Estimates of ambient background concentrations of trace metals in soils for risk assessment

摘要

Site-specific or soil type-specific ambient background concentrations (ABCs) of trace metals in soils are needed for risk assessment. We investigated three different methods for estimating ABCs in soils using a dataset of 5691 soil samples from England and Wales. The concentrations of Co, Cr and Ni were strongly associated with A1 and Fe, and multiple regressions explained 62%-85% of their variation. The concentrations of Al and Fe can be used to predict ABCs for these trace metals. Soil texture had a major influence on the concentrations of Cd, Co, Cr, Cu, Ni and Zn, and the medians were 3-5 fold higher in clayey than in sandy soils. This was used to predict soil texture-specific ABCs. Lead concentration was higher in acidic peaty soils than in other soils. A probability graph method was used to estimate ABC for Pb in a population of relatively uncontaminated soils.