Sources of information:

  1. 01

    More than 98% of a nationally representative US sample had detectable PFOS, PFOA, PFHxS and PFNA in serum.

    Calafat AM, Wong LY, Kuklenyik Z, Reidy JA, Needham LL. Polyfluoroalkyl chemicals in the U.S. population: NHANES 2003–2004 and comparisons with NHANES 1999–2000. Environmental Health Perspectives 2007;115(11):1596–1602. CDC Stacks record

  2. 02

    Six PFAS were detected in 100% of 72 participants; oat beta-glucan lowered long-chain PFAS in a randomized, placebo-controlled trial.

    Schlezinger JJ, et al. PFAS in circulation in a Canadian population: association with serum liver enzyme biomarkers and piloting a novel method to reduce serum PFAS. Environmental Health 2025. doi:10.1186/s12940-025-01165-8

  3. 03

    After exposure ended, half-lives were about 3.4 years for PFOS, 5.3 for PFHxS and 2.7 for PFOA.

    Li Y, Fletcher T, Mucs D, et al. Half-lives of PFOS, PFHxS and PFOA after end of exposure to contaminated drinking water. Occupational and Environmental Medicine 2018;75:46–51. doi:10.1136/oemed-2017-104651

  4. 04

    PFOA classified as carcinogenic to humans (IARC Group 1); PFOS as possibly carcinogenic (Group 2B).

    Zahm S, Bonde JP, Chiu WA, et al. Carcinogenicity of perfluorooctanoic acid and perfluorooctanesulfonic acid. The Lancet Oncology 2024;25(1):16–17. doi:10.1016/S1470-2045(23)00622-8

  5. 05

    Sufficient evidence of association with decreased antibody response, dyslipidemia, decreased infant and fetal growth, and kidney cancer.

    National Academies of Sciences, Engineering, and Medicine. Guidance on PFAS Exposure, Testing, and Clinical Follow-Up. Washington, DC: The National Academies Press; 2022. doi:10.17226/26156

  6. 06

    PFAS measured in American Red Cross adult blood donors across collections from 2000 to 2015.

    Olsen GW, Mair DC, Lange CC, et al. Per- and polyfluoroalkyl substances (PFAS) in American Red Cross adult blood donors, 2000–2015. Environmental Research 2017;157:87–95. PubMed 28528142

  7. 07

    Plastic particles quantified in the blood of 17 of 22 healthy volunteers.

    Leslie HA, van Velzen MJM, Brandsma SH, Vethaak AD, Garcia-Vallejo JJ, Lamoree MH. Discovery and quantification of plastic particle pollution in human blood. Environment International 2022;163:107199. doi:10.1016/j.envint.2022.107199

  8. 08

    Regular plasma or whole-blood donation lowered serum PFAS over 12 months in a randomized clinical trial.

    Gasiorowski R, Forbes MK, Silver G, et al. Effect of plasma and blood donations on levels of perfluoroalkyl and polyfluoroalkyl substances in firefighters in Australia: a randomized clinical trial. JAMA Network Open 2022;5(4):e226257. doi:10.1001/jamanetworkopen.2022.6257

  9. 09

    Cholestyramine reduced serum PFOS by a mean of 60% during treatment in 45 highly exposed adults.

    Møller JJ, Lyngberg AC, Hammer PEC, et al. Substantial decrease of PFAS with anion exchange resin treatment: a clinical cross-over trial. Environment International 2024. PubMed 38367552

  10. 10

    Earlier case series: cholestyramine increased gastrointestinal elimination of perfluorinated compounds.

    Genuis SJ, Curtis L, Birkholz D. Gastrointestinal elimination of perfluorinated compounds using cholestyramine and Chlorella pyrenoidosa. ISRN Toxicology 2013;2013:657849. doi:10.1155/2013/657849

  11. 11

    Most PFAS in blood are bound to serum proteins; shorter chains bind mainly to albumin, longer chains (seven or more carbons) increasingly to globulins.

    Fischer FC, Ludtke S, Thackray C, et al. Binding of per- and polyfluoroalkyl substances (PFAS) to serum proteins: implications for toxicokinetics in humans. Environmental Science & Technology 2024;58(2):1055–1063. doi:10.1021/acs.est.3c07415

  12. 12

    The carbon–fluorine bond is the strongest single bond in organic chemistry.

    O’Hagan D. Understanding organofluorine chemistry. An introduction to the C–F bond. Chemical Society Reviews 2008;37:308–319. doi:10.1039/B711844A

  13. 13

    The federal drinking-water limit for PFOA and for PFOS is 4.0 parts per trillion each. In 2026 EPA proposed more time for utilities to comply but kept both limits.

    U.S. Environmental Protection Agency. PFAS National Primary Drinking Water Regulation. Federal Register 89 FR 32532, 26 April 2024. Federal Register 2024-07773

  14. 14

    EPA’s chemical database lists more than 14,000 PFAS structures.

    U.S. Environmental Protection Agency. CompTox Chemicals Dashboard, PFAS structure list (PFASSTRUCT). EPA CompTox PFASSTRUCT