9 Using Bioavailability Information in Risk Assessment
Accounting for bioavailability in a human health risk assessment (HHRA) is compatible with, and is already reflected within, some existing HHRA methodologies. This approach more accurately estimates site-specific risks, as opposed to assuming that a given chemical present in the soil is 100% bioavailable to humans.
Accounting for site-specific bioavailability is a critical aspect in calculating potential risk to humans that live, work, or play near a given contaminated site. A site-specific bioavailability assessment ensures that a more accurate HHRA is produced with less uncertainty. This reduction in uncertainty allows for more effective remedial decision making, potentially freeing up resources and reducing unnecessary action, without compromising protection of human health.
This section describes how bioavailability can be used in risk calculations, to modify estimated exposures or assumed toxicity values, or generate cleanup objectives. Problems and potential solutions to the inevitable variability in relative oral bioavailability (RBA) estimates are presented. Finally, this section discusses how to communicate risk estimates when site-specific RBA is used.
