Methodology proposal for the derivation of soil guideline values for plant protection product residues. Part 1 - Review and comparison of international methodologies
Year: 2023
Type: report
Abstract: The Ecotox Centre, EnviBioSoil and the Swiss Soil Monitoring Network (NABO) were commissioned to develop a long-term monitoring of PPP residues in soil as a task of the measure 6.3.3.7 of the Action Plan for the reduction and sustainable use of Plant Protection Products in Switzerland. The NABO is in charge of the exposure monitoring of Plant Protection Product (PPP) residues in the soils and the Ecotox Centre and EnviBioSoil on the development of bioindicators and risk-based reference values for PPP residues. This report is the first part of a two-part report on the methodology for the derivation of Soil Guideline Values for Plant Protection Product residues and intends to review the current state of the methodologies used to derive risk-based reference values for PPPs. The first part will support the second part, which is a proposed methodology to derive reference values for PPP residues in agricultural soils from the Ecotox Centre and EnviBioSoil. The current report can be divided in four parts. The first part of the report (section 1) intends to give an overview of what are soil reference values, their application and use. The second part (section 2) describes the general steps used for the derivation of soil reference values. The third part (section 3) focuses on the description of some of the most important methodologies used in prospective and retrospective soil risk assessment. Finally, the fourth part (section 4), intends to compare the derivation process of some of the main methodologies by using two case studies. This extensive review has the focus on methodologies that have been used to derive values for PPPs and, when possible, under agricultural land use. Among all the methodologies reviewed and presented in this report, there are two for prospective and four for retrospective risk assessment that have been selected and described in more detail due to their relevance in the regulatory context. The two prospective methodologies are the one used by the European Food Safety Authority (EFSA) for the PPP authorization and the one used by the European Chemical Agency (ECHA) for the authorization of biocidal products. The four retrospective methodologies have been developed and applied in the following countries: The Netherlands, Canada, the US and Australia; and have been used as reference methodologies by many other countries. Two active ingredients used as PPPs were selected for the case studies: the herbicide diuron and the fungicide fluazinam. The two substances contrast in terms of datasets (quality and availability of data), mode of action and physico-chemical properties. The two prospective and the four retrospective methodologies previously mentioned were applied to both datasets (diuron and fluazinam). The results showed large differences between the soil protection values, mostly driven by the inclusion or exclusion of the most sensitive group of organisms from the dataset, the approach used for the derivation, the food chain model used (for highly bioaccumulative substances like Fluazinam) and the assessment factors applied to account for uncertainties. The review and better understanding of the methodologies and their feasibility after being applied to the case studies will be used as the foundation for a proposal of a methodology to derive risk-based reference values for PPP residues in agricultural soils in Switzerland.
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W7204016389