D10: Impact of Contaminants - Hydromod

Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas
EUROLAKES
D10: Impact of Contaminants
FP5_Contract No.: EVK1-CT1999-00004
Version: 4.0
Date: 25/07/01
File: D10-vers.4.0.doc
input effects
destiny, dispersion extrapolation
environmental concentration
(PEC)
PEC/PNEC
effect concentration
(PECEC)
< 1: no risk assessment
> 1: risk assessment is necessary
Page 41 of 136
Figure 6-3: Concept of the environmental or ecotoxicological risk assessment of chemical
substances [FENT 1998].
The PEC/PNEC-concept (see Figure 6-3) is a comparison of environmental concentrations
(exposition) with the effect concentrations (effects). Due to the lack of data about
the input and the behaviour of the substances in the environment, about the exposure
concentrations can often be made only an approximate estimate. This uncertain state
of data causes certain difficulties because there are often only a few experimentally
found NOEC or LOEC values. Often it is only possible to estimate upper bounds of
LOEC values or sphere of actions. Beyond this, the extrapolation and safety factors did
not base on strongly scientific criteria. The highness of this factors depend on the quality
and quantity of the existing ecotoxicological data. The fixing of such factors concerning
endocrine effecting substances is not clear [BÄTSCHER et al 1999].
The authors emphasise the great importance of clarification of the loading situation of
humans and wildlife, the environmental behaviour of the substances, the effects of different
species and populations as well as the clarification of effect mechanisms for a
risk assessment. At the moment an established risk assessment and evaluation is due
to the lack of data (insufficient exposition and effect data) hardly be made. A closing of
the existing research gaps should be made possible a risk analysis and assessment for
endocrine effects. But it is necessary that the research activities and question formula