P-FASE: Advancing and integrating knowledge and data on PFAS sources, fate and risks for UK environments.

CONTEXT: Per-(poly)-fluorinated substances (PFAS) are a very large and varied group of chemicals. Commonly referred to as ‘forever chemicals’, the ability of PFAS to persist in the environment and accumulate in wildlife and humans has raised concerns, leading to some restrictions in their use. As new PFAS replace banned substances, there is an ongoing lack of understanding as to how these new and different substances move around and accumulate in the environment, and the effects they then have on plants, animals and humans. Robust models that can predict the behaviours and effects of old and new PFAS are needed to allow risks to be properly characterised. CHALLENGE: PFAS are a diverse set of chemicals with different structures and functional groups. There are currently major gaps in our knowledge of how different PFAS occur and behave in the environment. For example, we do not know all the sources of these chemicals; how their different properties affect how long they persist and transform; where in the environment the various PFAS forms go; and how they accumulate in and affect organisms. Fate and exposure modelling is an essential approach for predicting and assessing the movement and bioavailability of chemicals in the environment. Any PFAS-specific fate model needs to be built from compound relevant knowledge of sources, behaviours, exposures and ecotoxicological effects. Building such a comprehensive fate and exposure model would allow us to better predict environmental concentrations of varied PFAS in our environment, providing key information towards the assessment of environmental risk. AIM: Our project will develop a model (P-FASE: PFAS Fate And Speciation in the Environment) specifically designed for predicting PFAS concentrations in the environment and biota across space and time. Our interdisciplinary approach will integrate knowledge and data on PFAS emission sources, how the physical and chemical properties of different PFAS influence their behaviour and movement within, and between, air, soil, surface water and groundwater; and the extent to which species are exposed to, and affected by, the concentrations they encounter. FIT TO SCOPE: Using state-of-the-art techniques to measure targeted PFAS compounds and total organic fluorine (TOF) in our experimental and environmental samples, we will track PFAS compounds in air, water, soils and biotic compartments. We will develop models of relationships between PFAS structures and their degradation and mobility in the environment and uptake by plants and animals in different environmental compartments. P-FASE will combine this with knowledge of emission pathways allowing predictions of PFAS distribution and concentrations in the environment, as well as bioavailability and bioaccumulation. Through experimental studies and field campaigns we will also investigate the effects of PFAS exposure, using biochemical and molecular biology approaches to assess whether these substances have impacts on species with different physiological and ecological traits. This will help us establish more reliable and relevant thresholds for ecological effects. APPLICATIONS/BENEFITS: We will deliver an open-source model specifically designed for predicting PFAS fate and exposure in the environment. Key policy makers and regulators facing the challenge of understanding the risk of diverse PFAS will have access to this model and the underlying data. Thus, our data and tools will support ongoing efforts to improve the regulatory management of this complex and diverse group of environmental pollutants.