Literature review to guide the PFAS field survey in the Westerschelde in 2023

A literature review was performed to create an overview of the available knowledge on the potential ecological impact of PFAS compounds. This will be used to guide the specific field survey for PFAS in the Westerschelde estuary that is planned for spring and autumn 2023, and to facilitate interpretation of the data that will be collected. The results of this review are summarised in overviews of relevant European Quality Standards, and effect concentrations of PFAS compounds in water and tissue of invertebrates, fish, birds and mammals. This can help interpretation of results of PFAS analyses in environmental samples. Further it was listed what PFAS have been detected in biota from the Westerschelde during previous research. Advice for the Westerschelde field campaign The WMR standard list of PFAS scheduled for analysis covers the most relevant PFAS compounds, based on the information from this review. It should be noted that since the field campaign in 2023 is restricted to analyses in biota it is, based on previous campaigns in the Westerschelde, likely that compounds PFBS, PFTeDA, PFDS, PFPeA, PFHxA and PFHpA will not be detected in the samples above limits of quantification. However, since these compounds are part of the standard list they can be analysed without additional costs. The additional measurement of biochemical biomarkers may be of interest for the Westerschelde field campaign, as they can be induced by or be a consequence of exposure to PFAS. However, other environmental parameters and contaminants can also play a role in these cases and clear relationships between PFAS and marker could be hard to detect. Nonetheless, we advise to perform a selection of biomarkers in blood samples from seals and harbour porpoises. This concerns biomarkers that are routinely applied in medical research to check functioning of the liver, kidneys, thyroid and the lipid metabolism that in humans can be disrupted by PFAS exposure.