Date: 2005/10/06 thursday 
Place: Via Fermi 1 I-212020 Ispra (VA) 
  European Chemicals Bureau, Inst Health & Consumer Protection 
  Joint Research Centre
Speaker: Tjalling Jager & Bas Kooijman
Affiliation: dept Theoretical Biology, Vrije Universiteit, Amsterdam
Title: Process-based toxicity analysis in risk assessment

Abstract: 

Both ISO and OECD are unhappy with the application of the No Observed
Effect Concentration (NOEC) as a summary statistic for the toxicity of
chemical compounds; the OECD recommended the development of
exposure-time explicit regression models for toxicity analysis
(Braunschweich, 1996). We developed such a method, called DEBtox,
which is based on the Dynamic Energy Budget (DEB) theory for the
uptake and use of resources by organisms for maintenance, development,
growth and reproduction. The DEBtox method not only allows the
estimation of a robust No Effect Concentration (NEC) as a summary
statistic for risk assessment, but also allows various types of
translations: from acute to chronic exposure, from effects on
individuals to that on populations, from laboratory to field
conditions, from one compound to another, from effects on one species
to another. It uses all available data, rather than just those at the
end of the experiment. This efficiency allows a reduction in the
required number of test organisms, while the translation potential of
the method can be helpful to fill in gaps in our knowledge about
particular compounds. Since the method can be applied to bioassays as
currently standardized, we think that this method is very useful for
routine application, and better suited for supporting informed risk
management decisions.