Per- and polyfluoroalkyl substances (PFAS) as contaminants in groundwater resources – A comprehensive review of subsurface transport processes

• Published in: Chemosphere (Oxford) Vol. 362; p. 142663
• Main Authors: Rasmusson, Kristina, Fagerlund, Fritjof
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2024
• Subjects: Biodegradation; Distribution coefficient; groundwater; Hydrologi; Hydrology; Per- and polyfluoroalkyl substances; PFAS; PFOS; Pollution; Sorption; transport; Unsaturated zone; Biodegradation; Sorption; Pollution; Unsaturated zone; Distribution coefficient; PFOS
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.142663

Per- and polyfluorinated alkyl substances (PFAS) are persistent contaminants in the environment. An increased awareness of adverse health effects related to PFAS has further led to stricter regulations for several of these substances in e.g. drinking water in many countries. Groundwater constitutes an important source of raw water for drinking water production. A thorough understanding of PFAS subsurface fate and transport mechanisms leading to contamination of groundwater resources is therefore essential for management of raw water resources. A review of scientific literature on the subject of processes affecting subsurface PFAS fate and transport was carried out. This article compiles the current knowledge of such processes, mainly focusing on perfluoroalkyl acids (PFAA), in soil- and groundwater systems. Further, a compilation of data on transport parameters such as solubility and distribution coefficients, as well as, insight gained and conclusions drawn from the reviewed material are presented. As the use of certain fire-fighting foams has been identified as the major source of groundwater contamination in many countries, research related to this type of pollution source has been given extra focus. Uptake of PFAS in biota is outside the scope of this review. The review showed a large spread in the magnitude of distribution coefficients and solubility for individual PFAS. Also, it is clear that the influence of multiple factors makes site-specific evaluation of distribution coefficients valuable. This article aims at giving the reader a comprehensive overview of the subject, and providing a base for further work. [Display omitted] •Review of processes governing PFAS contamination of groundwater resources.•Current knowledge on subsurface PFAS fate and transport behaviour is described.•A compilation of solubility, pKa, Kaw, Kd, Koc and Kia for 21 PFAA is presented.•A large spread in distribution coefficients and solubility was seen.•Influence of many factors on transport makes site-specific evaluation valuable.