Concentrations and Pollution Assessment of Six Heavy Metals in Quercus aquifolioides Forest Soils

Abstract

Concentrations characteristics of six heavy metals (Cu, Cr, Cd, Mn, Zn, Pb) in 7 soil sample from different loactions ofQuercus aquifolioidesfrest were investigated. The concentrations and potential ecological risk of heavy metals in the soils was assessed when compared to the background values of heavy metals in three different soils, i.e. total, yellow-brown and yellow soils in China. The average concentration of heavy metals inQuercus aquifolioidessoils was in the order Mn>Cr>Zn>Cu>Pb>Cd, while the average concentrations of all examined heavy metals were lower than those in the Environmental Quality Standard for Soil (grade I) in China. In all examined heavy metals, Mn (474.7mg/kg) had the highest average concentration and Cd (0.039mg/kg) had the lowest one, with variation coefficients ranged 33-87% for the six heavy metals. Correlation analyses showed that the three heavy metals (Cu, Mn and Pb) probably came from the same resources, and so did of Cr and Pb. Comprehensive pollution indices (0.57-1.71) indicated theQuercus aquifolioidessoils were slightly polluted by the six heavy metals and ecological risk indices (8.42-51.0) also show the situation of heavy metals was in the slight level in the soils. Among the examined heavy metals, Cu and Cr were two main heavy metals who making pollution and potential ecological risk to the soils.