Heavy metals were analyzed in rhizosphere soils and rice grains collected from typical black shale areas. The concentrations of As, Cd, Cu, and Zn in the rhizosphere soil exceeded the current soil environmental quality standards. Cd exhibited the highest bioaccumulation capacity, with 45% of rice grains exceeding food safety limit. Structural equation modeling (SEM) revealed that soil organic matter indicated that 34.79% of rice Cd accumulation and approximately 10%-25% of other metals were inhibited. Multiple regression modelling showed that in areas with high geological background of black shales, the screening and intervention values for soil Cd were adjusted to 0.24 mg kg