The Impact of Land Use Efficiency on County-Level PM2.5: Evidence from 1125 Counties in China

With the severe harm caused by high concentrations of PM2.5 pollution to human health and the environment, effectively reducing county-level PM2.5 concentrations has become an urgent environmental issue. This paper explores the potential of land use efficiency in mitigating county-level PM2.5 pollution, proposing that improving land use efficiency could be an effective approach to reducing PM2.5 emissions. Based on balanced panel data from 1125 counties in China from 2000 to 2021, this paper employs a two-way fixed effects model to analyze the impact of land use efficiency on county-level PM2.5 concentrations and further examines the mechanism effects of urbanization and industrialization. The main findings are as follows: (1) Improvements in land use efficiency significantly reduce county-level PM2.5 concentrations. This conclusion remains robust after a series of robustness tests. (2) Enhanced land use efficiency indirectly reduces PM2.5 concentrations by promoting urbanization and industrialization processes. (3) The suppressive effect of land use efficiency on PM2.5 is more pronounced in non-resource-based cities and non-traditional industrial cities. (4) As population density increases, the suppressive effect of land use efficiency on PM2.5 gradually weakens. (5) In regions with higher levels of economic development, the impact of land use efficiency on PM2.5 concentrations follows an inverted U-shaped curve. This study provides theoretical support and policy recommendations for optimizing land resource allocation, promoting urbanization and industrialization, and formulating targeted environmental policies.