Contaminant bioavailability in soil and sediment

Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. Although long employed in toxicology and agricultural sciences, the concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration for deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable then more contaminant mass can be left in place without additional risk. To date, the concept has affected cleanup goals at a small number of sites (Table 1), and enthusiasm for the idea is growing. After two years of deliberation, a National Research Council (NRC) committee recently weighed in on using bioavailability in soil and sediment management. This article summarizes the resulting report, Bioavailability of Contaminants in Soils and Sediments Processes, Tools and Applicants (1).