Pesticide exposure assessment for surface waters in the EU. Part 2: Determination of statistically based run‐off and drainage scenarios for Germany

Abstract

BACKGROUNDIn order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co‐ordination of pesticide fate models and their USe) surface water workgroup introduced four run‐off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst‐case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known.RESULTSUsing Germany as an example, the paper illustrates how national soil–climate scenarios can be developed to model entries of active substances into surface waters from run‐off and erosion (using the model PRZM) and from drainage (using the model MACRO). In the authorisation procedure for PPPs on Member State level, such soil–climate scenarios can be used to determine exposure endpoints with a defined overall percentile.CONCLUSIONThe approach allows the development of national specific soil–climate scenarios and to calculate percentile‐based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS‐SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPPs in Germany. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Statistically based approach to select worst-case groundwater scenarios for environmental risk assessment of pesticides in Brazil

“…However, none of them had the aim to take into consideration a pre-defined risk exceedance approach. On the other hand, Bach et al (2016) proposed an approach that considers full spatio-temporal distribution of PEC values in the intended area of pesticide use. Moreover, this approach allows scenario selection based on pre-defined overall percentile of concentration risk exceedance (i.e.…”

“…In the European Union (EU), the definition of exposure scenarios used for ERA of pesticides for surface and groundwater was based on expert judgment more than using statistically based approaches (Bach et al, 2016). However, some member states as Germany are developing their national ERA of pesticides and exposure scenarios using statistically based approaches that consider more robust and refined spatial data analysis.…”

“…This work had the aim to present in a systematic way a scientifically based approach to define worst-case groundwater exposure scenarios in Brazil using soil and climate data of Mato Grosso do Sul State. This approach is based on the work of Bach et al (2016) and has not been tested for definition of worst-case exposure scenarios in Brazil until now. Moreover, this approach can be used to develop Brazilian specific soilclimate exposure scenarios and to define overall percentilebased exposure endpoints within ERA of pesticides at different Brazilian agricultural areas of pesticide use.…”

Scientific report of EFSA on the ‘repair action’ of the FOCUS surface water scenarios

“…So, the risk for aquatic organisms is typically not only determined by the maximum exposure concentration (PEC max ) but also by the cumulative exposure (quantifiable as area under the curve (AUC)) and the time for recovery between peaks. A possible method for integrating effects of the overall exposure pattern based on TK/TD models is set out in the final report of the German GERDA project (Bach et al, 2016(Bach et al, , 2017a. As part of GERDA, various effect models were run through with a wide variety of exposure scenarios.…”

Determination of Pesticides in River Surface Waters of Central Chile Using Spe-Gc-MS Multi-Residue Method

“…Therefore, various countries around the world have developed monitoring programs to evaluate the level of pesticide contamination in bodies of water, taking the measures necessary to minimize the impact of these substances on the environment and protect the quality of water resources [11].…”