Study on methods for determining the remediation target value of soil arsenic in contaminated sites

The determination of remediation target value is an important part of the process of environmental regulation for contaminated sites, and is usually obtained based on risk assessment to calculate risk control values. However, when it comes to arsenic-contaminated sites, the remediation target values obtained by using the recommended model and parameter derived from Technical Guidelines for Risk Assessment of Soil Contamination of Land for Construction (HJ 25.3-2019) are often lower than the soil arsenic environmental background values, making it difficult to meet regulatory requirements. The methods for determining the target values of soil arsenic remediation in contaminated sites were systematically reviewed, and the implementation paths and practical applications based on soil environmental criteria values, traditional risk assessment, tiered risk assessment, equivalent risk assessment and soil arsenic environmental background values correction were discussed. Combining with China's regulatory strategy for contaminated sites and the current situation of arsenic-contaminated sites development and reuse, a method for determining soil arsenic remediation target values based on soil environmental background values, tiered risk assessment, and bioaccessibility-related parameter correction was proposed, aiming to provide more scientific and reasonable solutions for the remediation and safe reuse of arsenic contaminated sites in China.