Federal Contaminated Site Risk Assessment in Canada: Supplemental Guidance on Human Health Risk Assessment of Oral Bioavailability of Substances in Soil and Soil-Like Media 

2017
ISBN: 978-0-660-09285-0
Pub.: 170180

This guidance document entitled Federal Contaminated Site Risk Assessment in Canada: Supplemental Guidance on Human Health Risk Assessment for Oral Bioavailability of Substances in Soil and Soil-Like Media was prepared to provide guidance to custodians of federal contaminated sites.

This document provides guidance on how to incorporate oral bioavailability in detailed human health risk assessments for sites with contaminated soils or soil-like material or media (e.g. indoor settled dust, sediment, and waste materials such as mining tailings or slag). The application of bioavailability adjustments in risk assessments is used to refine the exposure estimates and thereby provide more realistic indicators of exposure estimates and potential risk. This can provide support for higher remediation targets while ensuring adequate protection of human health.

The application of bioavailability adjustments of a contaminant of potential concern (COPC) in soils or other environmental media at a contaminated site is used to refine the COPC exposure estimates in the exposure assessment, by comparing the bioavailability of the COPC in the soil.

Since the underlying science and methods for assessing oral bioavailability are rapidly evolving, the main body of this guidance focuses on the overall framework, approach and requirements for inclusion of oral bioavailability adjustments in HHRAs, particularly for inorganic substances. Specific technical methods considered current at the time of writing are summarized in the appendices.