Characteristics and Risk Assessment of Soil Available Heavy Metal Pollution in Guangzhou Based on Multi Method Fusion

Abstract

Assessment of the effective state concentrations of Zn, Pb, Cu, Ni, Cr, Cd, and As in 210 soil samples across the Guangzhou region in South China. The study also explores the pollution status, potential risks, and identifies the main hazard factors associated with these elements. The analysis of effective concentrations indicates average values of 13.66 mg/kg for Pb, 3.64 mg/kg for Ni, 17.92 mg/kg for Cu, 1.74 mg/kg for Cr, 51.77 mg/kg for Zn, 0.22 mg/kg for Cd, and 0.38 mg/kg for As. Notably, all heavy metals exhibited considerable variability. The single pollution index method and Nemerow index method both suggest that, with the exception of Cd, all heavy metals exhibit relatively low levels of contamination, indicating a slight overall pollution in the studied samples. The potential ecological risk index identifies Cd as the primary ecological risk factor among the available heavy metals in the soil of Guangzhou. The analysis using the potential health risk model suggests that the available forms of each heavy metal do not pose substantial health risks to both children and adults. The principal non-carcinogenic factors identified are Cu and Pb, whereas Cd and Cr emerge as the primary carcinogenic factors. The collaborative risk assessment analysis revealed that 79% of the samples in Guangzhou exhibited low potential risks, 20% showed potential risks, and only one sample indicated serious risks.