Health & Environmental Research Online (HERO)


PFHxA (307-24-4)


59 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

Corrigendum to "Comparative analysis of the toxicological databases for 6:2 fluorotelomer alcohol (6:2 FTOH) and perfluorohexanoic acid (PFHxA)" [Food Chem. Toxicol. 138 (2020) 1-16]

Authors: Rice, PA; Aungst, J; Cooper, J; Bandele, O; Kabadi, SV (2020) Food and Chemical Toxicology 139:111249. [Erratum] HERO ID: 6326945


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

Transformation of 6:2 Fluorotelomer Sulfonate by Cobalt(II)-Activated Peroxymonosulfate

Authors: Zhang, Y; Liu, J; Moores, A; Ghoshal, S (2020) Environmental Science and Technology 54:4631-4640. HERO ID: 6326944

[Less] Peroxymonosulfate (PMS)-based advanced oxidation processes generate highly reactive SO4•- and are promising . . . [More] Peroxymonosulfate (PMS)-based advanced oxidation processes generate highly reactive SO4•- and are promising for water treatment. In this study, we investigated the reaction mechanism of 6:2 fluorotelomer sulfonate (6:2 FTS) with Co2+-activated PMS. 6:2 FTS was simultaneously transformed to perfluoroalkyl carboxylic acids (C2-C7 PFCAs) of different chain lengths, with perfluorohexanoic acid (C6) as the predominant one. The mass balance of the intermediates and products versus the initially added 6:2 FTS was close to 100% over the reaction period. Using chemical scavenging methods, we identified that •OH, instead of SO4•-, was the oxidant initiating the reaction of 6:2 FTS. •OH was mainly produced from SO4•- reacting with H2O. Thus, the reactivity of 6:2 FTS was controlled by the factors affecting the production and scavenging of both SO4•- and •OH. Density functional theory calculations showed that •OH oxidizes 6:2 FTS by H-abstraction from ethyl carbons. This is the first study that demonstrates that •OH in Co2+-activated PMS can play a significant role in contaminant transformations. The results indicate that great caution should be taken when PMS or other agents that generate •OH are used for the treatment of water containing 6:2 FTS or its structural analogs.

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

Biotransformation of 6:2 fluorotelomer alcohol by the whole soybean (Glycine max L. Merrill) seedlings

Authors: Zhang, H; Wen, Bei; Huang, H; Wang, Sen; Cai, Z; Zhang, S (2020) Environmental Pollution 257:113513. HERO ID: 6322291

[Less] Fluorotelomer alcohols (FTOHs) are important precursors of perfluorocarboxylic acids (PFCAs) in the . . . [More] Fluorotelomer alcohols (FTOHs) are important precursors of perfluorocarboxylic acids (PFCAs) in the environment and biota. With the growing application of 6:2 FTOH [F(CF2)6CH2CH2OH] in product formulation, it is becoming increasingly urgent to investigate its biological fates in different species. In this study, biotransformation of 6:2 FTOH by young soybean plants (Glycine max L. Merrill) were investigated using hydroponic experiments. During the 144 h-exposure, 6:2 FTCA [F(CF2)6CH2COOH], 6:2 FTUCA [F(CF2)5CFCHCOOH], 5:3 FTUCA [F(CF2)5CHCHCOOH], 5:3 FTCA [F(CF2)5CH2CH2COOH], PFHxA [F(CF2)5COOH] and PFPeA [F(CF2)4COOH] were phase I metabolites in soybean. At the end of exposure, 5:3 FTCA (5.08 mol%), PFHxA (2.34 mol%) and PFPeA (0.58 mol%) were three main metabolites in soybean-solution system. 5:3 FTCA was predominant in soybean roots and stems, while PFHxA was the most abundant product in leaves. PFBA [F(CF2)3COOH] and 4:3 FTCA [F(CF2)4CH2CH2COOH] detected in the hydroponic solution most-likely came from the transformation of 5:3 FTCA by root-associated microbes. Moreover, phase II metabolites of 6:2 FTOH were identified and monitored in soybean tissues. Alcohol dehydrogenase, aldehyde dehydrogenase and glutathione S-transferase were found to participate in 6:2 FTOH metabolism. Based on the phase I and phase II metabolism of 6:2 FTOH in soybean, this study for the first time provides evidences for the transformation pathways of 6:2 FTOH 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

Behavioural effects and bioconcentration of per- and polyfluoroalkyl substances (PFASs) in zebrafish (Danio rerio) embryos

Authors: Menger, F; Pohl, J; Ahrens, L; Carlsson, G; Örn, S (2020) Chemosphere 245:125573. HERO ID: 6311635

[Less] Per- and polyfluoroalkyl substances (PFASs) are contaminants of emerging concern (CECs) that cause concern . . . [More] Per- and polyfluoroalkyl substances (PFASs) are contaminants of emerging concern (CECs) that cause concern regarding their environmental impact and risk to human health. In this study, zebrafish (Danio rerio) embryos were exposed to PFASs for six days, to investigate behaviour toxicity and bioconcentration factor (BCF). Nine individual PFASs (five C4-C8 perfluoroalkyl carboxylates (PFCAs) (PFPeA, PFHxA, PFHpA, PFOA, PFNA), three C4, C6 and C8 perfluoroalkyl sulfonates (PFSAs) (PFBS, PFHxS, PFOS) and 6:2 fluorotelomersulfonate (6:2 FTSA)) and a mixture of these were investigated at seven concentrations ranging from environmentally relevant to acutely toxic levels. In exposed embryos, significant differences were found in total swimming distance (PFHpA, PFOA, PFNA, PFHxS, PFOS, 6:2 FTSA, PFAS mixture), burst activity (PFOA, PFNA, PFHxS, PFOS, PFAS mixture) and startle response (PFNA, PFHxS, PFOS, PFAS mixture). Toxicity was only observed at concentrations well above environmental levels. The toxicity of the PFAS mixture generally followed that of the individual substances, but the mixture reduced the potencies of individual PFASs. BCF was determined for all nine PFASs and ranged between 0.9 (PFPeA) and 2700 (PFOS). Long-chain PFASs (C8) and PFASs with sulfonate as an active group showed the greatest toxic potential, while short-chain PFASs (C6 and C7) also caused significant behaviour alterations and accumulated in the embryos. To our knowledge, this is the first study to compare the behaviour toxicity of a PFAS mixture with that of the individual PFASs. Follow-up studies are needed to identify the mechanistic responses to PFAS mixtures.

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

Poly- and perfluoroalkyl substance concentrations in human breast milk and their associations with postnatal infant growth

Authors: Jin, H; Mao, L; Xie, J; Zhao, M; Bai, X; Wen, J; Shen, T; Wu, P (2020) Science of the Total Environment 713:136417. HERO ID: 6316202

[Less] Perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates are widespread in human breast milk. . . . [More] Perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates are widespread in human breast milk. However, the occurrence of chlorinated polyfluorinated ether sulfonates (Cl-PFESAs) and fluorotelomer alcohols (FTOHs) in breast milk and their effects on postnatal growth of infants through breast milk consumption are still not well known. This study characterized the occurrence of 16 poly- and perfluoroalkyl substances (PFASs) in breast milk from 174 women in Hangzhou, China and investigated the association between lactation exposure to these PFASs through breast milk consumption and the postnatal growth of infants. Our results showed that perfluorooctanoate (mean 87 pg/mL) was the predominant PFAS in breast milk, followed by perfluorohexanoate (41 pg/mL), 6:2 Cl-PFESA (28 pg/mL), and perfluorooctane sulfonate (25 pg/mL). The occurrence and levels of Cl-PFESAs in Chinese breast milk were firstly reported in the current study. The 8:2 and 10:2 FTOH were detected in half of breast milk samples, with the mean concentration of 9.0 pg/mL and 10 pg/mL, respectively. Breast milk concentrations of C8-C10 PFCAs and 6:2 Cl-PFESA were negatively correlated with infant's length gain rate. Exposed to higher levels of 8:2 FTOH were correlated with decreased infant's weight gain rate. Daily intakes of PFASs via the consumption of breast milk were calculated for infants. Overall, this study firstly demonstrated that lactation exposure to C8-C10 PFCAs, 8:2 FTOH, and 6:2 Cl-PFESA through breast milk consumption may affect the postnatal growth of infants.

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

Remediation of perfluorooctanoic acid (PFOA) polluted soil using pulsed corona discharge plasma

Authors: Zhan, J; Zhang, A; Héroux, P; Guo, Y; Sun, Z; Li, Z; Zhao, J; Liu, Y (2020) Journal of Hazardous Materials 387:121688. HERO ID: 6316920

[Less] Perfluorooctanoic acid (PFOA) from contaminated soil accumulates in higher organisms, and causes health . . . [More] Perfluorooctanoic acid (PFOA) from contaminated soil accumulates in higher organisms, and causes health risks to humans. In this research, 71 % of the PFOA was degraded, of which 51 % was decomposed into short chain by-products, 19 % mineralized, and 1 % volatilized with 30 kV of voltage, 50 Hz of discharge frequency, 1 % of soil moisture, 300 ppm of PFOA concentration and 6.3 of soil pH using pulsed positive discharge plasma. From a series of experiments, electrons were identified as the dominant active means of PFOA degradation. The decomposition by-products were analyzed by LC-MS. The results indicated that PFOA was decomposed into small by-products including perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), perfluorobutyric acid (PFBA), pentafluoropropionic acid (PFPrA) and trifluoroacetic acid (TFA). Moreover, in plasma treated soil, the concentration of ammonia nitrogen increased from less than 10 ppm-462 ppm, and the average dry weight of lettuce was 1.6 mg higher than that in natural soil. Additionally, Planctomycetes and Nitrospirae increased after treatment, indicating that plasma technology promotes the process of nitrogen cycle. Thus, PFOA polluted soil could be remediated using this pulse corona plasma technology, and simultaneously improve the fertility of soil without chemical injections.

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

Application of zero-valent iron coupled with biochar for removal of perfluoroalkyl carboxylic and sulfonic acids from water under ambient environmental conditions

Authors: Liu, Y; Ptacek, CJ; Baldwin, RJ; Cooper, JM; Blowes, DW (2020) Science of the Total Environment 719:137372. HERO ID: 6315690

[Less] Advanced oxidation and reduction processes have been intensively investigated as potential methods to . . . [More] Advanced oxidation and reduction processes have been intensively investigated as potential methods to promote the decomposition of perfluoroalkyl substances (PFASs). However, extreme operational conditions such as highly acidic pH, high temperature, and high pressure are required to promote degradation reactions, which makes these technologies costly and less feasible for full-scale applications. The objective of this study was to evaluate the effectiveness of zero-valent iron (ZVI) alone and a mixture of ZVI and biochar (ZVI + BC) for removal of seven target PFASs from water under ambient environmental conditions. Target PFASs included three perfluoroalkyl carboxylic acids (PFCAs) [perfluorooctanoic acid (PFOA, C8-PFCA), perfluoroheptanoic acid (C7-PFCA), and perfluorohexanoic acid (C6-PFCA)] and four perfluoroalkyl sulfonic acids (PFSAs) [perfluorooctane sulfonic acid (PFOS, C8-PFSA), perfluoroheptane sulfonic acid (C7-PFSA), perfluorohexane sulfonic acid (C6-PFSA), and perfluorobutane sulfonic acid (C4-PFSA)]. Batch test results show that PFSAs (up to 94% removal) were more effectively removed than PFCAs (up to 60% removal) when utilizing either ZVI or (ZVI + BC). About 20-60% of input PFOA (~18,550 μg L-1) and 90-94% of input PFOS (~18,580 μg L-1) were removed by ZVI alone or the mixture of (ZVI + BC). The removal efficiencies of PFCAs and PFSAs by reactive media increased with increasing chain length, from 0 to 17% for short-chain PFCAs (C6-C7) and 20 to 70% for short-chain PFSAs (C4-C7). About 5-10% of input PFOA and PFOS was partially defluorinated by ZVI alone as indicated by F- release; however, the defluorination efficiency may be underestimated due to the sorption of F- by the reactive media. Overall, the reactive mixture (ZVI + BC) may be an effective and environmentally sustainable material for removing PFASs from water under ambient environmental conditions.

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

Distribution of novel and legacy per-/polyfluoroalkyl substances in serum and its associations with two glycemic biomarkers among Chinese adult men and women with normal blood glucose levels

Authors: Duan, Y; Sun, H; Yao, Y; Meng, Y; Li, Y (2020) Environment International 134:105295. HERO ID: 5918597

[Less] In recent years, the occurrence of novel per-/polyfluoroalkyl substances (PFASs) such as polyfluoroalkyl . . . [More] In recent years, the occurrence of novel per-/polyfluoroalkyl substances (PFASs) such as polyfluoroalkyl ether sulfonates (PFAESs) in human samples have aroused attention due to the change in PFASs production profile, however, the data are still lacking. Furthermore, epidemiological studies have examined the associations of PFAS exposure with glucose homeostasis, but with inconsistent results. Therefore, in this study, fasting serum samples from 252 participants with an age range from 19 to 87 years old were collected in Tianjin, China. A total of 21 target PFASs were determined to analyze the levels and distribution of novel and legacy PFASs in serum and to further evaluate the cross-sectional associations of serum PFAS concentrations with two glycemic biomarkers (i.e., fasting glucose and glycated hemoglobin (HbA1c)). 6:2 chlorinated PFAES (6:2 Cl-PFAES) and trifluoroacetic acid (TFA) were widely detected novel PFASs (greater than90%) with relatively high median concentrations (8.64 ng/mL and 8.46 ng/mL, respectively), which were second only to the two dominant legacy PFASs, i.e., perfluorooctanoic acid (PFOA, 14.83 ng/mL) and perfluorooctane sulfonic acid (14.24 ng/mL). The percentage contributions to the total known PFASs were separately 17.6% and 17.2% for 6:2 Cl-PFAES and TFA. The levels of 6:2 Cl-PFAES were significantly correlated with age and BMI, and the concentrations of TFA were also significantly correlated with age. Furthermore, 1% increase in serum PFOA and perfluorononanoic acid (PFNA) was separately significantly associated with 0.018% [95% confidence interval (CI): 0.004%, 0.033%] and 0.022% (95% CI: 0.007%, 0.037%) increment in fasting glucose levels. Similarly, 1% increase in serum perfluorohexanoic acid, PFNA, and perfluorohexane sulfonic acid was significantly associated with 0.030% (95% CI: 0.010%, 0.051%), 0.018% (95% CI: 0.003%, 0.033%), 0.007% (95% CI: 0.003%, 0.011%) increment in HbA1c levels, respectively. These findings suggested that 6:2 Cl-PFAES and TFA showed greater contributions to PFASs in serum and supported an association of exposure to PFASs with fasting glucose and HbA1c.

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

Contaminant levels and endocrine disruptive effects in Clarias gariepinus exposed to simulated leachate from a solid waste dumpsite in Calabar, Nigeria

Authors: Ibor, OR; Andem, AB; Eni, G; Arong, GA; Adeougn, AO; Arukwe, A (2020) Aquatic Toxicology 219:105375. HERO ID: 6311681

[Less] Solid waste dumpsites (SWDs) and landfills are significant sources of emerging contaminants to terrestrial . . . [More] Solid waste dumpsites (SWDs) and landfills are significant sources of emerging contaminants to terrestrial and aquatic ecosystems. We have studied the endocrine disruptive effects of simulated leachate from a solid waste dumpsite in Calabar, Nigeria. Juvenile C. gariepinus were exposed to simulated leachate, diluted to 0:0 (control), 1:10, 1:50, 1:100 for 3, 7 and 14 days. In addition, 17β-estradiol (E2: 100 μg/L)-exposed positive control group was included. Hepatic transcripts for the genes encoding vitellogenin (vtg), estrogen receptor-α (er-α), and aromatase (cyp19a1) were analyzed by real-time PCR. Protein expression for Vtg and Cyp19 were measured by immunoblotting and plasma steroid hormones (testosterone: T and E2) were measured using enzyme immunoassay (EIA). Soil samples from the dumpsite were analyzed for selected group of contaminants showing that DEHP was the only detected phthalate ester (PE) at 1300 ± 400 ng/g. Further, perfluoroalkyl substances (PFASs) such as PFBS, PFOS, PFHxA, PFOA, PFNA, PFDA, PFUnDA and PFDoDA were detected in the soil samples from the dumpsite. We observed significant and apparent concentration-dependent increases in mRNA (vtg, er-α, and cyp19a1) and their corresponding functional protein products, after exposure to the simulated leachates. Further, the simulated leachate produced concentration-specific changes in plasma E2 and T levels. In general, the estrogenic endocrine and reproductive alterations in the exposed fish may directly be attributed to the PFASs and DEHP detected at the dumpsites. However, in addition to PFASs and DEHP, there could be other estrogenic contaminants in the leachate. Given the rapid utilization, for residential purposes, and increases in human settlement in areas around the Lemna SWDs, this study provides a direct cause-and-effect evidence of the potential contaminants at the dumpsite with significant environmental and human health consequences.

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 short-chain perfluorinated compounds PFBS, PFHxS, PFBA and PFHxA, disrupt human mesenchymal stem cell self-renewal and adipogenic differentiation

Authors: Liu, S; Yang, R; Yin, N; Faiola, F (2020) Journal of Environmental Sciences 88:187-199. HERO ID: 6315705

[Less] Per- and polyfluorinated alkyl substances (PFASs) are commonly used in industrial processes and daily . . . [More] Per- and polyfluorinated alkyl substances (PFASs) are commonly used in industrial processes and daily life products. Because they are persistent, they accumulate in the environment, wildlife and humans. Although many studies have focused on two of the most representative PFASs, PFOS and PFOA, the potential toxicity of short-chain PFASs has not yet been given sufficient attention. We used a battery of assays to evaluate the toxicity of several four-carbon and six-carbon perfluorinated sulfonates and carboxyl acids (PFBS, PFHxS, PFBA and PFHxA), with a human mesenchymal stem cell (hMSC) system. Our results demonstrate significant cyto- and potential developmental toxicity for all the compounds analyzed, with shared but also distinct mechanisms of toxicity. Moreover, the effects of PFBS and PFHxS were stronger than those of PFBA and PFHxA, but occurred at higher doses compared to PFOS or PFOA.