Ecological risk assessment of potentially toxic elements in selenium-rich soil with different land-use types

摘要

Dashan Village area is one of the repre-sentative areas in China with high selenium concen-tration in the natural environment.A total of 133 topsoil samples have been collected in the Dashan Village area to explore the potential toxic elements(PTEs)background concentrations in soils under dif-ferent land-use types for a comprehensive PTEs risk assessment(arsenic,cadmium,chromium,copper,mercury,nickel,lead,selenium and zinc).The results show that the geometric mean concentrations of As,Cr,Cu,Hg,Ni,Pb,Se and Zn found in the soil of the Dashan Village area were lower than the control standard for soil contamination risk in agriculturalland.However,the geometric mean concentrations of Cd exceeded their corresponding standard val-ues.For different land-use types,geometric mean concentrations of As,Cd,Cu,Hg,Ni and Pb in the arable soils were higher than in woodland soils and tea garden soils.Based on the potential ecological risk assessment,the woodland,arable and tea garden were at low-risk levels.Cadmium posed the highest ecological risk,while the other PTEs were of low risk in soils.Multiple statistical analyses and geostatisti-cal analysis indicated that the concentrations of Cr,Ni,Pb,Cu,Zn and Se originated mainly from natu-ral sources,while the concentrations of Cd,As and Hg could be influenced by anthropogenic activities.These results provide scientific support for the safe utilization and ecological sustainability of selenium-rich land resources.