Assessment of Heavy Metal Pollution and Ecological Risk in Riverbank Soils Along the Dagu River, Qingdao, China

In this study, 46 soil monitoring sites were established along the banks of the Dagu River in Qingdao to investigate the current status of heavy metal contamination.Soil samples were collected, and heavy metal concentrations were determined to assess pollution levels.Additionally, the ecological risk of heavy metals in the Dagu River Reclamation Zone was evaluated using the potential ecological risk index method (PERIM) and the nemero index method (NIMM).The results indicated that the aver-age concentrations of As, Cr, Cd, Pb, Zn, Hg, Cu, and Ni were 6. 40, 150.58, 5.67, 69.86, 193.51, 1.21, 66.56, and 73.39 mg/kg, respectively.Notably, Cd and Hg concentrations significantly exceeded the threshold values stipulated in the Grade II standard of GB 15618-2018, "Soil Environmental Quality Standard."Among the eight heavy metals analyzed, Cd and Hg posed the highest ecological risks.Both evaluation methods showed a strong ecological risk of cadmium(Cd) and mercury(Hg) in the Dagu River riparian soil.The results of this study will serve as a fundamental reference for future research on soil ecological restoration in the Dagu River Basin.