"Relative oral bioavailability of contaminants from soil". Overview of activities from 1996 to 2001 coupled to policy issues

In current risk assessment of soil contaminants, oral bioavailability of contaminants from soil in humans (Fsoil) is considered to be equal to the bioavailability of contaminants from the matrix used in the toxicological studies (Fmatrix tox. study) underlying the Maximal Permissible Risk level. There are indications that this consideration is not valid. Research on relative bioavailability factors (=Fsoil/ Fmatrix tox. study) of soil contaminants is needed for more insight into relative bioavailiability factors and to decide whether risk assessment can be improved by experimental determination of these factors. The (still ongoing) research on relative bioavailability factors of soil contaminants at the Laboratory of Exposure Assessment and Environmental Epidemiology of the National Institute for Public Health and the Environment in the 1996-2001 period has been summarised in the current report. To date, an in vitro digestion model and a (preliminary) mathematical model have been developed and tested to explore the relative bioavailability of contaminants in soil. It can be concluded that both models are promising tools to study relative bioavailability factors. The current report will be used to decide how research has to be continued.DGM-directie Bode