Non-polymer PFAS can build up in blood protein of animals, and is not always removed quickly. This means that predators eating PFAS-contaminated food will have higher levels in their bloodstream, and concentrations can increase up the food chain. Studies suggest that build up of PFAS is similar to those of other Persistent Organic Pollutants such as DDT.PFAS are estimated to be settling in arctic regions at rates of tens to hundreds of kilograms per year (25-850kg per year), depending on the specific PFAS chemical in question. Certain PFAS are released as gases to the environment and are blown a long way by wind and air currents in the atmosphere,. These gas PFAS will over time degrade to more persistent chemicals like PFOS and PFOA. This may be one reason why PFAS of environmental concern have been found in remote regions such as the Arctic as well as near PFAS production sitesPFAS including PFOS and PFOA have been found in air samples around Europe. The chemicals are found in small quantities, but appear in almost all samples tested. PFAS enters the atmosphere both from factories and the air inside our homes. https://www.ncbi.nlm.nih.gov/pubmed/17554424 PFAS is found in treated waste water from industrial and domestic sources and has been found in both rivers and groundwater. Conventional drinking water processes will not remove PFAS.PFAS-coated clothes that are thrown away will often end up either incinerated or in landfill. Unless incinerated at very high temperatures (>1000oC), fluorinated polymers could release more harmful PFAS during burning. PFAS of environmental concern have also been found in landfill leachate. Non-polymer PFAS are used in the production of fluorinated polymers. The manufacture of stain-resistant finishes generally releases these PFASs into the environment, both by air and water emissions. They are very hard to remove during water treatment. Workers in textiles factories are some of the population most exposed to these potentially harmful chemicals. Small quantities of PFAS will be removed during wash and wear of products containing PFAS. This includes fluorinated polymers used on stain-resistant coatings, and non-polymers that remain on clothes after production (Lassen et al. 2015).Most UK waste still ends up in landfill, and this includes PFAS-containing products. Studies have shown that the liquid coming from landfills (known as leachate) often contain non-polymer PFAS chemicals. In the USA the total quantities were estimated at 563-638 kg in 2013. To properly break down PFAS chemicals high temperature (1000oC or more) incineration is recommended. Incineration of municipal waste does not necessarily reach these temperatures (min temp. required is 850oC), and the incomplete breakdown could release non-polymer PFAS.Wash and wear of clothing that contains PFAS-based stain-resistant or water repellent finishes release PFAS to the environment. Coatings are thought to lose effectiveness after 20-30 washes. This can include non-polymer PFAS, remnant from production or as a break-down product of side-chain polymers (Lassen et al. 2015). The manufacture of stain-resistant finishes releases PFAS into the environment, both by air and water emissions. PFAS are very hard to remove during water treatment. Industrial emissions are estimated to be the biggest source of these chemicals to the environment.

References for PFAS Factsheet

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  2. US EPA. (2022). Human Health Toxicity Assessments for GenX Chemicals | US EPA. [online] Available at: <https://www.epa.gov/chemical-research/human-health-toxicity-assessments-genx-chemicals> [Accessed 3rd August 2022].
  3. Domingo, J. and Nadal, M., (2019). Human exposure to per- and polyfluoroalkyl substances (PFAS) through drinking water: A review of the recent scientific literature. Environmental Research, 177, p.108648
  4. Garnett, J., Halsall, C., Winton, H., Joerss, H., Mulvaney, R., Ebinghaus, R., Frey, M., Jones, A., Leeson, A. and Wynn, P., (2022). Increasing Accumulation of Perfluorocarboxylate Contaminants Revealed in an Antarctic Firn Core (1958–2017). Environmental Science& Technology. DOI: 10.1021/acs.est.2c02592.
  5. D’Ambro, E. and Murphy, B., (2021). Modeling PFAS Air Emissions, Deposition, and Chemistry. Webinar
  6. Chemical investigations programme Data access portal. (2022). Chemical investigations programme Data access portal. [online] Available at: <https://ukwir.org/eng/sign-up-and-access-the-chemical-investigations-programme-data-access-portal> [Accessed 2 August 2022].
  7. Walker, L.A., Potter, P.E.D., Bruguera, S.L, Shore, R.F. (2015). Perfluorinated compound (PFC) concentrations in northern gannet eggs 1977-2014: a Predatory Bird Monitoring Scheme (PBMS) report. Centre for Ecology & Hydrology, Lancaster, UK. 18 pp.   https://pbms.ceh.ac.uk/sites/default/files/PBMS_Gannet_PFCs_report_2013.pdf
  8. Fernandes, A.R. et al. (2018) Occurrence and spatial distribution of chemical contaminants in edible fish species collected from UK and proximate marine waters. Environmental International, 114, 219-230
  9. Law, R. J. et al. (2008), PFOS and PFOA in the livers of harbour porpoises (Phocoena phocoena) stranded or bycaught around the UK. Marine Pollution Bulletin, 56, 792-797.
  10. O’Rourke, E. et al. (2022). Anthropogenic Drivers of Variation in Concentrations of Perfluoroalkyl Substances in Otters (Lutra lutra) from England and Wales. Environmental Science & Technology, 56(3), 1675-1687. DOI: 10.1021/acs.est.1c05410
  11. https://www.ewg.org/interactive-maps/pfas_in_wildlife/map/
  12. HBM4EU work on Per- and Polyfluroalkyl Substances (PFAS). https://www.hbm4eu.eu/wp-content/uploads/2018/12/HBM4EU_PFAS_brief_v2.pdf [Accessed: 8th August 2022]
  13. European Food Safety Authority. (2022) PFAS in food: EFSA assesses risks and sets tolerable intake. [online] Available at: <https://www.efsa.europa.eu/en/news/pfas-food-efsa-assesses-risks-and-sets-tolerable-intake> [Accessed 8 August 2022].
  14. De Silva, A. O. et al. (2021) ‘PFAS Exposure Pathways for Humans and Wildlife: A Synthesis of Current Knowledge and Key Gaps in Understanding’, Environmental Toxicology and Chemistry, 40(3), pp. 631–657. doi: 10.1002/ETC.4935.
  15. Land, M. et al. (2018) What is the effect of phasing out long-chain per- and polyfluoroalkyl substances on the concentrations of perfluoroalkyl acids and their precursors in the environment? A systematic review, Environmental Evidence. BioMed Central. doi: 10.1186/s13750-017-0114-y.
  16. https://www.hse.gov.uk/reach/assets/docs/pfas-rmoa.pdf

Further Reading

– British Geological Society (2018) Emerging contaminants in groundwater.
– Pan Y, et al. (2018). Worldwide Distribution of Novel Perfluoroether Carboxylic and Sulfonic Acids in Surface Water. Environ Sci Technol. 2018 Jul 17;52(14):7621-7629. doi: 10.1021/acs.est.8b00829. Epub 2018 May 11. PMID: 29749740.
−  Environment Agency (2019). Perfluorooctane sulfonate (PFOS) and related substances: sources, pathways and environmental data.