DEBtox Workshop, 2-3 Dec. 2019
The organising committee, led by Andreas Focks, invited
participants to come to Wageningen (The Netherlands), to
discuss two days about DEBtox
models. The reasons for having this workshop was that
further development of DEBtox modelling approaches is needed
for the improvement of applicability in regulatory risk
assessment (as e.g., identified in the recent EFSA
SO on TKTD modelling).
The workshop aim was to discuss and make progress on the
following topics:
- Harmonised and consistent DEBtox modelling framework,
including matching between regulatory questions and
specific DEBtox model flavours
- List of ‘Research experiments’ targeting knowledge
gaps, and partners who are interested in doing this
research
- Improved approach for use of DEBtox in a regulatory
context: evaluation of DEBtox modelling, place in tiered
ERA system, scenarios, use of FOCUS output, sensitivity
and uncertainty analysis
- Requirements for a protocol for ‘Regulatory
experiments’ to parameterise DEBtox related experiments,
and partners who will work out and test these protocols
Download the detailed
agenda of the meeting.
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Participants: Alessio Ippolito, Alpar
Barsi, Andre Gergs, Andreas Focks, Benoit Goussen, Dino
Liesy, Dirk Nickisch, Hans Baveco, Josef Koch, Karel
Viaene, Neil Sherborne, Oliver Jakoby, Pernille Thorbek,
Roman Ashauer, Sandrine Charles, Thomas Preuss, Tjalling
Jager, Jan Baas, Paul van den Brink, Matthias Fürst,
Jeremias Becker, Magali Solé
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Background reading materials
These are the materials offered as
'workshop reader' that the authors have agreed to make
public.
- Challenges related to application of DEBtox modelling
in regulatory ERA (Andreas Focks). Download.
- DEBtox background, theory and models (Tjalling Jager).
Download.
- ...
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Presentations
These are the presentations that
the authors have agreed to make public.
- DEBtox flavours and necessary updates for ERA
(Tjalling Jager). Download.
- DEB-TKTD: consistent DEBtox terminology, problem
definition & model selection (Neil Sherborne). Download.
- When to use a standard Dynamic Energy Budget model
(André Gergs). Download.
- DEB(tox) development project (Benoit Goussen). Download.
- How to deal with inter-individual variability in DEB
parameters? First step: sensitivity analysis (Josef
Koch). Download.
- ...
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Workshop learnings
- New proposal for nomenclature was made and discussed
(DEB-TKTD), manuscript in preparation; a related
decision scheme would help choosing which model type to
use depending on the risk assessment question.
- Agreed on approach for the evaluation of FOCUS
profiles by using a moving time window. Definition of
minimum and maximum length might be related to the
time until onset of effects and the life span of the
species, respectively, but needs to be further detailed.
- Data for Daphnia and Mysid chronic studies allows
straight forward application for the calibration given
that intermediate measurements are available; while for
vertebrate the consequences of fitting DEB-TKTD models
to low numbers of observations over time need to be
analysed.
- Recognized potential of DEB-TKTD goes beyond aquatic
species and particularly promising for mammals.
- The application of GUTS TKTD models in Tier 1 would
allow a more robust estimation of acute endpoints
compared to current approaches. In principle, DEB-TKTD
models have the same potential for chronic endpoints.
- DEB-TKTD as building block for population models
might allow for consistent application for population
modelling in regulatory ERA.
- Agreed that more experimental and in silico case
studies are needed to inform further modelling choices.
- Therefore a follow-up workshop is needed, probably end
of 2021.
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Way forward
- Plan and carry out case studies for application of
DEB-TKTD modelling for environmental risk assessment.
- Test different options for applying DEB to FOCUS SW
profiles, in particular how to choose which time frame
to model.
- Establish minimum data requirements for a robust
DEB-TKTD model calibration (vertebrates).
- Method development for calculation of confidence and
credible intervals and propagation of parameter
uncertainty to model output;
- Development of robust, open source and ideally
user-friendly software for the use of DEB-TKTD models in
ERA.
- Keeping open communication about pathways to the
implementation of mechanistic effect models for the
improvement of ERA alive among all stakeholder groups.
- Ring test of developed software using a set of
standard data (real data sets + extreme cases to break
the model) and appropriate validation.
- Ask FOCUS Version Control Group at EFSA to cover also
DEB-TKTD models (group has a mandate from European
Commission).
- Determine which processes to be included depending on
the risk assessment question; e.g. accounting for
extrapolation to variable temperature or food levels.
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Relevant new publications, specifically related to the
workshop context
- Jager T (2020). Revisiting simplified DEBtox models
for analysing ecotoxicity data. Ecol Modell 416:108904.
https://doi.org/10.1016/j.ecolmodel.2019.108904
- Sherborne N and N Galic (2020). Modelling sublethal
effects of chemicals: application of a simplified
dynamic energy budget model to standard ecotoxicity
data. Environ Sci Technol 54(12):7420-7429. https://doi.org/10.1021/acs.est.0c00140
- Koch J and KAC De Schamphelaere (2020). Estimating
inter-individual variability of dynamic energy budget
model parameters for the copepod Nitocra spinipes
from existing life-history data. Ecol Modell 431:109091.
https://doi.org/10.1016/j.ecolmodel.2020.109091
- Sherborne N, N Galic and R Ashauer (2020). Sublethal
effect modelling for environmental risk assessment of
chemicals: problem definition, model variants,
application and challenges. Sci Total Environ
745:141027. https://doi.org/10.1016/j.scitotenv.2020.141027.
- Sherborne N, T Jager, B Goussen, M Trijau and R
Ashauer (2022). The application and limitations of
exposure multiplication factors in sublethal effect
modelling. Scientific Reports 12:6031. https://doi.org/10.1038/s41598-022-09907-1.
- Jager T, B Goussen and A Gergs (2023). Using the
standard DEB animal model for
toxicokinetic-toxicodynamic analysis. Ecol Modell
475:110187. https://doi.org/10.1016/j.ecolmodel.2022.110187
open access.
- Romoli C, T Jager, M Trijau, B Goussen and A Gergs
(Acc.). Environmental risk assessment with energy budget
models: a comparison between two models of different
complexity. Acc. Environ. Toxicol. Chem. https://doi.org/10.1002/etc.5795
open access.
- ...
For a (hopefully) complete list of DEB-TKTD papers,
please see the list of papers.
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