Policy-driven reduction in metal pollution: Evidence from source-oriented health risks and early warnings in the agricultural land of a typical industrial city

To protect public health, China has issued several strict environmental protection initiatives to address the risks posed by toxic metals (TMs). However, the effect of policy implementation on pollution reduction is still unclear. Herein, the spatiotemporal dynamics of TMs were monitored, and their source-oriented health risks were analyzed to explore the effect of policy implementation on mitigating pollution in the soil-rice system of a typical industrial city from 2006 to 2021 (2006–2010: Initial stage of policy implementation; 2011–2015: Development stage; 2016–2021: Strengthening Stage). After intensive policy implementation (2016–2021), the accumulation rates of Cd and Cu, primarily originating from industrial activities, decreased to −0.161 and 0.007 mg kg⁻¹ yr⁻¹, respectively. Meanwhile, the Pb content, mainly originating from traffic pollution sources, decreased to 33.34 mg kg⁻¹ in 2021. Human health risks also decreased with the decrease in the mean Cd content in rice from its peak of 0.16 mg kg⁻¹ in 2011 to 0.09 mg kg⁻¹ in 2021. However, despite the reduction in the contribution of industrial sources to cancer and non-cancer risks for all populations, they still pose the highest health risk. Based on the soil environmental quality prediction model, the percentage of contaminated soil areas is expected to shrink to 10.21 % and 8.77 % in 2030 and 2050, respectively, with continued implementation of policies. This study reveals that the TM contamination level and health risks varied depending on the emission source and the implementation of policies, which highlighted the need for targeted control of pollution sources and appropriate remediation measures to mitigate environmental pollution and health burdens.