Spatial distribution and sectoral characteristics of particulate matter-permitting emissions from heavy metal-emitting enterprises in China: Policy implications and environmental management strategies.

Industrial particulate matter (PM) emissions significantly contribute to air pollution and soil heavy metal contamination via deposition. In this study, the spatial distribution and sectoral variations in particulate matter-permitting emissions (PMpe) from heavy metal-emitting enterprises across China are analysed. We employed piecewise structural equation modelling to quantify the relative influences of geographic location, socioeconomic development, and climate conditions. The results revealed strong spatial agglomeration of enterprises, which exhibited a distinct "dense east, sparse west" pattern. High-emission clusters for PMpe (>0.200) were predominantly located in northern regions, specifically Northwest China (44.01 ×10 ³ t/a) and North China (31.86 ×10 ³ t/a). Significant sectoral differences were detected, with nonferrous metal smelting resulting in the highest total emissions (101.51 ×103 t/a) and average PMpe of each pollutant outlet (7.27 t/a). Geographical location had the strongest direct effect on PMpe, with the total effect value reaching 0.253. Climate conditions demonstrated notable positive direct impacts in North China, with the total effect value reaching 0.589. Socioeconomic factors showed weaker influences overall, although they exhibited significant positive direct effects in Central and Northeast China. Regionalization based on dominant influencing factors underscores the need for tailored pollution control strategies to increase mitigation precision. These findings provide crucial scientific support for the establishment of regionally differentiated prevention and control strategies for heavy metal emissions.