Fate of PFAS in the Aquatic Environment: From Source to Sink

Abstract

Per- and polyfluoroalkyl substances (PFAS) represent a diverse group of chemical compounds extensively used in consumer and industrial applications, contributing to persistent environmental contamination and associated health risks. This review explores the fate of PFAS in aquatic environments, synthesising existing knowledge and highlighting key research gaps. PFAS exhibit complex behaviours within aquatic ecosystems, influenced by diverse molecular structures and environmental conditions. Their accumulation in aquatic environments poses risks to organisms and ecosystems, with potential far-reaching consequences in highly industrial areas, as well as regions with little to no human interaction. This review underscores the need to comprehend the step-by-step pathways of PFAS fate in aquatic environments, encompassing different types of PFAS, sources, transport mechanisms, and final destinations. Existing studies predominantly focus on a limited subset of well-known PFAS compounds, leaving numerous other PFAS variants understudied. Key findings reveal that diverse PFAS, from well-known perfluoroalkyl acids to emerging alternatives like fluorotelomers and fluoropolymers, undergo transformations leading to the accumulation of terminal perfluoroalkyl acids in aquatic environments. However, the majority of studies overlook this diversity, concentrating on specific PFAS subsets and overlooking crucial transportation pathways. To advance our understanding, future research should prioritise detecting and characterising understudied PFAS and their interactions in various aquatic compartments. More specialised analytical approaches are needed to accurately assess PFAS concentrations and behaviours across interfaces and between aquatic compartments, enhancing our ability to mitigate PFAS-related environmental risks effectively. This review consolidates current knowledge on PFAS dynamics in aquatic environments, emphasising the need for comprehensive assessments of PFAS diversity and behaviours to guide effective environmental management strategies and future research.