title: Estimates of ambient background concentrations of trace metals in soils for risk assessment.
abstract: 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 Al and Fe, and multiple regressions explained 62-85% of their variation, and Al and Fe can therefore be used to predict ABCs for these 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 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. Potential applications of ABCs are discussed.
authors.affiliation: Agriculture and Environment Division, Rothamsted Research, Harpenden, Hertfordshire, UK. fangjie.zhao@bbsrc.ac.uk
authors.forename: F J
authors.initials: FJ
authors.lastname: Zhao
authors.forename: S P
authors.initials: SP
authors.lastname: McGrath
authors.forename: G
authors.initials: G
authors.lastname: Merrington
mesh_terms: D000535:Aluminum / Q000032:analysis; D002104:Cadmium / Q000032:analysis; D002857:Chromium / Q000032:analysis; D003300:Copper / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D007501:Iron / Q000032:analysis; D015999:Multivariate Analysis; D009532:Nickel / Q000032:analysis; D010316:Particle Size; D018570:Risk Assessment / Q000379:methods; D012989:Soil Pollutants / Q000032:analysis*; D014131:Trace Elements / Q000032:analysis*; D015032:Zinc / Q000032:analysis
chemical_list: D012989:Soil Pollutants; D014131:Trace Elements; D002104:Cadmium; D002857:Chromium; D003300:Copper; D009532:Nickel; D000535:Aluminum; D007501:Iron; D015032:Zinc