The use of PFAS has been regulated internationally by the Stockholm Convention on Persistent Organic Pollutants since 2009, with some jurisdictions, such as China and the European Union, planning further reductions and phase-outs. 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[23] or has moved production to countries such as Thailand, where there is less regulation.[24][25] In the United States, the Republican Party has filibustered bills regulating the chemicals.[23] Cover-ups and the suppression of studies in 2018 by the Trump administration led to bipartisan outrage.[26][27]
The market for PFAS was estimated to be $28 billion in 2023 and the majority are produced by 12 companies: 3M, AGC Inc., Archroma, Arkema, BASF, Bayer, Chemours, Daikin, Honeywell, Merck Group, Shandong Dongyue Chemical, and Solvay.[28] Sales of PFAS, which cost approximately $20 per kilogram, generate a total industry profit of $4 billion per year on 16% profit margins.[29] Due to health concerns, several companies have ended or plan to end the sale of PFAS or products that contain them; these include W. L. Gore & Associates (the maker of Gore-Tex), H&M, Patagonia, REI, and 3M.[30][31][32][33][34][35] PFAS producers have paid billions of dollars to settle litigation claims, the largest being a $10.3 billion settlement paid by 3M for water contamination in 2023.[36] Studies have shown that companies have known of the health dangers since the 1970s – DuPont and 3M were aware that PFAS was "highly toxic when inhaled and moderately toxic when ingested".[37]External costs, including those associated with remediation of PFAS from soil and water contamination, treatment of related diseases, and monitoring of PFAS pollution, may be as high as US$17.5 trillion annually, according to ChemSec.[29] The Nordic Council of Ministers estimated health costs to be at least €52–84 billion in the European Economic Area.[38] In the United States, PFAS-attributable disease costs are estimated to be US$6–62 billion.[39][40]
Definition
Skeletal structure of PFOS, an effective, persistent and bioaccumulative fluorosurfactantA physical sample of PFOA, appearing as a white solid as seen here in a relatively pure form. It is commonly referred to as the main harmful PFAS chemical and PFOA is responsible for many of the negative health effects commonly associated with PFAS.
Per- and polyfluoroalkyl substances are a group of synthetic organofluorinechemical 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.[41][42]
An early definition required that they contain at least one perfluoroalkylmoiety, −CnF2n+1.[12] 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 perfluorinatedmethyl group (−CF3) or a perfluorinated methylene group (−CF2−) is a PFAS."[2][43] This definition notably includes Carbon tetrafluoride.
The United States Environmental Protection Agency defines PFAS in the Drinking Water Contaminant Candidate List 5 as substances that contain "at least one of the following three structures: R−CF2−CF(R')R", where both the −CF2− and −CF− moieties are saturated carbons, and none of the R groups can be hydrogen; R−CF2−O−CF2−(R'), where both the −CF2− moieties are saturated carbons, and none of the R groups can be hydrogen; or CF3−C−(CF3)RR', where all the carbons are saturated, and none of the R groups can be hydrogen.[44]
A summary table of some PFAS definitions is provided in Hammel et al (2022).[45]
As with other surfactants, fluorosurfactants tend to concentrate at the phase interfaces.[47] 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.[16]
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. [48][49]
PFASs were originally considered to be chemically inert.[51][52] Early occupational studies revealed elevated levels of fluorochemicals, including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA, C8), in the blood of exposed industrial workers, but cited no ill health effects.[53][54] 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 12.70ppm, respectively, well below toxic and carcinogenic levels cited in animal studies.[54] Given, however, the serum elimination half-life of four to five years and widespread environmental contamination, molecules have been shown to accumulate in humans sufficiently to cause adverse health outcomes.[51]
Effects of exposure to PFASs on human health
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".[57]
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.[58][59][60]
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.[61]
Soil is also contaminated and the chemicals have been found in remote areas such as Antarctica.[62]Soil contamination can result in higher levels of PFAs found in foods such as white rice, coffee, and animals reared on contaminated ground.[63][64][65]
Adverse health outcomes
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 in response to landfill and wastewater dumping of PFAS-laden material from DuPont's West Virginia Washington Works plant.[66] The panel measured PFOA (also known as C8) serum concentrations in 69,000 individuals from around DuPont's Washington Works Plant and found a mean concentration of 83ng/mL, compared to 4ng/mL in a standard population of Americans.[67] This panel reported probable links between elevated PFOA blood concentration and hypercholesterolemia, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer as well as pregnancy-induced hypertension and preeclampsia.[68][69][70][71][72]
The severity of PFAS-associated health effects can vary based on the length of exposure, level of exposure, and health status.[73]
Pregnancy and lactation issues
Exposure to PFAS is a risk factor for various 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.[74] Human breast milk can harbor PFASs, which can be transferred from mother to infant via breastfeeding.[75][64]
Use of various personal care products, such as nail care products, fragrances, makeup, hair dyes and hair sprays, by pregnant women and lactating mothers has been shown to be associated with significantly higher levels of PFAS in the blood and breastmilk of the mothers. 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.[76]
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.[78][79]
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.[22] 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.[81]
Hypercholesterolemia
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.[82]
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.[83] These cytokine variations allude to immune response aberrations resulting in autoimmunity. One proposed mechanism is a shift towards anti-inflammatory M2 macrophages and/or 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.[84]
Thyroid disease
Hypothyroidism is the most common thyroid abnormality associated with PFAS exposure.[85] PFASs have been shown to decrease thyroid peroxidase, resulting in decreased production and activation of thyroid hormones in vivo.[86] Other proposed mechanisms include alterations in thyroid hormone signaling, metabolism and excretion as well as function of nuclear hormone receptor.[85]
Bioaccumulation and biomagnification
Bioaccumulation of PFAS: PFASs from sediments and water can accumulate in marine organisms. Animals higher up the food chain accumulate more PFAS because they absorb PFAS in the prey they consume.
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 C10–C14PFCAs.[87] 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.[88]
Biomagnification can be described using the estimation of the trophic magnification factor (TMF), which describes the relationship between the contamination levels in a species and their trophic level in the food web. TMFs are determined by graphing the log-transformed concentrations of PFAS against the assigned trophic level and taking the antilog of the regression slope (10slope).[16]
In a study done on a macrotidal estuary in Gironde, SW France, TMFs exceeded one for nearly all 19 PFAS compounds considered in the study and were particularly high for PFOA and PFNA (6.0 and 3.1 respectively).[16] A TMF greater than one signifies that accumulation in the organism is greater than that of the medium, with the medium being seawater in this case.
PFOS, a long-chain sulfonic acid, was found at the highest concentrations relative to other PFASs measured in fish and birds in northern seas such as the Barents Sea and the Canadian Arctic.[89]
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.[90][91]
Bioaccumulation and biomagnification of PFASs in marine species throughout the food web, particularly frequently consumed fish and shellfish, can have important impacts on human populations.[92] PFASs have been frequently documented in both fish and shellfish that are commonly consumed by human populations,[93] 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.[94] This has particular implications for populations that consume larger numbers of wild fish and shellfish species.[93] PFAS contamination has also resulted in disruptions to the food supply, such as closures and limits on fishing.[95]
Fluorosurfactants with shorter carbon chains may be less prone to accumulating in mammals;[50] there is still some concern that they may be harmful to both humans[96][97][98] and the environment.[99][19]
Suppression of information on health effects
Since the 1970s, DuPont and 3M were aware that PFAS was "highly toxic when inhaled and moderately toxic when ingested".[37] Producers used several strategies to influence science and regulation – most notably, suppressing unfavorable research and distorting public discourse.[37]
Concerns, litigation, and regulations in specific countries and regions
Arctic
In 2024, research at McGill University in Quebec,[100] indicated that PFASs were being brought to the Arctic from polluted southern waters by migrating birds.[101] 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.
Although PFASs are not manufactured in Canada, they may be present in imported goods and products. In 2008, products containing PFOS as well as PFOA were banned in Canada, with exceptions for products used in firefighting, the military, and some forms of ink and photo media.[105]
Health Canada has published drinking water guidelines for maximum concentrations of PFOS and PFOA to protect the health of Canadians, including children, over a lifetime's exposure to these substances. The maximum allowable concentration for PFOS under the guidelines is 0.0002 milligrams per liter. The maximum allowable concentration for PFOA is 0.0006 milligrams per liter.[106] In August 2024, Health Canada established an objective of 30 ng/L for the sum of the concentration of 25 PFASs[107] detected in drinking water.[108]
New Zealand
The New Zealand Environmental Protection Agency (EPA) has banned the use of per- and polyfluoroalkyl substances (PFAS) in cosmetic products starting from 31 December 2026. This will make the country one of the first in the world to take this step on PFAS to protect people and the environment.[109]
United Kingdom
The environmental consequences of PFAS, especially from firefighting activities, have been recognized since the mid-1990s and came to prominence after the Buncefield explosion on 11 December 2005. The Environment Agency has undertaken a series of projects to understand the scale and nature of PFAS in the environment. The Drinking Water Inspectorate requires water companies to report concentrations of 47 PFAS.[110]
In 2019, the European Council requested the European Commission to develop an action plan to eliminate all non-essential uses of PFAS due to the growing evidence of adverse effects caused by exposure to these substances; the evidence for the widespread occurrence of PFAS in water, soil, articles, and waste; and the threat it can pose to drinking water.[115] Germany, the Netherlands, Denmark, Norway, and Sweden submitted a so-called restriction proposal based on the REACH regulation to achieve a European ban on the production, use, sale and import of PFAS.[116] The proposal states that a ban is necessary for all use of PFAS, with different periods for different applications when the ban takes effect (immediately after the restriction comes into force, five years afterward, or 12 years afterward), depending on the function and the availability of alternatives. The proposal has not assessed the use of PFAS in medicines, plant protection products, and biocides because specific regulations apply to those substances (Biocidal Products Regulation, Plant Protection Products Regulation, Medicinal Products Regulation) that have an explicit authorization procedure that focuses on risk for health and the environment.
The proposal was submitted on 13 January 2023 and published by the European Chemicals Agency (ECHA) on 7 February. From 22 March to 21 September, citizens, companies, and other organizations commented on the proposal during a public consultation.[117] Based on the information in the restriction proposal and the consultation, two committees from ECHA formulate an opinion on the risk and socio-economic aspects of the proposed restriction. Within a year of publication, the opinions are sent to the European Commission, which makes a final proposal that is submitted to the EU Member States for discussion and decision.[118] Eighteen months after the publication of the restriction decision (which may differ from the original proposal), it will enter into force.[117]
Italy
127,000 residents in the Veneto region are estimated to have been exposed to contamination through tap water, and it is thought to be Europe's biggest PFAS-related environmental disaster.[20][119] While Italy's National Health Institute (ISS, Istituto Superiore di Sanità) set the threshold limit of PFOA in the bloodstream at 8 nanograms per milliliter (ng/mL), some residents had reached 262 and some industrial employees reach 91,900ng/mL. In 2021 some data was disclosed by Greenpeace and local citizens after a long legal battle against the Veneto Region and ISS, which for years has denied access to data, despite values known since or even before 2017. The Veneto region has not carried out further monitoring or taken resolutive actions to eliminate pollution and reduce, at least gradually, the contamination of non-potable water. Although in 2020 the European Food Safety Agency (EFSA) has reduced by more than four times the maximum tolerable limit of PFAS that can be taken through the diet, the region has not carried out new assessments or implemented concrete actions to protect the population and the agri-food and livestock sectors. Some limits were added to monitoring the geographical area, which does not include the orange zone and other areas affected by contamination, as well as the insufficiency of analysis on important productions widespread in the areas concerned: eggs (up to 37,100ng/kg), fish (18,600ng/kg) spinach and radicchio (only one sampling carried out), kiwis, melons, watermelons, cereals (only one sample was analyzed), soy, wines and apples.[120]
Japan
A study of public water bodies ending in March 2022 showed that the sum of PFOS and PFOA concentrations exceeded 50ng/L in 81 out of 1,133 test sites and in some cases are present at elevated levels in blood. This has led to pressure to increase regulations.[121]
Sweden
Highly contaminated drinking water has been detected at several locations in Sweden. Such locations include Arvidsjaur, Lulnäset, Uppsala and Visby.[122][123] In 2013, PFAS were detected at high concentrations in one of the two municipality drinking water treatment plants in the town of Ronneby, in southern Sweden. Concentrations of PFHxS and PFOS were found at 1700ng/L and 8000ng/L, respectively.[124] The source of contamination was later found to be a military fire-fighting exercise site in which PFAS containing fire-fighting foam had been used since the mid-1980s.[125]
Additionally, low-level contaminated drinking water has also been shown to be a significant exposure source of PFOA, PFNA, PFHxS and PFOS for Swedish adolescents (ages 10–21). Even though the median concentrations in the municipality drinking water were below oneng/L for each individual PFAS, positive associations were found between adolescent serum PFAS concentrations and PFAS concentrations in drinking water.[126]
United States
An estimated 26,000 U.S. sites are contaminated with PFASs.[127][128] More than 200 million Americans are estimated to live in places where the PFAS level in tap water, including PFOA and PFOS levels, exceeds the 1 ppt (part per trillion) limit set in 2022 by the EPA.[129]
Based on tap water studies from 716 locations from 2016 and 2021, the U.S. Geological Survey (USGS) found that the PFAS levels exceeded the EPA advisories in approximately 75% of the samples from urban areas and in approximately 25% of the rural area samples.[130]
Certain PFASs are no longer manufactured in the United States as a result of phase-outs including the PFOA Stewardship Program (2010–2015), in which eight major chemical manufacturers agreed to eliminate the use of PFOA and PFOA-related chemicals in their products and emissions from their facilities. However, they are still produced internationally and are imported into the U.S. in consumer goods.[131][132] Some types of PFAS are voluntarily not included in food packaging.[133]
The water in and around at least 126 U.S. military bases has been contaminated by high levels of PFASs because of their use of firefighting foams since the 1970s, according to a study by the U.S. Department of Defense. Of these, 90 bases reported PFAS contamination that had spread to drinking water or groundwater off the base.[136]
In 2022, a report by the Pentagon acknowledged that approximately 175,000 U.S. military personnel at two dozen American military facilities drank water contaminated by PFAS that exceeded the U.S. EPA limit. However, according to the Environmental Working Group, the Pentagon report downplayed the number of people exposed to PFAS, which was probably over 640,000 at 116 military facilities. The EWG found that the Pentagon also omitted from its report some types of diseases that are likely to be caused by PFAS exposure, such as testicular cancer, kidney disease, and fetal abnormalities.[137]
The EPA issued health advisories for four specific PFASs in June 2022, significantly lowering their safe threshold levels for drinking water. PFOA was reduced from 70 ppt to 0.004 ppt, while PFOS was reduced from 70 ppt to 0.02 ppt. A safe level for the compound GenX was set at 10 ppt, while that for PFBS was set at 2000 ppt. While not enforceable, these health advisories are intended to be acted on by states in setting their own drinking water standards.[148]
In August 2022, the EPA proposed to add PFOA and PFOS to its list of hazardous substances under the Superfund law.[149] EPA issued a final rule in April 2024, which requires that polluters pay for investigations and cleanup of these substances.[150][151]
USGS map showing the number of PFAS detections in tap water samples from select sites across the US.
In April 2024, the EPA issued a final drinking water rule for PFOA, PFOS, GenX, PFBS, PFNA, and PFHxS. Within three years, public water systems must remove these six PFAS to near-zero levels. States may be awarded grants up to $1 billion in aid to help with the initial testing and treatment of water for this purpose.[152][153][154][155][156]
Legal actions
In February 2017, DuPont and Chemours (a DuPont spin-off) agreed to pay $671 million to settle lawsuits arising from 3,550 personal injury claims related to the releasing of PFASs from their Parkersburg, West Virginia, plant into the drinking water of several thousand residents.[157] This was after a court-created independent scientific panel—the C8 Science Panel—found a "probable link" between C8 exposure and six illnesses: kidney and testicular cancer, ulcerative colitis, thyroid disease, pregnancy-induced hypertension and high cholesterol.[66]
In October 2018, a class action suit was filed by an Ohio firefighter against several producers of fluorosurfactants, including 3M and DuPont, on behalf of all U.S. residents who may have adverse health effects from exposure to PFASs.[158] The story is told in the film Dark Waters.[159]
In June 2023, 3M reached a US$10.3 billion settlement with several US public water providers to resolve water pollution claims tied to PFAS, while Chemours, DuPont and Corteva settled similar claims for $1.19 billion.[36]
In December 2023, as part of a four-year legal battle, the EPA banned Inhance, a Houston, Texas-based manufacturer that produces an estimated 200 million containers annually with a process that creates PFOA, from using the manufacturing process.[160][161] In March 2024, the United States Court of Appeals for the Fifth Circuit overturned the ban. While the court did not deny the containers’ health risks, it said that the EPA could not regulate the manufactured containers under Toxic Substances Control Act of 1976, which only addresses "new" chemicals.[162]
State actions
In 2021, Maine became the first U.S. state to ban these compounds in all products by 2030, except for instances deemed "currently unavoidable".[163][164]
As of October 2020[update], 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. The six chemicals (termed by the Massachusetts Department of Environmental Protection as PFAS6) are measured either individually or summed as a group depending on the standard; they are:[165]
In 2021 California banned PFASs for use in food packaging and from infant and children's products and also required PFAS cookware in the state to carry a warning label.[166]
Maine
A program licensed and promoted by the Maine Department of Environmental Protection that provided free municipal wastewater sludge (biosolids) to farmers as fertilizer has resulted in PFAS contamination of local drinking water and farm-grown produce.[167][168]
Michigan
The Michigan PFAS Action Response Team (MPART) was launched in 2017 and is the first multi-agency action team of its kind in the nation. Agencies representing health, environment, and other branches of state government have joined together to investigate sources and locations of PFAS contamination in the state, take action to protect people's drinking water, and keep the public informed. Groundwater is tested at locations throughout the state by various parties to ensure safety, compliance with regulations, and proactively detect and remedy potential problems. In 2010, the Michigan Department of Environmental Quality (MDEQ) discovered levels of PFASs in groundwater monitoring wells at the former Wurtsmith Air Force Base.[169] In 2024, citizen-led testing near the base in Oscoda discovered high levels of PFAS in foam along the shore of Lake Huron.[170] As additional information became available from other national testing, Michigan expanded its investigations into other locations where PFAS compounds were potentially used. In 2018, the MDEQ's Remediation and Redevelopment Division (RRD) established cleanup criteria for groundwater used as drinking water of 70 ppt of PFOA and PFOS, individually or combined. The RRD staff are responsible for implementing these criteria as part of their ongoing efforts to clean up sites of environmental contamination. The RRD staff are the lead investigators at most of the PFAS sites on the MPART website and also conduct interim response activities, such as coordinating bottled water or filter installations with local health departments at sites under investigation or with known PFAS concerns. Most of the groundwater sampling at PFAS sites under RRD's lead is conducted by contractors familiar with PFAS sampling techniques. The RRD also has a Geologic Services Unit, with staff who install monitoring wells and are also well versed with PFAS sampling techniques. The MDEQ has been conducting environmental clean-up of regulated contaminants for decades. Due to the evolving nature of PFAS regulations as new science becomes available, the RRD is evaluating the need for regular PFAS sampling at Superfund sites and is including an evaluation of PFAS sampling needs as part of a Baseline Environmental Assessment review. Earlier in 2018, the RRD purchased lab equipment that will allow the MDEQ Environmental Lab to conduct analyses of certain PFAS samples. (Currently, most samples are shipped to one of the few labs in the country that conduct PFAS analysis, in California, although private labs in other parts of the country, including Michigan, are starting to offer these services.) As of August 2018, RRD has hired additional staff to work on developing the methodology and conducting PFAS analyses.[171]
In 2020 Michigan Attorney General Dana Nessel filed a lawsuit against 17 companies, including 3M, Chemours, and DuPont, for hiding known health and environmental risks from the state and its residents. Nessel's complaint identifies 37 sites with known contamination.[172] The Michigan Department of Environment, Great Lakes, and Energy introduced some of the strictest drinking water standards in the country for PFAS, setting maximum contaminant levels (MCLs) for PFOA and PFOS to 8 and 16 ppt respectively (down from previous existing groundwater cleanup standards of 70 ppt for both), and introducing MCLs for five other previously unregulated PFAS compounds, limiting PFNA to six ppt, PFHxA to 400,000 ppt, PFHxS to 51 ppt, PFBS to 420 ppt and HFPO-DA to 370 ppt.[173] The change adds 38 additional sites to the state's list of known PFAS contaminated areas, bringing the total number of known sites to 137. About half of these sites are landfills and 13 are former plating facilities.[174]
In 2022 PFOS was found in beef produced at a Michigan farm: the cattle had been fed crops fertilized with contaminated biosolids. State agencies issued a consumption advisory, but did not order a recall, because there currently is no PFOS contamination in beef government standards.[175]
A 2024 study found that "atmospheric deposition could be a significant environmental pathway, particularly for the Great Lakes."[176][177]
Minnesota
In February 2018, 3M settled a lawsuit for $850 million related to contaminated drinking water in Minnesota.[178]
In 2019 NJDEP filed lawsuits against the owners of two plants that had manufactured PFASs, and two plants that were cited for water pollution from other chemicals. The companies cited are DuPont, Chemours, and 3M.[182] NJDEP also declared five companies to be financially responsible for statewide remediation of the chemicals. Among the companies accused were Arkema and Solvay regarding a West Deptford Facility in Gloucester County, where Arkema manufactured PFASs, but Solvay claims to have never manufactured but only handled PFASs.[183] The companies denied liability and contested the directive.[184] In June 2020, the EPA and New Jersey Department of Environmental Protection published a paper reporting that a unique family of PFAS used by Solvay, chloroperfluoropolyether carboxylates (ClPFPECAs), were contaminating the soils of New Jersey as far from the Solvay facility as 150km.[185] and the ClPFPECAs were found in water as well.[186]
Later in 2020, the New Jersey state attorney general filed suit in the New Jersey Superior Court against Solvay regarding PFAS contamination of the state's environment.[187] In May 2021, Solvay issued a press release that the company is "discontinuing the use of fluorosurfactants in the U.S.".[188]
New York
In 2016, New York, along with Vermont and New Hampshire, acknowledged PFOA contamination by requesting the EPA to release water quality guidance measures. Contamination has been observed by the New York State Department of Environmental Conservation in Hoosick Falls, Newburgh, Petersburgh, Poestenkill, Mahopac, and Armonk.[189]
After a class action lawsuit, in 2021, the village of Hoosick Falls received a $65.25 million settlement from Saint-Gobain Performance Plastics, Honeywell, 3M, and DuPont due to the disposal of PFAS chemicals into the groundwater of the local water treatment plant.[190]
Occupational exposure to PFASs occurs in numerous industries due to the widespread use of the chemicals in products and as an element of industrial process streams.[73] PFASs 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.[199] Occupational exposure to PFASs can occur at fluorochemical facilities that produce them and other manufacturing facilities that use them for industrial processing like the chrome plating industry.[73] 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 wear flame-resistant protective gear made with PFASs.[73][200][201]
Exposure pathways
People who are exposed to PFASs through their jobs typically have higher levels of PFASs in their blood than the general population.[73][202][203] While the general population is exposed to PFASs through ingested food and water, occupational exposure includes accidental ingestion, inhalation exposure, and skin contact in settings where PFAS become volatile.[204][12]
Professional ski wax technicians
Compared to the general public exposed to contaminated drinking water, professional ski wax technicians are more strongly exposed to PFASs (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.[205] During the coating process, the wax is heated, which releases fumes and airborne particles.[205] Compared to all other reported occupational and residential exposures, ski waxing had the highest total PFAS air concentrations.[206]
Manufacturing workers
People who work at fluorochemical production plants and in manufacturing industries that use PFASs in the industrial process can be exposed to PFASs in the workplace. Much of what we know about PFAS exposure and health effects began with medical surveillance studies of workers exposed to PFASs 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 PFASs participated in research studies that advanced scientific understanding of exposure pathways, toxicokinetic properties, and adverse health effects associated with exposure.[53][207][208]
The first research study to report elevated organic fluorine levels in the blood of fluorochemical workers was published in 1980.[53] It established inhalation as a potential route of occupational PFAS exposure by reporting measurable levels of organic fluorine in air samples at the facility.[53] 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 20,000ng/mL but have been reported as high as 100,000ng/mL, whereas the mean PFOA concentration among non-occupationally exposed cohorts in the same time frame was 4.9ng/mL.[209][54] Among fluorochemical workers, those with direct contact with PFASs have higher PFAS concentrations in their blood than those with intermittent contact or no direct PFAS contact.[207][209] Blood PFAS levels have been shown to decline when direct contact ceases.[209][210] 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.[207][211] Occupational exposure to PFASs in manufacturing continues to be an active area of study in China with numerous investigations linking worker exposure to various PFASs.[212][213][214]
Firefighters
Firefighters using aqueous film forming foam (AFFF)
PFASs are commonly 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.[215]
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 PFASs at elevated levels, without reaching statistical significance.[216] A 2014 study in Finland studying eight firefighters over three training sessions observed select PFASs (PFHxS and PFNA) increase in blood samples following each training event.[215] 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.[202]
Due to their use in training and testing, studies indicate occupational risk for military members and firefighters, as higher levels of PFASs exposure were indicated in military members and firefighters when compared to the general population.[217] 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.[218][219]
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.[220] 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.[220]
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.[220]
Mitigation measures
Several strategies have been proposed as a way to protect those who are at 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.[221]
Food and consumer goods
PFASs were found in many plant-based straws, such as paper straws.[222][223]
Several technologies are currently available for remediating PFASs in liquids. These technologies can be applied to drinking water supplies, groundwater, industrial wastewater, surface water, and other applications such as landfill leachate. Influent concentrations of PFASs can vary by orders of magnitude for specific media or applications. These influent values, along with other general water quality parameters (for example, pH) can influence the performance and operating costs of the treatment technologies. The technologies are:
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.[228] Most solutions involve on-site treatment systems, while others are leveraging off-site infrastructure and facilities, such as a centralized waste treatment facility, to treat and dispose of the PFAS pool of compounds.
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:[226]
Separation
Concentration
Destruction
The type of PFAS remediation technology selected is often a reflection of the PFAS contamination levels and the PFAS signature (i.e. the combination of short- and long-chain PFAS substances present) in conjunction with the site-specific water chemistry and cross contaminants present in the liquid stream. More complex waters such as landfill leachates and WWTP waters require more robust treatment solutions which are less vulnerable to blockage.
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.[229]
Destruction
In 2007, it was found that high-temperature incineration of sewage sludge reduced the levels of perfluorinated compounds significantly.[230]
A 2022 study published in the Journal of Environmental Engineering found that a heat- and pressure-based technique known as supercritical water oxidation destroyed 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, water-repellent substances such as PFASs dissolve much more readily.[227]
Theoretical and early-stage solutions
A possible solution for 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.[231]
Acidimicrobium sp. strain A6 has been shown to be a PFAS and PFOS remediator.[232] 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.[233]
Analytical methods for PFAS analysis fall into one of two general categories; targeted analysis or non-targeted analysis. Targeted analyses use reference standards to determine concentrations of specific PFAS, but this requires a high-purity standard for each compound of interest. Due to the large number of possible targets, unusual PFAS may go unreported by these methods. Non-targeted analyses measure other factors, such as total organic fluorine, which can be used to estimate the total concentration of PFAS in a sample, but cannot provide concentrations of individual compounds. The two types of analyses are often combined; by subtracting the mass of target analytes from the non-targeted analysis results, one can get an estimate for what fraction of PFAS has been "missed" by the 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.[237] 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.[238] 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.[239]
Non-targeted analyses include total organic fluorine (TOF, including variations, e.g., adsorbable organic fluorine, AOF; extractable organic fluorine, EOF), total oxidizable precursor assay, and other methods in development.[240][241]
Sample chemicals
Some common per- and polyfluoroalkyl substances include:[242][243]
Fluoropolymer, subclass of per- and polyfluoroalkyl substances
Euthenics, as the general category for policy interventions aiming to mitigate associated effects on human populations
Related Research Articles
The Cape Fear River is a 191.08-mile-long blackwater river in east-central North Carolina. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. The river is formed at the confluence of the Haw River and the Deep River in the town of Moncure, North Carolina. Its river basin is the largest in the state: 9,149 sq mi.
Perfluorooctanoic acid is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a material feedstock. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, n-heptyl "tail group" and a carboxylic acid "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic.
Perfluorooctanesulfonic acid (PFOS) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group, and thus it is a perfluorosulfonic acid and a perfluoroalkyl substance (PFAS). It is an anthropogenic (man-made) fluorosurfactant, now regarded as a global pollutant. PFOS was the key ingredient in Scotchgard, a fabric protector made by 3M, and related stain repellents. The acronym "PFOS" refers to the parent sulfonic acid and to various salts of perfluorooctanesulfonate. These are all colorless or white, water-soluble solids. Although of low acute toxicity, PFOS has attracted much attention for its pervasiveness and environmental impact. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in May 2009.
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.
Microwave popcorn is a convenience food consisting of unpopped popcorn in an enhanced, sealed paper bag intended to be heated in a microwave oven. In addition to the dried corn, the bags typically contain cooking oil with sufficient saturated fat to solidify at room temperature, one or more seasonings, and natural or artificial flavorings or both.
Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.
Drinking water quality in the United States is generally safe. In 2016, over 90 percent of the nation's community water systems were in compliance with all published U.S. Environmental Protection Agency standards. Over 286 million Americans get their tap water from a community water system. Eight percent of the community water systems—large municipal water systems—provide water to 82 percent of the US population. The Safe Drinking Water Act requires the US EPA to set standards for drinking water quality in public water systems. Enforcement of the standards is mostly carried out by state health agencies. States may set standards that are more stringent than the federal standards.
Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also an environmental contaminant found in people and wildlife along with PFOS and PFOA.
Perfluorobutanesulfonic acid (PFBS) is a PFAS chemical compound having a four-carbon fluorocarbon chain and a sulfonic acid functional group. It is stable and unreactive because of the strength of carbon–fluorine bonds. It can occur in the form of a colorless liquid or a corrosive solid. Its conjugate base is perfluorobutanesulfonate which functions as the hydrophobe in fluorosurfactants.
Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, while others are under extended investigation.
A perfluorinated compound (PFC) or perfluoro compound is an organofluorine compound that lacks C-H bonds. Many perfluorinated compounds have properties that are quite different from their C-H containing analogues. Common functional groups in PFCs are OH, CO2H, chlorine, O, and SO3H. Electrofluorination is the predominant method for PFC production. Due to their chemical stability, some of these perfluorinated compounds bioaccumulate.
Water contamination in Lawrence and Morgan Counties, Alabama, revolves around the presence of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in the water supply. After the US Environmental Protection Agency (EPA) released new health advisories in March 2016, there was concern over health risks of the levels of PFOA and PFOS present. The responses of different government officials, agencies, and companies raise questions as to whether or not there was any environmental injustice involved.
FRD-903 is a chemical compound that is among the class of per- and polyfluoroalkyl substances (PFASs). More specifically, this synthetic petrochemical is also described as a perfluoroalkyl ether carboxylic acid (PFECA) and a Fluorointermediate. It is not biodegradable and is not hydrolyzed by water.
GenX is a Chemours trademark name for a synthetic, short-chain organofluorine chemical compound, the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA). It can also be used more informally to refer to the group of related fluorochemicals that are used to produce GenX. DuPont began the commercial development of GenX in 2009 as a replacement for perfluorooctanoic acid, in response to legal action due to the health effects and ecotoxicity of PFOA.
Perfluorodecanoic acid (PFDA) is a fluorosurfactant and has been used in industry.
Perfluorobutane sulfonamide, also known as FBSA or H-FBSA, is a perfluorinated surfactant. FBSA and its N-alkylated derivatives have been patented by 3M for use in acid etch solutions with low surface tension. According to the inventors, FBSA and its derivatives are expected to have a smaller tendency to accumulate in living organisms than their perfluorooctanyl analogs such as PFOS. Nevertheless, a 2015 study found FBSA in 32 out of 33 samples of Canadian fish.
This timeline of events related to per- and polyfluoroalkyl substances (PFASs) includes events related to the discovery, development, manufacture, marketing, uses, concerns, litigation, regulation, and legislation, involving the human-made PFASs. The timeline focuses on some perfluorinated compounds, particularly perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) and on the companies that manufactured and marketed them, mainly DuPont and 3M. An example of PFAS is the fluorinated polymer polytetrafluoroethylene (PTFE), which has been produced and marketed by DuPont under its trademark Teflon. GenX chemicals and perfluorobutanesulfonic acid (PFBS) are organofluorine chemicals used as a replacement for PFOA and PFOS.
Perfluorohexanesulfonic acid (PFHxS) is a synthetic chemical compound. It is one of many compounds collectively known as per- and polyfluoroalkyl substances (PFASs). It is an anionic fluorosurfactant and a persistent organic pollutant with bioaccumulative properties. Although the use of products containing PFHxS and other PFASs have been banned or are being phased out in many jurisdictions, it remains ubiquitous in many environments and within the general population, and is one of the most commonly detected PFASs.
Sulfluramid (N-EtFOSA) is a chemical compound from the group of sulfonic acid amides and per- and polyfluoroalkyl substances (PFASs) that is effective as an insecticide.
Remediation of per- and polyfluoroalkyl substances refers to the destruction or removal of per- and polyfluoroalkyl substances (PFASs) from the environment. PFASs are a group of synthetic organofluorine compounds, used in diverse products such as non-stick cookware and firefighting foams, that have attracted great concern as persistent organic pollutants. Because they are pervasive and have adverse effects, much interest has focused on their removal.
1 2 Reconciling Terminology of the Universe of Per- and Polyfluoroalkyl Substances: Recommendations and Practical Guidance. OECD Series on Risk Management of Chemicals. OECD. 2021. p.23. doi:10.1787/e458e796-en. ISBN978-92-64-51128-6.
↑ Kovalchuk, N M; Trybala, A; Starov, V; Matar, O; Ivanova, N (August 2014). "Fluoro- vs hydrocarbon surfactants: why do they differ in wetting performance?". Advances in Colloid and Interface Science. 210: 65–71. doi:10.1016/j.cis.2014.04.003. hdl:10044/1/26321. PMID24814169.
↑ Wang Z, Cousins IT, Berger U, Hungerbühler K, Scheringer M (2016). "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". Environment International. 89–90: 235–247. Bibcode:2016EnInt..89..235W. doi:10.1016/j.envint.2016.01.023. PMID26922149.
↑ "Preliminary Lists of PFOS, PFAS, PFOA and Related Compounds and Chemicals that May Degrade to PFCA". OECD Papers. 6 (11): 1–194. 25 October 2006. doi:10.1787/oecd_papers-v6-art38-en. ISSN1609-1914.
1 2 3 4 Ubel FA, Sorenson SD, Roach DE (August 1980). "Health status of plant workers exposed to fluorochemicals—a preliminary report". American Industrial Hygiene Association Journal. 41 (8): 584–589. doi:10.1080/15298668091425310. PMID7405826.
1 2 3 Olsen GW, Burris JM, Burlew MM, Mandel JH (March 2003). "Epidemiologic assessment of worker serum perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations and medical surveillance examinations". Journal of Occupational and Environmental Medicine. 45 (3): 260–270. doi:10.1097/01.jom.0000052958.59271.10. PMID12661183. S2CID11648767.
↑ Song M, Kim YJ, Park YK, Ryu JC (August 2012). "Changes in thyroid peroxidase activity in response to various chemicals". Journal of Environmental Monitoring. 14 (8): 2121–2126. doi:10.1039/c2em30106g. PMID22699773.
↑ Martin JW, Mabury SA, Solomon KR, Muir DC (January 2003). "Bioconcentration and tissue distribution of perfluorinated acids in rainbow trout (Oncorhynchus mykiss)". Environmental Toxicology and Chemistry. 22 (1): 196–204. doi:10.1002/etc.5620220126. PMID12503765. S2CID12659454.
↑ Wang Z, Cousins IT, Scheringer M, Hungerbuehler K (February 2015). "Hazard assessment of fluorinated alternatives to long-chain perfluoroalkyl acids (PFAAs) and their precursors: status quo, ongoing challenges and possible solutions". Environment International. 75: 172–179. Bibcode:2015EnInt..75..172W. doi:10.1016/j.envint.2014.11.013. PMID25461427.
↑ Perry MJ, Nguyen GN, Porter ND (2016). "The Current Epidemiologic Evidence on Exposures to Poly- and Perfluoroalkyl Substances (PFASs) and Male Reproductive Health". Current Epidemiology Reports. 3 (1): 19–26. doi:10.1007/s40471-016-0071-y. ISSN2196-2995. S2CID88276945.
↑ Gyllenhammar I, Berger U, Sundström M, McCleaf P, Eurén K, Eriksson S, etal. (July 2015). "Influence of contaminated drinking water on perfluoroalkyl acid levels in human serum--A case study from Uppsala, Sweden". Environmental Research. 140: 673–683. Bibcode:2015ER....140..673G. doi:10.1016/j.envres.2015.05.019. PMID26079316.
↑ EPA (2021-03-03). "Announcement of Final Regulatory Determinations for Contaminants on the Fourth Drinking Water Contaminant Candidate List." Federal Register,86 FR12272
↑ EPA (2021-12-27). "Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems and Announcement of Public Meetings." Federal Register,86 FR73131
↑ Joyce Dinglasan-Panlilio M, Prakash SS, Baker JE (January 2014). "Perfluorinated compounds in the surface waters of Puget Sound, Washington and Clayoquot and Barkley Sounds, British Columbia". Marine Pollution Bulletin. 78 (1–2): 173–180. Bibcode:2014MarPB..78..173J. doi:10.1016/j.marpolbul.2013.10.046. PMID24262211.
↑ Nilsson H, Kärrman A, Westberg H, Rotander A, van Bavel B, Lindström G (March 2010). "A time trend study of significantly elevated perfluorocarboxylate levels in humans after using fluorinated ski wax". Environmental Science & Technology. 44 (6): 2150–2155. Bibcode:2010EnST...44.2150N. doi:10.1021/es9034733. PMID20158198.
↑ Fromme H, Tittlemier SA, Völkel W, Wilhelm M, Twardella D (May 2009). "Perfluorinated compounds—exposure assessment for the general population in Western countries". International Journal of Hygiene and Environmental Health. 212 (3): 239–270. Bibcode:2009IJHEH.212..239F. doi:10.1016/j.ijheh.2008.04.007. PMID18565792.
↑ Kärrman A, Harada KH, Inoue K, Takasuga T, Ohi E, Koizumi A (May 2009). "Relationship between dietary exposure and serum perfluorochemical (PFC) levels—a case study". Environment International. 35 (4): 712–717. Bibcode:2009EnInt..35..712K. doi:10.1016/j.envint.2009.01.010. PMID19250678.
↑ Paris-Davila T, Gaines LG, Lucas K, Nylander-French LA (May 2023). "Occupational exposures to airborne per- and polyfluoroalkyl substances (PFAS)-A review". American Journal of Industrial Medicine. 66 (5): 393–410. doi:10.1002/ajim.23461. PMID36719301. S2CID256481718.
1 2 3 Costa G, Sartori S, Consonni D (March 2009). "Thirty years of medical surveillance in perfluooctanoic acid production workers". Journal of Occupational and Environmental Medicine. 51 (3): 364–372. doi:10.1097/JOM.0b013e3181965d80. PMID19225424. S2CID34813716.
↑ Olsen GW, Burris JM, Burlew MM, Mandel JH (November 2000). "Plasma cholecystokinin and hepatic enzymes, cholesterol and lipoproteins in ammonium perfluorooctanoate production workers". Drug and Chemical Toxicology. 23 (4): 603–20. doi:10.1081/DCT-100101973. PMID11071397. S2CID30289350.
1 2 3 Sakr CJ, Kreckmann KH, Green JW, Gillies PJ, Reynolds JL, Leonard RC (October 2007). "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 of Occupational and Environmental Medicine. 49 (10): 1086–1096. doi:10.1097/JOM.0b013e318156eca3. PMID18000414. S2CID20124680.
↑ Olsen GW, Chang SC, Noker PE, Gorman GS, Ehresman DJ, Lieder PH, Butenhoff JL (February 2009). "A comparison of the pharmacokinetics of perfluorobutanesulfonate (PFBS) in rats, monkeys, and humans". Toxicology. 256 (1–2): 65–74. Bibcode:2009Toxgy.256...65O. doi:10.1016/j.tox.2008.11.008. PMID19059455.
↑ Steenland K, Zhao L, Winquist A (May 2015). "A cohort incidence study of workers exposed to perfluorooctanoic acid (PFOA)". Occupational and Environmental Medicine. 72 (5): 373–380. doi:10.1136/oemed-2014-102364. PMID25601914. S2CID28440634.
↑ Gao Y, Fu J, Cao H, Wang Y, Zhang A, Liang Y, etal. (June 2015). "Differential accumulation and elimination behavior of perfluoroalkyl Acid isomers in occupational workers in a manufactory in China". Environmental Science & Technology. 49 (11): 6953–6962. Bibcode:2015EnST...49.6953G. doi:10.1021/acs.est.5b00778. PMID25927957. S2CID23947500.
↑ Lu Y, Gao K, Li X, Tang Z, Xiang L, Zhao H, etal. (August 2019). "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". Environmental Science & Technology. 53 (16): 9800–9809. Bibcode:2019EnST...53.9800L. doi:10.1021/acs.est.9b01608. PMID31246438. S2CID195762433.
1 2 Laitinen JA, Koponen J, Koikkalainen J, Kiviranta H (December 2014). "Firefighters' exposure to perfluoroalkyl acids and 2-butoxyethanol present in firefighting foams". Toxicology Letters. 231 (2): 227–232. doi:10.1016/j.toxlet.2014.09.007. PMID25447453.
↑ Timshina, Alina; Aristizabal-Henao, Juan J.; Da Silva, Bianca F.; Bowden, John A. (2021). "The last straw: Characterization of per- and polyfluoroalkyl substances in commercially-available plant-based drinking straws". Chemosphere. 277. Elsevier BV: 130238. doi:10.1016/j.chemosphere.2021.130238. ISSN0045-6535. PMID33770693.
↑ Boisacq, Pauline; De Keuster, Maarten; Prinsen, Els; Jeong, Yunsun; Bervoets, Lieven; Eens, Marcel; Covaci, Adrian; Willems, Tim; Groffen, Thimo (24 August 2023). "Assessment of poly- and perfluoroalkyl substances (PFAS) in commercially available drinking straws using targeted and suspect screening approaches". Food Additives & Contaminants: Part A. 40 (9). Informa UK Limited: 1230–1241. doi:10.1080/19440049.2023.2240908. ISSN1944-0049. PMID37619405.
↑ Wen Y, Rentería-Gómez Á, Day GS, Smith MF, Yan TH, Ozdemir RO, etal. (July 2022). "Integrated Photocatalytic Reduction and Oxidation of Perfluorooctanoic Acid by Metal-Organic Frameworks: Key Insights into the Degradation Mechanisms". Journal of the American Chemical Society. 144 (26): 11840–11850. doi:10.1021/jacs.2c04341. PMID35732040. S2CID249956841.
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.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
