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PFHxS (355-46-4)


808 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

Per- and polyfluorinated compounds in saleswomen's urine linked to indoor dust in clothing shops

Authors: Wu, N; Cai, D; Guo, M; Li, M; Li, X (2019) Science of the Total Environment 667:594-600. HERO ID: 5080616

[Less] This study aims to investigate the characteristics of typical per- and polyfluorinated compounds (PFCs) . . . [More] This study aims to investigate the characteristics of typical per- and polyfluorinated compounds (PFCs) in indoor dust from clothing shops and urine sampled from saleswomen. A total of 58 indoor dust samples and 73 urine samples from saleswomen were collected from clothing shops in Shanghai, China. All samples were analyzed for PFCs using high-performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-MS/MS). The mean PFC concentrations in indoor dust ranged from 0.42 (PFDA) to 5.04 ng g-1 (PFDoA). PFDoA and PFHxS were the most prominent PFCs, with median concentrations of 2.95 ng g-1 and 1.49 ng g-1, respectively. The median PFC concentrations in urine ranged from 10.15 (PFDS) to 666.1 ng l-1 (PFOA) and PFOA was the most abundant chemical with concentrations ranging from 207 to 907 ng l-1. A significant positive correlation was obtained between long-chain PFCs in dust and in urine (p < 0.01). Daily intake values of PFCs via dust ingestion were also calculated, and even under high-end exposure scenarios, the intake of PFOA (36.5 pg day-1) and PFOS (56.7 pg day-1) were well within the tolerable daily intake values. These results are important to both characterize PFC levels and estimate the saleswomen's exposure to PFCs from indoor dust.

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

Maternal serum concentrations of perfluoroalkyl substances and birth size in British boys

Authors: Marks, KJ; Cutler, AJ; Jeddy, Z; Northstone, K; Kato, K; Hartman, TJ (2019) HERO ID: 5081319

[Less] Per- and polyfluoroalkyl substances (PFAS) have been widely used in commercial and industrial manufacturing . . . [More] Per- and polyfluoroalkyl substances (PFAS) have been widely used in commercial and industrial manufacturing processes since the 1950s. Inverse associations between prenatal exposure to PFAS and birth size have been found in populations around the globe. This study examined the association of prenatal maternal serum concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) and birth size in British boys. The study included 457 mother-son dyads participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Birth weight (g), crown to heel length (cm), and head circumference (cm) were collected at delivery. PFAS were detected in all maternal serum samples during pregnancy (median: 30 weeks gestation (interquartile range: 12-33)). Median concentrations (interquartile range) were 13.8 ng/mL (11.0, 17.7), 3.0 ng/mL (2.3, 3.8), 1.9 ng/mL (1.4, 2.5), and 0.4 ng/mL (0.3, 0.5) for PFOS, PFOA, PFHxS, and PFNA, respectively. In multivariable linear regression models, inverse associations were detected between PFOS (continuous) and birth weight (β = -8.50 g, 95% CI = -15.93, -1.07 g), crown to heel length (β = -0.04 cm, 95% CI = -0.08, -0.01 cm), and head circumference (β = -0.02 cm, 95% CI = -0.04, -0.002 cm). In conclusion, prenatal exposure to high levels of PFOS may be associated with reduced birth size in male 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

In vitro and in silico evaluations of binding affinities of perfluoroalkyl substances to baikal seal and human peroxisome proliferator-activated receptor α

Authors: Ishibashi, H; Hirano, M; Kim, EY; Iwata, H (2019) Environmental Science and Technology 53:2181-2188. HERO ID: 5024210

[Less] In this study, we assessed the binding affinities of perfluoroalkyl substances (PFASs), including perfluoroalkyl . . . [More] In this study, we assessed the binding affinities of perfluoroalkyl substances (PFASs), including perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs), to the ligand-binding domains (LBDs) of Baikal seal ( Pusa sibirica; bs) and human (h) peroxisome proliferator-activated receptor alpha (PPARα). An in vitro competitive binding assay showed that six PFCAs and two PFSAs could bind to recombinant bs and hPPARα LBD proteins in a dose-dependent manner. The relative binding affinities (RBAs) of PFASs to bsPPARα were as follows: PFOS > PFDA > PFNA > PFUnDA > PFOA > PFHxS > PFHpA > PFHxA. The RBAs to bsPPARα showed a significant positive correlation with those to hPPARα. In silico PPARα homology modeling predicted that there were two ligand-binding pockets (LBPs) in the bsPPARα and hPPARα LBDs. Structure-activity relationship analyses suggested that the binding potencies of PFASs to PPARα might depend on LBP binding cavity volume, hydrogen bond interactions, the number of perfluorinated carbons, and the hydrophobicity of PFASs. Interspecies comparison of the in vitro binding affinities revealed that bsPPARα had higher preference for PFASs with long carbon chains than hPPARα. The in silico docking simulations suggested that the first LBP of bsPPARα had higher affinities than that of hPPARα; however, the second LBP of bsPPARα had lower affinities than that of hPPARα. To our knowledge, this is the first evidence showing interspecies differences in the binding of PFASs to PPARαs and their structure-activity relationships.

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

Leaching and bioavailability of selected perfluoroalkyl acids (PFAAs) from soil contaminated by firefighting activities

Authors: Bräunig, J; Baduel, C; Barnes, CM; Mueller, JF (2019) Science of the Total Environment 646:471-479. HERO ID: 5079692

[Less] Historical usage of aqueous film-forming foam (AFFF) at firefighting training grounds (FTGs) is a potential . . . [More] Historical usage of aqueous film-forming foam (AFFF) at firefighting training grounds (FTGs) is a potential source of perfluoroalkyl acids (PFAAs) to the surrounding environment. In this study the leaching of PFAAs from field contaminated soil and their uptake into biota was investigated. Soil was sampled from FTGs at two airports and the total as well as the leachable concentration of 12 PFAAs was determined. A greenhouse study was carried out to investigate the uptake of PFAAs from soils into earthworms (Eisenia fetida) and wheat grass (Elymus scaber). Perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were the most dominant PFAAs in all soils samples, with concentrations of PFOS reaching 13,400 ng/g. Leachable concentrations of PFOS and PFHxS reached up to 550 μg/L and 22 μg/L, respectively. In earthworms concentrations of PFOS reached 65,100 ng/g after a 28-day exposure period, while in wheat grass the highest concentration was measured for uptake of PFHxS (2,800 ng/g) after a 10-week growth-period. Bioaccumulation factors (BAFs) for earthworms ranged from 0.1 for perfluorohexanoic acid (PFHxA) to 23 for perfluorododecanoic acid (PFDoA) and initially showed a decreasing trend with increasing perfluoroalkyl chain length, followed by an increase with increasing perfluoroalkyl chain length for perfluoroalkyl carboxylic acids (PFCAs). In wheat grass the highest BAF was found for perfluorobutanoic acid (BAF = 70), while the lowest was observed for perfluorononanoic acid (BAF = 0.06). BAFs in wheat grass decreased with increasing perfluoroalkyl chain length for both PFCAs and perfluoroalkyl sulfonic acids (PFSAs). The results show that PFAAs readily leach from impacted soils and are bioaccumulated into earthworms and plants in an analyte dependent way. This shows considerable potential for PFAAs to move away from the original source either by leaching or uptake into ecological receptors, which may be a potential entry route into the terrestrial foodweb.

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

Factors associated with exposure of pregnant women to perfluoroalkyl acids in North China and health risk assessment

Authors: Yang, J; Wang, H; Du, H; Xu, L; Liu, S; Yi, J; Qian, X; Chen, Y; Jiang, Q; He, G (2019) Science of the Total Environment 655:356-362. HERO ID: 5080660

[Less] Perfluoroalkyl acids (PFAAs) have been frequently found in blood of pregnant women, but the predictors . . . [More] Perfluoroalkyl acids (PFAAs) have been frequently found in blood of pregnant women, but the predictors and potential health risk have not been well studied in China. We recruited 534 pregnant women in Tangshan City of Hebei Province in North China between 2013 and 2014 and measured five PFAAs in serum during their early term of pregnancy, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluoro‑n‑undecanoic acid (PFUdA), and perfluorononanoic acid (PFNA). We explored the factors associated with the levels of serum PFAAs and assessed associated health risks. Food consumption information was obtained by food frequency questionnaire covering 100 items. Multiple linear regression model was used to determine the associations of sociodemographic, anthropometric, and food factors with the concentrations of serum PFAAs. Some PFAAs in serum were positively associated with age and body mass index (BMI). Consumption of beans, aquatic products, and eggs was positively associated with the concentrations of several PFAAs after adjusting for important covariates. Pregnant women who ate more cereal, vegetables, mushrooms and alga tended to have lower levels of serum PFOA, PFOS and PFNA. The Hazard index (HI) for reproductive toxicity and developmental toxicity was below 0.8, and the HI for hepatotoxicity beyond 1 was found in 0.37% of pregnant women. These results suggested that age, BMI, and some food consumption were predictors for the exposure to PFAAs in Chinese pregnant women. More attention should be paid to the hepatotoxicity for these exposures.

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

Concentrations of perfluoroalkyl substances (PFASs) in human embryonic and fetal organs from first, second, and third trimester pregnancies

Authors: Mamsen, LS; Björvang, RD; Mucs, D; Vinnars, MT; Papadogiannakis, N; Lindh, CH; Andersen, CY; Damdimopoulou, P (2019) Environment International 124:482-492. HERO ID: 5080595

[Less] BACKGROUND: The persistent environmental contaminants perfluoroalkyl substances (PFASs) . . . [More] BACKGROUND: The persistent environmental contaminants perfluoroalkyl substances (PFASs) have gained attention due to their potential adverse health effects, in particular following early life exposure. Information on human fetal exposure to PFASs is currently limited to one report on first trimester samples. There is no data available on PFAS concentrations in fetal organs throughout all three trimesters of pregnancy.

METHODS: We measured the concentrations of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorohexane sulfonic acid (PFHxS) in human embryos and fetuses with corresponding placentas and maternal serum samples derived from elective pregnancy terminations and cases of intrauterine fetal death. A total of 78 embryos and fetuses aged 7-42 gestational weeks were included and a total of 225 fetal organs covering liver, lung, heart, central nervous system (CNS), and adipose tissue were analyzed, together with 71 placentas and 63 maternal serum samples. PFAS concentrations were assayed by liquid chromatography/triple quadrupole mass spectrometry.

RESULTS: All evaluated PFASs were detected and quantified in maternal sera, placentas and embryos/fetuses. In maternal serum samples, PFOS was detected in highest concentrations, followed by PFOA > PFNA > PFDA = PFUnA = PFHxS. Similarly, PFOS was detected in highest concentrations in embryo/fetal tissues, followed by PFOA > PFNA = PFDA = PFUnA. PFHxS was detected in very few fetuses. In general, PFAS concentrations in embryo/fetal tissue (ng/g) were lower than maternal serum (ng/ml) but similar to placenta concentrations. The total PFAS burden (i.e. the sum of all PFASs) was highest in lung tissue in first trimester samples and in liver in second and third trimester samples. The burden was lowest in CNS samples irrespective of fetal age. The placenta:maternal serum ratios of PFOS, PFOA and PFNA increased across gestation suggesting bioaccumulation in the placenta. Further, we observed that the ratios were higher in pregnancies with male fetuses compared to female fetuses.

CONCLUSIONS: Human fetuses were intrinsically exposed to a mixture of PFASs throughout gestation. The compounds were detected in all analyzed tissues, suggesting that PFASs reach and may affect many types of organs. Collectively, our results demonstrate that PFASs pass the placenta and deposit to embryo and fetal tissues, calling for risk assessment of gestational exposures.

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

Characterization of age-based trends to identify chemical biomarkers of higher levels in children

Authors: Nguyen, VK; Colacino, JA; Arnot, JA; Kvasnicka, J; Jolliet, O (2019) HERO ID: 5043339

[Less] BACKGROUND: Chemical biomarker concentrations are driven by complex interactions between . . . [More] BACKGROUND: Chemical biomarker concentrations are driven by complex interactions between chemical use patterns, exposure pathways, and toxicokinetic parameters such as biological half-lives. Criteria to differentiate legacy from current exposures are helpful for interpreting variation in age-based and time trends of chemical exposure and identifying chemicals to which children are highly exposed. A systematic approach is needed to study temporal trends for a wide range of chemicals in the US population.

OBJECTIVES: Using National Health and Nutrition Examination Survey (NHANES) data on measured biomarker concentrations for 141 chemicals from 1999 to 2014, we aim to 1) understand the influence of temporal determinants, in particular time trends, biological half-lives, and restriction dates on age-based trends, 2) systematically define an age-based pattern to identify chemicals with ongoing and high exposure in children, and 3) characterize how age-based trends for six Per- and Polyfluoroalkyl Substances (PFASs) are changing over time.

METHODS: We performed an integrated analysis of biological half-lives and restriction dates, compared distributions of chemical biomarker concentrations by age group, and then applied a series of regression models to evaluate the linear (βage) and nonlinear (βage2) relationships between age and chemical biomarker levels.

RESULTS: For restricted chemicals, a minimum persistence of 1 year in the human body is needed to observe substantial differences between the less exposed young population and historically exposed adults. We define a metric ( [Formula: see text] ) that identifies several phthalates, brominated flame retardants, pesticides, and metals such as lead and tungsten as elevated and ongoing exposures in children. While a substantial reduction in children's exposures was reflected in PFOS and PFOA, levels of PFNA and PFHxS in children were higher in 2013-2014 compared to those in 1999-2000.

CONCLUSIONS: Integrating a series of regression models with systemized stratified analyses by age group enabled us to define an age-based pattern to identify chemicals that are of higher levels in children.

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

Decreased plasma levels of perfluoroalkylated substances one year after bariatric surgery

Authors: Jansen, A; Müller, MHB; Grønnestad, R; Klungsøyr, O; Polder, A; Skjerve, E; Aaseth, J; Lyche, JL (2019) Science of the Total Environment 657:863-870. HERO ID: 5081174

[Less] Per- and polyfluoroalkylated substances (PFASs) are classified as persistent organic pollutants (POPs), . . . [More] Per- and polyfluoroalkylated substances (PFASs) are classified as persistent organic pollutants (POPs), and known to be protein bound. The aim of the present study was to determine the levels of 17 different PFASs before and one year after bariatric surgery, and to assess whether weight loss and changed serum protein concentrations could be influencing factors. Plasma samples from 63 patients were analyzed for nine perfluoroalkyl carboxylic acids (PFCAs), three perfluoroalkane sulfonic acids (PFSAs), and five perfluoroalkyl sulfonamide based substances (PASF) before and after surgery. Protein determination was performed in the corresponding serum samples. Mean weight loss one year after surgery was 32.1 kg. The plasma levels of all PFASs decreased with 4-34% compared to preoperative values, and included perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorobutane sulfonate (PFBS), which have been identified with increasing levels in the general population during recent years. Serum protein concentrations also decreased with 7-8%. Although protein levels were positively correlated with PFOA, PFBS, PFHxS and PFOS, regression analysis revealed that neither weight loss nor reductions in concentrations of serum protein could explain the decreased PFAS levels. The type of surgical procedure did not influence the changes of PFAS levels between the two sample points. A reduced food intake and alterations in absorptions of nutrients after bariatric surgery may have influenced the observed decreasing plasma levels of PFASs.

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 substances in diamondback terrapins (Malaclemys terrapin) in coastal South Carolina

Authors: Bangma, JT; Ragland, JM; Rainwater, TR; Bowden, JA; Gibbons, JW; Reiner, JL (2019) Chemosphere 215:305-312. HERO ID: 5080394

[Less] This study focused on an estuarine wildlife species exhibiting high site fidelity and ubiquitous distribution . . . [More] This study focused on an estuarine wildlife species exhibiting high site fidelity and ubiquitous distribution in coastal environments along the Atlantic and Gulf coasts of the United States to monitor per- and polyfluoroalkyl substances (PFAS). A total of 75 diamondback terrapin (Malaclemys terrapin) plasma samples were collected from five creeks associated with Kiawah (Oyster Creek, Fiddler Creek, Sandy Creek, Gnat Creek) and Edisto (Townsend Creek) islands in Charleston County, South Carolina and investigated for 15 legacy PFAS. Of those, PFHxS was the only PFAS found in all terrapin plasma samples. Four additional PFAS were routinely detected (greater than 90% of the samples) and were included in statistical analyses: PFOS, PFNA, PFDA, and PFUnA. Sex-differences were observed for two creeks with male plasma containing higher PFAS than female plasma (PFHxS at Townsend Creek, PFOS at Oyster Creek). Sex-specific site differences in PFAS concentrations were observed primarily for males, suggesting male terrapins may be more sensitive indicators of localized contaminant profiles than females. Three PFAS were observed to have negative correlations with body mass: PFOS in males (p = 0.045, tau = -0.220), PFNA in males (p = 0.016, tau = -0.269), and PFHxS in both males (p = 0.007, tau = -0.302) and females (p = 0.001, tau = -0.379). No relationships for body mass and PFDA and PFUnA 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

Toxicokinetics of Perfluorinated Alkyl Acids Influences Their Toxic Potency in the Zebrafish Embryo ( Danio rerio)

Authors: Vogs, C; Johanson, G; Näslund, M; Wulff, S; Sjödin, M; Hellstrandh, M; Lindberg, J; Wincent, E (2019) Environmental Science and Technology 53:3898-3907. HERO ID: 5080626

[Less] Perfluorinated alkyl acids (PFAA) are highly persistent and bioaccumulative and have been associated . . . [More] Perfluorinated alkyl acids (PFAA) are highly persistent and bioaccumulative and have been associated with several adverse health effects. The chemical structure mainly differs in two ways: the length of the hydrophobic alkyl chain and the type of hydrophilic end group. Little is known how the chemical structure affects the toxicokinetics (TK) in different organisms. We studied the TK of four PFAA (PFOS, PFHxS, PFOA, and PFBA) with different chain lengths (4-8 carbons) and functional groups (sulfonic and carboxylic acid) in zebrafish ( Danio rerio) embryo. The time courses of the external (ambient water) and internal concentrations were determined at three exposure concentrations from 2 up to 120 h postfertilization (hpf). Three of the four PFAA showed a biphasic uptake pattern with slow uptake before hatching (around 48 hpf) and faster uptake thereafter. A two-compartment TK model adequately described the biphasic uptake pattern, suggesting that the chorion functions as an uptake barrier until 48 hpf. The bioconcentration factors (BCF) determined at 120 hpf varied widely between PFAA with averages of approximately 4000 (PFOS), 200 (PFHxS), 50 (PFOA), and 0.8 (PFBA) L kg dry weight-1, suggesting that both the alkyl chain length and the functional group influence the TK. The differences in toxic potency were reduced by 3 orders of magnitude when comparing internal effect concentrations instead of effective external concentrations.