Bioaccessibility and human health risk : chromium in Glasgow

The assessment of risk to human health from contaminated land is based on a comparison of predicted human exposure to a contaminant with a Health Criteria Value (HCV) that represents an exposure below which there is thought to be little or no risk to human health. Most assessment tools, such as the Contaminated Land Exposure Assessment Model (CLEA), use estimates of exposure based on intake (consumption rate) rather than on measures of uptake (the amount of contaminant which enters the bloodstream), thus allowing comparison with HCVs, which are also based on intake apposed to uptake. Soil Guideline Values (SGVs) derived using the CLEA model assume that a soil contaminant will be taken up into the body to the same extent as from the medium of exposure used to derive the oral HCV (e.g. soluble salts of Cr(VI)). This is a conservative assumption as contaminants can be tightly bound to other soil components, thus reducing bioavailability (the fraction of a contaminant that can be absorbed by the body).