Dynamic measures for ecotoxicity
Kooijman, S.A.L.M., Bedaux, J.J.M., Gerritsen, A.A.M., Oldersma, H. and Hanstveit, A.O. 1998.
Dynamic measures for ecotoxicity. In: Newman, M.C. and Strojan, C.
Risk Assessment: Logic and Measurement Ann Arbor Press, pp 187 - 224.
We review the problems with the No Observed Effect Concentration
(NOEC) to identify a concentration of test chemical that has no effect
on test organisms and conclude that effect models are required to
solve the problems. We then argue that the logit and probit models are
not suitable as effect models and identify three required components
of dynamic models for toxic effects: toxico kinetics, effects on a
target parameter coupled to the internal concentration and the
physiological component. The Dynamic Energy Budget (DEB) model, which
is used to model the latter component, relates a change in a target
parameter of a particular physiological process, such as the specific
costs for growth, to an output variable, such as the cumulative number
of offspring. We compare the logit/probit and the DEB-based models
conceptually and numerically and conclude that the DEB-based model is
more effective as an effect model. Contrary to the logit model, the
DEB-based model provides the required information to evaluate the
consequences of effects on individuals for population dynamics.
Quantitative Structure Activity Relationships are easier to derive on
the basis of the DEB-based model.