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Environmental Fate Modelling

environmental fate model


Dossier support and consulting:
Preparation of environmental fate risk assessments for active substances and plant protection products (dRR Part A and B) for Annex I registration and renewals, and for all regulatory zones in the EU and for all member states.

PEC calculations:
Calculation of PECs in surface water and sediment, air, soil and groundwater according to EU and country specific requirements: FOCUS tools (FOCUS TOXSWA, MACRO, PRZM, SWASH, PEARL, PELMO), national models (Exposit, EVA, HardSpec, FROGS, etc.), higher tier modelling.


Dossier support and consulting:
Preparation of environmental exposure and risk assessment for active substances and biocidal products (IUCLID 6) according to the Biocidal Product Regulation 528/2012.

Data gap analysis as well as planning and monitoring of required environmental fate or ecotoxicological studies.

PEC calculations:
Calculation of PECs in STP, surface water, sediment, air, soil and groundwater according to EU and country specific requirements: EUSES or custom spreadsheets and tools based on ESDs and the TGD, higher tier modelling.

Kinetic Analyses

Kinetic analyses of laboratory or field dissipation studies reveal DegT50 / DT50 values for parent substances and relevant metabolites. These endpoints are needed for subsequent exposure modelling. We provide support for standard kinetic analyses of soil dissipation and water sediment studies according to FOCUS (2006) and EFSA (2010) and we develop tailor-made models. Kinetic analyses (SFO, DFOP, FOMC, HS) are conducted using KinGUI, ModelMaker, R or other software.

PEC Calculations

pex calculationsHigher tier modelling or GIS analyses, incuding probabilistic approaches, can additionally help to obtain a realistic estimate of exposure for specific applications. In contrast to higher tier Step 4 PEC calculations (drift reduction, buffer zones) these tools focus on more realistic scenarios and they can take entire parameter distributions into account. Examples include Wang & Rautmann (2008) or Schad & Schulz (2011). With many years of experience with higher tier and probabilistic models we provide reliable services and solutions even in complex situations.

We also develop tools for novel higher tier approaches. Recently, the E-Link Workshop (Brock & al. 2009) proposed to include time-variable exposure profiles in the aquatic risk assessment. These exposure profiles are extracted with a new software tool EPAT from PEC result files. The inclusion of the exposure profiles offers new, more realistic endpoints for the ecotoxicological risk assessment.

GIS Modelling

Standard exposure or risk assessments are based on worst case assumptions and scenarios. While the use of these scenarios facilitates a time and cost efficient way to determine maximum theoretical concentrations, in certain cases more realistic assessments based on real landscapes instead of worst-case scenarios may be needed. Geographical Information Systems (GIS) are used for such landscape based evaluations. These approaches can take country specific geography or the location of agricultural areas into account and they can show which scenarios are representative for a particular country or region (e.g. regarding soil properties, climate, etc.). GIS applications may take into account how often surface waters are located near the crop under concern or they can include GIS models simulating exposure by spray drift, dust drift or other exposure routes. Do you have a complex problem for which GIS modelling might be appropriate? Just contact us and discuss your case with our certified GIS specialists.

Related references

  • Wang M. & Rautmann D. 2008. A simple probabilistic estimation of spray drift--factors determining spray drift and development of a model. Environ Toxicol Chem. 27: 2617-2626.
  • Wang M. 2010. EPAT v. 1.0 Exposure Pattern Analysis Tool. RIFCON GmbH Report No. R08270.
  • Schad T. & Schulz R. 2011. Xplicit, a novel approach in probabilistic spatiotemporally explicit exposure and risk assessment for plant protection products. Integr. Environ. Assess. Manag. 7: 612–623.
  • Brock T.C.M., Alix A., Brown C.D., Capri E., Gottesbüren B., Heimbach F., Lythgo C.M., Schulz R. & Streloke M. 2009. Linking Aquatic Exposure and Effects: Risk Assessment of Pesticides. CRC Press, Boca Raton, FL.