Key messages

• The scientific basis of the pesticide environmental risk assessment needs to be strengthened, and the regulatory complexity needs to be bechmarked;
• The validation status of exposure models in the environmental risk assessment of pesticides needs to be improved;
• Measured and predicted environmental pesticide concentrations have to be contextualized to assess the real exposure situation;
• The overall aim is the optimization of complexity within the regulatory exposure assessment of pesticides to ensure protectiveness.

Overview

This project is part of PARC Activity “Risk assessment to support and promote efficient overall protection of biodiversity”, which focuses on enhancing environmental risk assessment (ERA) methods. The aim of this project is to investigate the potential for simplifying and improving the predictions in the exposure assessment of the authorization process for plant protection products (PPP, commonly known as pesticides) under Regulation (EC) No 1107/2009. The current process is intricate and resource-intensive, prompting to optimize the space between necessary model complexity to achieve a protective predictive capacity and regulatory feasibility. The focus is on the ERA of pesticides with the long-term aim to expand the scope to support chemical ERA in general.

During Y 1-3, this project performed an extensive “reality-check” of the exposure predictions based on a comparison of predicted environmental concentrations (PECs) from a range of exposure models with measured environmental concentrations (MECs) from monitoring studies in various European countries, benchmarking the complexity of regulatory PEC models.

Initial results give no indication that complex models provide more accurate predictions of maximum MECs than simple models based on assumed key risk drivers, demonstrating that data-driven model refinement, grounded in real-world environmental monitoring and sensitivity analysis, can lead to more efficient and protective models.

Going into Year 4, PEC model analyses and model parameter sensitivity analyses will be continued; European MECs will be analyzed in more detail, considering e.g., national-level regulatory specificities and pesticide application. “Real” environmental concentrations (RECs) will be approximated and explored to optimize the comparison and assessment of protectiveness of PECs.

Policy relevance

The goal of of this project is to strengthen the scientific basis of ERA and to develop a clear risk profiling system for pesticides based on the investigation of available MECs in concert with the evaluation of PEC models and factors influencing their predictive capacity for the real exposure situation in the field (RECs). Contextualizing these exposure assessment-related aspects and assessing their transferability across different member states will provide insight into the state of realism and protectiveness and concrete improvement opportunities for chemical ERA.