Source Apportionment and Health Risk Assessment of Zn (II) Ions Based on Gridded Spatial Interpolation and Geochemical Equilibrium Simulation

Abstract Soil heavy metal pollution had become a global issue involving environmental safety and human health risks. A methodology was explored to quantify the sources of heavy metals in the soils and investigate the spatial distributions of heavy metals by the gridded spatial scale. The case study was implemented in the industrial waste sites in Suzhou city, Jiangsu province. Zinc (Zn) was screened out as the targeted metal (TM) through the potential ecological risk assessment, the species of which was simulated by the geochemical software PHREEQC. The aim of this research was to determine the dominant metal species of TM with potential hazardous health risk to local people to achieve key prevention and pollution control. Herein, according to the morphological evolution of metal species, the activity and concentration of the Zn species was calculated for both carcinogenic and non-carcinogenic health risk assessment. The evaluation of the optimized human health risk demonstrated that the associated health risk of Zn (II) depended predominantly on its metal speciation and was also affected by acidity and soil organic matter. Overall, the optimized carcinogenic and non-carcinogenic risk value of Zn2S32− for adults was 2.01E-04 and for children was 1.31 respectively, resulting in corresponding hazardous risk to human, which accounted for high risk level of 61.5% and 58.5%, respectively. This method could provide a reference for the decision-making of soil heavy metal pollution control and targeted hypotoxic convertion of metal species and remediation for certain heavy metal of polluted area.