Ecotoxicology

ecotoxicology

Agrochemicals

Dossier support:
Preparation of ecotoxicological risk assessments and complete dossier sections for active substances and plant protection products (dRR Part A and B) for all regulatory zones in the EU and for all member states.

Risk assessments:
We conduct standard and higher tier risk assessments and prepare dossiers for EU and national submissions according to (EC) No 1107/2009 and current guidance documents.

Biocides

Dossier support:
Preparation of ecotoxicological risk assessments for active substances and biocidal products (Doc I, Doc II, Doc III) and draft risk assessment (Article 95) for EU and for all member states.

Risk assessments:
Calculation of PEC/PNEC ratios in STP, surface water, sediment, air and soil according to EU and country specific requirements.

Standard and higher tier risk assessments, dossier preparation

Standard risk assessments, e.g. those applying TER calculations, are typically based on a series of worst-case assumptions. While this procedure ensures an quick and time saving estimation of the potential risk, it often provides a rather conservative estimation of the risk. To obtain a more realistic estimation of the risk higher tier risk assessments, based either on literature reviews, refined statistical analyses or simple modelling approaches are often an efficient alternative to costly laboratory or field studies. Due to our experience with national authorities and the participation in workshops and workgroups at EFSA (as hearing expert) and US EPA, we can help to develop scientifically sound risk assessments which are in agreement with the requirements of risk managers.

Services:

  • Higher tier risk assessment based on literature data or modelling approaches
  • Evaluation and re-evaluation of laboratory and field studies (see also Statistical Consulting)
  • Probabilistic risk assessments (Species Sensitivity Distributions or completely probabilistic approaches, Monte Carlo)
  • Toxicokinetic/body burden modelling, food chain modelling Population-level risk assessments with exisiting population models (e.g. MASTEP or others)
  • Development of new population models (experience in mammals, birds, arthropods and aquatic organisms)

Would you like to discuss your specific case?

Please contact us, after an overview of your data we'll provide an honest recommendation. Many years of experience in higher tier risk assessment helps us to give a realistic assessment of the situation.

Probabilistic risk assessments

Probabilistic risk assessments are a refinement option that helps to calculate the real risk by including entire data distributions instead of single worst-case values. These data distributions include the entire range of possible values observed in nature (e.g. in a laboratory or field study), including very rare values (on the tails of distributions), which are usually neglected in standard risk assessments. Therefore, the result from a probabilistic risk assessment provides a much more realistic estimate of the risk, taking the real variability into account. This is an advantage for both authorities and industry.

In the simplest case Species Sensitivity Distributions (SSD) may be used to obtain a refined endpoints for the risk assessment. More comprehensive methods are fully probabilitic models, such as those discussed by EUFRAM. Such approaches include the full variability of all parameters used in a risk assessment.

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Toxicokinetik/body burden modelling and feeding behaviour

When animals feed of food items, which may contain toxicants, the amount of residues in the food is usually not ingested at once and residues will also take a while until they reach the blood or organ where effects might occur. At the same time residues are also eliminated, e.g. via urine. Toxicokinetik modelling (or body burden modelling), often combined with information on feeding behaviour, is a useful method to obtain a realistic estimate of concentrations in animal bodies and subsequent effects. While this method has originally been developed for pharmaceutical studies, where it has reached a much more complex level compared to ecotoxicology, it is a rather new in ecotoxicological risk assessents. We help to find the needed data for your specific case and develop a tailor-made toxicokinetic model.

Population Modelling

Population modelling is a novel approach for evaluation of population effects and recovery. When a theoretical risk assessment indicates that an effect on a particular species is possible, population models can help to evaluate if this individual effect has actually an impact on the overall population development. If a short term population effect is observed population recovery can help to evaluate if the long-term population development is at risk (see EFSA 2010).

Landscape structure plays an important role regarding the population risk and the recovery potential (see e.g. Wang & Grimm, 2010).While theoretical risk assessments don't take landscape structure into account, populations models can easily include landscape structure, e.g. based on different landscape scenarios. Populations of free ranging animals may respond differently to population-level impacts than predicted by theoretical higher tier risk assessments, depending on the landscapes they live in.

Apart from developing population models, we also assist and coordiate population-level risk assessments, e.g. if you would like to use a specific, exisiting population model and need an experienced expert for the preparation of the subsequent population-level risk assessment or for presentation at authorities. Based on our experience and participation in workshops and workgroups at EFSA and US EPA, e.g. as hearing experts, we understand what authorities expect from a population-level risk assessment.

Related references

  • Wang M. 2012. Population level risk assessments – Science or fiction? Integrated Environmental Assessment and Management, Integr. Environ. Assess. Manag. 8: 383-385.
  • Wang M. & Luttik R. 2012. Population level risk assessment: practical considerations for evaluation of population models from a risk assessor's perspective. Environ. Sci. Europe 24: 3.
  • Kramer V.J., Etterson M.A., Hecker M., Murphy C.A., Roesijadi G., Spade D.J., Spromberg J., Wang M. & Ankley G.T., 2011. Adverse Outcome Pathways and Ecological Risk Assessment: Bridging to Population Level Effects. Environ. Toxicol. Chem. 30: 64–76.
  • Wang M. & Grimm V. 2010. Population models in pesticide risk assessment: Lessons for assessing population-level effects, recovery, and alternative exposure scenarios from modeling a small mammal. Environ. Toxicol. Chem. 29: 1292-1300.
  • Forbes V.E., Hommen U., Thorbek P., Heimbach F., van den Brink P.J., Wogram J., Thulke H.H. & Grimm G. 2009. Ecological models in support of regulatory risk assessments of pesticides: developing a strategy for the future. Integrated Environmental Assessment and Management 5 (1): 167–172.
  • Crocker J. & Wang M. 2008. How to estimate PT – Appendix 29. In: Scientific opinion of the panel on plant protection products and their residues on a request from the EFSA (European Food Safety Authority) PRAPeR Unit on risk assessment for birds and mammals. The EFSA Journal 734: 1-181.
  • Barnthouse L.W., Munns W.R. & Sorensen M.T. (eds.) 2007. Population-Level Ecological Risk Assessment. Taylor & Francis, Boca Raton, FL.