An Overview of the Formation of PFOA and PFOS in Drinking-Water and Wastewater Treatment Processes

Per‐ and Polyfluoroalkyl Substances in Water (2008–2022) and Fish (2015–2022) in The Netherlands: Spatiotemporal Trends, Fingerprints, Mass Discharges, Sources, and Bioaccumulation Factors

“…Therefore, most likely the fingerprints are primarily determined by emission patterns instead: Higher emissions will cause higher aqueous concentrations. In addition, the PFOA peak and the relatively high concentrations of PFOS may partly be explained by degradation of certain other PFAS (“precursors”) into these persistent C 8 degradation products (Liu & Mejia Avendaño, 2013; Prevedouros et al, 2006; Xiao, 2022), next to the fact that they are (still) being released themselves.…”

“…Also, in the author's opinion (considering the data variability caused by, e.g., seasonal fluctuations and analytical uncertainty), the value and applicability of any such trends are very limited. However, for PFOA and PFOS, clear and substantial long-term temporal trends are visible (see Figure 3 The observation that the concentrations of both compounds more or less stabilized 6 to 7 years ago, at least in the Rhine and Meuse, may be due to the following: (i) several (essential) applications of PFOS are still permitted; (ii) both compounds can be released during the production of other PFAS, during use or disposal of products still containing PFOS and PFOA (Ahrens & Bundschuh, 2014), and from historically contaminated environmental compartments (e.g., soils and sediments); and (iii) as mentioned before, both chemicals can be formed during the degradation of PFAS precursors (Liu & Mejia Avendaño, 2013;Prevedouros et al, 2006;Xiao, 2022).…”

“…Consequently, environmental emissions of PFAS are very large, although exact numbers are lacking (Glüge et al, 2020). The extensive emissions, combined with the fact that PFAS either are very persistent or break down into very persistent degradation products (Liu & Mejia Avendaño, 2013;Prevedouros et al, 2006;Xiao, 2022), cause the chemicals to be ubiquitous in the environment (Evich et al, 2022). The aquatic environment plays a central role in the transport and fate of PFAS following their emissions.…”

Tissue Bioconcentration Pattern and Biotransformation of Per-Fluorooctanoic Acid (PFOA) in Cyprinus carpio (European Carp)—An Extensive In Vivo Study

“…Due to their structural characteristics, PFAS possess high polarity, thermal, and chemical stability, which makes them suitable for a wide range of applications, such as surfactants in textile surface coatings, soil repellents, food packaging, cleaning products, cosmetics, medical devices, pesticides, and firefighting foams [ 2 ]. Consequently, they become persistent and difficult to manage in various environments, such as soil [ 3 ], water [ 4 , 5 ], air [ 6 ], sediment [ 7 , 8 , 9 ], surface water [ 7 , 9 , 10 , 11 ], rainwater [ 12 ], snow [ 12 , 13 ], wastewater [ 10 , 14 , 15 ], sewage sludge [ 10 ], food [ 16 , 17 , 18 ], biota [ 10 , 11 ], and even in the human body [ 1 , 19 , 20 , 21 ].…”

“…PFOA is released into the environment through industrial production and ends up in the food chain, similar to the rest of the persistent pollutants. The main ways by which PFOA can accumulate in human bodies are food (fish and seafood, meat and meat products, eggs, milk, and dairy products) [ 25 , 26 , 27 ] and through water sources [ 4 , 5 ]. Toxicological studies have suggested that peroxisome proliferation, hepatotoxicity, carcinogenicity, immunotoxicity, lipid metabolism, and developmental toxicity may be associated with chemical exposure to PFAS, especially PFOA [ 28 , 29 ].…”