The Superfund Basic Research Program (SBRP), in collaboration with the Environmental Protection Agency (EPA) Technology Innovation Program, presents the 2008 edition of RiskeLearning: "Bioavailability - Metals, Organics, and Policy". This series of online seminars will focus on the science and policy issues of incorporating bioavailability into risk and exposure assessments. Largely drawing from the successful SBRP Bioavailability Workshop: "Assessing Bioavailability as a Determinant of Pollutant Exposure" held in Tampa, FL (February 2008), the web seminar series will feature SBRP-funded and other academic researchers and EPA senior staff.
This, the first of three sessions, will feature Dr. Dominic Di Toro, Professor of Civil and Environmental Engineering, University of Delaware and Dr. Nicholas Basta, Professor, Soil and Environmental Chemistry, Ohio State University.
Understanding and quantifying metal bioavailability is of central importance in performing scientifically sound risk assessments. Dr. Di Toro will review available models - the Free Ion Activity Model, the Biotic Ligand Model and Equilibrium Partitioning - and supporting data for water column, sediments and soils and will present example applications to human health in his presentation titled "Environmental Control of Metal Bioavailability".
Incidental soil ingestion is an important exposure pathway for assessing public health risks associated with contaminated soils. The bioavailability of Pb (lead), As (arsenic), and possibly other contaminants in soils can be determined by conducting dosing trials using acceptable surrogate animal models. To overcome the difficulty and expense associated with in vivo trials, in vitro gastrointestinal (IVG) methods, that simulate human gastrointestinal conditions, have been developed. The science of contaminant bioaccessibility has matured and several IVG methods have been reported. Dr. Basta will present data gaps, uncertainties and research needed to apply IVG methods to contaminated sites in his presentation titled "Assessing Contaminant Human (Bio)availability in Soil with In Vitro Gastrointestinal: Uncertainties, Data Gaps, and Research Needs".
The session will be moderated by Aaron Yeow, Environmental Health Scientist, Office of Superfund Remediation and Technology Innovation, USEPA.