Accurate Identification and Source Analysis of Typical Wintertime Particulate Matter Pollution Processes in Southern Jiangsu Province: A Case Study of Suzhou New District

The rapid agglomeration of urban industries and population has led to increased emissions of air pollutants, exacerbating regional air pollution problems, especially in industrial parks. To clarify the characteristics and sources of typical particulate matter pollution in Southern Jiangsu, this study examines a continuous pollution process event in Suzhou New District in December 2022. Using the PM_2.5 component analysis, the study investigates the underlying causes and sources of the pollution. The results are as follows: (1) PM_2.5 concentrations are significantly correlated with meteorological factors such as temperature, humidity, and wind speed and direction. Meteorological conditions of low wind speed and high relative humidity are conducive to the hygroscopic growth of particulate matter and the prolonged residence of polluted air masses. (2) Regarding the contribution ratio of industry sources, the secondary formation of particulate matter accounts for a higher proportion (62%) compared to the primary emissions (38%). Among primary emission sources, process sources (12%), mobile sources (9%), and combustion sources such as coal and biomass (7%) are the most significant contributors. (3) In terms of regional transmission contribution, winter PM_2.5 in Suzhou New District is primarily influenced by transmission from outside of Suzhou (67.4%±15.5%), followed by transmission within Suzhou (20.5%±7.89%) and local generation within the industrial park (12.1%±5.53%). The study results can provide scientific basis for the delineating key areas for prevention and control of various air pollutants, formulating joint prevention and control action plans, and supporting environmental quality management and eco-city construction.