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Europe Interest Groups: Mechanistic Effect Models

2012 Mechanistic Effect Models for Ecological Risk Assessment of Chemicals Annual Report

2015 Mechanistic Effect Models for Ecological Risk Assessment of Chemicals Activity Report

The general aim of the Mechanistic Effect Models for Ecological Risk Assessment of Chemicals (MeMoRisk) Interest Group is to explore and evaluate the benefit of mechanistic effect modeling for the risk assessment of chemicals in Europe. This will be done by establishing a forum for better communication and cooperation of scientists in academia, business and government working on or with mechanistic modelling to analyse and predict effects of chemicals on organisms, populations and communities.

The group will deal with models to analyse and predict effects of chemicals on organisms, populations, communities and ecosystems in aquatic, soil and terrestrial environments. The term "ecological modeling” is avoided here, because it is often used for population, community, food web and ecosystem models, but the group will also consider models to describe and predict effects on the level of the single organism, e.g., toxicokinetic and toxicodynamic models (TK/TD), dynamic energy budget models (DEB), biotic ligand models (BLM).

Empirical statistical models (e.g., dose-response functions, species sensitivity distributions, multivariate models of community structure) and QSARs will not be the focus of the group.


  • to promote the use of mechanistic effect models, and facilitate communication, amongst modellers, regulators and risk assessors. This includes both informing modellers about the needs of the regulatory process and encouraging the regulators to be explicit about what they need to know;
  • to build a network of people developing, using and evaluating such models for the risk assessment of chemicals in Europe;
  • to provide an overview on ongoing activities in the area via the website and an e-mail distribution list;
  • to provide information on public data sources, models, and modelling tools;
  • to develop an online glossary on related terms (SETAC Forum / SETAC Wikipedia);
  • to organise session(s) at the SETAC Europe annual meetings;
  • to organise SETAC short courses on mechanistic effect models if possible;
  • to organise (alone or as one partner) or actively participate in expert workshops;
  • to organise or participate in workshops to teach modelling, model use and model evaluation;
  • to communicate with related Europe and World AGs, e.g., on bioaccumulation, ecological risk assessment, exposure modelling;
  • to be actively involved in the development of guidance documents on the use of modelling in ecological risk assessment in support of European legislation.


Mechanistic effect models have been applied to ecotoxicological questions for over 25 years now. However, their use in regulatory risk assessment has been very limited over the years. Their importance seems to be increasing as has been stated especially in the risk assessment of pesticides under the European Directive 91/414: modelling was mentioned as a valuable higher tier tool in the SETAC workshops AMPERE on mesocosm tests (2007) and AMRAP on macrophyte testing (2008). The ELINK workshop (2007) focused on the problem of extrapolation from usually simple exposure patterns in ecotoxicological tests to the complex exposure scenarios predicted by the exposure models used now. In the ELINK working group on tools for extrapolation, different types of models are discussed for the potential use to solve this problem. Finally, the LEMTOX workshop (2007) was organised especially to bring together international experts from Europe, Japan and North America to discuss pros and cons of ecological (here usually population) models for pesticide risk assessment.

Recent reviews have investigated the state of the art and pointed out the need for standardisation of model approaches. This requires concerted actions with all stakeholders involved.

Nevertheless, the use of such models is not restricted to pesticides and the following main application areas are generally seen in the framework of the European regulation of chemicals (plant protection products, biozides, pharmaceuticals, industrial chemicals):

  1. clarify ecological relevance of observed effects (usually on the level of individuals) in standard laboratory tests to the population level (e.g., relevance of effects on the reproduction of fish for the population level);
  2. extrapolation of effects from a tested exposure to other, untested exposure patterns (e.g., from the tested one-peak exposure in a mesocosm to the multiple peak exposure in the field due to multiple drift, run-off and drainage entries);
  3. extrapolating recovery processes (e.g., from intrinsic recovery tested in a mesocosm study to recovery including recolonisation in an agricultural landscape or from observed effects and recovery of species experimentally tested to effects and recovery of untested species with different life cycle types);
  4. analysis and prediction of possible indirect effects in communities (by the use of dynamic community or ecosystem models).


The MeMoRisk Interest Group is open to any interested scientists and students. SETAC membership is not required, but may facilitate access to SETAC scientific activities (e.g., short-courses, symposia) at preferential rates. The organisation of the work is done by a steering committee (SC) of up to 12 people from academia, industry and regulation.

If you are interested, click the "Join Group" button near the top of this page to become a member. Please note, you must be signed in to join this group.

Steering Committee

The main task of this steering committee is to bring the interest group into life and to organise its activities.

Current steering committee:

  • Thomas Preuss (Chair, RWTH Aachen University, Germany)
  • Udo Hommen (Chair, Fraunhofer IME, Germany)
  • Anne Alix (AFSSA, France)
  • Walter Schmitt (Bayer CropScience, Germany)
  • Franz Streissl (EFSA, EU)
  • Melissa Reed (PSD, UK)
  • Paul van den Brink (Alterra and Wageningen University, The Netherlands)
  • Pernille Thorbek (Syngenta, UK)
  • Philippe Ciffroy (EDF, France)
  • Roman Ashauer (EAWAG, Switzerland)
  • Valery Forbes (University of Roskilde, Denmark)
  • Virginie Ducrot (INRA, France)
Group Feed
Thomas Preuss wrote on the Europe Interest Groups: Mechanistic Effect Models wall: Dear members of the MeMoRisk interest group, if you have been to the SETAC meeting in Nantes, you will have noticed that there is finally a lot of discussion about mechanistic effect modelling in environmental risk assessments of chemicals. This indicates that the main aim of MeMoRisk was reached, to facilitate the communication on models within and between different stakeholder groups. Looking back to the SETAC conference in 2008 when there were only a few presentations dealing with MEM scattered around several sessions, we went through a phase with mechanistic modelling sessions in small rooms and reached now in Nantes the point to have a two-slot session in the largest room available. In Brussel this year we have again two-slots. Nevertheless some objectives of the interest group still have to be reached, e.g improve the credibility of the models by careful documentation and testing, and maybe new challenges will come up. A new start is always best accompanied with changes in the people responsible. Thus, we would like to determine a new steering committee for MeMoRisk. There is a lot we can do to make use of the positive energy that is still buzzing with the mention of the word "CREAM", and we are thinking about organizing workshops, courses, and of course sessions at SETAC meetings etc... Therefore, we think it is time to take up the work in our advisory group again! To fulfill SETAC requirements, we need for the Steering Committee 4 members from Academia, Government and Business each. The official procedure is as follows: MeMoRisk members who are also SETAC member, and interested to join the Steering Committee, please submit a short informal application with your motivation and major credits in this fields of expertise (one page max.) with a photo of yourself, your affiliation and sector (Academia, Business, Government) to Roel Evans (roel.evens@setac.org). This holds true for people from the old steering committee as well as anyone who is interested to join the steering committee. Deadline is the 17. April 2017. After that, there will be an official voting via Survey Monkey, organized by the SETAC office. All on the MeMoRisk list, thus, all SETAC members who have clicked MeMoRisk membership in their SETAC profile, will receive an invitation for the survey. The elected steering committee will then determine its new chair and co-chair. We hope to receive plenty of applications to become active in the MeMoRisk steering committee ! Best wishes Thomas Preuss & Udo Hommen
Posted Tuesday, March 28, 2017
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Udo Hommen
Thomas Preuss