correlated with wind speed and pressure. Characteristic ratio analysis showed that the PAHs in PM2.5 atmosphere were mainly from automobile combustion and exhaust sources. The trajectory clustering and PSCF analysis showed that the airflows in southwestern and southern Inner Mongolia, as well as in the Hexi Corridor have a significant impact on the air quality in Jinchang City. The sources of PAHs in PM2.5 atmosphere in Jinchang are mainly from combustion sources and exhaust from motor vehicles. In winter, they mainly originate from burning of coal and biomass as well as oil combustion. The results of this study reveal that, the pollution characteristics and the sources of PAHs in Jinchang City are widely distributed especially in autumn and winter seasons, which may be related to meteorological conditions.