Health & Environmental Research Online (HERO)


Per- and Polyfluoroalkyl Substances (PFAS)


451 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

An investigation of the effects of geometry design on refrigerant flow mal-distribution in parallel flow condenser using a hybrid method of finite element approach and CFD simulation

Authors: Shojaeefard, MH; Nourbakhsh, SD; Zare, J (2017) HERO ID: 3859952

[Less] Flow mal-distribution in tubes is an important problem in parallel flow heat exchangers (PFHXs) which . . . [More] Flow mal-distribution in tubes is an important problem in parallel flow heat exchangers (PFHXs) which should be considered in heat exchanger modeling. In the present study, a hybrid method is developed for flow distribution forecasting based on simultaneous use of computational fluid dynamics (CFD) simulation for 3D analysis of flow in PFHX headers and finite element model for solving flow within tubes. The developed method forecasts are verified against the experimental data of a parallel flow condenser (PFC) performance. The method is then utilized to investigate the effects of tube protrusion depth, inlet tube location, inlet tube diameter and combination of tube protrusion depth and inlet tube location on refrigerant flow mal-distribution. The data indicate flow mal-distribution increment (increase of standard deviation (STD) from 0.51% to 1.77%) by increasing the tube protrusion depth from 1/4 to 3/4 of header diameter which results in about 14% increment in pressure drop and 3.9% decrement in capacity. Also, reduction of flow mal-distribution in cases of increasing the inlet tube diameter and locating the header inlet on the top of the header, a small distance away from the first tube is observed. The presented model and results can be used to accurately design PFCs. (C) 2016 Elsevier Ltd. All rights reserved.

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

Developing a hybrid procedure of one dimensional finite element method and CFD simulation for modeling refrigerant flow mal-distribution in parallel flow condenser

Authors: Shojaeefard, MH; Zare, J; Nourbakhsh, SD (2017) HERO ID: 3859953

[Less] Mal-distribution of refrigerant flow in flat tubes is an important problem in parallel flow heat exchangers . . . [More] Mal-distribution of refrigerant flow in flat tubes is an important problem in parallel flow heat exchangers (PFHXs) which should be considered in heat exchanger modeling. In the present study, a hybrid method is developed for flow distribution forecasting based on simultaneous use of computational fluid dynamics (CFD) simulation for 3D analysis of flow in PFHX headers and one dimensional finite element model for solving flow within flat tubes. The experimental data of a parallel flow condenser (PFC) performance is collected to verify the developed method. The average absolute deviations of 2.8%, 4.1% and 3% from experimental data for pressure drop, capacity and outlet temperature respectively, indicate the model validity. Slight increase of mass flow rate with moving toward the bottom tubes of the inlet header shows insignificant effect of gravity when vapor-phase flow is present. Also, comparing the pressure drop data of the developed method with those of uniform distribution model demonstrates reduction of average absolute deviation from 28.7% to 2.8%. The proposed model has the advantage of predicting PFC overall performance and can be used to accurately design and optimize headers and multiport flat tubes. (C) 2016 Elsevier Ltd and IIR. All rights reserved.

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

A Robust Method for Routine Analysis of Perfluorooctane Sulfonate (PFOS) and Perfluorohexane Sulfonate (PFHxS) in Various Edible Crop Matrices

Authors: Xiang, Lei; Sun, TFei; Chen, Lei; Xiao, Tao; Cai, QY; Li, Hui; He, DeC; Wong, MH; Li, YanWen; Mo, CeHui (2017) HERO ID: 3859955

[Less] A reliable, sensitive, and efficient method was developed for routine analysis of perfluorooctane sulfonate . . . [More] A reliable, sensitive, and efficient method was developed for routine analysis of perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) in various edible crop matrices including cereal (grain), root vegetable (carrot), leafy vegetable (lettuce), and melon vegetable (pumpkin). The target analytes were extracted by ion-pair approach followed by solid-phase extraction clean-up and HPLC-MS/MS. The type of extraction solvent, clean-up cartridge, and the usage of Supelclean graphitized carbon were evaluated to reach an optimized pretreatment procedure. The matrix-matched standard calibrations relative to the isotope-labeled internal standard were used in the developed method to obtain more reliable quantitative results. The average recoveries at four spiked levels (0.5, 10, 25, 50 ng/g) in the diverse matrices ranged from 70.9 to 114.6% with relative standard deviations (RSD) lower than 11.5%. The matrix-dependent method detection limits using the common equipment (HPLC-MS/MS) were between 0.020 and 0.140 ng/g (dw), equivalent to the 3-130 pg/g (fw), corresponding to the sensitivity of superior equipment (e.g., UPLC-MS/MS and HPLC-QTOF-HRMS). Furthermore, the developed method was conferred with the practicality through determination of the analytes in actual crops sampled from several farms in China's Pearl River Delta.

Data/Software
Data/ Software

Products: Perfluorohexanesulfonate (CAS 355-46-4)

Author: LookChem (2017) HERO ID: 3981215


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

Plasma perfluoroalkyl and polyfluoroalkyl substances concentration and menstrual cycle characteristics in preconception women: Supplemental materials

Authors: Zhou, W; Zhang, L; Tong, C; Fang, F; Zhao, S; Tian, Y; Tao, Y; Zhang, J (2017) Environmental Health Perspectives 125. [Supplemental Data] HERO ID: 3860309

Abstract: Supplementary materials

Technical Report
Technical Report

Member State Committee support document for identification of perfluorohexane-1-sulphonic acid and its salts as substances of very high concern because of their vPvB1 (Article 57 E) properties

Author: ECHA (2017) European Chemicals Agency. HERO ID: 3875036


Technical Report
Technical Report

Annex XV report: Proposal for identification of a substance of very high concern on the basis of the criteria set out in REACH Article 57. Substance name(s): Perfluorohexane-1-sulphonic acid and its salts

Author: ECHA (2017) European Chemicals Agency. HERO ID: 3874974


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

Spatial distribution and source tracing of per- and polyfluoroalkyl substances (PFASs) in surface water in Northern Europe

Authors: Nguyen, MA; Wiberg, K; Ribeli, E; Josefsson, S; Futter, M; Gustavsson, J; Ahrens, L (2017) Environmental Pollution 220:1438-1446. HERO ID: 3605095

[Less] The impact of point and diffuse sources for 26 per- and polyfluoroalkyl substances (PFASs) in northern . . . [More] The impact of point and diffuse sources for 26 per- and polyfluoroalkyl substances (PFASs) in northern Europe were investigated by studying Swedish rivers (n = 40) and recipient seawater (Baltic Sea and Kattegat; n = 18). Different composition profiles were observed in the rivers, with ten rivers having a remarkably high fraction of perfluoroalkane sulfonic acids (PFSAs; 65% of the ƩPFASs) as compared to other rivers (19%) suggesting major impact of one or several source types dominated by PFSAs. Population density and low latitude (south) were strongly correlated to the widely used perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) as well as to perfluorohexanesulfonic acid (PFHxS). Significant relationships between several PFCAs and PFSAs (i.e. perfluorobutanoic acid (PFBA), perfluoroheptanoic acid (PFHpA), PFOA, perfluorobutanesulfonic acid (PFBS), and PFHxS) and dissolved organic carbon (DOC) were detected (p < 0.05), indicating chemical binding and co-transport with DOC in fresh water and seawater. Partial least squares regression analysis showed that perfluoroalkyl carboxylic acids (PFCAs) were related to latitude according to their perfluorocarbon chain length (C3, C7, C8, C9, C10 and C11), with longer chains associated with higher latitudes. This suggests the presence of mechanisms promoting higher prevalence of longer chained PFCAs in the north, e.g. precursor degradation, and/or aerosol associated stabilization of PFCAs and their precursors.

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

Estimating human exposure to perfluoroalkyl acids via solid food and drinks: Implementation and comparison of different dietary assessment methods

Authors: Papadopoulou, E; Poothong, S; Koekkoek, J; Lucattini, L; Padilla-Sánchez, JA; Haugen, M; Herzke, D; Valdersnes, S; Maage, A; Cousins, IT; Leonards, PEG; Småstuen Haug, L (2017) Environmental Research 158:269-276. HERO ID: 3859798

[Less] BACKGROUND: Diet is a major source of human exposure to hazardous environmental chemicals, . . . [More] BACKGROUND: Diet is a major source of human exposure to hazardous environmental chemicals, including many perfluoroalkyl acids (PFAAs). Several assessment methods of dietary exposure to PFAAs have been used previously, but there is a lack of comparisons between methods.

AIM: To assess human exposure to PFAAs through diet by different methods and compare the results.

METHODS: We studied the dietary exposure to PFAAs in 61 Norwegian adults (74% women, average age: 42 years) using three methods: i) by measuring daily PFAA intakes through a 1-day duplicate diet study (separately in solid and liquid foods), ii) by estimating intake after combining food contamination with food consumption data, as assessed by 2-day weighted food diaries and iii) by a Food Frequency Questionnaire (FFQ). We used existing food contamination data mainly from samples purchased in Norway and if not available, data from food purchased in other European countries were used. Duplicate diet samples (n=122) were analysed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to quantify 15 PFAAs (11 perfluoroalkyl carboxylates and 4 perfluoroalkyl sulfonates). Differences and correlations between measured and estimated intakes were assessed.

RESULTS: The most abundant PFAAs in the duplicate diet samples were PFOA, PFOS and PFHxS and the median total intakes were 5.6ng/day, 11ng/day and 0.78ng/day, respectively. PFOS and PFOA concentrations were higher in solid than liquid samples. PFOS was the main contributor to the contamination in the solid samples (median concentration 14pg/g food), while it was PFOA in the liquid samples (median concentrations: 0.72pg/g food). High intakes of fats, oils, and eggs were statistically significantly related to high intakes of PFOS and PFOA from solid foods. High intake of milk and consumption of alcoholic beverages, as well as food in paper container were related to high PFOA intakes from liquid foods. PFOA intakes derived from food diary and FFQ were significantly higher than those derived from duplicate diet, but intakes of PFOS derived from food diary and FFQ were significantly lower than those derived from duplicate diet. We found a positive and statistically significant correlation between the PFOS intakes derived from duplicate diet with those using the food diary (rho=0.26, p-value=0.041), but not with the FFQ. Additionally, PFOA intakes derived by duplicate diet were significantly correlated with estimated intakes from liquid food derived from the food diary (rho=0.34, p=0.008) and estimated intakes from the FFQ (rho=0.25, p-value=0.055).

CONCLUSIONS: We provide evidence that a food diary or a FFQ-based method can provide comparable intake estimates to PFOS and PFOA intakes derived from a duplicate diet study. These less burdensome methods are valuable and reliable tools to assess dietary exposure to PFASs in human studies.

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

Plasma perfluoroalkyl and polyfluoroalkyl substances concentration and menstrual cycle characteristics in preconception women

Authors: Zhou, W; Zhang, L; Tong, C; Fang, F; Zhao, S; Tian, Y; Tao, Y; Zhang, J; Shanghai Birth Cohort Study (2017) Environmental Health Perspectives 125:067012. HERO ID: 3859799

[Less] BACKGROUND: Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent synthetic . . . [More] BACKGROUND: Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent synthetic chemicals that are widely used in industrial applications and often detectable in humans. In rats, PFASs can interfere with the estrous cycle. In humans, menstruation has been viewed as a proxy of female fecundity, and periodic menstruation plays a critical role in endometrial sloughing in the absence of pregnancy and in preparing for embryo implantation.

OBJECTIVES: We investigated the association between PFAS exposure and menstrual cycle characteristics in women who plan to become pregnant.

METHODS: Plasma level of 10 PFASs was measured in 950 women who were attempting to become pregnant and recruited in two preconception care clinics in Shanghai, China, from August 2013 to April 2015. Information on menstrual cycle characteristics was collected by questionnaires. Associations between PFAS levels and menstrual cycle regularity, length, and bleeding volume were examined using multiple logistic regression models.

RESULTS: Pre-pregnant women with higher levels of log-transformed perfluorooctanate (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexanesulfonate (PFHxS) had increased odds of self-reported history of irregular menstrual cycle [ (95% CI: 1.08, 2.15); (95% CI: 0.98, 1.70); (95% CI: 1.03, 2.07); (95% CI: 1.17, 2.77)] and long menstrual cycle [ (95% CI: 1.06, 2.10); (95% CI: 1.02, 1.75); (95% CI: 1.05, 2.11); (95% CI: 1.13, 2.65)]. Log-transformed PFOA, PFOS, PFNA. and PFHxS levels were negatively associated with self-reported history of menorrhagia [ (95% CI: 0.21, 0.65); (95% CI: 0.37, 0.90); (95% CI: 0.26, 0.86); (95% CI: 0.06, 0.36)].

CONCLUSIONS: Certain PFASs are associated with abnormal menstruation in humans. https://doi.org/10.1289/EHP1203.