DEBtox information

Workshop 2019 results

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:
  1. Harmonised and consistent DEBtox modelling framework, including matching between regulatory questions and specific DEBtox model flavours
  2. List of ‘Research experiments’ targeting knowledge gaps, and partners who are interested in doing this research
  3. 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  
  4. 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.




Workshop participants
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

Background reading materials


These are the materials offered as 'workshop reader' that the authors have agreed to make public.
  1. Challenges related to application of DEBtox modelling in regulatory ERA (Andreas Focks). Download.
  2. DEBtox background, theory and models (Tjalling Jager). Download.
  3. ...

Presentations


These are the presentations that the authors have agreed to make public.
  1. DEBtox flavours and necessary updates for ERA (Tjalling Jager). Download.
  2. DEB-TKTD: consistent DEBtox terminology, problem definition & model selection (Neil Sherborne). Download.
  3. When to use a standard Dynamic Energy Budget model (André Gergs). Download.
  4. DEB(tox) development project (Benoit Goussen). Download.
  5. How to deal with inter-individual variability in DEB parameters? First step: sensitivity analysis (Josef Koch). Download.
  6. ...

Workshop learnings


  1. 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.
  2. 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.
  3. 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.
  4. Recognized potential of DEB-TKTD goes beyond aquatic species and particularly promising for mammals.
  5. 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.
  6.  DEB-TKTD as building block for population models might allow for consistent application for population modelling in regulatory ERA.
  7. Agreed that more experimental and in silico case studies are needed to inform further modelling choices.
  8. Therefore a follow-up workshop is needed, probably end of 2021.

Way forward


  1. Plan and carry out case studies for application of DEB-TKTD modelling for environmental risk assessment.
  2. Test different options for applying DEB to FOCUS SW profiles, in particular how to choose which time frame to model.
  3. Establish minimum data requirements for a robust DEB-TKTD model calibration (vertebrates).
  4. Method development for calculation of confidence and credible intervals and propagation of parameter uncertainty to model output;
  5. Development of robust, open source and ideally user-friendly software for the use of DEB-TKTD models in ERA.
  6. Keeping open communication about pathways to the implementation of mechanistic effect models for the improvement of ERA alive among all stakeholder groups.
  7. Ring test of developed software using a set of standard data (real data sets + extreme cases to break the model) and appropriate validation.
  8. Ask FOCUS Version Control Group at EFSA to cover also DEB-TKTD models (group has a mandate from European Commission).
  9. Determine which processes to be included depending on the risk assessment question; e.g. accounting for extrapolation to variable temperature or food levels.

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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