Mobility in the context of exposure‐based assessment of chemicals for drinking water resource protection. (16th December 2022)

• Record Type: Journal Article
• Authors: Pawlowski, Sascha; Aicher, Lothar; Berends, Albert; Curtis‐Jackson, Pippa; Häner, Andreas; Hollender, Juliane; Jene, Bernhard; Jenner, Karen; Redman, Aaron; Sanders, Gordon; Vallotton, Nathalie; Wang, Neil; Wheeler, James R.
• Is Part Of: Integrated environmental assessment and management. Volume 19:Number 3(2023)
• Page Start: 775
• Page End: 791
• Publication Date: 2022-12-16
• Subjects: Exposure -- groundwater -- mobility -- nonextractable residues -- persistence; Environmental management -- Periodicals; Pollution -- Periodicals; Environmental toxicology -- Periodicals; Environmental risk assessment -- Periodicals; Environmental impact analysis -- Periodicals; 628
• DOI: 10.1002/ieam.4705
• Languages: English
• ISSNs: 1551-3777

Abstract

Abstract: In order to protect European Union (EU) drinking water resources from chemical contamination, criteria for identifying persistent, mobile, and toxic (PMT) chemicals and very persistent and very mobile (vPvM) chemicals under the EU REACH Regulation were proposed by the German Environment Agency (Umweltbundesamt—UBA). Additionally, new hazard classes for PMT and vPvM substances in the revised EU classification, labeling, and packaging (CLP Regulation) are intended. Therefore, a reliable approach in the identification of potential drinking water resource contaminants is needed. The scientific basis of the property‐based PMT/vPvM criteria, focusing on mobility, which dictates the migration of chemical drinking water sources, was evaluated, and a critical analysis of the deviation of sorption metrics from simple behavior was carried out. Based on our evaluation, a K oc may be used for nonionic substances on a screening level only, requiring a higher tier assessment. It is considered inappropriate for hydrophilic and ionizable chemicals, particularly for soils with low organic carbon contents. The nonextractable residue formation is complex and not well understood but remains significant in limiting the mobility of chemicals through soils and sediments. In order to inform the EU commission's work on the introduction of new hazard classes for PMT and vPvM substances into the European legislation, the derivation of a tiered approach is proposed, which utilizes the weight of evidence available, with adoption of appropriate higher tier models commensurate with the nature of the substance and the data available. Integr Environ Assess Manag 2023;19:775–791. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: A K oc may be used for nonionic substances on a screening level only, requiring a higher tier assessment. The log K oc is considered inappropriate for hydrophilic and ionizable chemicals, particularly for soils with low organic carbon contents. Therefore, for the introduction of new hazard classes for PMT/vPvM substances into CLP, the derivation of a tiered approach is proposed, which utilizes the weight of evidence available, with adoption of appropriate higher tier models commensurate the nature of the substance and the data available.