Seabirds as sentinels for per- and polyfluoroalkyl substances exposure - A global analysis after year 2010

Per- and polyfluoroalkyl substances (PFAS) are a well-known group of persistent pollutants found in terrestrial and aquatic environments. Numerous international and national regulations govern the use of the PFAS that are potentially the most toxic and bioaccumulative. Due to their widespread use, PFAS leak into watersheds and can contaminate environments and food webs far from their source, including in the open ocean. Seabirds are exposed to PFAS through seawater and their diet, resulting in bioaccumulation and potential adverse effects. This article seeks to review the current literature on PFAS contamination in seabirds worldwide, and explore the relationship between PFAS contamination and proximity of the colony to urban areas. We analyzed scientific literature published between 2013 and 2025, using samples collected since 2010, to uncover current patterns of PFAS bioaccumulation in selected groups of seabird after the introduction of PFAS regulations. Perfluorooctanesulfonic acid (PFOS) remains the dominant compound in the profile of most species analyzed, followed by other compounds with high bioaccumulation potential, such as perfluorotridecanoic acid (PFTrDA) and perfluoroundecanoic acid (PFUdA). Plasma and eggs were the most commonly selected matrices, with the highest PFAS concentrations found in the Laridae, Procellariidae and Alcidae families. We found a positive correlation between urbanisation and the concentrations of all six PFAS analyzed in plasma and four in eggs across all seabirds, examined worldwide. There are still significant gaps in the coverage of species, particularly those threatened with extinction, and geographical areas, as well as in the analysis of new compounds replacing phased-out PFAS.