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| 2. |
- Johansson, Jana H., et al.
(författare)
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Spatial variation in the atmospheric deposition of perfluoroalkyl acids : source elucidation through analysis of isomer patterns
- 2018
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Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 20:7, s. 997-1006
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the relevance of different proposed sources of perfluoroalkyl acids (PFAAs) to air, their isomer patterns were analyzed in deposition samples collected from five geographical locations: two urban sites in China (>360 km from known operational fluorochemical manufacturing facilities), one remote marine site in the Azores archipelago and two Swedish sites representing urban and background conditions. Despite variable contributions from linear perfluorooctanoic acid (PFOA) in the samples, the pattern of branched PFOA isomers was similar to those of technical standards manufactured using electrochemical fluorination (ECF). This indicates that atmospheric fate processes have little influence on the isomer profiles of PFOA and that the relative contribution of PFOA manufactured using ECF (typically 20-26% branched isomers) and telomerization (typically one single linear isomer) can be determined in atmospheric deposition samples by analyzing the proportions of branched and linear isomers. In Chinese samples, branched isomers contributed 15-25% to the total loading of PFOA, indicating that the samples were dominated by ECF PFOA. Samples in the Azores had 8-10% contribution from branched PFOA isomers, indicating an approximately equal influence of ECF and telomer sources. Only three of the samples collected in Sweden displayed a quantifiable contribution from branched PFOA isomers (8-13% of overall PFOA loading in the samples). One branched PFNA isomer was observed in samples from the marine sites. Direct manufacturing discharges, transport of sea spray aerosols and degradation of precursors are all suggested to be contributing sources, albeit to different extents, to PFAAs in air at the different geographical locations where precipitation was sampled.
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| 3. |
- Johansson, Jana, 1985-, et al.
(författare)
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Spatial variation in the atmospheric deposition of perfluoroalkyl acids: source elucidation through analysis of homologue and isomer patterns
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- To evaluate the relevance of different proposed sources of perfluoroalkyl acids (PFAAs) to air, PFAA homologue and isomer patterns were analysed in precipitation collected from five geographical locations suspected to be influenced by these different types of sources. In Chinese samples, perflourooctanoic acid (PFOA) dominated the homologue patterns with concentrations exceeding those observed in European samples by a factor of 2-59. Furthermore, the isomer pattern of PFOA in Chinese samples was close to that of technical standards for PFOA manufactured using electrochemical fluorination (ECF). This finding suggests that direct manufacturing emissions of PFOA to air dominate the loading of PFOA in air in these regions of China. The PFAA homologue pattern observed in precipitation sampled in Stockholm was dominated by perfluorohexanoic acid, perfluorononanoic acid (PFNA) and PFOA. The isomer pattern of PFOA was to a large degree linear indicating that telomer-based sources, i.e. most likely atmospheric degradation of fluorotelomer alcohols, dominate in this urban area. Samples from the Azores, a group of islands located in the open Atlantic, were dominated by perfluorooctane sulfonic acid (PFOS), PFNA and PFOA, which displayed an isomer patttern suggestive of input from both ECF and telomer sources. A similar pattern was observed in precipitation collected during winter months at a rural site on the Swedish west coast, while samples taken at this site during summer displayed homologue and isomer patterns more like those observed in Stockholm. We hypothesize that the contribution from ECF PFOA observed in European samples was due to influence from sea spray aerosols and this requires further detailed investigation.
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| 4. |
- Ritscher, Amélie, et al.
(författare)
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Zurich Statement on Future Actions on Per - and Polyfluoroalkyl Substances (PFASs)
- 2018
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Ingår i: Journal of Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 126:8
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Tidskriftsartikel (refereegranskat)abstract
- Per - and polyfluoroalkyl substances (PFASs) are man-made chemicals that contain at least one perfluoroalkyl moiety, -CnF2n-. To date, over 4,000 unique PFASs have been used in technical applications and consumer products, and some of them have been detected globally in human and wildlife biomonitoring studies. Because of their extraordinary persistence, human and environmental exposure to PFASs will be a long-term source of concern. Some PFASs such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) have been investigated extensively and thus regulated, but for many other PFASs, knowledge about their current uses and hazards is still very limited or missing entirely. To address this problem and prepare an action plan for the assessment and management of PFASs in the coming years, a group of more than 50 international scientists and regulators held a two-day workshop in November, 2017. The group identified both the respective needs of and common goals shared by the scientific and the policy communities, made recommendations for cooperative actions, and outlined how the science-policy interface regarding PFASs can be strengthened using new approaches for assessing and managing highly persistent chemicals such as PFASs.
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| 5. |
- Shi, Yali, et al.
(författare)
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Human Exposure and Elimination Kinetics of Chlorinated Polyfluoroalkyl Ether Sulfonic Acids (Cl-PFESAs)
- 2016
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:5, s. 2396-2404
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Tidskriftsartikel (refereegranskat)abstract
- The incomplete mass-balance of organic fluorine in human serum indicates the existence of unknown per- and polyfluoroalkyl substances (PFASs) with persistent and bioaccumulative properties. Here we characterized human exposure and elimination kinetics of chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) in metal plating workers (n = 19), high fish consumers (n = 45), and background controls (n = 8). Cl-PFESAs were detected in >98% of the sampled individuals with serum concentrations ranging <0.019-5040 ng/mL. Statistically higher median serum levels were observed in high fish consumers (93.7 ng/mL) and metal plating workers (51.5 ng/mL) compared to the background control group (4.78 ng/mL) (Kruskal Wallis rank sum test, p < 0.01). Cl-PFESAs could account for 0.269 to 93.3% of Sigma PFASs in human serum indicating that this compound class may explain a substantial fraction of previously unidentified organic fluorine in the Chinese population. Estimated half-lives for renal clearance (median 280 years; range 7.1-4230 years) and total elimination (median 15.3 years; range 10.1-56.4 years) for the eight carbon Cl-PFESA suggest that this is the most biopersistent PFAS in humans reported to date. The apparent ubiquitous distribution and slow elimination kinetics in humans underscore the need for more research and regulatory actions on Cl-PFESAs and PFAS alternatives with similar chemical structures.
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| 6. |
- Shi, Yali, et al.
(författare)
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Probing the Differential Tissue Distribution and Bioaccumulation Behavior of Per- and Polyfluoroalkyl Substances of Varying Chain-Lengths, Isomeric Structures and Functional Groups in Crucian Carp
- 2018
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:8, s. 4592-4600
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the bioaccumulation mechanisms of per- and polyfluoroalkyl substances (PFASs) across different chain-lengths, isomers and functional groups represents a monumental scientific challenge with implications for chemical regulation. Here, we investigate how the differential tissue distribution and bioaccumulation behavior of 25 PFASs in crucian carp from two field sites impacted by point sources can provide information about the processes governing uptake, distribution and elimination of PFASs. Median tissue/blood ratios (TBRs) were consistently <1 for all PFASs and tissues except bile which displayed a distinct distribution pattern and enrichment of several perfluoroalkyl sulfonic acids. Transformation of concentration data into relative body burdens (RBBs) demonstrated that blood, gonads, and muscle together accounted for >90% of the amount of PFASs in the organism. Principal component analyses of TBRs and RBBs showed that the functional group was a relatively more important predictor of internal distribution than chain length for PFASs. Whole body bioaccumulation factors (BAFs) for short-chain PFASs deviated from the positive relationship with hydrophobicity observed for longer-chain homologues. Overall, our results suggest that TBR, RBB, and BAF patterns were most consistent with protein binding mechanisms although partitioning to phospholipids may contribute to the accumulation of long-chain PFASs in specific tissues.
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| 7. |
- Shi, Yali, et al.
(författare)
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Tissue Distribution and Whole Body Burden of the Chlorinated Polyfluoroalkyl Ether Sulfonic Acid F-53B in Crucian Carp (Carassius carassius) : Evidence for a Highly Bioaccumulative Contaminant of Emerging Concern
- 2015
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 49:24, s. 14156-14165
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Tidskriftsartikel (refereegranskat)abstract
- Following the global actions to phase out perfluoroctanesulfonic acid (PFOS) a large number of alternative per- and polyfluoroalkyl substances, with poorly defined hazard properties, are being used in increasing quantities. Here, we report on the first detection of the chlorinated polyfluoroalkyl ether sulfonic acid F-53B in biological samples and determine the tissue distribution and whole body bioaccumulation factors (BAF(whole body)) in crucian carp (Carassius carassius). Analysis of fish samples from Xiaoqing River (XR) and Tangxun Lake (TL) demonstrated a similar level of F-53B contamination with median concentrations in blood of 41.9 and 20.9 ng/g, respectively. Tissue/blood ratios showed that distribution of F-53B primarily occurs to the kidney (TL: 0.48, XR: 0.54), gonad (TL: 0.36, XR: 0.54), liver (TL: 0.38, XR: 0.53), and heart (TL: 0.47, XR: 0.47). Median Log BAF(whole body) values for F-53B (XR: 4.124, TL: 4.322) exceeded regulatory bio accumulation criterion and were significantly higher than those of PFOS in the same data sets (XR: 3.430, TL: 3.279). On the basis of its apparent omnipresence and strong bioaccumulation propensity, it is hypothesized that F-53B could explain a significant fraction of previously unidentified organofluorine in biological samples from China, and regulatory actions for this compound are encouraged.
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| 8. |
- Song, Xiaowei, et al.
(författare)
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A Matrix Correction Approach to Estimate the Bioaccumulation Potential of Emerging PFASs
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent studies employing high-resolution mass spectrometry have discovered numerous emerging per- and polyfluoroalkyl substances (PFASs) in the environment, but the lack of authentic standards for these contaminants hampers quantitative evaluation of hazard properties. Here we tested a matrix correction methodology for determining the bioaccumulation potential of emerging PFASs based on peak area in crucian carp from Xiaoqing river, China. Fortification experiments of emerging PFASs extracted from surface water and sediment samples demonstrated that the quantification bias in fish tissues was <34% for analytes detected in fish and water. Tissue distribution ratios (TBRs) and whole-body bioaccumulation factors (BAFs) were subsequently calculated by correcting for analyte- and tissue-specific matrix effects. A model evaluation set including 7 reference PFASs demonstrated that peak area-based TBRs and BAFs were strongly correlated with those calculated from quantified concentrations (p<0.05, Adjusted r2>0.91, slope: 0.99-1.34). Among the detected substances, the trimer acid of hexafluoropropylene oxide and C9 monoether per- and polyfluoroalkyl ether carboxylic acid (PFECA) were identified as bioaccumulative substances. C8 PFECA and C8 mono chlorine-substituted perfluoroalkyl carboxylic acid displayed similar BAFs value compared to perfluorooctanoic acid. Overall, the proposed methodology provides a rapid hazard screening tool which could be used to assess emerging contaminants without access to authentic standards.
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| 9. |
- Song, Xiaowei, et al.
(författare)
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A Matrix Correction Approach to Estimate the Bioaccumulation Potential of Emerging PFASs
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent studies employing high-resolution mass spectrometry have discovered numerous emerging per- and polyfluoroalkyl substances (PFASs) in the environment, but the lack of authentic standards for these contaminants hampers quantitative evaluation of hazard properties. Here we tested a matrix correction methodology for determining the bioaccumulation potential of emerging PFASs based on peak area in crucian carp from Xiaoqing river, China. Fortification experiments of emerging PFASs extracted from surface water and sediment samples demonstrated that the quantification bias in fish tissues was <34% for analytes detected in fish and water. Tissue distribution ratios (TBRs) and whole-body bioaccumulation factors (BAFs) were subsequently calculated by correcting for analyte- and tissue-specific matrix effects. A model evaluation set including 7 reference PFASs demonstrated that peak area-based TBRs and BAFs were strongly correlated with those calculated from quantified concentrations (p<0.05, Adjusted r2>0.91, slope: 0.99-1.34). Among the detected substances, the trimer acid of hexafluoropropylene oxide and C9 monoether per- and polyfluoroalkyl ether carboxylic acid (PFECA) were identified as bioaccumulative substances. C8 PFECA and C8 mono chlorine-substituted perfluoroalkyl carboxylic acid displayed similar BAFs value compared to perfluorooctanoic acid. Overall, the proposed methodology provides a rapid hazard screening tool which could be used to assess emerging contaminants without access to authentic standards.
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| 10. |
- Wang, Yuan, et al.
(författare)
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Identification, Tissue Distribution, and Bioaccumulation Potential of Cyclic Perfluorinated Sulfonic Acids Isomers in an Airport Impacted Ecosystem
- 2016
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:20, s. 10923-10932
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Tidskriftsartikel (refereegranskat)abstract
- The use of cyclic perfluoroalkyl acids as anticorrosive agents in hydraulic fluids remains a poorly characterized source of organofluorine compounds to the environment. Here, we investigated the presence of perfluoroethylenecyclohexanesulfonate (PFECHS) isomers in environmental samples for the first time using a combination of high resolution and tandem mass spectrometry. Five distinct peaks attributed to different isomers of PFECHS and perfluoropropylcyclopentanesulfonate (PFPCPeS) were identified in environmental samples. The sum of PFECHS and PFPCPeS isomers displayed logarithmically decreasing spatial trends in water (1.04-324 ng/L) and sediment samples (
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