Site-specific risk assessment and integrated management decision-making: A case study of a typical heavy metal contaminated site, Middle China

Abstract

<p>A typical contaminated land was spatially investigated and assessed based on Chinese guidelines to establish remediation strategy for exploring the shortcomings of the current guidelines to suggest improvements. Results showed that Cr, As, Pb, and Cd should be regarded as the priority pollutants under sensitive land use, while Cr and As should be regarded as the priority pollutants under insensitive land use. Ingestion of soil for each studied metal appeared to be the main exposure pathway under both the land uses. The calculated screening values of the priority metals were conservative to certain extent—even some were lower than their background values. Therefore, an integrated risk management strategy was suggested and the hierarchic clean-up values were proposed considering the health risk, local background value, land remediation cases, current remediation technology, and financial cost. Consequently, it was suggested the clean-up values of Cr(VI), Cr, As, Pb, and Cd, under future sensitive land use, should be 7.5, 1000, 30, 250, and 1.4 mg/kg in the first class control layer, respectively. For future insensitive land use, the clean-up values of Cr(VI), Cr, As, Pb, and Cd should be 20.4, 8000, 60, 580, and 4.3 mg/kg in the first class control layer, respectively.</p