Spatial patterns of soil heavy metal(loid)s outside the boundaries of China's iron and steel enterprises during 2015-2025: Environmental drivers, mechanistic insights, and policy implications.

Long-term spatiotemporal patterns of soil heavy metal(loid) contamination outside the boundaries of China's iron and steel enterprises have not been adequately characterized at the national scale. To address this gap, a long-term database of soil heavy metal(loid) concentrations during 2015-2025 was established to investigate environmental drivers, mechanistic processes, and policy implications at the macroscale. According to the proportion of samples exceeding China's 2018 agricultural land risk control standards, the exceedance rates of Cu, Zn, Ni, Pb, Cr, Cd, As, and Hg were 3.82%, 2.38%, 1.34%, 0.52%, 0.83%, 12.50%, 0.62%, and 1.03%, respectively. Both environmental and anthropogenic factors shaped these patterns, while topography and soil properties regulated metal accumulation through hydrothermal redistribution, organic matter dynamics, and adsorption. Climate variables, especially temperature, precipitation, and wind speed, were the dominant controls, and thresholds of ∼15 °C were identified for As, Cd, and Pb. Vegetation coverage predominantly affected Hg, whereas socio-economic factors and industrial emissions significantly modulated the distributions of Cu, Hg, Ni, and Zn. Provincial analysis showed uneven emission performance: relatively low performance occurred in Shanghai and Guangdong, medium performance was found in most northern and central-southern provinces, and comparatively high performance was concentrated in several eastern and northeastern regions. Contamination patterns differed clearly among the heavy metals, with Cd and Hg recognized as the dominant pollutants. Risk-index evaluation indicated greater ecological risks in northern and northeastern areas. These findings support pollution control and sustainable development in the iron and steel industry.