{{Short description|Class of perfluorinated chemical compounds}} {{other uses}} {{Use American English|date=May 2023}} {{Use dmy dates|date=May 2023}} '''Per- and polyfluoroalkyl substances''' ('''PFAS'''<ref>{{cite web |date=2025-01-07 |title=Per- and Polyfluoroalkyl Substances (PFAS) |url=https://www.epa.gov/pfas |publisher=U.S. Environmental Protection Agency (EPA) |location=Washington, D.C.}}</ref> or '''PFASs'''<ref name=Terminology/>) are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain.<ref name="Schymanski-2023">{{Cite journal |last1=Schymanski |first1=Emma |last2=Zhang |first2=Jian |last3=Thiessen |first3=Paul |last4=Chirsir |first4=Parviel |last5=Kondic |first5=Todor |last6=Bolton |first6=Evan |date=23 October 2023 |title=Per- and Polyfluoroalkyl Substances (PFAS) in PubChem: 7 Million and Growing |journal=Environmental Science and Technology |volume=57 |issue=44 |pages=16918–16928 |bibcode=2023EnST...5716918S |doi=10.1021/acs.est.3c04855 |pmc=10634333 |pmid=37871188}}</ref> The high chemical and thermal stability of PFAS leads to these compounds having long environmental lifetimes, hence the common nickname "'''forever chemicals'''".<ref>{{Cite news |last=Geddes |first=Linda |date=2024-05-25 |title=What are PFAS? Everything you need to know about the 'forever chemicals' surrounding us every day |url=https://www.theguardian.com/environment/article/2024/may/25/what-are-pfas-everything-you-need-to-know-about-the-forever-chemicals-surrounding-us-every-day |access-date=2025-02-11 |work=The Guardian |issn=0261-3077}}</ref><ref>{{Cite web |date=2023-10-19 |title=Can we take the 'forever' out of forever chemicals? |url=https://www.bbc.com/future/article/20231016-cleaning-up-pfas-forever-chemicals |access-date=2025-02-11 |publisher=BBC}}</ref><ref>{{cite news |date=January 2, 2018 |title=Opinion: These toxic chemicals are everywhere — even in your body. And they won't ever go away |url=https://www.washingtonpost.com/opinions/these-toxic-chemicals-are-everywhere-and-they-wont-ever-go-away/2018/01/02/82e7e48a-e4ee-11e7-a65d-1ac0fd7f097e_story.html |url-status=live |archive-url=https://web.archive.org/web/20190509013619/https://www.washingtonpost.com/opinions/these-toxic-chemicals-are-everywhere-and-they-wont-ever-go-away/2018/01/02/82e7e48a-e4ee-11e7-a65d-1ac0fd7f097e_story.html |archive-date=May 9, 2019 |newspaper=The Washington Post |issn=0190-8286}}</ref>
Widespread use of PFAS began in 1938 with the invention of Teflon, a fluoropolymer coating that resists heat, oil, stains, grease, and water. Since their inception, over 7 million individual PFAS compounds have been created.<ref name="Schymanski-2023" /> They are used in a wide variety of products including waterproof fabric, yoga pants, carpets, shampoo, mobile phone screens, wall paint, furniture, adhesives, food packaging, firefighting foam, electrical insulation, and cosmetics.
Exposure to PFAS, some of which are carcinogens or endocrine disruptors, has been linked to diseases and health conditions including cancers, ulcerative colitis, thyroid disease, suboptimal antibody response or decreased immunity, decreased fertility, hypertensive disorders in pregnancy, fetal and child developmental issues, obesity, and high cholesterol. PFAS are often found in rain, drinking water, groundwater, and wastewater, especially in areas near airports and air force bases due to contamination from PFAS containing firefighting foam. Further, crop uptake of PFAS and bioaccumulation of PFAS into fish, livestock, and wildlife can act as potential routes of human exposure. Due to health and environmental concerns associated many PFAS such as PFOA and PFOS, PFAS use has been regulated internationally by the Stockholm Convention on Persistent Organic Pollutants since 2009. However, it is challenging to assess the potential risks of all PFAS due to the large number of compounds that exist.
In some jurisdictions, such as the European Union, further reductions and phase-outs of PFAS are planned. Several companies are voluntarily ending or planning to end the sale of PFAS and PFAS-containing products due to health and litigation concerns. However, major producers and users such as the United States, Israel, and Malaysia have not ratified the agreement and the chemical industry has lobbied governments to reduce regulations.
== Definition ==
thumb|A sample of PFOA, appearing here as a white solid.
Per- and polyfluoroalkyl substances are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. Different organizations use different definitions for PFAS, leading to estimates of between 8,000 and 7 million chemicals within the group. The EPA toxicity database, DSSTox, lists 14,735 unique PFAS chemical compounds.<ref>{{cite web |title=PFAS structures in DSSTox |url=https://comptox.epa.gov/dashboard/chemical-lists/PFASSTRUCT |archive-url=https://web.archive.org/web/20220803134926/https://comptox.epa.gov/dashboard/chemical-lists/PFASSTRUCT |archive-date=2022-08-03 |website=CompTox Chemicals Dashboard |publisher=United States Environmental Protection Agency}} "List consists of all DTXSID records with a structure assigned, and using a set of substructural filters based on community input."{{Date missing}}</ref><ref>{{cite journal |last1=Gaines |first1=Linda G. T. |last2=Sinclair |first2=Gabriel |last3=Williams |first3=Antony J. |date=2023 |title=A proposed approach to defining per- and polyfluoroalkyl substances (PFAS) based on molecular structure and formula |journal=Integrated Environmental Assessment and Management |volume=19 |issue=5 |pages=1333–1347 |bibcode=2023IEAM...19.1333G |doi=10.1002/ieam.4735 |issn=1551-3777 |pmc=10827356 |pmid=36628931}}</ref> 7 million are listed in PubChem.<ref name="Schymanski-2023" />
An early definition required that PFAS contain at least one perfluoroalkyl moiety, {{chem2|\sC_{''n''}F_{2''n''+1}|}}.<ref name="Buck2011">{{cite journal |display-authors=6 |vauthors=Buck RC, Franklin J, Berger U, Conder JM, Cousins IT, de Voogt P, Jensen AA, Kannan K, Mabury SA, van Leeuwen SP |date=October 2011 |title=Perfluoroalkyl and polyfluoroalkyl substances in the environment: terminology, classification, and origins |journal=Integrated Environmental Assessment and Management |volume=7 |issue=4 |pages=513–541 |bibcode=2011IEAM....7..513B |doi=10.1002/ieam.258 |pmc=3214619 |pmid=21793199}}</ref> Beginning in 2021, the OECD expanded its terminology, stating that "PFAS are defined as fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom (without any H/Cl/Br/I atom attached to it), i.e., with a few noted exceptions, any chemical with at least a perfluorinated methyl group (''{{chem2|\sCF3}}'') or a perfluorinated methylene group ({{chem2|\sCF2\s}}) is a PFAS."<ref name="Terminology">{{cite book |title=Reconciling Terminology of the Universe of Per- and Polyfluoroalkyl Substances: Recommendations and Practical Guidance |date=2021 |publisher=OECD |isbn=978-92-64-51128-6 |series=OECD Series on Risk Management of Chemicals |page=23 |doi=10.1787/e458e796-en}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Wang Z, Buser AM, Cousins IT, Demattio S, Drost W, Johansson O, Ohno K, Patlewicz G, Richard AM, Walker GW, White GS, Leinala E |date=December 2021 |title=A New OECD Definition for Per- and Polyfluoroalkyl Substances |journal=Environmental Science & Technology |volume=55 |issue=23 |pages=15575–15578 |bibcode=2021EnST...5515575W |doi=10.1021/acs.est.1c06896 |pmid=34751569 |s2cid=243861839 |doi-access=free}}</ref>
The United States Environmental Protection Agency (EPA) defines PFAS more narrowly in the ''Drinking Water Contaminant Candidate List 5'' as substances that contain "at least one of the following three structures: {{chem2|R\sCF2\sCF(R')R"}}, where both the {{chem2|\sCF2\s}} and {{chem2|\sCF\s}} moieties are saturated carbons, and none of the R groups can be hydrogen; {{chem2|R\sCF2\sO\sCF2\s(R')}}, where both the {{chem2|\sCF2\s}} moieties are saturated carbons, and none of the R groups can be hydrogen; or {{chem2|CF3\sC\s(CF3)RR'}}, where all the carbons are saturated, and none of the R groups can be hydrogen.<ref>EPA. (2022-11-14). "Drinking Water Contaminant Candidate List 5–Final." ''Federal Register,'' {{USFR|87|68060}}</ref> A summary table of some PFAS definitions is provided in Hammel et al (2022).<ref>{{Cite journal |last1=Hammel |first1=Emily |last2=Webster |first2=Thomas F. |last3=Gurney |first3=Rich |last4=Heiger-Bernays |first4=Wendy |date=April 2022 |title=Implications of PFAS definitions using fluorinated pharmaceuticals |journal=iScience |volume=25 |issue=4 |article-number=104020 |bibcode=2022iSci...25j4020H |doi=10.1016/j.isci.2022.104020 |issn=2589-0042 |pmc=8933701 |pmid=35313699}}</ref>
=== Sample chemicals ===
[[File:Perfluorooctanesulfonic acid.svg|class=skin-invert-image|thumb|upright=1.15|Skeletal structure of Perfluorooctanesulfonic acid (PFOS), an effective, persistent and bioaccumulative fluorosurfactant]]
Common PFAS include:<ref>{{cite web |date=August 22, 2017 |title=Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS): Frequently Asked Questions |url=https://www.atsdr.cdc.gov/pfas/docs/pfas_fact_sheet.pdf |url-status=live |archive-url=https://web.archive.org/web/20201018004606/https://www.atsdr.cdc.gov/pfas/docs/pfas_fact_sheet.pdf |archive-date=October 18, 2020 |publisher=Centers for Disease Control}}</ref><ref>{{cite web |date=March 11, 2019 |title=ORD subset of PFAS with ongoing work methods; CompTox Chemicals Dashboard |url=https://www.epa.gov/sites/default/files/2019-05/documents/pfas_research_list.pdf |url-status=live |archive-url=https://web.archive.org/web/20190715212833/https://www.epa.gov/sites/production/files/2019-05/documents/pfas_research_list.pdf |archive-date=July 15, 2019 |publisher=United States Environmental Protection Agency}}</ref>
* Perfluoroalkyl carboxylic acids (PFCAs), such as trifluoroacetic acid (TFA) * Perfluorosulfonic acids (PFSAs), such as perfluorooctanesulfonic acid (PFOS) * Precursors to PFCAs, such as fluorotelomers, including as fluorotelomer alcohols (FTOHs) * Precursors to PFSAs, such as perfluorobutane sulfonamide (H-FBSA), perfluorooctanesulfonamide (PFOSA), perfluorobutanesulfonyl fluoride (PFOSB) or perfluorooctanesulfonyl fluoride (PFOSF) * Fluoropolymers such as polytetrafluoroethylene (PTFE, aka Teflon)
== Uses ==
=== Products ===
PFAS are used to produce fluoropolymers by emulsion polymerization. Because they resist heat, oil, stains, grease, and water, they are ingredients in stain repellents, polishes, paints, and coatings.<ref name="long">{{cite journal |vauthors=Renner R |date=January 2006 |title=The long and the short of perfluorinated replacements |journal=Environmental Science & Technology |volume=40 |issue=1 |pages=12–13 |bibcode=2006EnST...40...12R |doi=10.1021/es062612a |pmid=16433328 |doi-access=free}}</ref> They came into use with the invention of Teflon in 1938. They are used in products including waterproof fabric such as nylon, yoga pants, carpets, shampoo, feminine hygiene products, mobile phone screens, wall paint, furniture, adhesives, food packaging, firefighting foam, and the insulation of electrical wires.<ref>{{cite web |date=2024-10-03 |title=PFAS Explained |url=https://www.epa.gov/pfas/pfas-explained |publisher=United States Environmental Protection Agency}}</ref><ref>{{Cite magazine |last=Kluger |first=Jeffrey |date=May 19, 2023 |title=All The Stuff in Your Home That Might Contain PFAS 'Forever Chemicals' |url=https://time.com/6281242/pfas-forever-chemicals-home-beauty-body-products/ |magazine=Time (magazine) |access-date=22 June 2024 |archive-date=27 February 2025 |archive-url=https://web.archive.org/web/20250227154646/https://time.com/6281242/pfas-forever-chemicals-home-beauty-body-products/ }}</ref><ref>{{cite web |date=17 January 2024 |title=PFAS and Your Health |url=https://www.atsdr.cdc.gov/pfas/about/?CDC_AAref_Val=https://www.atsdr.cdc.gov/pfas/health-effects/overview.html |access-date=12 December 2024 |publisher=Centers for Disease Control and Prevention}}</ref> PFAS are used by the cosmetic industry in the majority of cosmetics and personal care products, including lipstick, eye liner, mascara, foundation, concealer, lip balm, blush, and nail polish.<ref>{{cite news |last=Perkins |first=Tom |date=June 15, 2021 |title=Toxic 'forever chemicals' widespread in top makeup brands, study finds |url=https://www.theguardian.com/fashion/2021/jun/15/pfas-makeup-forever-chemicals |url-status=live |archive-url=https://web.archive.org/web/20210707070534/https://www.theguardian.com/fashion/2021/jun/15/pfas-makeup-forever-chemicals |archive-date=July 7, 2021 |work=The Guardian}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Whitehead HD, Venier M, Wu Y, Eastman E, Urbanik S, Diamond ML, Shalin A, Schwartz-Narbonne H, Bruton TA, Blum A, Wang Z |date=15 June 2021 |title=Fluorinated Compounds in North American Cosmetics |journal=Environmental Science & Technology Letters |volume=8 |issue=7 |pages=538–544 |bibcode=2021EnSTL...8..538W |doi=10.1021/acs.estlett.1c00240 |hdl=20.500.11850/495857 |s2cid=236284279 |hdl-access=free}}</ref> Pesticides including fluazinam and flufenacet break down to produce trifluoroacetic acid.<ref>{{cite journal |last1=Arp |first1=Hans Peter H. |last2=Gredelj |first2=Andrea |last3=Glüge |first3=Juliane |last4=Scheringer |first4=Martin |last5=Cousins |first5=Ian T. |date=12 November 2024 |title=The Global Threat from the Irreversible Accumulation of Trifluoroacetic Acid (TFA) |journal=Environmental Science & Technology |volume=58 |issue=45 |pages=19925–19935 |bibcode=2024EnST...5819925A |doi=10.1021/acs.est.4c06189 |pmc=11562725 |pmid=39475534}}</ref><ref>{{cite journal |author1=European Food Safety Authority |date=September 2024 |title=Peer review of the pesticide risk assessment of the active substance flufenacet |journal=EFSA Journal |volume=22 |issue=9 |article-number=e8997 |doi=10.2903/j.efsa.2024.8997 |pmc=11427894 |pmid=39345971}}</ref><ref>{{cite news |title=Denmark Bans Pesticides Containing Problematic PFAS Ingredients {{!}} Food Safety |url=https://www.food-safety.com/articles/10543-denmark-bans-pesticides-containing-problematic-pfas-ingredients |access-date=11 November 2025 |work=Food Safety Magazine |language=en}}</ref>
=== Fluorosurfactants ===
[[File:A water droplet DWR-coated surface2 edit1 (cropped).jpg|thumb|upright=1.15|alt=A shiny spherical drop of water on blue cloth|Fluorine-containing durable water repellent makes a fabric water-resistant.]]
''Fluorinated surfactants'' or ''fluorosurfactants'' are a subgroup of PFAS characterized by a hydrophobic fluorinated "tail" and a hydrophilic "head" that behave as surfactants. These are more effective at reducing the surface tension of water than comparable hydrocarbon surfactants.<ref>{{cite journal |last1=Kovalchuk |first1=N M |last2=Trybala |first2=A |last3=Starov |first3=V |last4=Matar |first4=O |last5=Ivanova |first5=N |date=August 2014 |title=Fluoro- vs hydrocarbon surfactants: why do they differ in wetting performance? |journal=Advances in Colloid and Interface Science |volume=210 |pages=65–71 |doi=10.1016/j.cis.2014.04.003 |hdl=10044/1/26321 |pmid=24814169 |hdl-access=free}}</ref>
Fluorosurfactants tend to concentrate at the phase interfaces.<ref>{{Cite journal |last1=Schaefer |first1=Charles E. |last2=Culina |first2=Veronika |last3=Nguyen |first3=Dung |last4=Field |first4=Jennifer |date=2019-11-05 |title=Uptake of Poly- and Perfluoroalkyl Substances at the Air–Water Interface |url=https://pubs.acs.org/doi/10.1021/acs.est.9b04008 |journal=Environmental Science & Technology |volume=53 |issue=21 |pages=12442–12448 |bibcode=2019EnST...5312442S |doi=10.1021/acs.est.9b04008 |issn=0013-936X |pmid=31577432 |url-access=subscription}}</ref> Fluorocarbons are both lipophobic and hydrophobic, repelling both oil and water. Their lipophobicity results from the relative lack of London dispersion forces compared to hydrocarbons, a consequence of fluorine's large electronegativity and small bond length, which reduce the polarizability of the surfactants' fluorinated molecular surface. Fluorosurfactants are more stable than hydrocarbon surfactants due to the stability of the carbon–fluorine bond. Perfluorinated surfactants persist in the environment for the same reason.<ref name="Evidence">{{cite journal |display-authors=6 |vauthors=Munoz G, Budzinski H, Babut M, Drouineau H, Lauzent M, Menach KL, Lobry J, Selleslagh J, Simonnet-Laprade C, Labadie P |date=August 2017 |title=Evidence for the Trophic Transfer of Perfluoroalkylated Substances in a Temperate Macrotidal Estuary |url=https://hal.archives-ouvertes.fr/hal-02067250/file/Main%20text_R1_2017-06-27.pdf |journal=Environmental Science & Technology |volume=51 |issue=15 |pages=8450–8459 |bibcode=2017EnST...51.8450M |doi=10.1021/acs.est.7b02399 |pmid=28679050}}</ref>
Fluorosurfactants such as PFOS, PFOA, and perfluorononanoic acid (PFNA) have caught the attention of regulatory agencies because of their persistence, toxicity, and widespread occurrence in the blood of general populations.<ref>{{cite journal |vauthors=Calafat AM, Wong LY, Kuklenyik Z, Reidy JA, Needham LL |date=November 2007 |title=Polyfluoroalkyl chemicals in the U.S. population: data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and comparisons with NHANES 1999-2000 |journal=Environmental Health Perspectives |volume=115 |issue=11 |pages=1596–1602 |bibcode=2007EnvHP.115.1596C |doi=10.1289/ehp.10598 |doi-broken-date=4 March 2026 |pmc=2072821 |pmid=18007991}}</ref><ref>{{cite journal |vauthors=Wang Z, Cousins IT, Berger U, Hungerbühler K, Scheringer M |year=2016 |title=Comparative assessment of the environmental hazards of and exposure to perfluoroalkyl phosphonic and phosphinic acids (PFPAs and PFPiAs): Current knowledge, gaps, challenges and research needs |journal=Environment International |volume=89-90 |pages=235–247 |bibcode=2016EnInt..89..235W |doi=10.1016/j.envint.2016.01.023 |pmid=26922149}}</ref>
=== Market ===
The market for PFAS was estimated to be US$28 billion in 2023. The majority are produced by 12 companies: 3M, AGC Inc., Archroma, Arkema, BASF, Bayer, Chemours, Daikin, Honeywell, Merck Group, Shandong Dongyue Chemical, and Solvay.<ref>{{cite news |date=May 25, 2023 |title=The top 12 PFAS producers in the world and the staggering societal costs of PFAS pollution |url=https://chemsec.org/reports/the-top-12-pfas-producers-in-the-world-and-the-staggering-societal-costs-of-pfas-pollution/ |work=ChemSec}}</ref> Sales of PFAS, which cost approximately $20 per kilogram, generated a total industry profit of $4 billion per year on 16% profit margins in 2023.<ref name="cost">{{cite news |last=Perkins |first=Tom |date=May 12, 2023 |title=Societal cost of 'Forever Chemicals' About $17.5tn Across Global Economy—Report |url=https://www.theguardian.com/environment/2023/may/12/pfas-forever-chemicals-societal-cost-new-report |work=The Guardian}}</ref>
Many different consumer goods contain PFAS. Since the 1950s, they have been found in firefighting foam, non-stick cookware, cosmetics, shampoo, stain-resistant furniture and fabrics, food packaging, and water-repellent clothing.<ref>{{Cite web |title=What are PFAS? - EHN |url=https://www.ehn.org/what-are-pfas |access-date=2026-04-28 |website=www.ehn.org |language=en}}</ref> This can lead to contamination in a multitude of ways such as absorption by skin, consumption, and inhalation.<ref>{{Cite web |last=US EPA |first=OW |date=2021-10-14 |title=Our Current Understanding of the Human Health and Environmental Risks of PFAS |url=https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas |access-date=2026-04-28 |website=www.epa.gov |language=en}}</ref>
== Environmental effects ==
{{Pollution sidebar}}
===Prevalence in rain, soil, water bodies, and air=== In 2022, levels of at least four perfluoroalkyl acids (PFAAs) in rain water worldwide greatly exceeded the EPA's lifetime drinking water health advisories as well as comparable Danish, Dutch, and European Union safety standards, leading to the conclusion that "the global spread of these four PFAAs in the atmosphere has led to the planetary boundary for chemical pollution being exceeded".<ref>{{cite journal |vauthors=Cousins IT, Johansson JH, Salter ME, Sha B, Scheringer M |date=August 2022 |title=Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS) |journal=Environmental Science & Technology |publisher=American Chemical Society |volume=56 |issue=16 |pages=11172–11179 |bibcode=2022EnST...5611172C |doi=10.1021/acs.est.2c02765 |pmc=9387091 |pmid=35916421}}</ref> The most common PFAS found in the environment is Trifluoroacetic acid (TFA).<ref>{{Cite journal |last1=Arp |first1=Hans Peter H. |last2=Gredelj |first2=Andrea |last3=Glüge |first3=Juliane |last4=Scheringer |first4=Martin |last5=Cousins |first5=Ian T. |date=2024-11-12 |title=The Global Threat from the Irreversible Accumulation of Trifluoroacetic Acid (TFA) |journal=Environmental Science & Technology |volume=58 |issue=45 |pages=19925–19935 |bibcode=2024EnST...5819925A |doi=10.1021/acs.est.4c06189 |issn=0013-936X |pmc=11562725 |pmid=39475534}}</ref> Its presence is ubiquitous in the environment, especially in aquatic ecosystems, where it persists with increasing concentrations globally.<ref>{{Cite journal |last1=Hanson |first1=Mark L. |last2=Madronich |first2=Sasha |last3=Solomon |first3=Keith |last4=Sulbaek Andersen |first4=Mads P. |last5=Wallington |first5=Timothy J. |date=2024-10-01 |title=Trifluoroacetic Acid in the Environment: Consensus, Gaps, and Next Steps |url=https://academic.oup.com/etc/article/43/10/2091/7829385 |journal=Environmental Toxicology and Chemistry |volume=43 |issue=10 |pages=2091–2093 |bibcode=2024EnvTC..43.2091H |doi=10.1002/etc.5963 |issn=0730-7268 |pmid=39078279}}</ref>
It had been thought that PFAAs would eventually end up in the oceans, where they would be diluted over decades, but a field study published in 2021 by researchers at Stockholm University found that they are often transferred from water to air when waves reach land, are a significant source of air pollution, and eventually get into rain. The researchers concluded that pollution may impact large areas.<ref>{{Cite news |last=Perkins |first=Tom |date=18 December 2021 |title=PFAS 'forever chemicals' constantly cycle through ground, air and water, study finds |url=https://www.theguardian.com/environment/2021/dec/17/pfas-forever-chemicals-constantly-cycle-through-ground-air-and-water-study-finds |newspaper=The Guardian}}</ref><ref>{{cite journal |vauthors=Sha B, Johansson JH, Tunved P, Bohlin-Nizzetto P, Cousins IT, Salter ME |date=January 2022 |title=Sea Spray Aerosol (SSA) as a Source of Perfluoroalkyl Acids (PFAAs) to the Atmosphere: Field Evidence from Long-Term Air Monitoring |journal=Environmental Science & Technology |publisher=American Chemical Society |volume=56 |issue=1 |pages=228–238 |bibcode=2022EnST...56..228S |doi=10.1021/acs.est.1c04277 |pmc=8733926 |pmid=34907779}}</ref><ref>{{Cite journal |last1=Sha |first1=Bo |last2=Johansson |first2=Jana H. |last3=Salter |first3=Matthew E. |last4=Blichner |first4=Sara M. |last5=Cousins |first5=Ian T. |date=2024 |title=Constraining global transport of perfluoroalkyl acids on sea spray aerosol using field measurements |journal=Science Advances |volume=10 |issue=14 |article-number=eadl1026 |bibcode=2024SciA...10L1026S |doi=10.1126/sciadv.adl1026 |pmc=10997204 |pmid=38579007}}</ref> Soil is also contaminated and the chemicals have been found in remote areas such as Antarctica.<ref>{{cite news |last=McGrath |first=Matt |date=August 2, 2022 |title=Pollution: 'Forever chemicals' in rainwater exceed safe levels |url=https://www.bbc.com/news/science-environment-62391069 |work=BBC News}}</ref> Soil contamination can result in higher levels of PFAS found in foods such as white rice, coffee, and animals reared on contaminated ground.<ref>{{cite news |last=Perkins |first=Tom |date=2022-03-22 |title='I don't know how we'll survive': the farmers facing ruin in America's 'forever chemicals' crisis |url=https://www.theguardian.com/environment/2022/mar/22/i-dont-know-how-well-survive-the-farmers-facing-ruin-in-americas-forever-chemicals-crisis |access-date=2024-07-04 |newspaper=The Guardian |issn=0261-3077}}</ref><ref name="auto">{{Cite journal |last1=Wang |first1=Yuting |last2=Gui |first2=Jiang |last3=Howe |first3=Caitlin G. |last4=Emond |first4=Jennifer A. |last5=Criswell |first5=Rachel L. |last6=Gallagher |first6=Lisa G. |last7=Huset |first7=Carin A. |last8=Peterson |first8=Lisa A. |last9=Botelho |first9=Julianne Cook |last10=Calafat |first10=Antonia M. |last11=Christensen |first11=Brock |last12=Karagas |first12=Margaret R. |last13=Romano |first13=Megan E. |display-authors=4 |date=July 2024 |title=Association of diet with per- and polyfluoroalkyl substances in plasma and human milk in the New Hampshire Birth Cohort Study |journal=Science of the Total Environment |volume=933 |article-number=173157 |bibcode=2024ScTEn.93373157W |doi=10.1016/j.scitotenv.2024.173157 |issn=0048-9697 |pmc=11247473 |pmid=38740209}}</ref><ref>{{Cite news |last=Perkins |first=Tom |date=2024-07-04 |title=Coffee, eggs and white rice linked to higher levels of PFAS in human body |url=https://www.theguardian.com/environment/article/2024/jul/04/pfas-toxic-forever-chemicals-food |access-date=2024-07-04 |newspaper=The Guardian |issn=0261-3077}}</ref> In 2024, a worldwide study of 45,000 groundwater samples found that 31% of samples contained levels of PFAS that were harmful to human health; these samples were taken from areas not near any obvious source of contamination.<ref>{{cite news |last=Erdenesanaa |first=Delger |date=April 8, 2024 |title=PFAS 'Forever Chemicals' Are Pervasive in Water Worldwide |url=https://www.nytimes.com/2024/04/08/climate/pfas-forever-chemicals-water.html |url-access=limited |newspaper=The New York Times}}</ref>
Contamination has also been seen in water wells and other sources of drinking water. This contamination is seen in US, United Kingdom, Germany, Japan, and Canada, but information from most developing countries is nearly nonexistent.<ref>{{Cite journal |last1=Adewuyi |first1=Adewale |last2=Li |first2=Qilin |date=2024-09-01 |title=Emergency of per- and polyfluoroalkyl substances in drinking water: Status, regulation, and mitigation strategies in developing countries |journal=Eco-Environment & Health |volume=3 |issue=3 |pages=355–368 |bibcode=2024EcoEH...3..355A |doi=10.1016/j.eehl.2024.05.008 |issn=2772-9850 |pmc=11399586 |pmid=39281067}}</ref> The lack of information on PFAS contamination in developing countries, especially those in Africa, are due to structural socioeconomic inequality and primitive technological.<ref name="Aborode-2025">{{Cite journal |last1=Aborode |first1=A. T. |last2=Adesola |first2=R. O. |last3=Idris |first3=I. |last4=Sakariyau Adio |first4=W. |last5=Olapade |first5=S. |last6=Oluwafisayo |first6=G. |last7=Onifade |first7=I. A. |last8=Fakorede |first8=S. |last9=Bakare-Abidola |first9=T. |last10=Olaoye |first10=J. |last11=Ogunyemi |first11=A. D. |last12=Ogundijo |first12=O. A. |last13=Banwo |first13=O. G. |last14=Bakre |first14=A. A. |last15=Oladoye |first15=P. |display-authors=4 |date=2025 |title=Challenges Associated With PFAS Detection Method in Africa |journal=Environmental Health Insights |language=en |volume=19 |doi=10.1177/11786302241310430 |issn=1178-6302 |pmc=11694309 |pmid=39759477 |last16=Adegoye |first16=G. |last17=Jinadu |first17=N. A. |article-number=11786302241310430 |bibcode=2025EnvHI..1910430A }}</ref>
=== Bioaccumulation and biomagnification ===
;In marine species of the food web Bioaccumulation controls internal concentrations of pollutants, including PFAS, in individual organisms. When bioaccumulation is looked at in the perspective of the entire food web, it is called biomagnification, which is important to track because lower concentrations of pollutants in environmental matrices such as seawater or sediments, can very quickly grow to harmful concentrations in organisms at higher trophic levels, including humans. Notably, concentrations in biota can even be greater than 5000 times those present in water for PFOS and C<sub>10</sub>–C<sub>14</sub> PFCAs.<ref>{{cite journal |vauthors=Munoz G, Budinski H, Babut M, Drouineau H, Lauzent M, Menach KL |date=July 2017 |title=Evidence for the trophic transfer of perfluoroalkylated substances in a temperate macrotidal estuary |url=https://hal.archives-ouvertes.fr/hal-02067250/file/Main%20text_R1_2017-06-27.pdf |journal=Environ. Sci. Technol. |volume=51 |issue=15 |pages=8450–8459 |bibcode=2017EnST...51.8450M |doi=10.1021/acs.est.7b02399 |pmid=28679050}}</ref> PFAS can enter an organism by ingestion of sediment, through the water, or directly via their diet. It accumulates namely in areas with high protein content, in the blood and liver, but it is also found to a lesser extent in tissues.<ref>{{cite journal |display-authors=6 |vauthors=Ballutaud M, Drouineau H, Carassou L, Munoz G, Chevillot X, Labadie P, Budzinski H, Lobry J |date=March 2019 |title=EStimating Contaminants tRansfers Over Complex food webs (ESCROC): An innovative Bayesian method for estimating POP's biomagnification in aquatic food webs |url=https://hal.archives-ouvertes.fr/hal-02289120 |journal=The Science of the Total Environment |volume=658 |pages=638–649 |bibcode=2019ScTEn.658..638B |doi=10.1016/j.scitotenv.2018.12.058 |pmid=30580218 |s2cid=58660816}}</ref>
[[File:PFAS Biomagnification.png|thumb|upright=1.35 |left|'''Bioaccumulation of PFAS:''' PFAS from sediments and water can accumulate in marine organisms. Animals higher up the food chain accumulate more because they absorb PFAS in the prey they eat.]]
In a study done on a macrotidal estuary in Gironde, SW France, PFOA and PFNA were found to be highly bioaccumulative.<ref name="Evidence" /> PFOS, a long-chain sulfonic acid, was found at the highest concentrations relative to other PFAS measured in fish and birds in northern seas such as the Barents Sea and the Canadian Arctic.<ref>{{cite journal |vauthors=Martin JW, Mabury SA, Solomon KR, Muir DC |date=January 2003 |title=Bioconcentration and tissue distribution of perfluorinated acids in rainbow trout (''Oncorhynchus mykiss'') |journal=Environmental Toxicology and Chemistry |volume=22 |issue=1 |pages=196–204 |bibcode=2003EnvTC..22..196M |doi=10.1002/etc.5620220126 |pmid=12503765 |s2cid=12659454}}</ref> A global meta-analysis found that PFAS concentrations increase, on average, twofold with each trophic level, with substantial variation among compounds.<ref name="Ricolfi-2025" /> Notably, the industrial replacement compound F-53B exhibited the highest trophic magnification, exceeding that of several legacy PFAS it was intended to replace.<ref name="Ricolfi-2025">{{Cite journal |last1=Ricolfi |first1=Lorenzo |last2=Yang |first2=Yefeng |last3=Pottier |first3=Patrice |last4=Morrison |first4=Kyle |last5=Williams |first5=Coralie |last6=Pollo |first6=Pietro |last7=Hesselson |first7=Daniel |last8=Neely |first8=G. Gregory |last9=Taylor |first9=Matthew D. |last10=Nakagawa |first10=Shinichi |last11=Lagisz |first11=Malgorzata |display-authors=4 |date=2025-11-28 |title=Unravelling the magnitude and drivers of PFAS trophic magnification: a meta-analysis |journal=Nature Communications |language=en |volume=16 |issue=1 |article-number=10720 |bibcode=2025NatCo..1610720R |doi=10.1038/s41467-025-65746-4 |issn=2041-1723 |pmc=12663151 |pmid=41315316}}</ref>
A study published in 2023 analyzing 500 composite samples of fish fillets collected across the United States from 2013 to 2015 under the EPA's monitoring programs showed freshwater fish ubiquitously contain high levels of harmful PFAS, with a single serving typically significantly increasing the blood PFOS level.<ref>{{cite news |last=LaMotte |first=Sandee |date=January 17, 2023 |title=Locally caught fish are full of dangerous chemicals called PFAS, study finds |url=https://edition.cnn.com/2023/01/17/health/freshwater-fish-pfas-contamination-wellness/index.html |url-status=live |archive-url=https://web.archive.org/web/20230214213701/https://edition.cnn.com/2023/01/17/health/freshwater-fish-pfas-contamination-wellness/index.html |archive-date=14 February 2023 |work=CNN}}</ref><ref>{{cite journal |vauthors=Barbo N, Stoiber T, Naidenko OV, Andrews DQ |date=March 2023 |title=Locally caught freshwater fish across the United States are likely a significant source of exposure to PFOS and other perfluorinated compounds |journal=Environmental Research |volume=220 |article-number=115165 |bibcode=2023ER....22015165B |doi=10.1016/j.envres.2022.115165 |pmid=36584847 |s2cid=255248441 |doi-access=free}}</ref>
Bioaccumulation and biomagnification of PFAS in marine species such as fish and shellfish can have important impacts on human populations.<ref>{{cite journal |vauthors=Choi S, Kim JJ, Kim MH, Joo YS, Chung MS, Kho Y, Lee KW |date=June 2020 |title=Origin and organ-specific bioaccumulation pattern of perfluorinated alkyl substances in crabs |journal=Environmental Pollution |volume=261 |article-number=114185 |bibcode=2020EPoll.26114185C |doi=10.1016/j.envpol.2020.114185 |pmid=32114125 |s2cid=211727091}}</ref> PFAS have been frequently documented in both fish and shellfish that are commonly consumed by human populations,<ref name="edible">{{cite journal |vauthors=Fair PA, Wolf B, White ND, Arnott SA, Kannan K, Karthikraj R, Vena JE |date=April 2019 |title=Perfluoroalkyl substances (PFASs) in edible fish species from Charleston Harbor and tributaries, South Carolina, United States: Exposure and risk assessment |journal=Environmental Research |volume=171 |pages=266–277 |bibcode=2019ER....171..266F |doi=10.1016/j.envres.2019.01.021 |pmc=6943835 |pmid=30703622}}</ref> which poses health risks to humans and studies on the bioaccumulation in certain species are important to determine daily tolerable limits for human consumption, and where those limits may be exceeded causing potential health risks.<ref>{{Cite journal |vauthors=Teunen L, Bervoets L, Belpaire C, De Jonge M, Groffen T |date=March 29, 2021 |title=PFAS accumulation in indigenous and translocated aquatic organisms from Belgium, with translation to human and ecological health risk |journal=Environmental Sciences Europe |volume=33 |issue=1 |article-number=39 |bibcode=2021ESEur..33...39T |doi=10.1186/s12302-021-00477-z |hdl=10067/1769070151162165141 |issn=2190-4715 |s2cid=232414650 |doi-access=free |hdl-access=free}}</ref> This has particular implications for populations that consume larger numbers of wild fish and shellfish species.<ref name=edible/> PFAS contamination has also resulted in disruptions to the food supply, such as closures and limits on fishing.<ref>{{Cite web |date=June 2023 |title=Proceedings of the 2023 National Forum on Contaminants in Fish |url=https://www.epa.gov/system/files/documents/2023-06/2023proceedings.pdf |publisher=United States Environmental Protection Agency}}</ref>
PFAS are brought to the Arctic from polluted southern waters by migrating birds.<ref>{{cite journal |last1=Léandri-Breton |first1=Don-Jean |last2=Jouanneau |first2=William |last3=Legagneux |first3=Pierre |last4=Tarroux |first4=Arnaud |last5=Moe |first5=Bo̷rge |last6=Angelier |first6=Frédéric |last7=Blévin |first7=Pierre |last8=Bråthen |first8=Vegard S. |last9=Fauchald |first9=Per |last10=Gabrielsen |first10=Geir W. |last11=Herzke |first11=Dorte |last12=Nikiforov |first12=Vladimir A. |last13=Elliott |first13=Kyle H. |last14=Chastel |first14=Olivier |display-authors=4 |date=2024 |title=Winter Tracking Data Suggest that Migratory Seabirds Transport Per- and Polyfluoroalkyl Substances to Their Arctic Nesting Site |url=https://pubs.acs.org/doi/abs/10.1021/acs.est.4c02661 |journal=Environmental Science & Technology |volume=58 |issue=29 |pages=12909–12920 |bibcode=2024EnST...5812909L |doi=10.1021/acs.est.4c02661 |pmid=38991194 |url-access=subscription}}</ref> Although it is much less than compared to the introduction by wind and the oceans, the birds become vectors, transmitting the toxic chemicals. Rainer Lohmann, an oceanographer at the University of Rhode Island, noted that this has a significant localized affect that is devastating for Arctic predators who accumulate toxins in their bodies because the contaminants from the birds often enter the food chain directly since the birds are the prey of many species.<ref>{{cite magazine |last=von Herff |first=William |date=October 4, 2024 |title=Migrating Seabirds Are Bringing Forever Chemicals Into the Arctic |url=https://hakaimagazine.com/news/migrating-seabirds-are-briging-forever-chemicals-into-the-arctic/ |access-date=1 December 2025 |magazine=Hakai Magazine}}</ref>
Fluorosurfactants with shorter carbon chains may be less prone to accumulating in mammals;<ref name=long/> there is still some concern that they may be harmful to both humans<ref>{{cite journal |vauthors=Wang Z, Cousins IT, Scheringer M, Hungerbuehler K |date=February 2015 |title=Hazard assessment of fluorinated alternatives to long-chain perfluoroalkyl acids (PFAAs) and their precursors: status quo, ongoing challenges and possible solutions |journal=Environment International |volume=75 |pages=172–179 |bibcode=2015EnInt..75..172W |doi=10.1016/j.envint.2014.11.013 |pmid=25461427}}</ref><ref>{{cite journal |vauthors=Birnbaum LS, Grandjean P |date=May 2015 |title=Alternatives to PFASs: perspectives on the science |journal=Environmental Health Perspectives |volume=123 |issue=5 |pages=A104–105 |bibcode=2015EnvHP.12309944B |doi=10.1289/ehp.1509944 |doi-broken-date=4 March 2026 |pmc=4421778 |pmid=25932670}}</ref><ref>{{cite journal |vauthors=Perry MJ, Nguyen GN, Porter ND |year=2016 |title=The Current Epidemiologic Evidence on Exposures to Poly- and Perfluoroalkyl Substances (PFASs) and Male Reproductive Health |journal=Current Epidemiology Reports |volume=3 |issue=1 |pages=19–26 |doi=10.1007/s40471-016-0071-y |issn=2196-2995 |s2cid=88276945}}</ref> and the environment.<ref>{{cite journal |vauthors=Scheringer M, Trier X, Cousins IT, de Voogt P, Fletcher T, Wang Z, Webster TF |date=November 2014 |title=Helsingør statement on poly- and perfluorinated alkyl substances (PFASs) |journal=Chemosphere |volume=114 |pages=337–339 |bibcode=2014Chmsp.114..337S |doi=10.1016/j.chemosphere.2014.05.044 |hdl=20.500.11850/84912 |pmid=24938172 |s2cid=249995685 |doi-access=free |hdl-access=free}}</ref><ref>{{Cite web |date=June 7, 2023 |title=Our Current Understanding of the Human Health and Environmental Risks of PFAS |url=https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas}}</ref>
== Health effects == <!--this chapter could be split out as a separate article, leaving a 'main' link and summary-->
PFAS were originally considered to be chemically inert.<ref name="guide">{{cite journal |last=Hogue |first=Cheryl |date=May 27, 2019 |title=A guide to the PFAS found in our environment |url=https://cen.acs.org/sections/pfas.html |journal=Chemical & Engineering News |volume=97 |issue=21 |page=12 |doi=10.1021/cen-09721-polcon2 |issn=2474-7408 |s2cid=199655540 |url-access=subscription}}</ref><ref>{{cite journal |date=October 25, 2006 |title=Preliminary Lists of PFOS, PFAS, PFOA and Related Compounds and Chemicals that May Degrade to PFCA |journal=OECD Papers |volume=6 |issue=11 |pages=1–194 |doi=10.1787/oecd_papers-v6-art38-en |issn=1609-1914}}</ref> Early occupational studies revealed elevated levels of fluorochemicals, including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in the blood of exposed industrial workers, but cited no ill health effects.<ref name="status">{{cite journal |vauthors=Ubel FA, Sorenson SD, Roach DE |date=August 1980 |title=Health status of plant workers exposed to fluorochemicals—a preliminary report |journal=American Industrial Hygiene Association Journal |volume=41 |issue=8 |pages=584–589 |bibcode=1980AIHAJ..41..584U |doi=10.1080/15298668091425310 |pmid=7405826}}</ref><ref name="assessment">{{cite journal |vauthors=Olsen GW, Burris JM, Burlew MM, Mandel JH |date=March 2003 |title=Epidemiologic assessment of worker serum perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations and medical surveillance examinations |journal=Journal of Occupational and Environmental Medicine |volume=45 |issue=3 |pages=260–270 |doi=10.1097/01.jom.0000052958.59271.10 |pmid=12661183 |s2cid=11648767}}</ref> These results were consistent with the measured serum concentrations of PFOS and PFOA in 3M plant workers ranging from 0.04 to 10.06 ppm and 0.01 to 12.70 ppm, respectively, well below toxic and carcinogenic levels cited in animal studies.<ref name=assessment/>
Some PFAS have half-lives of over eight years in the body. They are not broken down in the body but instead cleared from the body in urine.<ref>{{Cite journal |last1=Rosato |first1=Isabella |last2=Bonato |first2=Tiziano |last3=Fletcher |first3=Tony |last4=Batzella |first4=Erich |last5=Canova |first5=Cristina |date=2024 |title=Estimation of per- and polyfluoroalkyl substances (PFAS) half-lives in human studies: a systematic review and meta-analysis |url=https://www.sciencedirect.com/science/article/pii/S0013935123025471 |journal=Environmental Research |volume=242 |article-number=117743 |page=11743 |doi=10.1016/j.envres.2023.117743 |hdl=11577/3502363 |pmid=38008199 |bibcode=2024ER....24217743R |via=Elsevier Science Direct |hdl-access=free}}</ref> This lengthy residence time and widespread environmental contamination lead to accumulation of PFAS in humans sufficient to cause adverse health outcomes.<ref name="guide" />
[[File:Effects of exposure to PFASs on human health.svg|thumb|upright=2.5|Effects of exposure to PFAS on human health<ref>{{cite web |date=December 12, 2019 |title=Emerging chemical risks in Europe — 'PFAS' |url=https://www.eea.europa.eu/publications/emerging-chemical-risks-in-europe/emerging-chemical-risks-in-europe |publisher=European Environment Agency |location=Copenhagen}}</ref><ref>{{cite book |title=IARC Monographs on the Evaluation of Carcinogenic Risks to Humans |year=2016 |volume=110 |chapter=Some Chemicals Used as Solvents and in Polymer Manufacture |chapter-url=https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Chemicals-Used-As-Solvents-And-In-Polymer-Manufacture-2016 |archive-url=https://web.archive.org/web/20200324104056/https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Chemicals-Used-As-Solvents-And-In-Polymer-Manufacture-2016 |archive-date=March 24, 2020}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Fenton SE, Reiner JL, Nakayama SF, Delinsky AD, Stanko JP, Hines EP, White SS, Lindstrom AB, Strynar MJ, Petropoulou SE |date=June 2009 |title=Analysis of PFOA in dosed CD-1 mice. Part 2. Disposition of PFOA in tissues and fluids from pregnant and lactating mice and their pups |journal=Reproductive Toxicology |volume=27 |issue=3–4 |pages=365–372 |bibcode=2009RepTx..27..365F |doi=10.1016/j.reprotox.2009.02.012 |pmc=3446208 |pmid=19429407}}</ref>|left]]
From 2005 to 2013, three epidemiologists known as the C8 Science Panel conducted health studies in the Mid-Ohio Valley as part of a contingency to a class action lawsuit brought by communities in the Ohio River Valley against DuPont.<ref>{{cite web |title=C8 Science Panel |url=http://www.c8sciencepanel.org/ |url-status=live |archive-url=https://web.archive.org/web/20190618160631/http://www.c8sciencepanel.org/ |archive-date=June 18, 2019 |website=c8sciencepanel.org}}</ref> The panel measured PFOA serum concentrations in 69,000 individuals from around DuPont's Washington Works Plant and found a mean concentration of 83 ng/mL, compared to 4 ng/mL in a standard population of Americans.<ref>{{cite journal |vauthors=Steenland K, Jin C, MacNeil J, Lally C, Ducatman A, Vieira V, Fletcher T |date=July 2009 |title=Predictors of PFOA levels in a community surrounding a chemical plant |journal=Environmental Health Perspectives |volume=117 |issue=7 |pages=1083–1088 |bibcode=2009EnvHP.117.1083S |doi=10.1289/ehp.0800294 |doi-broken-date=4 March 2026 |pmc=2717134 |pmid=19654917}}</ref> This panel reported probable links between elevated PFOA blood concentration and high cholesterol, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer, pregnancy-induced hypertension and preeclampsia.<ref>{{cite web |date=October 29, 2012 |title=Probable Link Evaluation for heart disease (including high blood pressure, high cholesterol, coronary artery disease) |url=http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_Heart_Disease_29Oct2012.pdf |work=C8 Science Panel}}</ref><ref>{{cite web |date=30 July 2012 |title=Probable Link Evaluation of Autoimmune Disease |url=http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_Autoimmune_Disease_30Jul2012.pdf |work=C8 Science Panel}}</ref><ref>{{cite web |date=30 July 2012 |title=Probable Link Evaluation of Thyroid disease |url=http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_Thyroid_30Jul2012.pdf |work=C8 Science Panel}}</ref><ref>{{cite web |date=15 April 2012 |title=Probable Link Evaluation of Cancer |url=http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_Cancer_16April2012_v2.pdf |work=C8 Science Panel}}</ref><ref>{{cite web |date=5 December 2011 |title=Probable Link Evaluation of Pregnancy Induced Hypertension and Preeclampsia |url=http://www.c8sciencepanel.org/pdfs/Probable_Link_C8_PIH_5Dec2011.pdf |work=C8 Science Panel}}</ref> The severity of PFAS-associated health effects can vary based on the length of exposure, level of exposure, and health status.<ref name=profile/>
=== Pregnancy and lactation issues ===
Exposure to PFAS is a risk factor for hypertensive disorders in pregnancy including preeclampsia and high blood pressure. It is not clear whether PFAS exposure is associated with wider cardiovascular disorders during pregnancy.<ref>{{cite journal |vauthors=Erinc A, Davis MB, Padmanabhan V, Langen E, Goodrich JM |date=June 2021 |title=Considering environmental exposures to per- and polyfluoroalkyl substances (PFAS) as risk factors for hypertensive disorders of pregnancy |journal=Environ Res |type=Review |volume=197 |article-number=111113 |bibcode=2021ER....19711113E |doi=10.1016/j.envres.2021.111113 |pmc=8187287 |pmid=33823190}}</ref> Human breast milk can harbor PFAS, which can be transferred from mother to infant via breastfeeding.<ref>{{Cite web |date=17 January 2024 |title=PFAS and Breastfeeding |url=https://www.atsdr.cdc.gov/pfas/health-effects/pfas-breastfeeding.html |publisher=Agency for Toxic Substances and Disease Registry |access-date=16 April 2024 |archive-date=7 April 2022 |archive-url=https://web.archive.org/web/20220407213524/https://www.atsdr.cdc.gov/pfas/health-effects/pfas-breastfeeding.html }}</ref><ref name="auto"/>
Use of personal care products, such as nail care products, fragrances, makeup, hair dyes and hair sprays, by pregnant women and lactating mothers is associated with raised levels of PFAS in blood and breastmilk. For example, PFOS levels of women who dyed their hair at least twice during pregnancy were more than a third higher than those who did not. PFOS is one of the most common and most dangerous of the PFAS compounds.<ref name="Perkins-2024">{{Cite news |last=Perkins |first=Tom |date=2024-11-23 |title=Makeup, fragrance and hair dye use in pregnancy leads to more PFAS in breast milk – study |url=https://www.theguardian.com/environment/2024/nov/23/personal-care-products-pfas-pregnancy |access-date=2024-12-15 |work=The Guardian}}</ref>
=== Fertility issues ===
Endocrine disruptors, including PFAS, are linked with the male infertility crisis.<ref>{{cite book |last1=Swan |first1=Shanna H. |url=https://books.google.com/books?id=kjUXEAAAQBAJ |title=Count down: how our modern world is threatening sperm counts, altering male and female reproductive development, and imperiling the future of the human race |last2=Colino |first2=Stacey |date=February 23, 2021 |publisher=Charles Scribner's Sons |isbn=978-1-9821-1366-7}}</ref> A report in 2023 by the Icahn School of Medicine at Mount Sinai linked high exposure to PFAS with a 40% decrease in the ability for a woman to have a successful pregnancy as well as hormone disruption and delayed puberty onset.<ref>{{Cite news |last=Huet |first=Natalie |date=March 24, 2023 |title=Can't get pregnant? PFAS chemicals in household products may be slashing women's fertility by 40% |url=https://www.euronews.com/health/2023/03/24/infertility-pfas-forever-chemicals-may-slash-pregnancy-odds-by-40-per-cent-study-finds |work=Euronews}}</ref><ref>{{Cite press release |title=Exposure to Chemicals Found in Everyday Products Is Linked to Significantly Reduced Fertility |date=March 17, 2023 |url=https://www.mountsinai.org/about/newsroom/2023/exposure-to-chemicals-found-in-everyday-products-is-linked-to-significantly-reduced-fertility |work=Icahn School of Medicine at Mount Sinai}}</ref>
=== Human developmental issues ===
Fetuses and children are especially vulnerable to the harms of PFAS chemicals because they have been shown to be linked to major adverse health conditions, including abnormally small birth weight syndrome in newborns, preterm birth, shorter lactation periods, breastmilk of diminished nutritional content, one or more neurodevelopmental disorders, and decreased response to childhood vaccines.<ref name="Perkins-2024" />
=== Liver issues ===
A meta-analysis for associations between PFAS and human clinical biomarkers for liver injury, analyzing PFAS effects on liver biomarkers and histological data from rodent experimental studies, concluded that evidence exists that PFOA, perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) caused hepatotoxicity in humans.<ref>{{cite journal |display-authors=6 |vauthors=Costello E, Rock S, Stratakis N, Eckel SP, Walker DI, Valvi D, Cserbik D, Jenkins T, Xanthakos SA, Kohli R, Sisley S, Vasiliou V, La Merrill MA, Rosen H, Conti DV, McConnell R, Chatzi L |date=April 2022 |title=Exposure to per- and Polyfluoroalkyl Substances and Markers of Liver Injury: A Systematic Review and Meta-Analysis |journal=Environmental Health Perspectives |volume=130 |issue=4 |article-number=046001 |page=46001 |bibcode=2022EnvHP.130d6001C |doi=10.1289/EHP10092 |doi-broken-date=4 March 2026 |pmc=9044977 |pmid=35475652}}</ref>
=== Cancers ===
PFOA is classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer (IARC) based on "sufficient" evidence for cancer in animals and "strong" mechanistic evidence in exposed humans. IARC also classified PFOS as possibly carcinogenic to humans (Group 2b) based on "strong" mechanistic evidence.<ref>{{cite journal |display-authors=6 |vauthors=Zahm S, Bonde JP, Chiu WA, Hoppin J, Kanno J, Abdallah M, Blystone CR, Calkins MM, Dong GH, Dorman DC, Fry R, Guo H, Haug LS, Hofmann JN, Iwasaki M, Machala M, Mancini FR, Maria-Engler SS, Møller P, Ng JC, Pallardy M, Post GB, Salihovic S, Schlezinger J, Soshilov A, Steenland K, Steffensen IL, Tryndyak V, White A, Woskie S, Fletcher T, Ahmadi A, Ahmadi N, Benbrahim-Tallaa L, Bijoux W, Chittiboyina S, de Conti A, Facchin C, Madia F, Mattock H, Merdas M, Pasqual E, Suonio E, Viegas S, Zupunski L, Wedekind R, Schubauer-Berigan MK |date=November 2023 |title=Carcinogenicity of perfluorooctanoic acid and perfluorooctanesulfonic acid |url=https://research.birmingham.ac.uk/en/publications/7651d868-53db-4aeb-8158-86f7c4482230 |journal=The Lancet |volume=25 |issue=1 |pages=16–17 |doi=10.1016/S1470-2045(23)00622-8 |pmc=12183505 |pmid=38043561 |s2cid=265571186}}</ref> There is a lack of high-quality epidemiological data on the associations between many specific PFAS chemicals and specific cancer types, and research is ongoing.<ref>{{cite journal |vauthors=Steenland K, Winquist A |date=March 2021 |title=PFAS and cancer, a scoping review of the epidemiologic evidence |journal=Environmental Research |type=Review |volume=194 |article-number=110690 |bibcode=2021ER....19410690S |doi=10.1016/j.envres.2020.110690 |pmc=7946751 |pmid=33385391}}</ref>
=== High cholesterol ===
A response is observed in humans where elevated PFOS levels were significantly associated with elevated total cholesterol and LDL cholesterol, highlighting significantly reduced PPAR expression and alluding to PPAR independent pathways predominating over lipid metabolism in humans compared to rodents.<ref>{{cite journal |display-authors=6 |vauthors=DeWitt JC, Shnyra A, Badr MZ, Loveless SE, Hoban D, Frame SR, Cunard R, Anderson SE, Meade BJ, Peden-Adams MM, Luebke RW, Luster MI |date=8 January 2009 |title=Immunotoxicity of perfluorooctanoic acid and perfluorooctane sulfonate and the role of peroxisome proliferator-activated receptor alpha |journal=Critical Reviews in Toxicology |volume=39 |issue=1 |pages=76–94 |doi=10.1080/10408440802209804 |pmid=18802816 |s2cid=96896603}}</ref>
=== Ulcerative colitis ===
PFOA and PFOS have been shown to significantly alter immune and inflammatory responses in human and animal species. In particular, IgA, IgE (in females only) and C-reactive protein have been shown to decrease whereas antinuclear antibodies increase as PFOA serum concentrations increase.<ref>{{cite journal |vauthors=DeWitt JC, Peden-Adams MM, Keller JM, Germolec DR |date=November 22, 2011 |title=Immunotoxicity of perfluorinated compounds: recent developments |journal=Toxicologic Pathology |volume=40 |issue=2 |pages=300–311 |doi=10.1177/0192623311428473 |pmid=22109712 |s2cid=35549835 |doi-access=free}}</ref> These cytokine variations allude to immune response aberrations resulting in autoimmunity. One proposed mechanism is a shift towards anti-inflammatory M2 macrophages and/or {{nowrap|T-helper}} (TH2) response in intestinal epithelial tissue which allows sulfate-reducing bacteria to flourish. Elevated levels of hydrogen sulfide result, which reduce beta-oxidation and nutrient production, leading to a breakdown of the colonic epithelial barrier.<ref>{{cite journal |vauthors=Steenland K, Zhao L, Winquist A, Parks C |date=August 2013 |title=Ulcerative colitis and perfluorooctanoic acid (PFOA) in a highly exposed population of community residents and workers in the mid-Ohio valley |journal=Environmental Health Perspectives |volume=121 |issue=8 |pages=900–905 |bibcode=2013EnvHP.121..900S |doi=10.1289/ehp.1206449 |doi-broken-date=4 March 2026 |pmc=3734500 |pmid=23735465}}</ref>
=== Thyroid disease ===
Hypothyroidism is the most common thyroid abnormality associated with PFAS exposure.<ref name="hormones">{{cite journal |vauthors=Lee JE, Choi K |date=March 2017 |title=Perfluoroalkyl substances exposure and thyroid hormones in humans: epidemiological observations and implications |journal=Annals of Pediatric Endocrinology & Metabolism |volume=22 |issue=1 |pages=6–14 |doi=10.6065/apem.2017.22.1.6 |pmc=5401824 |pmid=28443254}}</ref> PFAS have been shown to decrease thyroid peroxidase, resulting in decreased production and activation of thyroid hormones in vivo.<ref>{{cite journal |vauthors=Song M, Kim YJ, Park YK, Ryu JC |date=August 2012 |title=Changes in thyroid peroxidase activity in response to various chemicals |journal=Journal of Environmental Monitoring |volume=14 |issue=8 |pages=2121–2126 |doi=10.1039/c2em30106g |pmid=22699773}}</ref> Other proposed mechanisms include alterations in thyroid hormone signaling, metabolism and excretion as well as function of nuclear hormone receptor,<ref name=hormones/> Additionally, a complex nonlinear association to the activitiy of step-up deiodinases (SPINA-GD)<ref>{{cite journal |last1=Yu |first1=X |last2=Liu |first2=Y |last3=Wang |first3=M |last4=Jia |first4=P |last5=Yang |first5=S |last6=Sun |first6=F |last7=Jin |first7=Y |last8=Wang |first8=X |last9=Guo |first9=Z |last10=Zhao |first10=G |last11=Gao |first11=B |display-authors=4 |date=18 November 2024 |title=Association between per- and polyfluoroalkyl substance exposures and thyroid homeostasis parameters. |journal=The Journal of Clinical Endocrinology and Metabolism |volume=110 |issue=8 |article-number=e2723–e2736 |doi=10.1210/clinem/dgae798 |pmid=39556482}}</ref> has been described. This suggests a strong influence on peripheral rather than central thyroid hormone sensitivity.
== Responses to knowledge of harmful effects ==
=== Ending manufacture ===
Citing health concerns, several manufacturing companies have ended or stated that they plan to end the sale of PFAS or products that contain them. These companies include W. L. Gore & Associates (the maker of Gore-Tex),<ref>{{Cite news |last=Condon |first=Christine |date=February 15, 2024 |title=Amid pollution investigation, maker of Gore-Tex cuts PFAS from outdoor clothing |url=https://www.spokesman.com/stories/2024/feb/15/amid-pollution-investigation-maker-of-gore-tex-cut/ |work=The Spokesman-Review |agency=The Baltimore Sun}}</ref> Patagonia,<ref>{{Cite news |last=Ram |first=Archana |date=March 22, 2023 |title=Say Goodbye to "Forever Chemicals" |url=https://www.patagonia.com/stories/say-goodbye-to-forever-chemicals/story-133800.html |work=Patagonia, Inc.}}</ref> REI,<ref>{{Cite news |last=Snider |first=Mike |date=February 22, 2023 |title=REI announces plan to remove 'forever chemicals' from its products by 2026 |url=https://www.usatoday.com/story/money/shopping/2023/02/22/rei-stores-forever-chemicals-products/11321761002/ |work=USA TODAY}}</ref> H&M,<ref>{{Cite news |date=February 27, 2019 |title=Phasing out PFAS |url=https://hmgroup.com/our-stories/phasing-out-pfas/ |work=H&M}}</ref> and 3M.<ref>{{cite magazine |last=Tullo |first=Alexander H. |date=December 29, 2022 |title=3M says it will end PFAS production by 2025 |url=https://cen.acs.org/environment/persistent-pollutants/3M-says-end-PFAS-production/101/i1 |url-access=limited |magazine=Chemical & Engineering News |page=4 |volume=101 |issue=1 |doi=10.1021/cen-10101-leadcon}}</ref><ref>{{cite press release |title=3M to Exit PFAS Manufacturing by the End of 2025 |date=December 20, 2022 |publisher=3M |url=https://news.3m.com/2022-12-20-3M-to-Exit-PFAS-Manufacturing-by-the-End-of-2025}}</ref> An alternative for some companies may have been to move production to countries such as Thailand and India, where there is less regulation.<ref>{{Cite journal |last1=DeWitt |first1=Jamie C. |last2=Glüge |first2=Juliane |last3=Cousins |first3=Ian T. |last4=Goldenman |first4=Gretta |last5=Herzke |first5=Dorte |last6=Lohmann |first6=Rainer |last7=Miller |first7=Mark |last8=Ng |first8=Carla A. |last9=Patton |first9=Sharyle |last10=Trier |first10=Xenia |last11=Vierke |first11=Lena |last12=Wang |first12=Zhanyun |last13=Adu-Kumi |first13=Sam |last14=Balan |first14=Simona |last15=Buser |first15=Andreas M. |display-authors=6 |date=April 22, 2024 |title=Zürich II Statement on Per- and Polyfluoroalkyl Substances (PFASs): Scientific and Regulatory Needs |journal=Environmental Science & Technology Letters |volume=11 |issue=8 |pages=786–797 |bibcode=2024EnSTL..11..786D |doi=10.1021/acs.estlett.4c00147 |hdl=20.500.11850/679165 |pmc=11325642 |pmid=39156923 |doi-access=free |hdl-access=free |last16=Fletcher |first16=Tony |last17=Haug |first17=Line Småstuen |last18=Huang |first18=Jun |last19=Kaserzon |first19=Sarit |last20=Leonel |first20=Juliana |last21=Sheriff |first21=Ishmail |last22=Shi |first22=Ya-Li |last23=Valsecchi |first23=Sara |last24=Scheringer |first24=Martin}}</ref><ref>{{Cite web |date=April 2019 |title=PFAS Pollution Across the Middle East and Asia |url=https://ipen.org/sites/default/files/documents/pfas_pollution_across_the_middle_east_and_asia.pdf |work=International Pollutants Elimination Network |quote=The authors hypothesize that multinational companies are shifting PFAS use to developing countries such as Thailand where they are not regulated.}}</ref><ref>{{Cite news |last1=Liva |first1=Gianluca |last2=Tommasoli |first2=Filippo |last3=Violato |first3=Anna |last4=Frigerio |first4=Marta |date=2025-10-31 |title=Where does a western chemical plant that contaminated drinking water go next? To India |url=https://www.theguardian.com/environment/2025/oct/31/miteni-factory-pfas-plant-italy-india |access-date=2025-12-08 |work=The Guardian |language=en-GB |issn=0261-3077}}</ref>
=== Suppressing information on health effects ===
Since the 1970s, DuPont and 3M were aware that PFAS was "highly toxic when inhaled and moderately toxic when ingested".<ref name="Devil">{{cite journal |vauthors=Gaber N, Bero L, Woodruff TJ |date=June 1, 2023 |title=The Devil they Knew: Chemical Documents Analysis of Industry Influence on PFAS Science |journal=Annals of Global Health |volume=89 |issue=1 |article-number=37 |doi=10.5334/aogh.4013 |pmc=10237242 |pmid=37273487 |doi-access=free}}</ref> Producers used several strategies to influence science and regulation – most notably, suppressing unfavorable research and distorting public discourse.<ref name=Devil/> In 2018, under the first presidency of Donald Trump, White House staff and the EPA pressured the U.S. Agency for Toxic Substances and Disease Registry to suppress a study that showed PFAS to be more dangerous than previously thought.<ref>{{cite web |last=Halpern |first=Michael |date=May 16, 2018 |title=Bipartisan Outrage as EPA, White House Try to Cover Up Chemical Health Assessment |url=https://blog.ucsusa.org/michael-halpern/bipartisan-outrage-as-epa-white-house-try-to-cover-up-chemical-health-assessment |url-status=live |archive-url=https://web.archive.org/web/20200305211354/https://blog.ucsusa.org/michael-halpern/bipartisan-outrage-as-epa-white-house-try-to-cover-up-chemical-health-assessment |archive-date=March 5, 2020 |publisher=Union of Concerned Scientists |location=Cambridge, Massachusetts}}</ref><ref>{{cite news |last=SNIDER |first=ANNIE |date=May 14, 2018 |title=White House, EPA headed off chemical pollution study |url=https://www.politico.com/story/2018/05/14/emails-white-house-interfered-with-science-study-536950 |url-status=live |archive-url=https://web.archive.org/web/20180516023718/https://www.politico.com/story/2018/05/14/emails-white-house-interfered-with-science-study-536950 |archive-date=May 16, 2018 |work=Politico}}</ref>
=== Litigation and regulations ===
{{main|PFAS litigation and regulations by country}}
External costs, including those associated with remediation of soil and water contamination, treatment of related diseases, and monitoring of pollution, may be as high as US$17.5 trillion annually, according to ChemSec.<ref name=cost/> PFAS have been a subject of multiple lawsuits worldwide.<ref>{{cite web |date=2024-06-26 |title='Just the start': The growing legal battle over PFAS in Europe |url=https://chemsec.org/just-the-start-the-growing-legal-battle-over-pfas-in-europe/ |url-status=live |archive-url=https://web.archive.org/web/20250109100316/https://chemsec.org/just-the-start-the-growing-legal-battle-over-pfas-in-europe/ |archive-date=2025-01-09 |access-date=2025-01-09 |website=Chemsec}}</ref><ref>{{cite web |last1=Roe |first1=Isobel |last2=Taouk |first2=Maryanne |last3=Gregory |first3=Xanthe |date=2023-05-15 |title=Commonwealth settles $132.7 million class action over PFAS contamination across Australia |url=https://www.abc.net.au/news/2023-05-15/pfas-class-action-commonsettlement-reached-with-30-000-claimants/102346274 |url-status=live |archive-url=https://web.archive.org/web/20250109100411/https://www.abc.net.au/news/2023-05-15/pfas-class-action-commonsettlement-reached-with-30-000-claimants/102346274 |archive-date=2025-01-09 |access-date=2025-01-09 |website=ABC News}}</ref><ref>{{cite magazine |last=Kluger |first=Jeffrey |date=2023-07-12 |title='Forever Chemical' Lawsuits Could Ultimately Eclipse the Big Tobacco Settlement |url=https://time.com/6292482/legal-liability-pfas-chemicals-lawsuit/ |url-status=live |archive-url=https://web.archive.org/web/20250109100651/https://time.com/6292482/legal-liability-pfas-chemicals-lawsuit/ |archive-date=2025-01-09 |access-date=2025-01-09 |magazine=Time (magazine)}}</ref> In the United States, settlements stemming from PFAS pollution claims have reached $18 billion by 2024.<ref>{{cite web |date=2024-04-05 |title=PFAS Litigation Could Generate Billions in Ground-Up Losses |url=https://core.verisk.com/Insights/Emerging-Issues/Articles/2024/April/Week-1/PFAS-Litigation-Could-Generate-Billions-in-Ground-Up-Losses |url-status=live |archive-url=https://web.archive.org/web/20250109095847/https://core.verisk.com/Insights/Emerging-Issues/Articles/2024/April/Week-1/PFAS-Litigation-Could-Generate-Billions-in-Ground-Up-Losses |archive-date=2025-01-09 |access-date=2025-01-09 |publisher=Verisk Analytics |location=Jersey City, New Jersey}}</ref> In 2023, Sweden's Supreme Court set a legal precedent by awarding damages to citizens who were supplied PFAS contaminated drinking water.<ref>{{cite web |date=2023-12-05 |title=The Supreme Court delivers judgment in PFAS case |url=https://www.domstol.se/en/supreme-court/news-archive/the-supreme-court-delivers-judgment-in-pfas-case/ |url-status=live |archive-url=https://web.archive.org/web/20250109095540/https://www.domstol.se/en/supreme-court/news-archive/the-supreme-court-delivers-judgment-in-pfas-case/ |archive-date=2025-01-09 |access-date=2025-01-09 |publisher=Supreme Court of Sweden |location=Stockholm}}</ref>
Countries such as Canada have published drinking water guidelines for PFOS and PFOA<ref>{{cite web |date=April 2019 |title=Water talk: Perfluoroalkylated substances in drinking water |url=https://www.canada.ca/en/services/health/publications/healthy-living/water-talk-drinking-water-screening-values-perfluoroalkylated-substances.html |url-status=live |archive-url=https://web.archive.org/web/20200815112519/https://www.canada.ca/en/services/health/publications/healthy-living/water-talk-drinking-water-screening-values-perfluoroalkylated-substances.html |archive-date=August 15, 2020 |website=Water Quality - Reports and Publications |publisher=Health Canada |location=Ottawa, Ontario}}</ref> The European Union is developing an action plan to eliminate non-essential uses of PFAS.<ref>{{cite press release |title=Council Conclusions on Chemicals |url=https://www.consilium.europa.eu/en/press/press-releases/2019/06/26/council-conclusions-on-chemicals/ |website=European Council}}</ref> The United Nations has listed PFOS, PFOA, PFHxS, long-chain PFCAs and related chemicals as persistent organic pollutants under the Stockholm Convention on Persistent Organic Pollutants between 2009 and 2025.<ref>{{cite journal |display-authors=6 |vauthors=Blum A, Balan SA, Scheringer M, Trier X, Goldenman G, Cousins IT, Diamond M, Fletcher T, Higgins C, Lindeman AE, Peaslee G, de Voogt P, Wang Z, Weber R |date=May 2015 |title=The Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs) |journal=Environmental Health Perspectives |volume=123 |issue=5 |pages=A107-111 |bibcode=2015EnvHP.12309934B |doi=10.1289/ehp.1509934 |doi-broken-date=4 March 2026 |pmc=4421777 |pmid=25932614}}</ref><ref>{{cite web |last=Lin |first=Melisa |date=May 2014 |title=Phasing out PFOS under the Stockholm Convention |url=https://www.oecd.org/chemicalsafety/portal-perfluorinated-chemicals/webinars/Presentation%203_Melisa.pdf |work=OECD}}</ref>
The United States Environmental Protection Agency has published non-enforceable drinking water health advisories for PFOA and PFOS.<ref>{{cite web |date=December 9, 2020 |title=Drinking Water Health Advisories for PFOA and PFOS |url=https://www.epa.gov/sdwa/past-pfoa-and-pfos-health-effects-science-documents |url-status=live |archive-url=https://web.archive.org/web/20201228004056/https://www.epa.gov/ground-water-and-drinking-water/drinking-water-health-advisories-pfoa-and-pfos |archive-date=December 28, 2020 |publisher=United States Environmental Protection Agency}}</ref><ref>{{cite web |date=November 2016 |title=Fact Sheet; PFOA & PFOS Drinking Water Health Advisories |url=https://www.epa.gov/ground-water-and-drinking-water/supporting-documents-drinking-water-health-advisories-pfoa-and-pfos |archive-url=https://web.archive.org/web/20201226125900/https://www.epa.gov/ground-water-and-drinking-water/supporting-documents-drinking-water-health-advisories-pfoa-and-pfos |archive-date=December 26, 2020 |id=EPA 800-F-16-003}}</ref> In 2021, Maine became the first U.S. state to ban these compounds in all products by 2030.<ref>{{cite news |last=Perkins |first=Tom |date=July 16, 2021 |title=Maine bans toxic 'forever chemicals' under groundbreaking new law |url=https://www.theguardian.com/us-news/2021/jul/15/maine-law-pfas-forever-chemicals-ban |archive-url=https://web.archive.org/web/20210716071833/https://www.theguardian.com/us-news/2021/jul/15/maine-law-pfas-forever-chemicals-ban |archive-date=July 16, 2021 |work=The Guardian}}</ref> {{As of|October 2020}}, the states of California, Connecticut, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Vermont, and Wisconsin had enforceable drinking water standards for between two and six types of PFAS.<ref>{{cite web |author=Massachusetts Department of Environmental Protection |date=October 21, 2020 |title=MassDEP's PFAS6 Drinking Water Standard |url=https://mecc.memberclicks.net/assets/Presentations/I-495%20PFAS6%20MCL%2010-21-2020.pdf}}</ref>
However, some major producers and users such as the United States, Israel, and Malaysia have not ratified the agreement on reducing use of PFAS, and the chemical industry has lobbied governments to reduce regulations. For example in the United States, bills on cosmetics, food packaging, and textiles meant to regulate PFAS failed to pass through Congress in 2022.<ref>{{cite news |last=Perkins |first=Tom |date=January 13, 2023 |title=Bills to regulate toxic 'forever chemicals' died in Congress – with Republican help |url=https://www.theguardian.com/environment/2023/jan/13/pfas-toxic-forever-chemicals-republican-house |newspaper=The Guardian}}</ref>
In 2026, the UK increased testing for PFAS as part of a national plan to tackle the substances, which have prompted environmental and health concerns. The government says that by 2029 it wants to align more closely with regulations issued by the EU, which is looking to prohibit all non-essential uses.<ref>{{Cite web |date=2026-02-03 |title='Forever chemical' testing to be ramped up amid growing concerns. |url=https://www.bbc.com/news/articles/cz9vz249keno |access-date=2026-02-03 |website=www.bbc.com |language=en-GB}}</ref>
== Occupational exposure ==
Occupational exposure to PFAS occurs in numerous industries due to the widespread use of the chemicals in products and as an element of industrial process streams.<ref name="profile">{{cite journal |date=2018 |title=Toxicological profile for Perfluoroalkyls |url=https://wwwn.cdc.gov/TSP/ToxProfiles/ToxProfiles.aspx?id=1117&tid=237 |journal=Agency for Toxic Substances and Disease Registry |doi=10.15620/cdc:59198 |archive-url=https://web.archive.org/web/20210512154522/https://wwwn.cdc.gov/TSP/ToxProfiles/ToxProfiles.aspx?id=1117&tid=237 |archive-date=May 12, 2021 |doi-access=free}}</ref> PFAS are used in more than 200 different ways in industries as diverse as electronics and equipment manufacturing, plastic and rubber production, food and textile production, and building and construction.<ref>{{cite journal |display-authors=6 |vauthors=Glüge J, Scheringer M, Cousins IT, DeWitt JC, Goldenman G, Herzke D, Lohmann R, Ng CA, Trier X, Wang Z |date=October 2020 |title=An overview of the uses of per- and polyfluoroalkyl substances (PFAS) |journal=Environmental Science: Processes & Impacts |volume=22 |issue=12 |pages=2345–2373 |doi=10.1039/D0EM00291G |pmc=7784712 |pmid=33125022}}</ref> Occupational exposure to PFAS can occur at fluorochemical facilities that produce them and other manufacturing facilities that use them for industrial processing like the chrome plating industry.<ref name=profile/> Workers who handle PFAS-containing products can also be exposed during their work, such as people who install PFAS-containing carpets and leather furniture with PFAS coatings, professional ski-waxers using PFAS-based waxes, and fire-fighters using PFAS-containing foam and wearing flame-resistant protective gear made with PFAS.<ref name=profile/><ref>{{cite journal |vauthors=Nilsson H, Kärrman A, Westberg H, Rotander A, van Bavel B, Lindström G |date=March 2010 |title=A time trend study of significantly elevated perfluorocarboxylate levels in humans after using fluorinated ski wax |journal=Environmental Science & Technology |volume=44 |issue=6 |pages=2150–2155 |bibcode=2010EnST...44.2150N |doi=10.1021/es9034733 |pmid=20158198}}</ref><ref>{{cite journal |vauthors=Trowbridge J, Gerona RR, Lin T, Rudel RA, Bessonneau V, Buren H, Morello-Frosch R |date=March 2020 |title=Exposure to Perfluoroalkyl Substances in a Cohort of Women Firefighters and Office Workers in San Francisco |journal=Environmental Science & Technology |volume=54 |issue=6 |pages=3363–3374 |bibcode=2020EnST...54.3363T |doi=10.1021/acs.est.9b05490 |pmc=7244264 |pmid=32100527}}</ref>
=== Exposure pathways ===
People who are exposed to PFAS through their jobs typically have higher levels of PFAS in their blood than the general population.<ref name=profile/><ref name="exposed">{{cite journal |vauthors=Rotander A, Toms LM, Aylward L, Kay M, Mueller JF |date=September 2015 |title=Elevated levels of PFOS and PFHxS in firefighters exposed to aqueous film forming foam (AFFF) |journal=Environment International |volume=82 |pages=28–34 |bibcode=2015EnInt..82...28R |doi=10.1016/j.envint.2015.05.005 |pmid=26001497}}</ref><ref>{{cite journal |vauthors=Fromme H, Tittlemier SA, Völkel W, Wilhelm M, Twardella D |date=May 2009 |title=Perfluorinated compounds—exposure assessment for the general population in Western countries |journal=International Journal of Hygiene and Environmental Health |volume=212 |issue=3 |pages=239–270 |bibcode=2009IJHEH.212..239F |doi=10.1016/j.ijheh.2008.04.007 |pmid=18565792}}</ref> While the general population is exposed to PFAS through ingested food and water, occupational exposure includes accidental ingestion, inhalation exposure, and skin contact in settings where PFAS become volatile.<ref>{{cite journal |vauthors=Kärrman A, Harada KH, Inoue K, Takasuga T, Ohi E, Koizumi A |date=May 2009 |title=Relationship between dietary exposure and serum perfluorochemical (PFC) levels—a case study |journal=Environment International |volume=35 |issue=4 |pages=712–717 |bibcode=2009EnInt..35..712K |doi=10.1016/j.envint.2009.01.010 |pmid=19250678}}</ref><ref name=Buck2011/><ref>{{cite news |last=Perkins |first=Tom |date=15 June 2021 |title=Toxic 'Forever Chemicals' Widespread in Top Makeup Brands, Study Finds; Researchers Find Signs of PFAS in over Half of 231 Samples of Products Including Lipstick, Mascara and Foundation |url=https://www.theguardian.com/fashion/2021/jun/15/pfas-makeup-forever-chemicals |archive-url=https://web.archive.org/web/20210626211117/https://www.theguardian.com/fashion/2021/jun/15/pfas-makeup-forever-chemicals |archive-date=June 26, 2021 |newspaper=The Guardian}}</ref>
=== Professional ski wax technicians ===
Compared to the general public exposed to contaminated drinking water, professional ski wax technicians are more strongly exposed to PFAS (PFOA, PFNA, PFDA, PFHpA, PFDoDA) from the glide wax used to coat the bottom of skis to reduce the friction between the skis and snow.<ref name="review">{{cite journal |vauthors=Lucas K, Gaines LG, Paris-Davila T, Nylander-French LA |date=May 2023 |title=Occupational exposure and serum levels of per- and polyfluoroalkyl substances (PFAS): A review |journal=American Journal of Industrial Medicine |volume=66 |issue=5 |pages=379–392 |bibcode=2023AJIM...66..379L |doi=10.1002/ajim.23454 |pmid=36573587 |s2cid=255211077 |doi-access=free}}</ref> During the coating process, the wax is heated, which releases fumes and airborne particles.<ref name=review/> Compared to all other reported occupational and residential exposures, ski waxing had the highest total PFAS air concentrations.<ref>{{cite journal |vauthors=Paris-Davila T, Gaines LG, Lucas K, Nylander-French LA |date=May 2023 |title=Occupational exposures to airborne per- and polyfluoroalkyl substances (PFAS)-A review |journal=American Journal of Industrial Medicine |volume=66 |issue=5 |pages=393–410 |doi=10.1002/ajim.23461 |pmid=36719301 |s2cid=256481718}}</ref>
===Manufacturing workers===
People who work at fluorochemical production plants and in manufacturing industries that use PFAS in the industrial process can be exposed to PFAS in the workplace. Much of what we know about PFAS exposure and health effects began with medical surveillance studies of workers exposed to PFAS at fluorochemical production facilities. These studies began in the 1940s and were conducted primarily at U.S. and European manufacturing sites. Between the 1940s and 2000s, thousands of workers exposed to PFAS participated in research studies that advanced scientific understanding of exposure pathways, toxicokinetic properties, and adverse health effects associated with exposure.<ref name=status/><ref name="Thirty">{{cite journal |vauthors=Costa G, Sartori S, Consonni D |date=March 2009 |title=Thirty years of medical surveillance in perfluooctanoic acid production workers |journal=Journal of Occupational and Environmental Medicine |volume=51 |issue=3 |pages=364–372 |doi=10.1097/JOM.0b013e3181965d80 |pmid=19225424 |s2cid=34813716}}</ref><ref>{{cite journal |vauthors=Olsen GW, Burris JM, Burlew MM, Mandel JH |date=November 2000 |title=Plasma cholecystokinin and hepatic enzymes, cholesterol and lipoproteins in ammonium perfluorooctanoate production workers |journal=Drug and Chemical Toxicology |volume=23 |issue=4 |pages=603–20 |doi=10.1081/DCT-100101973 |pmid=11071397 |s2cid=30289350}}</ref>
The first research study to report elevated organic fluorine levels in the blood of fluorochemical workers was published in 1980.<ref name=status/> It established inhalation as a potential route of occupational PFAS exposure by reporting measurable levels of organic fluorine in air samples at the facility.<ref name=status/> Workers at fluorochemical production facilities have higher levels of PFOA and PFOS in their blood than the general population. Serum PFOA levels in fluorochemical workers are generally below 20,000 ng/mL but have been reported as high as 100,000 ng/mL, whereas the mean PFOA concentration among non-occupationally exposed cohorts in the same time frame was 4.9 ng/mL.<ref name="Cross">{{cite journal |vauthors=Sakr CJ, Kreckmann KH, Green JW, Gillies PJ, Reynolds JL, Leonard RC |date=October 2007 |title=Cross-sectional study of lipids and liver enzymes related to a serum biomarker of exposure (ammonium perfluorooctanoate or APFO) as part of a general health survey in a cohort of occupationally exposed workers |journal=Journal of Occupational and Environmental Medicine |volume=49 |issue=10 |pages=1086–1096 |doi=10.1097/JOM.0b013e318156eca3 |pmid=18000414 |s2cid=20124680}}</ref><ref name=assessment/> Among fluorochemical workers, those with direct contact with PFAS have higher PFAS concentrations in their blood than those with intermittent contact or no direct PFAS contact.<ref name=Thirty/><ref name=Cross/> Blood PFAS levels have been shown to decline when direct contact ceases.<ref name=Cross/><ref>{{cite journal |vauthors=Olsen GW, Chang SC, Noker PE, Gorman GS, Ehresman DJ, Lieder PH, Butenhoff JL |date=February 2009 |title=A comparison of the pharmacokinetics of perfluorobutanesulfonate (PFBS) in rats, monkeys, and humans |journal=Toxicology |volume=256 |issue=1–2 |pages=65–74 |bibcode=2009Toxgy.256...65O |doi=10.1016/j.tox.2008.11.008 |pmid=19059455}}</ref> PFOA and PFOS levels have declined in U.S. and European fluorochemical workers due to improved facilities, increased usage of personal protective equipment, and the discontinuation of these chemicals from production.<ref name=Thirty/><ref>{{cite journal |vauthors=Steenland K, Zhao L, Winquist A |date=May 2015 |title=A cohort incidence study of workers exposed to perfluorooctanoic acid (PFOA) |journal=Occupational and Environmental Medicine |volume=72 |issue=5 |pages=373–380 |bibcode=2015OccEM..72..373S |doi=10.1136/oemed-2014-102364 |pmid=25601914 |s2cid=28440634}}</ref> Occupational exposure to PFAS in manufacturing continues to be an active area of study in China with numerous investigations linking worker exposure to various PFAS.<ref>{{cite journal |vauthors=Fu J, Gao Y, Wang T, Liang Y, Zhang A, Wang Y, Jiang G |date=March 2015 |title=Elevated levels of perfluoroalkyl acids in family members of occupationally exposed workers: the importance of dust transfer |journal=Scientific Reports |volume=5 |issue=1 |article-number=9313 |bibcode=2015NatSR...5.9313F |doi=10.1038/srep09313 |pmc=5380130 |pmid=25791573}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Gao Y, Fu J, Cao H, Wang Y, Zhang A, Liang Y, Wang T, Zhao C, Jiang G |date=June 2015 |title=Differential accumulation and elimination behavior of perfluoroalkyl Acid isomers in occupational workers in a manufactory in China |journal=Environmental Science & Technology |volume=49 |issue=11 |pages=6953–6962 |bibcode=2015EnST...49.6953G |doi=10.1021/acs.est.5b00778 |pmid=25927957 |s2cid=23947500 }}</ref><ref>{{cite journal |display-authors=6 |vauthors=Lu Y, Gao K, Li X, Tang Z, Xiang L, Zhao H, Fu J, Wang L, Zhu N, Cai Z, Liang Y, Wang Y, Jiang G |date=August 2019 |title=Mass Spectrometry-Based Metabolomics Reveals Occupational Exposure to Per- and Polyfluoroalkyl Substances Relates to Oxidative Stress, Fatty Acid β-Oxidation Disorder, and Kidney Injury in a Manufactory in China |journal=Environmental Science & Technology |volume=53 |issue=16 |pages=9800–9809 |bibcode=2019EnST...53.9800L |doi=10.1021/acs.est.9b01608 |pmid=31246438 |s2cid=195762433}}</ref>
=== Firefighters ===
thumb|upright=1.15|Firefighters using aqueous film forming foam (AFFF)
PFAS are used in Class B firefighting foams due to their hydrophobic and lipophobic properties, as well as the stability of the chemicals when exposed to high heat.<ref name="foams">{{cite journal |vauthors=Laitinen JA, Koponen J, Koikkalainen J, Kiviranta H |date=December 2014 |title=Firefighters' exposure to perfluoroalkyl acids and 2-butoxyethanol present in firefighting foams |journal=Toxicology Letters |volume=231 |issue=2 |pages=227–232 |bibcode=2014ToxL..231..227L |doi=10.1016/j.toxlet.2014.09.007 |pmid=25447453}}</ref>
Research into occupational exposure for firefighters is emergent, though frequently limited by underpowered study designs. A 2011 cross-sectional analysis of the C8 Health Studies found higher levels of PFHxS in firefighters compared to the sample group of the region, with other PFAS at elevated levels, without reaching statistical significance.<ref>{{cite journal |vauthors=Jin C, Sun Y, Islam A, Qian Y, Ducatman A |date=March 2011 |title=Perfluoroalkyl acids including perfluorooctane sulfonate and perfluorohexane sulfonate in firefighters |journal=Journal of Occupational and Environmental Medicine |volume=53 |issue=3 |pages=324–328 |doi=10.1097/jom.0b013e31820d1314 |pmid=21346631 |s2cid=41993931}}</ref> A 2014 study in Finland studying eight firefighters over three training sessions observed select PFAS (PFHxS and PFNA) increase in blood samples following each training event.<ref name=foams/> Due to this small sample size, a test of significance was not conducted. A 2015 cross-sectional study conducted in Australia found that PFOS and PFHxS accumulation was positively associated with years of occupational AFFF exposure through firefighting.<ref name=exposed/>
Due to their use in training and testing, studies indicate occupational risk for military members and firefighters, as higher levels of PFAS exposure were indicated in military members and firefighters when compared to the general population.<ref>{{cite journal |vauthors=Barton KE, Starling AP, Higgins CP, McDonough CA, Calafat AM, Adgate JL |date=January 2020 |title=Sociodemographic and behavioral determinants of serum concentrations of per- and polyfluoroalkyl substances in a community highly exposed to aqueous film-forming foam contaminants in drinking water |journal=International Journal of Hygiene and Environmental Health |volume=223 |issue=1 |pages=256–266 |bibcode=2020IJHEH.223..256B |doi=10.1016/j.ijheh.2019.07.012 |pmc=6878185 |pmid=31444118}}</ref> PFAS exposure is prevalent among firefighters not only due to its use in emergencies but also because it is used in personal protective equipment. In support of these findings, states like Washington and Colorado have moved to restrict and penalize the use of Class B firefighting foam for firefighter training and testing.<ref>{{cite report |url=https://digital.library.unt.edu/ark:/67531/metadc1279934/ |title=Colorado economic impact study on the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado state fiscal year 1993 |date=November 12, 1993 |doi=10.2172/10112187 |osti=10112187 |archive-url=https://web.archive.org/web/20210625165124/https://digital.library.unt.edu/ark:/67531/metadc1279934/ |archive-date=June 25, 2021 |url-status=live |url-access=subscription |doi-access=free}}</ref><ref>{{Cite web |title=Toxics in firefighting |url=https://ecology.wa.gov/waste-toxics/reducing-toxic-chemicals/washingtons-toxics-in-products-laws/toxics-in-firefighting |work=Washington State Department of Ecology}}</ref>
=== Exposure after September 11 attacks ===
The September 11 attacks and resulting fires caused the release of toxic chemicals used in materials such as stain-resistant coatings.<ref name="plasma">{{cite journal |vauthors=Tao L, Kannan K, Aldous KM, Mauer MP, Eadon GA |date=May 2008 |title=Biomonitoring of perfluorochemicals in plasma of New York State personnel responding to the World Trade Center disaster |url=https://figshare.com/articles/journal_contribution/2941570 |journal=Environmental Science & Technology |volume=42 |issue=9 |pages=3472–3478 |bibcode=2008EnST...42.3472T |doi=10.1021/es8000079 |pmid=18522136 |url-access=subscription}}</ref> First responders to this incident were exposed to PFOA, PFNA, and PFHxS through inhalation of dust and smoke released during and after the collapse of the World Trade Center.<ref name=plasma/>
Fire responders who were working at or near ground zero were assessed for respiratory and other health effects from exposure to emissions at the World Trade Center. Early clinical testing showed a high prevalence of respiratory health effects. Early symptoms of exposure often presented with persistent coughing and wheezing. PFOA and PFHxS levels were present in both smoke and dust exposure, but first responders exposed to smoke had higher concentrations of PFOA and PFHxS than those exposed to dust.<ref name=plasma/>
=== Mitigation measures ===
Several strategies have been proposed as a way to protect people at the greatest risk of occupational exposure to PFAS, including exposure monitoring, regular blood testing, and the use of PFAS-free alternatives such as fluorine-free firefighting foam and plant-based ski wax.<ref>{{Cite journal |vauthors=Horst J, Quinnan J, McDonough J, Lang J, Storch P, Burdick J, Theriault C |date=April 2021 |title=Transitioning Per- and Polyfluoroalkyl Substance Containing Fire Fighting Foams to New Alternatives: Evolving Methods and Best Practices to Protect the Environment |journal=Groundwater Monitoring & Remediation |volume=41 |issue=2 |pages=19–26 |bibcode=2021GMRed..41b..19H |doi=10.1111/gwmr.12444 |issn=1069-3629 |s2cid=235578939 |doi-access=free}}</ref>
== Remediation ==
{{main|Remediation of per- and polyfluoroalkyl substances}}
=== Water treatment ===
Several technologies can be applied to drinking water supplies, groundwater, industrial wastewater, surface water, and other applications such as landfill leachate, including:
* Sorption (including granular activated carbon,<ref>{{Cite journal |last1=Sun |first1=Runze |last2=Alinezhad |first2=Ali |last3=Altarawneh |first3=Mohammednoor |last4=Ateia |first4=Mohamed |last5=Blotevogel |first5=Jens |last6=Mai |first6=Jiamin |last7=Naidu |first7=Ravi |last8=Pignatello |first8=Joseph |last9=Rappe |first9=Anthony |last10=Zhang |first10=Xuejia |last11=Xiao |first11=Feng |display-authors=4 |date=2024-12-17 |title=New Insights into Thermal Degradation Products of Long-Chain Per- and Polyfluoroalkyl Substances (PFAS) and Their Mineralization Enhancement Using Additives |url=https://pubs.acs.org/doi/10.1021/acs.est.4c05782 |journal=Environmental Science & Technology |volume=58 |issue=50 |pages=22417–22430 |bibcode=2024EnST...5822417S |doi=10.1021/acs.est.4c05782 |issn=0013-936X |pmid=39626076 |url-access=subscription}}</ref> biochar,<ref>{{Cite journal |last1=Scotland |first1=Phelecia |last2=Wyss |first2=Kevin M. |last3=Cheng |first3=Yi |last4=Eddy |first4=Lucas |last5=Beckham |first5=Jacob L. |last6=Sharp |first6=Justin |last7=Chung |first7=Youngkun |last8=Choi |first8=Chi Hun |last9=Si |first9=Tengda |last10=Wang |first10=Bo |last11=Donoso |first11=Juan A. |last12=Deng |first12=Bing |last13=Shen |first13=Yu-Yi |last14=Zetterholm |first14=Sarah Grace |last15=Griggs |first15=Christopher |display-authors=4 |date=April 2025 |title=Mineralization of captured perfluorooctanoic acid and perfluorooctane sulfonic acid at zero net cost using flash Joule heating |url=https://www.nature.com/articles/s44221-025-00404-z |journal=Nature Water |language=en |volume=3 |issue=4 |pages=486–496 |bibcode=2025NatWa...3..486S |doi=10.1038/s44221-025-00404-z |issn=2731-6084 |url-access=subscription}}</ref><ref>{{Cite web |last=Ottewell |first=Seán |date=2025-05-02 |title=Rice Process Eliminates PFAS, Generates Graphene |url=https://www.chemicalprocessing.com/processing-equipment/reaction-synthesis/news/55287585/rice-process-eliminates-pfas-generates-graphene |access-date=2026-01-24 |website=Chemical Processing |language=en}}</ref> and ion exchange resins<ref>{{Cite news |last=Perkins |first=Tom |date=2026-01-23 |title=New filtration technology could be gamechanger in removal of Pfas 'forever chemicals' |url=https://www.theguardian.com/environment/2026/jan/23/pfas-forever-chemicals-filtration |access-date=2026-01-24 |work=The Guardian |language=en-GB |issn=0261-3077}}</ref><ref>{{Cite journal |last1=Kim |first1=Keon-Han |last2=Chung |first2=Youngkun |last3=Kenyon |first3=Philip |last4=Tran |first4=Thi Nhung |last5=Rees |first5=Nicholas H. |last6=Choi |first6=Seung-Ju |last7=Huang |first7=Xiaopeng |last8=Choi |first8=Jong Hui |last9=Scotland |first9=Phelecia |last10=Kim |first10=Sion |last11=Ateia |first11=Mohamed |last12=Lee |first12=Do-Kyoung |last13=Tour |first13=James M. |last14=Alvarez |first14=Pedro J. J. |last15=Wong |first15=Michael S. |display-authors=4 |date=2026 |title=Regenerable Water Remediation Platform for Ultrafast Capture and Mineralization of Per- and Polyfluoroalkyl Substances |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202509842 |journal=Advanced Materials |language=en |volume=38 |issue=1 |article-number=e09842 |doi=10.1002/adma.202509842 |issn=1521-4095 |pmid=40996360 |url-access=subscription}}</ref>) * Membrane filtration (reverse osmosis, nanofiltration<ref name="12treatment" />) * Foam fractionation<ref>{{Cite journal |last1=Burns |first1=David J. |last2=Hinrichsen |first2=Helena M. |last3=Stevenson |first3=Paul |last4=Murphy |first4=Peter J. C. |date=June 1, 2022 |title=Commercial-scale remediation of per- and polyfluoroalkyl substances from a landfill leachate catchment using Surface-Active Foam Fractionation (SAFF®) |journal=Remediation Journal |volume=32 |issue=3 |pages=139–150 |bibcode=2022RemJ...32..139B |doi=10.1002/rem.21720 |issn=1051-5658 |doi-access=free}}</ref> * Precipitation/flocculation/coagulation * Supercritical water oxidation<ref name="Destroy">{{cite magazine |last=Fischer |first=Lars |date=January 31, 2022 |title=How to Destroy 'Forever Chemicals' |url=https://www.scientificamerican.com/article/how-to-destroy-forever-chemicals/ |magazine=Scientific American}}</ref> * Photodegradation<ref>{{Cite journal |last1=Bertucci |first1=Simone |last2=Lova |first2=Paola |date=May 2024 |title=Exploring Solar Energy Solutions for Per- and Polyfluoroalkyl Substances Degradation: Advancements and Future Directions in Photocatalytic Processes |journal=Solar RRL |volume=8 |issue=9 |article-number=2400116 |doi=10.1002/solr.202400116 |issn=2367-198X |doi-access=free}}</ref>
Private and public sector applications of one or more of these methodologies above are being applied to remediation sites throughout the United States and other international locations.<ref>{{cite web |date=August 23, 2018 |title=Reducing PFAS in Drinking Water with Treatment Technologies |url=https://www.epa.gov/sciencematters/reducing-pfas-drinking-water-treatment-technologies |website=Science Matters |publisher=United States Environmental Protection Agency}}</ref>
The US-based Interstate Technology and Regulatory Council (ITRC) has undertaken an extensive evaluation of ex-situ and in-situ treatment technologies for PFAS-impacted liquid matrices. These technologies are divided into field-implemented technologies, limited application technologies, and developing technologies and typically fit into one of three technology types, namely separation, concentration, and destruction.<ref name="12treatment">{{Cite web |title=12 Treatment Technologies |url=https://pfas-1.itrcweb.org/12-treatment-technologies/ |work=Interstate Technology and Regulatory Council}}</ref>
==== Stripping and enrichment ====
Foam Fractionation utilizes the air/water interface of a rising air bubble to collect and harvest PFAS molecules. The hydrophobic tail of many long-chain criteria PFAS compounds adhere to this interface and rise to the water surface with the air bubble where they present as a foam for harvesting and further concentration. The foam fractionation technique is a derivation of traditional absorptive bubble separation techniques used by industries for decades to extract amphiphilic contaminants. The absence of a solid absorptive surface reduces consumables and waste byproducts and produces a liquid hyper-concentrate which can be fed into one of the various PFAS destruction technologies. Across various full-scale trials and field applications, this technique provides a simplistic and low operational cost alternative for complex PFAS-impacted waters.<ref>{{Cite journal |last1=We |first1=Angel Chyi En |last2=Zamyadi |first2=Arash |last3=Stickland |first3=Anthony D. |last4=Clarke |first4=Bradley O. |last5=Freguia |first5=Stefano |date=March 5, 2024 |title=A review of foam fractionation for the removal of per- and polyfluoroalkyl substances (PFAS) from aqueous matrices |journal=Journal of Hazardous Materials |volume=465 |article-number=133182 |bibcode=2024JHzM..46533182W |doi=10.1016/j.jhazmat.2023.133182 |issn=0304-3894 |pmid=38071776 |doi-access=free}}</ref>
==== Destruction ====
High-temperature incineration of sewage sludge reduces the levels of perfluorinated compounds significantly.<ref>{{cite journal |last1=Loganathan |first1=Bommanna G. |last2=Sajwan |first2=Kenneth S. |last3=Sinclair |first3=Ewan |last4=Kurunthachalam Senthil |first4=Kumar |last5=Kannan |first5=Kurunthachalam |date=December 2007 |title=Perfluoroalkyl sulfonates and perfluorocarboxylates in two wastewater treatment plant facilities in Kentucky and Georgia |journal=Water Research |volume=41 |issue=20 |pages=4611–4620 |doi=10.1016/j.watres.2007.06.045 |pmid=17632203}}</ref>
A heat- and pressure-based technique known as ''supercritical water oxidation'' destroys 99% of the PFAS present in a water sample. During this process, oxidizing substances are added to PFAS-contaminated water and then the liquid is heated above its critical temperature of 374 degrees Celsius at a pressure of more than 220 bars. The water becomes supercritical, and, in this state, PFAS dissolve much more readily.<ref name=Destroy/>
==== Theoretical and early-stage methods ====
A possible method PFAS-contaminated wastewater treatment has been developed by the Michigan State University-Fraunhofer team. Boron-doped diamond electrodes are used for the electrochemical oxidation system where it is capable of breaking PFAS molecular bonds which essentially eliminates the contaminates, leaving fresh water.<ref>{{cite news |last=Cameron |first=Layne |date=October 9, 2018 |title=Diamond technology cleans up PFAS-contaminated wastewater |url=https://msutoday.msu.edu/news/2018/diamond-technology-cleans-up-pfas-contaminated-wastewater |url-status=live |archive-url=https://web.archive.org/web/20181219182632/https://msutoday.msu.edu/news/2018/diamond-technology-cleans-up-pfas-contaminated-wastewater/ |archive-date=19 December 2018 |work=Michigan State University}}</ref>
''Acidimicrobium'' sp. strain A6 has been shown to be a PFAS and PFOS remediator.<ref>{{cite web |last=Mandelbaum |first=Ryan F. |date=September 18, 2019 |title=A New Jersey Soil Bacteria Is First to Break Down Toxic 'Forever Chemical' |url=https://gizmodo.com/a-new-jersey-soil-bacteria-is-first-to-break-down-toxic-1838215840 |url-status=live |archive-url=https://web.archive.org/web/20190920132218/https://earther.gizmodo.com/a-new-jersey-soil-bacteria-is-first-to-break-down-toxic-1838215840 |archive-date=September 20, 2019 |work=Gizmodo}}</ref> PFAS with unsaturated bonds are easier to break down: the commercial dechlorination culture KB1 (contains ''Dehalococcoides'') is capable of breaking down such substances, but not saturated PFAS. When alternative, easier-to-digest substrates are present, microbes may prefer them over PFAS.<ref>{{cite web |last=Lim |first=XiaoZhi |date=21 January 2025 |title=Can microbes save us from PFAS? |url=https://cen.acs.org/environment/persistent-pollutants/microbes-save-us-PFAS/99/i10 |url-access=subscription |work=American Chemical Society}}</ref>
Researchers at the University of Missouri demonstrated in small scale the degradation of PFAS chemicals can be done using readily available Activated Carbon at significantly lower temperatures that previously needed, 300C as opposed to 700C.<ref>{{Cite web |last=Schwinke |first=Theo |title=A material used to clean household aquariums offers a simple solution to break down forever chemicals |url=https://phys.org/news/2025-02-material-household-aquariums-simple-solution.html |access-date=2025-02-11 |website=phys.org}}</ref>
=== Chemical treatment ===
Perfluoroalkyl carboxylic acids (PFCAs) can be mineralized via heating in a polar aprotic solvent such as dimethyl sulfoxide. Heating PFCAs in an 8 to 1 mixture of dimethyl sulfoxide and water at {{cvt|80-120|C|F|0|abbr=on}} in the presence of sodium hydroxide caused the removal of the carboxylic acid group at the end of the carbon chain, creating a perfluoroanion that mineralizes into sodium fluoride and other salts such as sodium trifluoroacetate, formate, carbonate, oxalate, and glycolate. The process does not work on perfluorosulfonic acids such as PFOS.<ref>{{cite journal |vauthors=Trang B, Li Y, Xue XS, Ateia M, Houk KN, Dichtel WR |date=August 2022 |title=Low-temperature mineralization of perfluorocarboxylic acids |journal=Science |volume=377 |issue=6608 |pages=839–845 |bibcode=2022Sci...377..839T |doi=10.1126/science.abm8868 |pmid=35981038 |doi-access=free}}</ref> A 2022 study shows breakdown of C-F bonds and their mineralization as YF<sub>3</sub> or YF<sub>6</sub> clusters.<ref>{{cite journal |display-authors=6 |vauthors=Abbas M, Maceda AM, Firouzi HR, Xiao Z, Arman HD, Shi Y, Zhou HC, Balkus KJ |date=December 2022 |title=Fluorine extraction from organofluorine molecules to make fluorinated clusters in yttrium MOFs |journal=Chemical Science |volume=13 |issue=48 |pages=14285–14291 |doi=10.1039/D2SC05143E |pmc=9749115 |pmid=36545134}}</ref> Another study described the PFAS breakdown using metal-organic frameworks (MOFs).<ref>{{cite journal |display-authors=6 |vauthors=Wen Y, Rentería-Gómez Á, Day GS, Smith MF, Yan TH, Ozdemir RO, Gutierrez O, Sharma VK, Ma X, Zhou HC |date=July 2022 |title=Integrated Photocatalytic Reduction and Oxidation of Perfluorooctanoic Acid by Metal-Organic Frameworks: Key Insights into the Degradation Mechanisms |journal=Journal of the American Chemical Society |volume=144 |issue=26 |pages=11840–11850 |bibcode=2022JAChS.14411840W |doi=10.1021/jacs.2c04341 |pmid=35732040 |s2cid=249956841}}</ref>
=== Constructed wetlands ===
Constructed wetlands are planted, saturated areas designed to mimic natural processes of human benefit, most commonly waste or stormwater management.<ref name="Awad-2024">{{Cite journal |last1=Awad |first1=John |last2=Navarro |first2=Divina |last3=Kirby |first3=Jason |last4=Walker |first4=Christopher |last5=Juhasz |first5=Albert |date=2024-12-16 |title=Long-term management of PFAS contaminated water using constructed floating wetlands: Opportunities, limitations, and implementation considerations |journal=Critical Reviews in Environmental Science and Technology |volume=54 |issue=24 |pages=1709–1733 |bibcode=2024CREST..54.1709A |doi=10.1080/10643389.2024.2360762 |hdl=11541.2/39097 |issn=1064-3389 |hdl-access=free}}</ref><ref name="Wetlands-2015">{{Cite web |date=2015-09-23 |title=Constructed Wetlands |url=https://www.epa.gov/wetlands/constructed-wetlands |access-date=2025-06-02 |publisher=United States Environmental Protection Agency}}</ref> Removal of contaminants occurs by processes of plant-uptake, adherence to substrates, microbial degradation, and UV exposure. The recent public concern towards PFAS chemicals has sparked research efforts towards CWs as a treatment method for wastewater, stormwater, and landfill leachate. Granular Activated carbon has the highest average removal rate as a substrate, with biochar (charcoal) as a low cost and environmentally friendlier alternative.<ref name="Savvidou-2024">{{Cite journal |last1=Savvidou |first1=Pinelopi |last2=Dotro |first2=Gabriela |last3=Campo |first3=Pablo |last4=Coulon |first4=Frederic |last5=Lyu |first5=Tao |date=2024-07-15 |title=Constructed wetlands as nature-based solutions in managing per-and poly-fluoroalkyl substances (PFAS): Evidence, mechanisms, and modelling |url=https://www.sciencedirect.com/science/article/pii/S0048969724033849 |journal=Science of the Total Environment |volume=934 |article-number=173237 |bibcode=2024ScTEn.93473237S |doi=10.1016/j.scitotenv.2024.173237 |issn=0048-9697 |pmid=38761940}}</ref> Magnetite and quartz sand mixes have been shown to be preferable in certain applications.<ref name="Amen-2023">{{Cite journal |last1=Amen |first1=Rabia |last2=Ibrahim |first2=Alhassan |last3=Shafqat |first3=Waqar |last4=Hassan |first4=El Barbary |date=2023-11-21 |title=A Critical Review on PFAS Removal from Water: Removal Mechanism and Future Challenges |journal=Sustainability |volume=15 |issue=23 |article-number=16173 |bibcode=2023Sust...1516173A |doi=10.3390/su152316173 |issn=2071-1050 |doi-access=free}}</ref> Overall performance of the wetland is a balance between its hydraulic loading rate and retention time. Beneficial plant species for PFAS uptake are characterized by having a high root surface area, high protein content, are easily harvested, and degrade slowly in nature. Some species are ''Eichhornia (Pontederia) crassipes, Cyperus alternifolius'', and ''Ceratophyllum demersum.'' Removal is normally done by harvesting of mature plants.<ref name="Wetlands-2015"/><ref name="Savvidou-2024"/>
Biodegradation is limited to the strong C-F bonds that characterize PFAS molecules. In experiments ''Acidimicrobium'' bacterium- A6 has shown the ability to detoxify waters. ''Rhizobacter'', '' Burkholderia'', ''Nitrosomonas'', ''Nitrospira'', and ''Opitutus'' can strip fluorine atoms from the central carbon chain in iron mineral-based wetlands. The introduction of a 1:2 gravel magnetite mix can increase the CW's biological ability to degrade PFAS.<ref name="Amen-2023"/> Several fungi have effectively degraded PFAS in isolated experiments. A primary concern of managing PFAS with CWs is the high concentration of exposure pathways to fauna.<ref name="Awad-2024" /> Machine learning based neural networks have demonstrated superior efficiency in modeling emerging contaminant removal when there is limited knowledge on chemical specific properties.<ref name="Awad-2024"/>
== Analytical methods ==
Analytical methods for PFAS analysis fall into one of two general categories; targeted analysis and non-targeted analysis. Targeted analysis generally use liquid chromatography–mass spectrometry (LC-MS) instruments. Currently, EPA Method 537.1 is approved for use in drinking water and includes 18 PFAS.<ref>{{Cite web |date=2020-03-19 |title=Method 537.1. Determination of Selected Per- and Polyflourinated Alkyl Substances in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) |url=https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=348508&Lab=CESER&simpleSearch=0&showCriteria=2&searchAll=537.1&TIMSType=&dateBeginPublishedPresented=03/24/2018 |archive-url=https://web.archive.org/web/20200401193759/https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=348508&Lab=CESER&simpleSearch=0&showCriteria=2&searchAll=537.1&TIMSType=&dateBeginPublishedPresented=03%2F24%2F2018 |archive-date=1 April 2020 |website=Science Inventory |publisher=United States Environmental Protection Agency}}</ref> EPA Method 1633 is undergoing review for use in wastewater, surface water, groundwater, soil, biosolids, sediment, landfill leachate, and fish tissue for 40 PFAS, but is currently being used by many laboratories in the United States.<ref>{{Cite web |date=2024-12-09 |title=CWA Analytical Methods for Per- and Polyfluorinated Alkyl Substances |url=https://www.epa.gov/cwa-methods/cwa-analytical-methods-and-polyfluorinated-alkyl-substances-pfas |website=Clean Water Act Analytical Methods |publisher=United States Environmental Protection Agency}}</ref> Fast flow SPE has been discovered as a optimized version of Method 1633A to lower the turnover time and Method Detection Limit (MDL).<ref>{{Cite journal |last1=Timalsina |first1=Deepak |last2=Ramisetty |first2=Bhargavi Srija |last3=Wang |first3=Michael Zhuo |date=2026-03-30 |title=Achieving sub-part per trillion trace level PFAS quantification in drinking water using an optimized fast flow solid-phase extraction and UPLC-MS/MS method |journal=PLOS Water |language=en |volume=5 |issue=3 |article-number=e0000501 |doi=10.1371/journal.pwat.0000501 |doi-access=free |issn=2767-3219}}</ref> Regulatory limits for PFOA and PFOS set by the US EPA (4 parts-per-trillion) are limited by the capability of methods to detect low level concentrations.<ref>{{Cite web |date=2024-03-14 |title=Biden-Harris Administration Proposes First-Ever National Standard to Protect Communities from PFAS in Drinking Water |url=https://www.epa.gov/newsreleases/biden-harris-administration-proposes-first-ever-national-standard-protect-communities |publisher=United States Environmental Protection Agency |id=News release}}</ref>
Non-targeted analyses include total organic fluorine (TOF, including variations, e.g., adsorbable organic fluorine, AOF; extractable organic fluorine, EOF) by combustion ion chromatography (CIC), total oxidizable precursor assay, and other methods in development.<ref>{{Cite journal |last1=Ateia |first1=Mohamed |last2=Chiang |first2=Dora |last3=Cashman |first3=Michaela |last4=Acheson |first4=Carolyn |date=April 11, 2023 |title=Total Oxidizable Precursor (TOP) Assay─Best Practices, Capabilities and Limitations for PFAS Site Investigation and Remediation |journal=Environmental Science & Technology Letters |volume=10 |issue=4 |pages=292–301 |bibcode=2023EnSTL..10..292A |doi=10.1021/acs.estlett.3c00061 |issn=2328-8930 |pmc=10259459 |pmid=37313434}}</ref><ref>{{Cite journal |last1=Wang |first1=Qi |last2=Ruan |first2=Yuefei |last3=Yuen |first3=Calista N.T. |last4=Lin |first4=Huiju |last5=Yeung |first5=Leo W.Y. |last6=Leung |first6=Kenneth M.Y. |last7=Lam |first7=Paul K.S. |date=December 2023 |title=Tracing per- and polyfluoroalkyl substances (PFASs) in the aquatic environment: Target analysis and beyond |journal=TrAC Trends in Analytical Chemistry |volume=169 |article-number=117351 |doi=10.1016/j.trac.2023.117351 |hdl=2031/24f1b07f-0308-46aa-b21f-723d73aa78b8 |doi-access=free |hdl-access=free}}</ref> For the determination of AOF in water samples, the standards EPA Method 1621 and ISO 18127 were developed. Both standards use combustion ion chromatography for the analysis. <ref>{{cite web |title = ISO 18127:2026 – Water quality – Determination of adsorbable organically bound fluorine, chlorine, bromine and iodine (AOF, AOCl, AOBr, AOI) – Method using combustion and subsequent ion chromatographic measurement |url = https://www.iso.org/standard/85176.html |website = International Organization for Standardization (ISO) |publisher = ISO |date = 2026 |access-date = 14 April 2026 }}</ref><ref>{{cite web |title = Method 1621: Determination of Adsorbable Organic Fluorine (AOF) in Aqueous Matrices by Combustion Ion Chromatography (CIC) |url = https://www.epa.gov/system/files/documents/2024-01/method-1621-for-web-posting.pdf |website = United States Environmental Protection Agency |publisher = U.S. EPA |date = January 2024 |access-date = 14 April 2026 }}</ref>
Detection technology for PFAS using amplifying fluorescent polymers (AFPs) is attracting attention as a rapid and highly sensitive on-site detection method that can replace conventional mass spectrometry.<ref>{{Cite journal |last1=Concellón |first1=Alberto |last2=Castro-Esteban |first2=Jesús |last3=Swager |first3=Timothy M. |date=May 24, 2023 |title=Ultratrace PFAS Detection Using Amplifying Fluorescent Polymers |url=https://zaguan.unizar.es/record/132256/files/texto_completo.pdf |journal=Journal of the American Chemical Society |language=en |volume=145 |issue=20 |pages=11420–11430 |doi=10.1021/jacs.3c03125 |issn=0002-7863 |pmid=37167538 |bibcode=2023JAChS.14511420C }}</ref><ref>{{Cite journal |last1=Chugh |first1=Vibhas |last2=Gaskin |first2=Paul |last3=Zhang |first3=Waye |date=2026 |title=Recent progress in current and emerging techniques for the detection of PFAS – the forever chemicals |journal=Sensors & Diagnostics |language=en |volume=5 |issue=3 |pages=305–325 |doi=10.1039/D5SD00166H|doi-access=free }}</ref>
== In popular culture ==
=== Films ===
* ''The Devil We Know'' (2018): a documentary detailing the health dangers of PFAS.<ref>{{Cite web |title=THE DEVIL THEY KNEW: PFAS CONTAMINATION AND THE NEED FOR CORPORATE ACCOUNTABILITY |url=https://www.congress.gov/event/116th-congress/house-event/LC64180/text |access-date=2026-03-02 |website=www.congress.gov}}</ref> * ''Dark Waters'' (2019): a thriller movie based on the corporate defense of PFAS and DuPont.<ref>{{Cite web |date=2024-05-09 |title='Dark Waters', a Gripping Film Uncovering a US PFAS Pollution Scandal Now Available on Netflix |url=https://chemtrust.org/news/dark-waters-on-netflix/ |access-date=2026-03-02 |website=CHEM Trust |language=en-US}}</ref> * ''Contaminated: The Carpet Industry's Toxic Legacy'' (2026): documentary about the history of PFAS and the carpet industry.<ref>{{Cite web |title="Contaminated": New Documentary Investigates the Carpet Industry's Toxic PFAS Legacy in the South |url=https://www.pbs.org/wgbh/frontline/announcement/contaminated-new-documentary-investigates-the-carpet-industrys-toxic-pfas-legacy-in-the-south/ |access-date=2026-04-28 |website=FRONTLINE {{!}} PBS {{!}} Official Site {{!}} Documentary Series |language=en}}</ref> * ''Everywhere & Forever: Blood. Water. And the Politics of PFAS'' (2025): a documentary about PFAS and the struggles to manage the contamination.<ref>{{Cite web |last=Augustine |first=Joe |date=2025-07-29 |title=Watch the 3M PFAS documentary {{!}} Everywhere & Forever: Blood. Water. And the Politics of PFAS |url=https://www.fox9.com/news/everywhere-forever-blood-water-politics-pfas-documentary |access-date=2026-04-28 |website=FOX 9 |language=en-US}}</ref> * ''Revealed: How to Poison A Planet'' (2024): a documentary detailing the negative externalities from PFAS creation.<ref>{{Cite web |title="How to Poison a Planet" Documentary Tells the True Story of PFAS Contamination |url=https://levinlaw.com/newsroom/how-to-poison-a-planet/ |access-date=2026-04-28 |website=Levin Law |language=en-US}}</ref>
== See also == <!---♦♦♦ Please keep the list in alphabetical order ♦♦♦---> * Entegris, formerly Fluoroware, of Chaska, MN, manufacturer of teflon components for health and semiconductor Fabs * Euthenics, as the general category for policy interventions aiming to mitigate associated effects on human populations * Fluoropolymer, subclass of per- and polyfluoroalkyl substances * FSI International, now TEL FSI * Persistent, bioaccumulative and toxic substances * Polytetrafluoroethylene (PTFE) * Timeline of events related to per- and polyfluoroalkyl substances
== References ==
{{reflist|30em}}
== Further reading ==
{{refbegin}} * Lerner, Sharon, "You Make Me Sick: How corporate scientists discovered – and then helped to conceal – the dangers of forever chemicals", ''The New Yorker'', 27 May 2024, pp. 38–47. * {{cite journal |vauthors=Lindstrom AB, Strynar MJ, Libelo EL |date=October 2011 |title=Polyfluorinated compounds: past, present, and future |journal=Environmental Science & Technology |volume=45 |issue=19 |pages=7954–7961 |bibcode=2011EnST...45.7954L |doi=10.1021/es2011622 |pmid=21866930 |s2cid=206946893}} * {{cite journal |vauthors=Ritter SK |date=July 13, 2015 |title=The Shrinking Case For Fluorochemicals |url=https://cen.acs.org/articles/93/i28/Shrinking-Case-Fluorochemicals.html |url-status=live |journal=Chemical & Engineering News |volume=93 |issue=28 |pages=27–29 |doi=10.1021/cen-09328-scitech1 |url-access=limited |archive-url=https://web.archive.org/web/20160818040400/http://cen.acs.org/articles/93/i28/Shrinking-Case-Fluorochemicals.html |archive-date=August 18, 2016}} * {{cite journal |vauthors=Lehmler HJ |date=March 2005 |title=Synthesis of environmentally relevant fluorinated surfactants—a review |journal=Chemosphere |volume=58 |issue=11 |pages=1471–1496 |bibcode=2005Chmsp..58.1471L |doi=10.1016/j.chemosphere.2004.11.078 |pmid=15694468}} {{refend}}
== External links == {{Commonscat}} * [https://ntp.niehs.nih.gov/research/topics/pfas Per- and Polyfluoroalkyl Substances (PFAS)] at the National Toxicology Program * [https://www.atsdr.cdc.gov/pfas/ Per- and Polyfluoroalkyl Substances and Your Health] at the Agency for Toxic Substances and Disease Registry * [https://www.epa.gov/pfas Per- and Polyfluoroalkyl Substances (PFAS)] at the EPA * [https://echa.europa.eu/hot-topics/perfluoroalkyl-chemicals-pfas Per- and polyfluoroalkyl substances (PFASs)] at the European Chemicals Agency * [https://www.lemonde.fr/en/les-decodeurs/article/2023/02/23/forever-pollution-explore-the-map-of-europe-s-pfas-contamination_6016905_8.html PFAS contamination map of Europe] * https://www.cdc.gov/niosh/pfas/ Per- and Polyfluoroalkyl substances], National Institute for Occupational Safety and Health * [https://foreverpollution.eu/ The Forever Pollution Project – Journalists tracking PFAS across Europe] * [https://onesearch.slq.qld.gov.au/permalink/61SLQ_INST/tqqf2h/alma99183795520502061 PFAS contamination in Queensland, Australia], State Library of Queensland * {{Cite episode |title=Contaminated: The Carpet Industry's Toxic Legacy |url=https://www.pbs.org/wgbh/frontline/documentary/contaminated-the-carpet-industrys-toxic-legacy/ |series=Frontline |series-link=Frontline (American TV program) |network=PBS |station=WGBH |date=February 3, 2026 |season=44 |number=8 |access-date=February 25, 2026}}
{{Authority control}}
Category:Chemical hazards Category:Environment and health Category:Organofluorides Category:Pollutants Category:Surfactants