Drs. J. Baas
Effects of mixtures of compounds
Current risk assessment is based on the effects of single compounds,
but organisms are subjected to numerous chemicals with a variety of
effects. This combined exposure may cause effects that are not
expected when only individual compounds are considered. For instance
in "het Westland" an agricultural area in the Netherlands of about 100
km2 where almost 50 % of the surface is built with
greenhouses a variety of pesticides is found in surface waters. Often
all individual compounds are found below their environmental safety
level, and so classical risk assessment (based on individual
compounds) tells that there are no effects to be expected. Still the
biological diversity in these surface waters may be quite different
from comparable surface waters in nearby parts of the Netherlands. In
addition to this it is now estimated that 25 till 33 % of the burden
of disease in the industrialized western countries can be attributed
to long term exposure to low concentrations of complex mixtures of
compounds.
This leads to the conclusion that classical risk assessment does not have
a good answer to the combined toxicity of compounds at relatively low
concentration levels. To improve the current situation, the EU
commissioned a project with the aim to make more realistic risk
assessment, based on the simultaneous exposure to different chemicals.
The work that will be done at our laboratory is part of a very large
research project in which 38 research groups in Europe are working
together. The whole project is split in four subjects:
- Risk scenario studies
- Exposure estimates
- Effect assessment
- Risk assessment
Our research is focused on risk assessment. In our laboratory we will
model the effects of different toxicants (sets of two toxicants and
mixtures of many different toxicants) on different organisms. Our modeling
work will be carried out in a close collaboration with the other research
groups, especially with the research groups working on effect assessment.
Jan has 4 highligthed articles among the 14 publications of this project:
BaasJage2009a
BaasWill2009
BaasKooy2010
JageVand2010
The NoMiracle leadership exposed this application of DEB research as being of high relevance to European Environmental Policy
This is the symposium that concludes my project
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