Research progress on the environmental risk assessment and remediation technologies of heavy metal pollution in agricultural soil.

• Regulating soil pH, etc. can reduce the bioavailability of heavy metals. • Reconstructing appropriate mathematical models for risk assessment is critical. • The application potentials of remediation techniques have been systematically compared. • Heavy metal-polluted soil can be cost-effectively remediated by phytoremediation. • Effective risk assessment can guide the choice of remediation techniques. Controlling heavy metal pollution in agricultural soil has been a significant challenge. These heavy metals seriously threaten the surrounding ecological environment and human health. The effective assessment and remediation of heavy metals in agricultural soils are crucial. These two aspects support each other, forming a close and complete decision-making chain. Therefore, this review systematically summarizes the distribution characteristics of soil heavy metal pollution, the correlation between soil and crop heavy metal contents, the presence pattern and migration and transformation mode of heavy metals in the soil-crop system. The advantages and disadvantages of the risk evaluation tools and models of heavy metal pollution in farmland are further outlined, which provides important guidance for an in-depth understanding of the characteristics of heavy metal pollution in farmland soils and the assessment of the environmental risk. Soil remediation strategies involve multiple physical, chemical, biological and even combined technologies, and this paper compares the potential and effect of the above current remediation technologies in heavy metal polluted farmland soils. Finally, the main problems and possible research directions of future heavy metal risk assessment and remediation technologies in agricultural soils are prospected. This review provides new ideas for effective assessment and selection of remediation technologies based on the characterization of soil heavy metals. [ABSTRACT FROM AUTHOR]