Health & Environmental Research Online (HERO)


PFHxA (307-24-4)


198 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Perfluoroalkyl acids in surface waters and tapwater in the Qiantang River watershed-Influences from paper, textile, and leather industries

Authors: Lu, GH; Gai, N; Zhang, P; Piao, HT; Chen, S; Wang, XC; Jiao, XC; Yin, XC; Tan, KY; Yang, YL (2017) Chemosphere 185:610-617. HERO ID: 3859699

[Less] Perfluoroalkyl acids (PFAAs) are widely used as multi-purpose surfactants or water/oil repellents. In . . . [More] Perfluoroalkyl acids (PFAAs) are widely used as multi-purpose surfactants or water/oil repellents. In order to understand the contamination level and compositional profiles of PFAAs in aqueous environment in textile, leather, and paper making industrial areas, surface waters and tap waters were collected along the watershed of the Qiantang River where China's largest textile, leather, and paper making industrial bases are located. For comparison, surface water and tapwater samples were also collected in Hangzhou and its adjacent areas. 17 PFAAs were analyzed by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. The results show that the total concentrations of PFAAs (ΣPFAAs) in the Qiantang River waters ranged from 106.1 to 322.9 ng/L, averaging 164.2 ng/L. The contamination levels have been found to be extremely high, comparable to the levels of the most serious PFAA contamination in surface waters of China. The PFAA composition profiles were characterized by the dominant PFOA (average 58.1% of the total PFAAs), and PFHxA (average 18.8%). The ΣPFAAs in tap water ranged from 9.5 to 174.8 ng/L, showing PFAA compositional pattern similar to the surface waters. Good correlations between PFAA composition profiles in tap waters and the surface waters were observed.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Per- and polyfluoroalkyl substances (PFASs) in San Francisco Bay wildlife: Temporal trends, exposure pathways, and notable presence of precursor compounds

Authors: Sedlak, MD; Benskin, JP; Wong, A; Grace, R; Greig, DJ (2017) Chemosphere 185:1217-1226. HERO ID: 3859702

[Less] Concentrations of perfluorooctane sulfonate (PFOS) in San Francisco Bay (SF Bay) wildlife have historically . . . [More] Concentrations of perfluorooctane sulfonate (PFOS) in San Francisco Bay (SF Bay) wildlife have historically been among the highest reported globally. To track continuing exposures to PFASs and assess the impact of the 2002 phase-out of production of PFOS and related chemicals in the US, nine perfluoroalkyl carboxylic acids (PFCAs; C4-C12), three perfluoroalkyl sulfonic acids (PFSAs; C4, C6, C8) and perfluorooctane sulfonamide (PFOSA, a PFOS precursor) were measured in SF Bay cormorant eggs in 2012 and harbor seal serum sampled between 2009 and 2014. PFOS remained the dominant perfluoroalkyl acid (PFAA) in both cormorant eggs (36.1-466 ng/g) and seals (12.6-796 ng/g) from 2012 and 2014, respectively. Concentrations in seal and bird eggs from the South Bay have declined approximately 70% in both matrices. To elucidate potential pathways of exposure, prey fish, sediments and wastewater effluent were analyzed for PFASs, and in the case of sediment and effluent, a suite of PFAA precursors. PFOS was the dominant PFAA in prey fish and sediment. In effluent, different mixtures of PFAAs were measured, with PFOS, PFHxA, and PFOA detected in the highest concentrations. Polyfluoroalkyl phosphate diesters (PFCA-precursors) were observed at concentrations over an order of magnitude higher than PFCAs in sediment, highlighting their importance as a potential, on-going source of PFCAs to SF Bay wildlife. These findings suggest that the PFOS phase-out has resulted in reduced burdens to wildlife in SF Bay, but that exposure to diverse and incompletely characterized PFASs continues.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The use of carbon adsorbents for the removal of perfluoroalkyl acids from potable reuse systems

Authors: Inyang, M; Dickenson, ERV (2017) Chemosphere 184:168-175. HERO ID: 3858250

[Less] Bench- and pilot-scale sorption tests were used to probe the performance of several biochars at removing . . . [More] Bench- and pilot-scale sorption tests were used to probe the performance of several biochars at removing perfluoroalkyl acids (PFAA) from field waters, compared to granular activated carbon (GAC). Screening tests using organic matter-free water resulted in hardwood (HWC) (Kd = 41 L g(-1)) and pinewood (PWC) (Kd = 49 L g(-1)) biochars having the highest perfluorooctanoic acid (PFOA) removal performance that was comparable to bituminous coal GAC (Kd = 41 L g(-1)). PWC and HWC had a stronger affinity for PFOA sorbed in Lake Mead surface water (KF = 11 mg((1-n)) L(n) g(-1)) containing a lower (2 mg L(-1)) dissolved organic carbon (DOC) concentration than in a tertiary-filtered wastewater (KF = 8 mg((1-n)) L(n) g(-1)) with DOC of 4.9 mg L(-1). A pilot-scale study was performed using three parallel adsorbers (GAC, anthracite, and HWC biochar) treating the same tertiary-filtered wastewater. Compared to HWC, and anthracite, GAC was the most effective in mitigating perfluoropentanoic acid (PFPnA), perfluorohexanoic acid (PHxA), PFOA, perfluorooctane sulfonic acid (PFOS), and DOC (45-67% removed at 4354 bed volumes) followed by HWC, and then anthracite. Based on bench- and pilot-scale results, shorter-chain PFAA [perfluorobutanoic acid (PFBA), PFPnA, or PFHxA] were more difficult to remove with both biochar and GAC than the longer-chain, PFOS and PFOA.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Atmospheric chlorinated polyfluorinated ether sulfonate and ionic perfluoroalkyl acids in 2006 to 2014 in Dalian, China

Authors: Liu, W; Qin, H; Li, J; Zhang, Q; Zhang, H; Wang, Z; He, X (2017) Environmental Toxicology and Chemistry 36:2581-2586. HERO ID: 3856455

[Less] Chlorinated polyfluorinated ether sulfonate (Cl-PFESA; trade name F-53B) is an alternative product for . . . [More] Chlorinated polyfluorinated ether sulfonate (Cl-PFESA; trade name F-53B) is an alternative product for perfluorooctane sulfonate (PFOS) used in metal plating; little is known about its levels in the environment and its risks. To our knowledge, the present study constitutes the first report of Cl-PFESA in the atmosphere. In 2006 to 2014, C8 Cl-PFESA, along with ionic perfluoroalkyl acids (PFAAs), was detected in atmospheric particulate matter in Dalian, China. Concentrations of C8 Cl-PFESA increased from 140 pg/m(3) in 2007 to 722 pg/m(3) in 2014. Levels of 11 (total) ionic PFAAs increased in 2006 to 2008 and decreased afterward, with a range of 35.7 to 860 pg/m(3) . The PFAAs in the particulate matter were dominated by perfluorocarboxylates, with perfluorooctanoate detected at the highest concentration at a mean level of 71.7 pg/m(3) , followed by perfluoroheptanoate and perfluorohexanoate. Perfluorosulfonates were detected at lower levels, with mean concentrations of PFOS, perfluorobutanesulfonate, and perfluorohexane sulfonate of 5.73, 1.64, and 1.24 pg/m(3) , respectively. Back-trajectory analysis suggested that the air mass approaching Dalian during the sampling originated from the northwest, where fluorochemical industry parks and metal plating industries are densely located. No significant correlation was observed between Cl-PFESA and the ionic PFAAs. The relatively high Cl-PFESA concentrations suggested that it possibly contributed largely to the previously reported exposure to undefined organic fluorine compounds, for which further research on emission and environmental risks is needed. Environ Toxicol Chem 2016;9999:1-6. © 2017 SETAC.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Serum concentrations of per- and poly-fluoroalkyl substances and factors associated with exposure in the general adult population in South Korea

Authors: Lee, JH; Lee, CK; Suh, CH; Kang, HS; Hong, CP; Choi, SN (2017) International Journal of Hygiene and Environmental Health 220:1046-1054. HERO ID: 3858472

[Less] Per- and polyfluoroalkyl substances (PFASs) are ubiquitous contaminants found worldwide, including in . . . [More] Per- and polyfluoroalkyl substances (PFASs) are ubiquitous contaminants found worldwide, including in South Korea. As a result, they are frequently detected in Koreans. However, there is limited representative data and information on potential sources in Korea. Therefore, we measured the serum concentrations of ten PFASs in nationally representative samples of the Korean population (n=1874, 18-69 years) and evaluated the factors associated with their exposure. Serum PFOS, PFDA, PFOA, and PFNA were detected in nearly all participants (83.1-99.9%). However, serum PFPA, PFHxA, and PFHpA were almost undetected (<0.5% of participants). PFOS had the highest population-weighted geometric mean of 10.23ng/mL (95% CI: 9.99-10.47), which was followed by PFOA with 2.85ng/mL (95% CI: 2.73-2.97) and PFDA with 2.17ng/mL (95% CI: 2.12-2.23). PFNA, PFDA, PFHxS, PFOA, and PFOS concentrations were higher in males (p<0.001) and older adults (p<0.001). PFNA was higher in those who used wax, polish, and water-resistant materials (adjusted proportional change=1.14; 95% CI: 1.08-1.22), and those who ate cooked fish (1.16; 95% CI: 1.03-1.31) compared to those who ate nearly no fish. PFDA was higher in those who used herbicides and pesticides (1.05; 95% CI: 1.02-1.09), those who drank beverages in a plastic bag on a daily basis (1.10; 95% CI: 1.03-1.19), and those who ate raw fish (1.15; 95% CI: 1.03-1.29) or cooked fish (1.13; 95% CI: 1.05-1.23) compared to those who ate nearly no fish. PFHxS was higher in those who used traditional Korean health supplement foods (1.08; 95% CI: 1.01-1.15). PFOA was higher in those who used plastic wrap in a microwave daily or weekly (1.08; 95% CI: 1.00-1.16), and those who used disposable paper cups (1.07; 95% CI: 1.01-1.13). PFOS was lower in underweight participants (0.84; 95%CI: 0.75-0.93) compared to those who were obese, and higher in those who exercised regularly (1.08; 95% CI: 1.03-1.14) or irregularly (1.06, 95% CI: 1.01-1.12) compared to those who did not exercise. Subjects who used severely damaged Teflon appliances had lower concentrations of PFOA (0.78, 95% CI: 0.65-0.95), while regular use of Gore-Tex goods was related to higher PFNA (1.15, 95% CI: 1.03-1.28) and PFDA (1.11; 95% CI: 1.02-1.20) levels. These findings suggest that most Koreans are frequently exposed to PFASs, and that serum concentrations of PFASs vary with age, sex, and exposure factors.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Thermodynamic Study of Aggregation of Cholinium Perfluoroalkanoate Ionic Liquids

Authors: Florindo, C; Tome, LC; Marrucho, IM (2016) HERO ID: 3859910

[Less] To advance the ionic liquid (IL) platform to tailor fluorinated surfactant properties, the aim of this . . . [More] To advance the ionic liquid (IL) platform to tailor fluorinated surfactant properties, the aim of this work is to evaluate the surfactant properties of cholinium-based salts bearing perfluoroalkanoate anions. Novel surfactant ILs containing the cholinium cation [Ch](+) combined with different perfluoroalkanoate anions, namely perfluoropentanoate [PFPent](-), perfluorohexanoate [PFHex](-), perfluoroheptanoate [PFHept](-), and perfluorooctanoate [PFOct](-), were synthesized. The critical micelle concentrations (CMCs) were determined using an ionic conductivity method, at different temperatures. Thermodynamic parameters of micellization were also evaluated. The results indicate that the CMC value decreases in a linear manner with the increment of the fluoroalkyl chain length in the anion. The evaluation of the thermodynamic parameters shows that the micellization is spontaneous and entropically driven and that the enthalpy of micellization is very small. It was also observed that the introduction of the cholinium cation in these surfactants allows for smaller CMC values when compared to that of other tetraalkylammonium-based surfactants with the same fluorinated anions, in short to more efficient and green surfactants. This result is probably due to counterion association and not to counterion binding to micelle surface.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Residual organic fluorinated compounds from thermal treatment of PFOA, PFHxA and PFOS adsorbed onto granular activated carbon (GAC)

Authors: Watanabe, N; Takemine, S; Yamamoto, K; Haga, Y; Takata, M (2016) HERO ID: 3859930

[Less] Perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonate (PFOS) adsorbed . . . [More] Perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonate (PFOS) adsorbed onto granular activated carbon (GAC) were thermally treated in N-2 gas stream. The purpose was to assess the fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) during thermal regeneration of GAC, which had been used for water treatment. Mineralized F, residual PFASs including short-chained species, and volatile organic fluorine (VOF) were determined. In a temperature condition of 700 A degrees C, VOF were 13.2, 4.8, and 5.9 % as for PFOA, PFHxA, and PFOS. However, the VOF decreased to 0.1 %, if the GAC and off-gas were kept at 1000 A degrees C. No PFASs remained in GAC at 700-1000 A degrees C; at the same time, short-chained PFASs were slightly detected in the aqueous trapping of off-gas at 800 and 900 A degrees C conditions. The destruction of PFASs on GAC could be perfect if the temperature is higher than 700 A degrees C; however, the process is competitive against volatile escape from GAC. Destruction in gaseous phase needs a temperature as high as 1000 A degrees C. Destruction of PFASs on the surface of GAC, volatile escape from the site, and thermolysis in gas phase should be considered, as to thermal regeneration of GAC.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Release of per- and polyfluoroalkyl substances (PFASs) from carpet and clothing in model anaerobic landfill reactors

Authors: Lang, JR; Allred, BM; Peaslee, GF; Field, JA; Barlaz, MA (2016) Environmental Science and Technology 50:5024-5032. HERO ID: 3859757

[Less] Discarded carpet and clothing are potential sources of per- and polyfluoroalkyl substances (PFASs) in . . . [More] Discarded carpet and clothing are potential sources of per- and polyfluoroalkyl substances (PFASs) in landfill leachate, but little is known about their release when disposed in landfills. The concentrations of 70 PFASs in the aqueous phase of anaerobic model landfill reactors filled with carpet or clothing were monitored under biologically active and abiotic conditions. For carpet, total PFAS release was greater in live than abiotic reactors, with an average of 8.5 nmol/L and 0.62 nmol/L after 552 days, respectively. Release in live carpet reactors was primarily due to 5:3 fluorotelomer carboxylic acid (FTCA - 3.9 nmol/L) and perfluorohexanoic carboxylic acid (PFHxA - 2.9 nmol/L). For clothing, release was more dependent on sample heterogeneity than the presence of biological activity, with 0.63, 21.7, 2.6, and 6.3 nmol/L for two live and two abiotic reactors after 519 days, respectively. Release in the clothing reactors was largely due to perfluorooctatonic carboxylic acid (PFOA), with low relative concentrations of measured biotransformation precursors (FTCAs). For carpet and clothing reactors, the majority of PFAS release was not measured until after day 100. Results demonstrate that carpet and clothing are likely sources of PFASs in landfill leachate.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Uptake, Translocation, and Metabolism of 8:2 Fluorotelomer Alcohol in Soybean (Glycine max L. Merrill)

Authors: Zhang, H; Wen, B; Hu, X; Wu, Y; Pan, Y; Huang, H; Liu, L; Zhang, S (2016) Environmental Science and Technology 50:13309-13317. HERO ID: 3859253

[Less] Biotransformation of fluorotelomer alcohols (FTOHs) is widely considered as an additional source of . . . [More] Biotransformation of fluorotelomer alcohols (FTOHs) is widely considered as an additional source of perfluorocarboxylic acids (PFCAs) in environmental biota. Compared with the extensive studies conducted in animals and microbes, biotransformation pathways of FTOHs in plants are still unclear. In this study, a hydroponic experiment was conducted to investigate the uptake, translocation and metabolism of 8:2 FTOH in soybean (Glycine max L. Merrill) over 144 h. 8:2 FTOH and its metabolites were found in all parts of soybean plants. At the end of the exposure, 7:3 FTCA [F(CF2)7CH2CH2COOH] was the primary metabolite in roots and stems, while PFOA [F(CF2)7COOH] was predominant in leaves. PFOA and 7:3 FTCA in the soybean-solution system accounted for 6.01 and 5.57 mol % of the initially applied 8:2 FTOH, respectively. Low levels of PFHpA [F(CF2)6COOH] and PFHxA [F(CF2)5COOH] in solutions and soybean roots resulted from microbial metabolism and plant root uptake. Glutathione-conjugated metabolites in soybean tissues were also identified. The activities of alcohol dehydrogenase, aldehyde dehydrogenase, and glutathione S-transferase in soybean roots increased during the exposure, suggesting their roles in 8:2 FTOH metabolism in soybean. This study provides important information for a better understanding of the uptake and metabolism of FTOHs and fluorotelomer-based compounds in plants.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Perfluorinated alkyl substances (PFASs) in household dust in Central Europe and North America

Authors: Karásková, P; Venier, M; Melymuk, L; Bečanová, J; Vojta, Š; Prokeš, R; Diamond, ML; Klánová, J (2016) Environment International 94:315-324. HERO ID: 3358129

[Less] Concentrations of 20 perfluorinated alkyl substances (PFASs) were measured in dust samples from 41 homes . . . [More] Concentrations of 20 perfluorinated alkyl substances (PFASs) were measured in dust samples from 41 homes in Canada, the Czech Republic, and United States in the spring-summer of 2013. The most frequently detected compounds were perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonate (PFOS). PFOS and perfluorooctanoic acid (PFOA) had the highest concentrations of PFASs in all countries. PFOS median concentrations for the three countries were between 9.1 and 14.1ng/g, and PFOA medians ranged between 8.2 and 9.3ng/g. In general, concentrations in North America were higher than in the Czech Republic, which is consistent with usage patterns. No differences were found for perfluorooctane sulfonamides/sulfonamidoethanols (FOSA/Es) levels due to the low number of detections. Homologue profiles suggest that the shift from longer to shorter chain PFASs is more advanced in North America than in Europe. Significant relationships were found among individual homologues and between PFAS concentrations in dust and type of floor, number of people living in the house, and building age.