A comprehensive attribution analysis of PM2.5 in typical industrial cities during the winter of 2016-2018: Effect of meteorology and emission reduction

The frequent occurrence of air pollution in winter has aroused widespread concern. Identifying the detailed source composition of PM2.5 and assessing the reduction effects of different emission sources are crucial steps in improving pollution levels. In this study, we conducted a comprehensive evaluation of emission source reductions, encompassing ten local and ten regional sources. Furthermore, we analyzed the influence of meteorological changes on the abatement of PM2.5 in Tangshan, Shijiazhuang, Xingtai, and Handan during the winter period from 2016 to 2018. Our findings indicate that, in comparison to the winter of 2016, there were significant decreases in the average concentrations of PM2.5 during the winter of 2017. These decreases were attributed to favorable meteorological conditions and emission reductions. However, during the winter of 2018, there was a rebound in PM2.5 concentrations for all four cities. This rebound was primarily caused by adverse meteorological diffusion conditions. Throughout the entire research period spanning from the winter of 2016 to 2018, emission reduction played a significant role in PM2.5 abatement, contributing to 68% in Tangshan, 87% in Shijiazhuang, 93% in Xingtai, and 96% in Handan, respectively. The source apportionment analysis revealed that industrial and residential sources were the dominant contributors to PM2.5 concentrations in the cities. These findings not only confirm the effectiveness of existing industrial and residential pollution control policies but also highlight the imperative need for implementing non-point source control and joint control measures for regional elevated sources in the future.