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Cited by 937Per- and polyfluoroalkyl substances researchToxic Organic Pollutants ImpactFluorine in Organic Chemistry

Per- and polyfluoroalkyl substances in water and wastewater: A critical review of their global occurrence and distribution

Open access
Kurwadkar, Sudarshan, Dane, Jason, Kanel, Sushil R., Nadagouda, Mallikarjuna N., Cawdrey, Ryan W., Ambade, Balram, Struckhoff, Garrett C., Wilkin, Richard·2022·Science of The Total Environment
DOI 10.1016/j.scitotenv.2021.151003PMC PMC10184764
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Abstract

Per- and polyfluoroalkyl substances (PFAS) are a family of fluorinated organic compounds of anthropogenic origin. Due to their unique chemical properties, widespread production, environmental distribution, long-term persistence, bioaccumulative potential, and associated risks for human health, PFAS have been classified as persistent organic pollutants of significant concern. Scientific evidence from the last several decades suggests that their widespread occurrence in the environment correlates with adverse effects on human health and ecology. The presence of PFAS in the aquatic environment demonstrates a close link between the anthroposphere and the hydrological cycle, and concentrations of PFAS in surface and groundwater range in value along the ng L−1–μg L−1 scale. Here, we critically reviewed the research published in the last decade on the global occurrence and distribution of PFAS in the aquatic environment. Ours is the first paper to critically evaluate the occurrence of PFAS at the continental scale and the evolving global regulatory responses to manage and mitigate the adverse human health risks posed by PFAS. The review reports that PFAS are widespread despite being phased out—they have been detected in different continents irrespective of the level of industrial development. Their occurrence far from the potential sources suggests that long-range atmospheric transport is an important pathway of PFAS distribution. Recently, several studies have investigated the health impacts of PFAS exposure—they have been detected in biota, drinking water, food, air, and human serum. In response to the emerging information about PFAS toxicity, several countries have provided administrative guidelines for PFAS in water, including Canada, the United Kingdom, Sweden, Norway, Germany, and Australia. In the US, additional regulatory measures are under consideration. Further, many PFAS have now been listed as persistent organic pollutants. This comprehensive review provides crucial baseline information on the global occurrence, distribution, and regulatory framework of PFAS.

AI snapshot

Written from the paper’s full text.

TL;DR

This critical review synthesizes global occurrence and distribution of PFAS in water and wastewater, with emphasis on PFOA and PFOS, and finds widespread detection across continents even after phase-outs. It also reviews regulatory responses and concludes that long-range atmospheric transport and consumer/industrial sources contribute to PFAS ubiquity.

Key findings

  • PFAS are detected globally in surface water and groundwater at ng L−1–μg L−1 levels, including remote areas; Tibetan ice cores from Mt. Muztagata (1980–1999) had PFOS at 61.4–346 pg L−1 and PFOA at 40.8–243 pg L−1, suggesting long-range atmospheric transport.
  • In the US UCMR 3 survey (2013–2015), 4% of public water systems tested positive for at least one PFAS and 1.3% exceeded the US EPA Lifetime Health Advisory of 70 ng L−1; PFOA and PFOS exceeded the LHA in 0.3% and 0.8% of systems, respectively. A 2017 analysis estimated drinking water supplies for 6 million US residents exceeded the LHA.
  • PFAS occur in drinking water worldwide; among 25 US drinking water treatment plants, cumulative PFAS average concentrations ranged from <1 to 1102 ng L−1, with median source water at 21.4 ng L−1 and treated water at 19.5 ng L−1. NHANES reported trace PFAS in 98% of human serum samples collected in 2003–2004.
  • Regulatory responses have expanded: PFOS was listed under Stockholm Convention Annex B in 2009 and PFOA under Annex A in 2019; several countries have PFAS water guidelines, while novel PFAS such as GenX chemicals and PFBS are persistent, mobile, and detected near industrial facilities.

Methods

  • Critical review of research published in the last decade on global PFAS occurrence and distribution in the aquatic environment, with literature searches focused on studies since 2000 and keywords including PFAS, PFOA, PFOS, occurrence, distribution, and POPs.
  • Sources included academic literature and reputable non-academic records from federal, state, and local government agencies; studies were screened for relevance, rigor, and focus, with priority given to PFOA and PFOS and large-scale multi-country/multi-media studies.
  • Main analysis is a narrative synthesis organized by continent and regulatory framework; no formal meta-analysis or quantitative pooling is reported.

Limitations

  • Stated: the authors note difficulty compiling all concentration and occurrence results and prioritized PFOA and PFOS and mainly large-scale multi-country studies, so not all studies, PFAS, or regions are comprehensively covered.
  • Stated: data gaps and uncertainty include lack of robust, reliable, reproducible data; unavailable data for small water systems and private wells; shortage of PFAS monitoring data in Latin America and the Caribbean; and few African studies due to limited resources, technology, and skills.
  • Evident: as a narrative critical review, no systematic search protocol, quantitative synthesis, or risk-of-bias assessment is reported.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.scitotenv.2021.151003

Cites

110 of 110 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 287 cited sources checked · 0 supported · 0 flagged

  • Findingnone given

    Concentrations of PFAS in surface and groundwater range in value along the ng L−1-μg L−1 scale.

    “concentrations of PFAS in surface and groundwater range in value along the ng L−1–μg L−1 scale.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.
  • Findingcitation

    Many PFAS have now been listed as persistent organic pollutants.

    “Further, many PFAS have now been listed as persistent organic pollutants.”
    • Also stated in: § Sources and occurrence of PFAS in the environment · plain
      “In 2009, PFOS was listed in Annex B, and in 2019 PFOA was listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites UNEP, 2019

      Not checked in the free run.

    • cites Barceló and Ruan, 2019

      Not checked in the free run.

    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.
  • Findingcitation

    Several countries have provided administrative guidelines for PFAS in water, including Canada, the United Kingdom, Sweden, Norway, Germany, and Australia.

    “several countries have provided administrative guidelines for PFAS in water, including Canada, the United Kingdom, Sweden, Norway, Germany, and Australia.”
    • Also stated in: § Evolving regulatory response to PFAS · plain
      “Several countries have published administrative guidelines for levels of PFAS in water, including Canada, the United Kingdom, Sweden, Norway, Germany, and Australia (Cheremisinoff, 2017) (Table 1).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Cheremisinoff, 2017

      Not checked in the free run.

    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.
  • Findingnone given

    In most samples from aqueous environments, PFAS concentrations range from non-detect to low ng L−1.

    “In most samples from aqueous environments, PFAS concentrations range from Non-detect (ND) - low ng L−1−.”
    Quote in the paperNot a substantial claim
  • Findingnone given

    The log Koc of PFOA and PFOS is similar to that of benzene.

    “The log Koc of PFOA and PFOS is similar to that of benzene.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 100
  • Classified as probably not a substantial claim. 30

  • May combine two claims.

    Findingnone given

    PFAS are widespread in the environment despite being phased out, and have been detected on different continents irrespective of the level of industrial development.

    “The review reports that PFAS are widespread despite being phased out—they have been detected in different continents irrespective of the level of industrial development.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    PFAS have been detected in biota, drinking water, food, air, and human serum.

    “they have been detected in biota, drinking water, food, air, and human serum.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    In the US, additional regulatory measures for PFAS are under consideration.

    “In the US, additional regulatory measures are under consideration.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The large-scale studies reviewed are representative of global PFAS occurrence and distribution.

  • May combine two claims.

    Findingnone given

    The water-solubility of PFOA is 5.3 times higher, whereas that of PFOS is 2.6 times lower compared to those of benzene.

    “The water-solubility of PFOA is 5.3 times higher, whereas that of PFOS is 2.6 times lower compared to those of benzene.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Findingnone given

    The molecular weights of PFOA and PFOS are higher than that of benzene by 5.3 and 6.4 times, respectively.

    “The molecular weights of PFOA and PFOS are higher than that of benzene by 5.3 and 6.4 times, respectively.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Findingnone given

    The boiling points of PFOA and PFOS are higher than that of benzene by 2.4 and 3.2 times, respectively, whereas their respective vapor pressures are 181 and 4760 times lower than that of benzene.

    “The boiling points of PFOA and PFOS are higher than that of benzene by 2.4 and 3.2 times, respectively, whereas their respective vapor pressures are 181 and 4760 times lower than that of benzene.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Data from the UCMR 3 survey indicated that 4% of public water systems tested positive for at least one PFAS with 1.3% of the water systems exceeded the US EPA's LHA threshold of 70 ng L−1.

    “Data from the UCMR 3 survey indicated that 4% of public water systems tested positive for at least one PFAS with 1.3% of the water systems exceeded the US EPA’s LHA threshold of 70 ng L-1.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites USEPA, 2016

      Not checked in the free run.

    • cites Crone et al., 2019 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The US military has historically been the largest consumer of AFFF, and specific sites where AFFFs were traditionally used include military bases and airports.

    “The US military has historically been the largest consumer of AFFF, and specific sites where AFFFs were traditionally used include military bases and airports (Moody and Field, 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Moody and Field, 2020

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Hydrophilic short-chain PFAS (C ≤ 8) are typically found in surface waters, whereas hydrophobic long-chain PFAS (C > 8) tend to bioaccumulate in fish tissues and sediments.

    “Their chain length and functional moieties determine their environmental occurrence and distribution with hydrophilic short-chain PFAS (C ≤ 8) typically found in surface waters, whereas the hydrophobic long-chain PFAS (C > 8) tend to bioaccumulate in fish tissues and sediments (Goodrow et al., 2020; Bai and Son, 2021).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Goodrow et al., 2020 source

      Not checked in the free run.

    • cites Bai and Son, 2021 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    WWTPs are among the most thoroughly studied point sources of PFAS in surface waters.

    “WWTPs are among the most thoroughly studied point sources of PFAS in surface waters.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Based on USGS groundwater monitoring and UCMR data, benzene was detected in 1.3% of public water supply wells between 1993 and 2007, whereas PFOA/PFOS was detected in 1% of groundwater samples monitored between 2013 and 2015.

    “Based on groundwater monitoring conducted by the United States Geological Survey (USGS) and data obtained from the Unregulated Contaminant Monitoring Rule (UCMR) program, benzene was detected in 1.3% of public water supply wells between 1993 and 2007, whereas PFOA/PFOS was detected in 1% of groundwater samples monitored between 2013 and 2015 (Newell et al., 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Newell et al., 2020 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    PFOS and PFOA are among the most commonly used PFAS, the most frequently detected in the environment, and the most researched of these compounds.

    “PFOS (C8F17SO3H) and PFOA (C7F15COOH) are among the most commonly used PFAS, and are the most frequently detected in the environment, and most researched of these compounds (Buck et al., 2011).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Buck et al., 2011 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFAS possess high polarity and strong, chemically inert carbon-fluorine bonds, giving them extremely high thermal and chemical stability.

    “They possess high polarity, and strong, chemically inert carbon-fluorine (CF) bonds, which give them unique chemical attributes, including extremely high thermal and chemical stability (Rahman et al., 2014; Fernandez et al., 2016).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Rahman et al., 2014 source

      Not checked in the free run.

    • cites Fernandez et al., 2016

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Treated effluent often contains numerous micro-pollutants, including PFAS, that may impact human health, and surface water and groundwater quality.

    “treated effluent often contains numerous micro-pollutants, including PFAS, that may impact human health, and surface water and groundwater quality (Plumlee et al., 2008; Díaz-Cruz et al., 2009; Xiao, 2017; Szabo et al., 2018).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Plumlee et al., 2008

      Not checked in the free run.

    • cites Díaz-Cruz et al., 2009

      Not checked in the free run.

    • cites Xiao, 2017 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    These unique properties make PFAS highly stable, persistent, and recalcitrant chemicals, making it difficult to manage their occurrence in soil, water, and air.

    “These unique properties of PFAS make them highly stable, persistent, and recalcitrant chemicals, thereby making it difficult to manage their occurrence in various environmental media such as soil, water, and air.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Most PFAS compounds have not been thoroughly evaluated, and their adverse impacts on human health or ecology have not been fully understood.

    “Most PFAS compounds have not been thoroughly evaluated, and their adverse impacts on human health or ecology have not been fully understood (Buck et al., 2011).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Buck et al., 2011 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The retardation factor (R) determines the relative mobility of compounds in the subsurface environment, and benzene (R = 1.305) and PFOA (R = 1.5) move at a similar rate, whereas PFOS (R = 6) moves nearly four times slower.

    “The retardation factor (R) determines the relative mobility of compounds in the subsurface environment, and benzene (R = 1.305) and PFOA (R = 1.5) move at a similar rate, whereas PFOS (R = 6) moves nearly four times slower (Newell et al., 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Newell et al., 2020 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Between 2004 and 2010, analysis of surface water samples from 41 cities in 15 countries revealed the presence of PFOS and PFOA in all samples with average concentrations ranging from non-detect to 70.1 ng L−1 for PFOS and 0.2-1630.2 ng L−1 for PFOA.

    “Between 2004 and 2010, the analysis of surface water samples from 41 cities in 15 countries revealed the presence of PFOS and PFOA in all samples with average concentrations ranging from non-detect ND – 70.1 ng L−1, and 0.2–1630.2 ng L−1, respectively (Kunacheva et al., 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Kunacheva et al., 2012

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In 2009, PFOS was listed in Annex B, and in 2019 PFOA was listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants.

    “In 2009, PFOS was listed in Annex B, and in 2019 PFOA was listed in Annex A of the Stockholm Convention on Persistent Organic Pollutants.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites UNEP, 2019

      Not checked in the free run.

    • cites Barceló and Ruan, 2019

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationnone given

    Over the last three decades, growing evidence of widespread contamination of water resources, human exposure, and the potential toxicity of PFAS has prompted action from regulatory bodies worldwide.

    “Over the last three decades, growing evidence of widespread contamination of water resources, human exposure, and the potential toxicity of PFAS has prompted action from regulatory bodies worldwide.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Bioaccumulation of PFAS varies among species within the natural food web, making it difficult to accurately assess ecological risks due to vast differences in species' habitat, exposure, and bioaccumulation.

    “Bioaccumulation of PFAS varies among species within the natural food web, making it difficult to accurately assess ecological risks due to the vast differences in species’ habitat, exposure, and bioaccumulation (Ahrens and Bundschuh, 2014).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Ahrens and Bundschuh, 2014 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    PFAS can easily undergo bioaccumulation due to their long persistence times.

    “Further, PFAS can easily undergo bioaccumulation due to their long persistence times.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    In Eastern Spain, PFAS were detected in water, sediments, and biota from the Jucar River with concentrations ranging from 0.04-83.1 ng L−1, 0.22-11.5 ng g−1, and 0.63-274 μg kg−1, respectively.

    “In Eastern Spain, PFAS were detected in water, sediments, and biota from the Jucar River with concentrations ranging from 0.04–83.1 ng L−1, 0.22–11.5 ng g−1, and 0.63–274 μg kg−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Campo et al., 2016

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Linear PFAS prefer to partition into soil and sediments, whereas branched isomers prefer to remain in the aqueous phase.

    “Linear PFAS prefer to partition into the soil and sediments, whereas the branched isomers prefer to remain in aqueous phase.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites ITRC, 2020

      Not checked in the free run.

    • cites Schulz et al., 2020 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFAS exposure may result in decreased spleen and thymus weights and cellularity, reduced production of specific antibodies, reduced survival after influenza infection, immunosuppression, and altered cytokine production.

    “PFAS exposure may result in decreased spleen and thymus weights and cellularity, reduced production of specific antibodies, reduced survival after influenza infection, immunosuppression, and altered cytokine production (Grandjean et al., 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Grandjean et al., 2012 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    The US Air Force has identified approximately 200 installations in the USA where PFAS-containing AFFFs have been used.

    “The US Air Force has identified approximately 200 installations in the USA where PFAS-containing AFFFs have been used.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Between 2003 and 2006, the annual production of PFAS-related chemicals increased significantly, leading to the frequent detection of these compounds in the aquatic environment.

    “Between 2003 and 2006, the annual production of PFAS-related chemicals increased significantly leading to the frequent detection of these compounds in the aquatic environment (Wang et al., 2015), and PFAS have been detected in seven major river systems and their main tributaries in China.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Wang et al., 2015 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    These chemicals are not currently regulated due to the lack of robust, reliable, and reproducible data.

    “These chemicals are not currently regulated due to the lack of robust, reliable, and reproducible data.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    Given the widespread occurrence of PFAS in China, there is a high likelihood of exposure to residents living in adjacent areas.

    “Given the widespread occurrence of PFAS in China, there is a high likelihood of exposure to residents living in adjacent areas.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    Considerable uncertainty surrounds the monitoring of PFAS due to various factors, including the choice of sampling locations and variation in sources.

    “Additionally, considerable uncertainty surrounds the monitoring of PFAS due to various factors, including the choice of sampling locations and variation in sources.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The measured concentrations of PFOA and PFOS in the Pearl River were lower in 2013, with PFOA at 0.71-8.7 ng/L and PFOS at 0.52-11 ng/L.

    “The measured concentrations of PFOA and PFOS in the Pearl River were lower in 2013, with PFOA at 0.71–8.7 ng L−1 and PFOS at 0.52–11 ng L−1 (Liu et al., 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Liu et al., 2018

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The current LHA limit of 70 ng L−1 for PFOA and PFOS in drinking water does not have an adequate enforcement mechanism, and manufacturers have already phased out the use of these compounds.

    “The current LHA limit of 70 ng L−1 for PFOA and PFOS in drinking water does not have an adequate enforcement mechanism, and besides, manufacturers have already phased out the use of these compounds (Dean et al., 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Dean et al., 2020

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  • May combine two claims.

    Premisecitation

    PFOS concentrations in surface waters of China, Japan, South Korea, Philippines, and Thailand ranged from ND-47, 0.02-230, 0.12-33, 0.39-4.2, and ND-54 ng/L, respectively.

    “For example, PFOS concentrations in the surface waters of China, Japan, South Korea, Philippines, and Thailand ranged from ND – 47 ng L−1, 0.02–230 ng L−1, 0.12–33 ng L−1, 0.39–4.2 ng L−1, and ND – 54 ng L−1, respectively (UNEP, 2017).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites UNEP, 2017

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  • May combine two claims.

    Premisecitation

    Both Huangpu River and Dongguan are located in an area with extensive manufacturing of electronics, plastics, and textiles.

    “Both Huangpu River and Dongguan are located in the area with extensive manufacturing of electronics, plastics, and textiles (Chen et al., 2009).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Chen et al., 2009

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  • May combine two claims.

    Premisecitation

    The maximum allowable concentration is 36 μg kg−1 for inland surface waters, and 9.1 μg kg−1 for biota; while the mean annual concentration limit is 0.65 ng L−1 for inland surface waters.

    “The maximum allowable concentration is 36 μg kg−1 for inland surface waters, and 9.1 μg kg−1 for biota; while the mean annual concentration limit is 0.65 ng L−1 for inland surface waters (Pignotti et al., 2017).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pignotti et al., 2017 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Premisenone given

    Compounds such as GenX chemicals and short-chain PFAS are being manufactured as replacements for PFOS and PFOA; however, their toxicities, bioaccumulation behaviors, persistence, and interaction with the environment are still unknown.

    “Compounds such as GenX chemicals and short-chain PFAS are being manufactured as replacements for PFOS and PFOA; however, their toxicities, bioaccumulation behaviors, persistence, and interaction with the environment are still unknown.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    The presence of ionic/neutral PFAS in leaves and tree bark could potentially be used as bioindicators for the presence of atmospheric PFAS.

    “Neutral PFAS can be converted to ionic PFAS via photochemical and biological processes; thus, the presence of ionic/neutral PFAS in leaves and tree bark could potentially be used as bioindicators for the presence of atmospheric PFAS (Q. Wang et al., 2020; S. Wang et al., 2020).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Q. Wang et al., 2020

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    • cites S. Wang et al., 2020

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    • Rests on an assumption: Ionic PFAS are more soluble and tend to accumulate in water, sediment, and soil, whereas neutral PFAS are generally more volatile and commonly found in the atmosphere.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisenone given

    In 2012, through its Water Framework Directive, the EC established a threshold concentration for PFOS in drinking water and fish for environmental quality assessment; and in 2013, it established Environmental Quality Standards against which to measure PFOS concentrations in inland surface waters and biota.

    “In 2012, through its Water Framework Directive, the EC established a threshold concentration for PFOS in drinking water and fish for environmental quality assessment; and in 2013, it established Environmental Quality Standards against which to measure PFOS concentrations in inland surface waters and biota.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Exposure to short-chain PFAS - such as perfluorohexanoic acid (PFHxA) and related fluorotelomer precursors - reportedly has negligible risks to human health based on the current environmental levels of these compounds.

    “Exposure to short-chain PFAS – such as perfluorohexanoic acid (PFHxA) and related fluorotelomer precursors – reportedly has negligible risks to human health based on the current environmental levels of these compounds (Anderson et al., 2019).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Anderson et al., 2019 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Huangpu River contained PFOA at 105 ng/L and PFOS at 5.4 ng/L.

    “The Huangpu river, a downstream tributary of the Yangtze river which flows through Shanghai Province and links Lake Taihu to eastern China, was found to contain PFOA (105 ng L−1) and PFOS (5.4 ng L−1) (Lu et al., 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lu et al., 2015

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOA was the most prevalent PFAS in samples collected from all provinces, whereas PFHxA was the most prevalent in Zhejiang province.

    “Further, PFOA was the most prevalent PFAS in samples collected from all provinces, whereas PFHxA was the most prevalent in Zhejiang province.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lu et al., 2015

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In all three provinces (Shanghai, Jiangsu, Zhejiang), PFOA was detected at higher concentrations than PFOS, especially in Zhejiang Province, where PFOA ranged 0.29-200 ng/L and PFOS ranged ND-5 ng/L.

    “In all three provinces, PFOA was detected at higher concentrations than PFOS especially in samples from Zhejiang Province, where the PFOA concentration range was 0.29–200 ng L−1 and that of PFOS was ND – 5 ng L−1 (Lu et al., 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lu et al., 2015

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  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Premisenone given

    The European Commission has declared PFAS as emerging organic contaminants, and PFOS and its derivative as priority hazardous substances.

    “The European Commission (EC) has declared PFAS as emerging organic contaminants, and PFOS and its derivative as priority hazardous substances.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    PFOS was detected in 59% of surface water samples and 45% of groundwater samples in Vietnam.

    “PFOA was detected in 98% of surface water samples and 36% of groundwater samples, while PFOS was detected in 59% of surface water samples and 45% of groundwater samples.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Duong et al., 2015 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Average PFOA concentrations in tap water and groundwater in Vietnam were 0.14 and 1.93 ng L−1, respectively.

    “The average PFOA concentrations detected in tap water and groundwater – 0.14 ng L−1 and 1.93 ng L−1, respectively – were also relatively low at the Vietnam sampling sites.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lam et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Average PFOA and PFOS concentrations in Vietnam surface waters were primarily low, below 2.3 and 0.5 ng L−1, respectively.

    “However, besides the aforementioned samples, the average PFOA and PFOS concentrations were primarily low in surface waters, measuring below 2.3 ng L−1 and 0.5 ng L−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lam et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOS was detected at only one location in the Red River, at a concentration of 0.21 ng L−1.

    “PFOA concentrations in the Red River were generally low, ranging from 0.16–0.52 ng L−1, and PFOS was detected at only one location at a concentration of 0.21 ng L−1 (Duong et al., 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Duong et al., 2015 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Duong et al. (2015) reported that PFOA and PFOS were among the most detected PFAS in urban river waters in Vietnam, with maximum concentrations of 18 and 5.3 ng L−1, respectively.

    “Duong et al. (2015) focused on the occurrence of PFAS in Vietnam and reported that PFOA and PFOS were among the most detected PFAS in urban river waters at maximum concentrations of 18 and 5.3 ng L−1, respectively; while the maximum concentrations of these pollutants detected in groundwater were 4.5 and 8.2 ng L−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Duong et al., 2015 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOA was detected in 98% of surface water samples and 36% of groundwater samples in Vietnam.

    “PFOA was detected in 98% of surface water samples and 36% of groundwater samples, while PFOS was detected in 59% of surface water samples and 45% of groundwater samples.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Duong et al., 2015 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    PFAS pollution in groundwater in the Ganges region is likely due to infiltration, spills, and the use of river water for irrigation.

    “The emissions from urban residents living along the bank of the Ganges River are likely responsible for PFCAs and PFSAs pollution, whereas PFAS pollution in groundwater is likely due to infiltration, spills, and the use of river water for irrigation purposes.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Sharma et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Twelve of the 13 remote surface water samples contained PFAS, with maximum measured concentrations of 0.4 ng/L for PFOA and 2.4 ng/L for PFOS.

    “Twelve of the samples contained PFAS with maximum measured concentrations of 0.4 ng L−1 and 2.4 ng L−1 for PFOA and PFOS, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jin et al., 2009

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The Yangtze River flows through multiple urban, industrial, and commercial areas and is therefore vulnerable to PFAS pollution.

    “The Yangtze River, for example, flows through multiple urban, industrial, and commercial areas and is therefore vulnerable to PFAS pollution.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The Daling River discharged 40.57 kg/y of PFOA and 1.74 kg/y of PFOS into the Bohai Sea.

    “For example, the Daling River, located in one of the most developed regions of northern China, had discharged 40.57 kg y−1 and 1.74 kg y−1 of PFOA and PFOS, respectively, into the Bohai sea (Li et al., 2017).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Li et al., 2017

      Not checked in the free run.

    • Rests on an assumption: The unregulated discharge of industrial wastewater is a major source of PFAS.

  • May combine two claims.

    Premisecitation

    In groundwater samples from the Ganges region, PFBA and PFBS had the highest concentrations among PFCAs and PFSAs, respectively.

    “The discharge of PFOA and PFOS to the Ganges River varied dramatically along the transect (0.2–190 and 0.03–150 g d−1, respectively), and in groundwater samples, perfluorobutanoic acid (PFBA) and PFBS had the highest concentrations among PFCAs and PFSAs, respectively (Sharma et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sharma et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOA was the most abundant PFAS detected in the aqueous phase of an urban water reservoir in Singapore, followed by PFOS and PFHxS.

    “PFOA was the most abundant PFAS detected in the aqueous phase, followed by PFOS and PFHxS, with average concentrations of 58, 31, and 25 ng L−1, respectively (Nguyen et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Nguyen et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The observation that higher PFAS concentrations occur in industrialized and urbanized areas is consistent with established research indicating that increases in PFAS concentrations in surface waters are related to trends in industrialization and urbanization, which are expected to increase across China.

    “This observation is consistent with established research which indicates that the increase in the concentration of PFAS in surface waters is related to trends in industrialization and urbanization, which are expected to increase across China (Chen et al., 2009; Bao et al., 2011; B. Wang et al., 2013; X. Wang et al., 2013; Lu et al., 2015; Li et al., 2017).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Chen et al., 2009

      Not checked in the free run.

    • cites Bao et al., 2011

      Not checked in the free run.

    • cites B. Wang et al., 2013

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The presence of PFAS in China's major river systems is not surprising, as numerous industrial areas are positioned along these rivers.

    “The presence of PFAS in China’s major river systems is not surprising, as numerous industrial areas are positioned along these rivers.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    PFOS was detected in all five Great Lakes at concentrations ranging from 0.14 to 9.5 ng L−1, with lake-specific ranges.

    “PFOS concentrations measured in these lakes ranged from 0.14–0.40 ng L−1; 1.7–2.4 ng L−1; 2.5–3.4 ng L−1; 0.24–5.5 ng L−1; and 2.6–9.5 ng L−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Silva et al. (2011) source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The lowest concentrations of PFOS and PFOA were found in Lake Superior, and the highest were found in Lake Erie and Lake Ontario, which are both downstream from Lake Superior.

    “The lowest concentrations of PFOS and PFOA were found in Lake Superior, and the highest were found in Lake Erie and Lake Ontario, which are both downstream from Lake Superior.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    PFAS were present in all drinking water samples from 25 US drinking water treatment plants, with cumulative PFAS average concentrations ranging from less than 1 ng L−1 to 1102 ng L−1.

    “A comprehensive study investigating the occurrence of 17 PFAS in source water and treated drinking water from 25 drinking water treatment plants across the United States (24 states) reported that PFAS were present in all drinking water samples with the cumulative PFAS average concentration ranging from less than 1 ng L−1 to 1102 ng L−1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Boone et al., 2019 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    75% of biosolid samples in Australia contained PFOS, making it the most frequently detected contaminant, with concentrations ranging from 4.7 to 86 μg kg−1.

    “Furthermore, 75% of biosolid samples contained PFOS, making it the most frequently detected contaminant with concentrations ranging from 4.7–86 μg kg−1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sleep and Juhasz, 2020

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOA was detected in all five Great Lakes at concentrations ranging from 0.66 to 7.2 ng L−1, with lake-specific ranges.

    “a study by Silva et al. (2011) also confirmed the presence PFOA in Lake Superior, Lake Michigan, Lake Erie, Lake Huron, and Lake Ontario, with concentrations of the pollutant ranging from 0.75–1.2 ng L−1; 3.7–5.2 ng L−1; 3.4–7.2 ng L−1; 0.66–4.3 ng L−1; and 3.3–6.7 ng L−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Silva et al. (2011) source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Recycled wastewater used for irrigation can serve as a diffuse source of PFAS and can affect groundwater quality.

    “Recycled wastewater used for irrigation purposes can serve as a diffuse source of PFAS and can affect groundwater quality.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Szabo et al., 2018

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In 2006, NJDEP detected low-level concentrations of PFOA in 58% and PFOS in 78% of water systems sampled.

    “In 2006, the New Jersey Department of Environmental Protection (NJDEP) detected low-level concentrations of PFOA and PFOS in 58% and 78% of water systems sampled, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites NJDEP, 2014

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Munoz et al. (2017) first confirmed that PFAS were present in French Guiana, Guadeloupe, Martinique, Mayotte, and Reunion, with concentrations significantly lower than those detected in metropolitan France.

    “This research was the first to confirm that PFAS were present in these regions; however, concentrations were significantly lower than those detected in metropolitan France.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Munoz et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In the 2008 Upper Mississippi River Basin study, about 80% of PFAS occurred below 10 ng L−1, while maximum PFOA and PFOS were 125 and 245 ng L−1, respectively, suggesting other point sources contributed to pollution.

    “A comprehensive study conducted during 2008 investigated the PFAS contamination in the Upper Mississippi River Basin and found that the majority of PFAS (around 80%) occurred at levels below 10 ng L−1; however, the maximum measured concentrations of PFOA and PFOS were 125 ng L−1 and 245 ng L−1, respectively, suggesting that other point sources were contributing to pollution in the river basin (Nak”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Nakayama et al., 2010 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In the NJDEP 2009-2010 study, PFAS were detected in 67% of samples, PFOA was most frequently detected in nearly 55% of samples, PFOA was detected in 92% of surface water samples at 6-100 ng L−1, and PFOS was detected in 33% of groundwater samples at 9-57 ng L−1.

    “Overall, PFAS were detected in 67% of samples, with PFOA being the most frequently detected in nearly 55% of samples. PFOA was detected in 92% of surface water samples with concentrations ranging from 6 to 100 ng L−1, and PFOS was detected in 33% of groundwater samples with concentrations ranging from 9 to 57 ng L−1 (NJDEP, 2014).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites NJDEP, 2014

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Total PFAS concentration in surface waters of Las Vegas Wash and Truckee River were 2234 ng/L and 441.7 ng/L, respectively.

    “The total PFAS concentration in surface waters of the Las Vegas Wash and Truckee River were 2234 ng L−1 and 441.7 ng L−1; while in sediments it was 345.7 μg kg−1 (dry weight) and 272.9 μg kg−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Bai and Son, 2021 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOS was not detected in bottled water, whereas PFOA was detected in 33% of samples at a mean concentration of 7.6 ng/L.

    “However, PFOS was not detected in bottled water, whereas PFOA was detected in 33% of samples at a mean concentration of 7.6 ng L−1 (Schwanz et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Schwanz et al., 2016

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In a 2017 study, 23 different PFAS were detected in surface water from rural, urban, and AFFF-impacted sites in Canada, with FHxSA most prevalent.

    “In a study published in 2017, surface water collected from rural, urban, and AFFF-impacted sites in Canada was analyzed using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) and 23 different PFAS were detected, of which perfluorohexane sulfonamide (FHxSA) was most prevalent.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites D’Agostino and Mabury, 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFAS were detected in groundwater close to several industrial sites, including oil refineries and electrical power plants, but the highest concentration of PFOS was detected in sediment and surface water samples.

    “PFAS were detected in groundwater close to several industrial sites, including oil refineries and electrical power plants, but the highest concentration of PFOS was detected in sediment and surface water samples.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Munoz et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Sulfluramid contains EtFOSA, a PFOS-precursor used in the production of insect baits for controlling leaf cutter ants.

    “Sulfluramid contains Ethyl Perfluorooctane sulfonamide (EtFOSA); a PFOS-precursor which is used in the production of insect baits with sulfluramid for controlling leaf cutter ants (Rauert et al., 2018; UNEP, 2020).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Rauert et al., 2018

      Not checked in the free run.

    • cites UNEP, 2020

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Total PFAS concentration in sediments of Las Vegas Wash and Truckee River were 345.7 μg/kg dry weight and 272.9 μg/kg, respectively.

    “The total PFAS concentration in surface waters of the Las Vegas Wash and Truckee River were 2234 ng L−1 and 441.7 ng L−1; while in sediments it was 345.7 μg kg−1 (dry weight) and 272.9 μg kg−1, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Bai and Son, 2021 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOSAs were detected in all soil samples from agricultural areas in Southern Ontario amended with wastewater biosolids, with concentrations ranging from 41.87-622.46 ng/g dry weight and a mean concentration of 236.36 ng/g.

    “They also analyzed 13 soil samples collected from agricultural areas in Southern Ontario, Canada, amended with wastewater biosolids, and detected PFOSAs in all soil samples with concentrations ranging from 41.87–622.46 ng g−1 (dry weight) with a mean concentration of 236.36 ng g−1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Chu and Letcher, 2017

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Drinking water provides an exposure pathway for the population of Brazil because both bottled water and tap water are contaminated with some level of PFAS.

    “Given that both bottled water and tap water are contaminated with some level of PFAS, drinking water certainly provides an exposure pathway for the population of Brazil.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    PFOSAs were present in all sediment samples from western Lake Erie and Saginaw Bay, with concentrations ranging from 0.18-461.59 ng/g dry weight.

    “The results indicated that perfluorooctane sulfonamides (PFOSAs) were present in all sediment samples, with concentrations ranging from 0.18–461.59 ng g−1 (dry weight).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Chu and Letcher, 2017

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Critical data gaps exist for small water systems and private wells, from which nearly one-third of the American public receives its water supply.

    “Furthermore, the study also indicated some critical data gaps, including unavailable data for small water systems and private wells, from which nearly one-third of the American public receives its water supply (Hu et al., 2016).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hu et al., 2016

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Lake Mead, downstream from Las Vegas Wash, is a source of drinking water to 30 million residents.

    “Lake Mead, which is located downstream from the Las Vegas Wash, is a source of drinking water to 30 million residents and has registered seasonal PFAS concentrations of 271.9 and 14.8 ng L−1 in winter and summer, respectively (Bai and Son, 2021).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Bai and Son, 2021 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Washington State Department of Ecology 2008 statewide survey found PFOA in concentrations from below the limit of quantification to 95.6 ng L−1 and PFOS from non-detect to 7.6 ng L−1 in surface waters.

    “the Washington State Department of Ecology (WDOE) conducted a statewide survey of surface waters in Spring and Fall of 2008, which found PFOA and PFOS in concentrations ranging from below the limit of quantification (LOQ) to 95.6 ng L−1 and ND – 7.6 ng L−1, respectively.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Furl and Meredith, 2010

      Not checked in the free run.

    • cites WDOE, 2010

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Washington County Landfill registered very high concentrations of PFOA (42,000 ng L−1) and PFOS (2700 ng L−1) in groundwater.

    “The Washington County Landfill is a closed, unlined landfill site that historically accepted waste from the plant and registered very high concentrations of PFOA (42,000 ng L−1) and PFOS (2700 ng L−1) in groundwater.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Oliaei et al. (2013) source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The presence of PFAS in groundwater near Upper Silver and Coyote Creeks was likely due to infiltration from the stream, but other sources could not be ruled out.

    “The presence of PFAS in groundwater was likely due to infiltration from the stream; however, other sources could not be ruled out (Plumlee et al., 2008).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Plumlee et al., 2008

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOS was detected in all tap water samples, whereas PFOA was detected in 33% of samples; both pollutants occurred at mean concentrations of 16 ng/L.

    “PFOS was detected in all tap water samples, whereas PFOA was detected in 33% of samples; both pollutants occurred at mean concentrations of 16 ng L−1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Schwanz et al., 2016

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Perfluorobutane sulfonamides were detected in 80% of sediment samples, with concentrations ranging from <0.03 to 24.08 ng/g.

    “In contrast, perfluorobutane sulfonamides were detected in 80% of sediment samples, with concentrations ranging from <0.03 to 24.08 ng g−1.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Chu and Letcher, 2017

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In June 2021, NHDES reported that 78% of 1880 drinking water sources had been sampled for PFAS; 30% of wells were contaminated with PFOA, PFOS, PFHxS, and PFNA; and 103 wells exceeded the NHDES MCL/AGQS.

    “In June 2021, NHDES released a census stating that 78% of the 1880 sources of drinking water have been sampled and analyzed for the presence of PFAS. Overall, 30% of the wells were found to be contaminated with PFOA, PFOS, PFHxS, and PFNA. Furthermore, contaminant concentration levels in 103 wells exceeded the current NHDES MCL/Ambient Groundwater Quality Standard (AGQS).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites NHDES, 2021

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFAS concentrations in drinking water from Miami, Florida, exceeded the stipulated US EPA LHA limit, with concentrations ranging from <70 ng L−1 to 2000 ng L−1.

    “Cui et al. (2020) found that PFAS concentrations in drinking water from Miami, Florida, exceeded the stipulated US EPA LHA limit with concentrations ranging from <70 ng L−1 to 2000 ng L−1 (Cui et al., 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Cui et al., 2020 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    A total of 21 PFAS were documented from the Ebro and Guadalquivir River basins, with PFBA, PFPeA, and PFOA most frequently detected.

    “The authors documented a total of 21 PFAS from these river basins, PFBA, perfluoropentanoic acid (PFPeA) and PFOA were the most frequently detected.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lorenzo et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    A long-term study in Hesse, Germany (1999-2018) reported that detection frequency and maximum concentrations of PFOA decreased, whereas detection frequency of short-chained PFAS increased especially after 2014.

    “This study investigated the temporal variation and overall trends in PFAS occurrence and reported that detection frequency and maximum concentrations of PFOA decreased during the study period, whereas the detection frequency of short-chained PFAS increased especially after 2014 (Janousek et al., 2019).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Janousek et al., 2019 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Twelve different PFAS were detected in fish tissue samples from the Ebro River, whereas only PFOS was detected in samples from the Guadalquivir River.

    “Twelve different PFAS were detected in fish tissue samples from the Ebro River, whereas only PFOS was detected in samples from the Guadalquivir River.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lorenzo et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In sediments from the Ebro River, PFOA was found at higher concentrations (maximum 32.3 ng/g), whereas PFBA was found at higher concentrations in Guadalquivir River sediments (maximum 63.8 ng/g).

    “In the sediments from the Ebro River, PFOA was found in higher concentrations (maximum = 32.3 ng g−1), whereas PFBA was found in higher concentrations in sediment samples from the Guadalquivir River (maximum = 63.8 ng g−1).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lorenzo et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PFOA and PFOS were the most frequently detected PFAS in the Swedish survey and were found more regularly in surface water samples than in groundwater samples.

    “PFOA and PFOS were the most frequently detected PFAS, and they were found more regularly in surface water samples than in groundwater samples.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Banzhaf et al., 2016

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    Uruguay is the only country that maintains a national program to monitor PFOS.

    “Currently, Uruguay is the only country that maintains a national program to monitor PFOS.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The highest concentration of any PFAS was 200 ng/L, measured for PFOA in the Po River; the total estimated discharge of PFOA into European rivers was 14 Mg/y.

    “Overall, the highest concentration of any PFAS was 200 ng L−1, which was measured for PFOA in the Po River; and the total estimated discharge of PFOA into European rivers was 14 Mg y−1 (McLachlan et al., 2007).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites McLachlan et al., 2007 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The maximum measured PFBA concentration was 251.3 ng/L in water from the Ebro River basin and 742.9 ng/L in the Guadalquivir River basin.

    “The maximum measured concentration of PFBA was 251.3 ng L−1 and 742.9 ng L−1 in water samples from the Ebro and Guadalquivir River basins, respectively.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lorenzo et al., 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In the Vaal River study, PFAS were detected in all environmental media, PFOS was the most frequently detected pollutant in aquatic biota samples, and PFPeA was predominantly detected in river water samples.

    “PFAS were detected in all environmental media, and PFOS was the most frequently detected pollutant in aquatic biota samples, whereas PFPeA was predominantly detected in river water samples.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Groffen et al., 2018

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Rhine-Herne and Wesel-Datteln Canals contained PFOA at concentrations of 34 and 36 ng/L, respectively.

    “The Rhine-Herne and Wesel-Datteln Canals contained PFOA at concentrations of 34 and 36 ng L−1 respectively.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Skutlarek et al., 2006 source

      Not checked in the free run.

    • cites Exner and Färber, 2006 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Detection of PFAS in the remote Maltese Islands is attributed to precipitation, with detected PFAS concentrations in precipitation ranging from 0.38-6 ng/L.

    “Interestingly, the authors noted that detection of PFAS in this remote island is attributed to precipitation, and the detected PFAS concentrations measured in precipitation ranged from 0.38–6 ng L−1.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Sammut et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The use of biosolids from wastewater treatment plants in agriculture is a known source of PFAS pollution in river systems, which suffer due to surface runoff originating from agricultural lands.

    “The use of biosolids from wastewater treatments plants in agriculture is a known source of PFAS pollution in river systems, which suffer due to the surface runoff originating from agricultural lands.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Analysis of river water samples collected downstream of a fluorochemical production plant in Dordrecht, Netherlands indicated the presence of GenX chemicals, with the highest concentration (812 ng/L) measured near the plant.

    “Analysis of river water samples collected downstream of a fluorochemical production plant in Dordrecht, Netherlands, indicated the presence of the novel PFAS, GenX chemicals, with the highest concentration (812 ng L−1) measured near the plant.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Gebbink et al., 2017 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Average concentrations of PFAS in the Vaal River ranged from <LOQ to 38.5 ng/L in water, <LOQ in sediment, and <LOQ to 34.0 ng/g in aquatic biota.

    “The average concentrations of PFAS ranged from <LOQ to 38.5 ng L−1 in water; <LOQ in sediment; and <LOQ to 34.0 ng g−1 in aquatic biota (Groffen et al., 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Groffen et al., 2018

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Regulatory agencies have recommended a series of screening/advisory values for drinking water.

    “Recently, regulatory agencies have recommended a series of screening/advisory values for drinking water have been recommended.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisenone given

    At this time, identifying all precursors of PFAS remains a significant challenge.

    “At this time, identifying all precursors of PFAS remains a significant challenge and such research is needed to accurately quantify the mass influx of PFOS and PFOA entering the environment.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    PFOS used in the electroplating industry and firefighting foam manufacturing is being replaced with PFESA, FTSA, PFBS, and F53B; PFOA used in manufacturing high-performance fluoropolymer materials is being replaced by PFECA and GenX chemicals.

    “The PFOS used in the electroplating industry and firefighting foam manufacturing is being replaced with PFESA, FTSA, PFBS, and F53B; and the PFOA used in the manufacturing of high-performance fluoropolymer materials is being replaced by PFECA and GenX chemicals (DuPontTM, 2010; Buck et al., 2011; B. Wang et al., 2013; X. Wang et al., 2013; Ahrens and Bundschuh, 2014; Newton et al., 2017; USEPA, 20”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites DuPontTM, 2010

      Not checked in the free run.

    • cites Buck et al., 2011 source

      Not checked in the free run.

    • cites USEPA, 2018

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    The UNEP's Stockholm Convention has included many PFAS on the persistent organic pollutant list.

    “The UNEP’s Stockholm Convention has included many PFAS on the persistent organic pollutant list.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    The Stockholm Convention has restricted the use of firefighting foam containing PFOS and its salts if all releases arising from such activities are not contained.

    “It has also restricted the use of firefighting foam containing PFOS, and its salts, if all the releases arising from such activities are not contained.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Concentrations of PFCAs and PFSAs in Nigerian wastewater sludge ranged from 0.010-0.597 and 0.014-0.540 ng/g, respectively, and hospital wastewater treatment plants contained measurable levels of PFAS.

    “The concentrations of PFCAs and PFSAs ranged from 0.010–0.597 and 0.014–0.540 ng g−1, respectively, and even wastewater from hospitals’ treatment plants contained measurable levels of PFAS (Sindiku et al., 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sindiku et al., 2013

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The EPA 2021 human health toxicity assessment proposed a chronic reference dose for PFBS of 0.0003 mg/kg/d, a chronic reference dose for GenX chemicals of 0.000003 mg/kg/d, and a sub-chronic dose of 0.00003 mg/kg/d.

    “The chronic reference dose of PFBS was set at 0.0003 (3×10−4) mg kg−1 d−1, whereas for the GenX chemicals it was set at 0.000003 (3×10−6) mg kg−1 d−1, and sub-chronic dose at 0.00003 (3×10−5) mg kg−1 d−1, respectively (USEPA, 2021).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites USEPA, 2021

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Although major manufacturers have phased out legacy PFAS, the proposed novel/alternative PFAS, initially thought to be environmentally benign, may in fact be just as problematic as their predecessors.

    “Although major manufacturers have phased out legacy PFAS, the proposed novel/alternative PFAS–initially thought to be environmentally benign–may in fact be just as problematic as their predecessors.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    PFOS and PFOA were phased out of use in the early 2000s.

    “PFOS and PFOA were phased out of use in the early 2000s.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Premisenone given

    The US EPA has included PFAS on the contaminant candidate list (CCL5), which means that their levels are monitored but are not subject to US EPA's drinking water regulation.

    “Currently, the US EPA has included PFAS on the contaminant candidate list (CCL5) which means that their levels are monitored but are not subject to US EPA’s drinking water regulation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Novel PFAS have gained acceptance in various industries as usable alternatives.

    “These novel PFAS have gained acceptance in various industries as usable alternatives.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites DuPontTM, 2010

      Not checked in the free run.

    • cites Buck et al., 2011 source

      Not checked in the free run.

  • May combine two claims.

    Premiseown data

    Although detected pollutant concentrations in Africa were lower than those reported from other parts of the world, the extent of PFAS monitoring in Nigeria and Africa as a whole is minimal.

    “Although the detected pollutant concentrations were lower than those reported from other parts of the world, the extent of PFAS monitoring in Nigeria–and Africa as a whole–is minimal (Fig. 6).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    PFOA was detected in 60% of surface water samples from Lake Tana with concentrations ranging from ND-0.69 ng/L, and PFOS was detected in 40% of samples with concentrations ranging from ND-0.22 ng/L.

    “PFOA was detected in 60% of the surface water samples, with concentrations ranging from ND – 0.69 ng L−1; and PFOS was detected in 40% of the samples with concentrations ranging from ND – 0.22 ng L−1 (Ahrens and Bundschuh, 2014).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Ahrens and Bundschuh, 2014 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The significant variation in the worldwide distribution of novel PFAS is mainly because legacy PFAS were phased out long ago in North America and Europe, whereas developing regions of Asia, Africa, and Latin America are still using legacy PFAS to some extent.

    “This is mainly because legacy PFAS were phased out long ago in North America and Europe, whereas the developing regions of Asia, Africa, and Latin America are still using legacy PFAS to some extent (Pan et al., 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pan et al., 2018 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Both PFBS and GenX chemicals are toxic, persistent, and mobile in surface and subsurface environments.

    “For example, both PFBS and GenX chemicals are toxic, persistent, and mobile in surface and subsurface environments (USEPA, 2018).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites USEPA, 2018

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    GenX chemicals were present in the waste stream (mean 2.2 μg/L), onsite WWTP effluent (mean 134 μg/L), municipal WWTP effluent (mean 375 μg/L), and surface water upstream (mean 0.75 ng/L) near the Netherlands facility.

    “The presence of GenX chemicals was reported in the waste stream (mean = 2.2 μg L−1) originating from the facility; effluent from the onsite WWTP (mean = 134 μg L−1); effluent from the municipal WWTP that receives pre-treated wastewater from the facility (mean = 375 μg L−1); and in surface water sampled upstream from the facility (mean = 0.75 ng L−1) (Gebbink and van Leeuwen, 2020).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Gebbink and van Leeuwen, 2020

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The pollutants detected in the Tennessee River included polyfluorinated carboxylic acids, polyfluorinated sulfate, and a series of perfluorobutane sulfonamido substances.

    “The detected pollutants included polyfluorinated carboxylic acids, polyfluorinated sulfate, and a series of perfluorobutane sulfonamido substances (Newton et al., 2017).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Newton et al., 2017

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Legacy PFAS were phased out long ago in North America and Europe, whereas the developing regions of Asia, Africa, and Latin America are still using legacy PFAS to some extent.

    “This is mainly because legacy PFAS were phased out long ago in North America and Europe, whereas the developing regions of Asia, Africa, and Latin America are still using legacy PFAS to some extent (Pan et al., 2018).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Pan et al., 2018 source

      Not checked in the free run.

117 of 117

  • The paper relies on this without support.

    The large-scale studies reviewed are representative of global PFAS occurrence and distribution.

    “We mainly reviewed large-scale studies that had analyzed multiple samples from various media across multiple countries.”

  • The paper relies on this without support.

    PFAS concentrations measured in different studies are comparable despite different analytical methods and sampling designs.

    “We gathered information from academic sources, as well as reputable non-academic sources, including federal, state, and local government records, and reports obtained from agency websites.”

  • The paper relies on this without support.

    PFAS are among the largest group of chemicals widely used in industrial and commercial products and are frequently detected in environments worldwide in drinking water, surface water, and groundwater across industrialized and developing countries.

    “PFAS are among the largest group of chemicals widely used in industrial and commercial products and have been frequently detected in environments worldwide in drinking water, surface water, and groundwater across industrialized and developing countries.”

  • The paper relies on this without support.

    Ionic PFAS are more soluble and tend to accumulate in water, sediment, and soil, whereas neutral PFAS are generally more volatile and commonly found in the atmosphere.

    “Ionic PFAS are more soluble and tend to accumulate in water, sediment, and soil, whereas neutral PFAS are generally more volatile and are commonly found in the atmosphere.”

  • The paper relies on this without support.

    The unregulated discharge of industrial wastewater is a major source of PFAS.

    “The unregulated discharge of industrial wastewater is a major source of PFAS.”

  • The paper relies on this without support.

    PFOA and PFOS are still used in several industries in China.

    “Although the production and use of PFOA and PFOS have been significantly scaled down in many developed countries, they are still used in several industries in China; and contamination from industrial wastes is still considered a primary source of PFAS in the environment.”

  • The paper relies on this without support.

    Contamination from industrial wastes is still considered a primary source of PFAS in the environment.

    “Although the production and use of PFOA and PFOS have been significantly scaled down in many developed countries, they are still used in several industries in China; and contamination from industrial wastes is still considered a primary source of PFAS in the environment.”

  • The paper relies on this without support.

    Few studies have investigated the presence of PFAS in the Indian environment.

    “Few studies have investigated the presence of PFAS in the Indian environment.”

  • The paper relies on this without support.

    Few studies have monitored PFAS contamination in developing countries of the Asia-Pacific region because of a lack of resources, available technology, and skills.

    “Although global agencies, such as the United Nations Environmental Programme (UNEP), have taken the initiative to monitor PFAS contamination in the developing countries of this region, few studies have been conducted due to a lack of resources, available technology, and skills.”

  • The paper relies on this without support.

    The PFAS occurrence data reported by the cited studies are representative of the broader regions and time periods discussed.

    “A review of multiple worldwide regions indicates that PFAS are distributed throughout the environment, irrespective of the level of economic/industrial development.”

  • The paper relies on this without support.

    The analytical methods used in the cited studies reliably measured the reported PFAS concentrations.

    “In a study published in 2017, surface water collected from rural, urban, and AFFF-impacted sites in Canada was analyzed using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) and 23 different PFAS were detected, of which perfluorohexane sulfonamide (FHxSA) was most prevalent.”

  • The paper relies on this without support.

    PFAS exposure causes adverse human health effects.

    “The widespread occurrence of these substances and their potential impact on human health remain primary public concern as recent epidemiological studies conclusively demonstrated the adverse health effects of PFAS exposure.”
12 of 12

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Variability in PFAS concentrations was likely driven by a diffuse set of PFAS sources common to urban watersheds and degradation of multiple precursor PFAS into common degradation products.

    “Variability in concentrations were likely driven by a diffuse set of PFAS sources common to urban watersheds35 and degradation of multiple precursor PFAS into common degradation products.”

    From Integrating Contaminant Source Indicators, Water Quality Measures, and Ecotoxicity to Characterize Contaminant Mixtures and Per- and Polyfluoroalkyl Substance (PFAS) Variability in an Urban Watershed (2025) · cites this paper as [35]

    The “Sources and occurrence of PFAS in the environment” section (page unavailable) describes diffuse, multiple-source PFAS releases, including precursor breakdown. The review also links variation in PFAS concentrations to different pollution sources in eastern China, but it does not establish that diffuse sources common to urban watersheds drove the variability described in the citing sentence. (LLM, conf=0.83)

    Experimental — accuracy not yet measured

  • PFAS are present in the entire water cycle, including stormwater runoff.

    “PFAS are present in the entire water cycle, including stormwater runoff (Kurwadkar et al., 2022)”

    From Review of emerging contaminants in green stormwater infrastructure: antibiotic resistance genes, microplastics, tire wear particles, PFAS, and temperature (2024) · cites this paper as Kurwadkar et al., 2022

    The 'Sources and occurrence of PFAS in the environment' section describes PFAS in ocean, groundwater and surface waters and lists surface runoff among routes of release. In 'Worldwide distribution of PFAS—The occurrence of PFAS in the Asia-Pacific region,' the review says rainy-season findings suggest stormwater runoff could be a PFAS source; it does not report direct detection in stormwater runoff. The unqualified claim of presence in stormwater runoff therefore goes beyond the cited evidence. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

  • PFAS have been widely used since the 1940s and are present in surface waters due to contamination from wastewater treatment plants, landfill sites, manufacturing emissions, and sites where AFFFs are used e.g. airports.

    “PFAS have been widely used since the 1940s, and are present in surface waters due to contamination from wastewater treatment plants (WWTP), landfill sites, manufacturing emissions, and sites where AFFFs are used e.g. airports (Kurwadkar et al., 2022).”

    From Stormwater discharges affect PFAS occurrence, concentrations, and spatial distribution in water and bottom sediment of urban streams (2025) · cites this paper as Kurwadkar et al., 2022

  • PFAS are extensively used in urban environments and are found in urban stormwater.

    “Per- and polyfluoroalkyl substances (PFAS) are extensively used in urban environments and are, thus, found in urban stormwater.”

    From Stormwater discharges affect PFAS occurrence, concentrations, and spatial distribution in water and bottom sediment of urban streams (2025) · cites this paper as Kurwadkar et al., 2022

  • Despite being phased out in the early 2000s, legacy PFAS PFOS and PFOA are still among the most frequently quantified in surface waters and stormwater runoff.

    “Despite being phased out in the early 2000s (Directive 2006/123/EC, 2006), legacy PFAS, PFOS and PFOA are still among the most frequently quantified in surface waters (Kurwadkar et al., 2022; Podder et al., 2021) and stormwater runoff (Codling et al., 2020; Gasperi et al., 2022; Murakami et al., 2009).”

    From Stormwater discharges affect PFAS occurrence, concentrations, and spatial distribution in water and bottom sediment of urban streams (2025) · cites this paper as Kurwadkar et al., 2022

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • PFOA is classified as both long-chain and short-chain

    Minor

    The first classification makes PFOA a long-chain acid because its stated formula has n = 7. The later classification calls PFAS with C ≤ 8 short-chain; PFOA's stated formula has eight carbons in total.

1 of 1

Cites

1 retracted

Flagged first, then by citations

Research works printed but not linked: 7

  1. Banzhaf, 2016, A review of contamination of surface-, ground-, and drinking water in Sweden by perfluoroalkyl and polyfluoroalkyl substances (PFASs), Ambio, 463, 335
  2. Chen, 2009, 25, 163
  3. Dean, 2020, A Framework for Regulation of New and Existing PFAS by EPA, J. Sci. Policy Gov. POLICY Anal. Regul. PFAS BY EPA www.sciencepolicyjournal.org JSPG, 16
  4. Houde, 2011, Monitoring of, Environ. Sci. Technol., 45, 7962, 10.1021/es104326w · DOI · Paper page
  5. Moody, 2020, Perfluorinated surfactants and the environmental implications of their use in fire-fighting foams, Environ. Sci. Technol., 34, 1544
  6. Skutlarek, 2006, Perfluorinated surfactants in surface and drinking water, Environ. Sci. Pollut. Res., 13, 299, 10.1065/espr2006.07.326 · DOI · Paper page
  7. So, 2007, 68, 2085

Cited by

Sorted by citations

Authors
Kurwadkar, S., Dane, J., Kanel, S. R., Nadagouda, M. N., Cawdrey, R. W., Ambade, B., Struckhoff, G. C., & Wilkin, R.
Affiliations
  • Environmental Protection Agency (US)
  • California State University, Fullerton (US)
  • Wright State University (US)
  • National Institute of Technology Jamshedpur (IN)
Corresponding author
  • Kurwadkar, Sudarshan
  • Wilkin, Richard
ORCID
Venue
Science of The Total Environment
Publisher
Elsevier BV
Published
2022-02
Volume
809
Pages
151003
ISSN
0048-9697 (ISSN-L)
DOI
10.1016/j.scitotenv.2021.151003
PMC
PMC10184764
OpenAlex
W3209102624
Cited by
937
References
110
Citations by year
2026: 230 · 2025: 277 · 2024: 219 · 2023: 142 · 2022: 69
FWCI
7.97
Type
journal article
Language
en
Open access
Licence
Locations
  • The Science of The Total Environment (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion, cc-by)
Funders
  • California State University
  • U.S. Environmental Protection Agency
  • Office of Research and Development
Topics
  • Physical Sciences › Environmental Science › Environmental Chemistry › Per- and polyfluoroalkyl substances research
  • Physical Sciences › Environmental Science › Health, Toxicology and Mutagenesis › Toxic Organic Pollutants Impact
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Fluorine in Organic Chemistry
Keywords
per- and polyfluoroalkyl substances, PFAS, aquatic environment, surface water, groundwater, wastewater, long-range transport, persistent organic pollutants, PFAS regulation, human health risk, bioaccumulation, drinking water, food contamination
MeSH terms
Fluorocarbons, Humans, Water Pollutants, Chemical, Alkanesulfonic Acids, Drinking Water, Wastewater

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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