[Characteristics and Origin Analysis of Air Pollution During the Spring Festival in Linfen, Fenwei Plain]

In recent years, frequent haze episodes have resulted in the deterioration of air quality of the Fenwei Plain during winter and holidays. Besides coal combustion and industrial emissions, the topography and climate of the Fenwei Plain were also the main causes of the haze. The samples were collected in Linfen of Fenwei Plain during the Spring Festival from February 2 to February 13, 2019. The 13 elements(Li, Be, Ti, Rb, Sc, Y, La, Ce, Zr, V, Tl, U, and Sn) in PM_2.5 were determined by inductively coupled plasma mass spectrometry(ICP-MS). Combined with the meteorological data, the spatial and temporal distribution of pollutants and potential source analysis were evaluated by cluster analysis and backward trajectory. The average concentration of SO₂ was 58.39 μg·m^-3 during the sampling period, which exceeded the 24 h average mass concentration limit(50.00 μg·m^-3) of national ambient air quality standard(GB 3095-2012). The average concentrations of O₃, NO₂, and CO was 52.15 μg·m^-3, 29.02 μg·m^-3, and 2.29 mg·m^-3, respectively. The results showed that SO₂ was the dominated pollutant. NO₂ and CO were mainly affected by diffusion from urban areas. The backward trajectory analysis indicated that the basin topography of the Fenwei Plain may be the main cause of the haze. The analysis of potential source contribution function(PSCF) of soil sources showed that the potential dominated areas included Northern Shaanxi, southern Gansu and Southern Ningxia., which were mainly affected by the monsoon climate.