| 1. |
- Awchi, Mo, et al.
(författare)
-
Development, validation, and application of a new method for the quantitative determination of monohydrogen-substituted perfluoroalkyl carboxylic acids (H-PFCAs) in surface water
- 2022
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 287
-
Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFASs) are a large and diverse class of chemicals. While some have been phased out internationally due to concerns over their human and environmental health risks, novel alternative PFASs continue to be manufactured and detected in environmental samples. The occurrence and fate of these alternatives remain poorly understood. The present study investigated the occurrence of an emerging class of PFAS alternative, the monohydrogen-substituted perfluoroalkyl carboxylic acids (H-PFCAs), in conjunction with the more well-known PFCAs. A weak anion exchange solid phase extraction-liquid chromatography tandem mass spectrometry method for quantitative determination of H-PFCAs in surface water was developed, validated, and applied on samples collected from the Netherlands. To improve chromatography, especially for short-chain (H-) PFCAs, an ion-pairing agent, tetrabutylammonium hydrogen sulphate, was used. The method was validated for linearity (R2 > 0.99), instrumental detection limits (0.01-0.09 ng/mL), method detection limits (0.03-0.75 ng/ mL), matrix effects (<20%), percent absolute- and relative recovery (57-121%), trueness (130-80%), repeatability (<20%), and within-lab reproducibility (<20%). Eleven out of fourteen PFASs showed acceptable results. Application of the newly validated method to surface water throughout the Netherlands revealed trace levels of H-PFCAs (including two new H-PFCAs) and high concentrations of PFCAs.
|
|
| 2. |
- Benskin, Jonathan P., et al.
(författare)
-
Perfluorinated Acid Isomer Profiling in Water and Quantitative Assessment of Manufacturing Source
- 2010
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:23, s. 9049-9054
-
Tidskriftsartikel (refereegranskat)abstract
- A method for isomer profiling of perfluorinated compounds (PFCs) in water was developed and applied to quantitatively assess the contributions from electrochemical (ECF) and telomer manufacturing processes around source regions of North America, Asia, and Europe. With the exception of 3 sites in Japan, over 80% of total perfluorooctanoate (PFOA, C7F15COO -) was from ECF, with the balance attributable to strictly linear (presumably telomer) manufacturing source(s). Comparing PFOA isomer profiles in samples from China, with PFOA obtained from a local Chinese manufacturer, indicated <3% difference in overall branched isomer content; thus, exclusive contribution from local ECF production cannot be ruled out. In Tokyo Bay, ECF, linear-telomer, and isopropyl-telomer sources contributed to 33%, 53%, and 14% of total PFOA, respectively. Perfluorooctane sulfonate (PFOS, C 8F17SO3-) isomer profiles were enriched in branched content (i.e., >50% branched) in the Mississippi River but in all other locations were similar or only slightly enriched in branched content relative to historical ECF PFOS. Isomer profiles of other PFCs are also reported. Overall, these data suggest that, with the exception of Tokyo Bay, ECF manufacturing has contributed to the bulk of contamination around these source regions, but other sources are significant, and remote sites should be monitored.
|
|
| 3. |
- Benskin, Jonathan P., et al.
(författare)
-
Perfluoroalkyl Acids in the Atlantic and Canadian Arctic Oceans
- 2012
-
Ingår i: Environmental Science and Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 46:11, s. 5815-5823
-
Tidskriftsartikel (refereegranskat)abstract
- We report here on the spatial distribution of C-4, C-6, and C-8 perfluoroalkyl sulfonates, C-6-C-14 perfluoroalkyl carboxylates, and perfluorooctanesulfonamide in the Atlantic and Arctic Oceans, including previously unstudied coastal waters of North and South America, and the Canadian Arctic Archipelago. Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were typically the dominant perfluoroalkyl acids (PFAAs) in Atlantic water. In the midnorthwest Atlantic/Gulf Stream, sum PFAA concentrations (Sigma PFAAs) were low (77-190 pg/L) but increased rapidly upon crossing into U.S. coastal water (up to 5800 pg/L near Rhode Island). Sigma PFAAs in the northeast Atlantic were highest north of the Canary Islands (280-980 pg/L) and decreased with latitude. In the South Atlantic, concentrations increased near Rio de la Plata (Argentina/Uruguay; 350-540 pg/L Sigma PFAAs), possibly attributable to insecticides containing N-ethyl perfluorooctanesulfonamide, or proximity to Montevideo and Buenos Aires. In all other southern hemisphere locations, Sigma PFAAs were less than210 pg/L. PFOA/PFOS ratios were typically greater than= 1 in the northern hemisphere, similar to 1 near the equator, and less than= 1 in the southern hemisphere. In the Canadian Arctic, Sigma PFAAs ranged from 40 to 250 pg/L, with perfluoroheptanoate, PFOA, and PFOS among the PFAAs detected at the highest concentrations. PFOA/PFOS ratios (typically greater thangreater than1) decreased from Baffin Bay to the Amundsen Gulf; possibly attributable to increased atmospheric inputs. These data help validate global emissions models and contribute to understanding of long-range transport pathways and sources of PFAAs to remote regions.
|
|
| 4. |
- Monclús, Laura, et al.
(författare)
-
Legacy and emerging organohalogenated compounds in feathers of Eurasian eagle-owls (Bubo bubo) in Norway : Spatiotemporal variations and associations with dietary proxies (δ13C and δ15N)
- 2022
-
Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 204
-
Tidskriftsartikel (refereegranskat)abstract
- The occurrence of organohalogenated compounds (OHCs) in wildlife has received considerable attention over the last decades. Among the matrices used for OHCs biomonitoring, feathers are particularly useful as they can be collected in a minimally or non-invasive manner. In this study, concentrations of various legacy OHCs –polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs)–, as well as emerging OHCs –per- and polyfluoroalkyl substances (PFAS) and organophosphate ester flame retardants (OPEs)– were determined in feathers of 72 Eurasian eagle-owls (Bubo bubo) from Norway, with the goal of studying spatiotemporal variation using a non-invasive approach. Molted feathers were collected at nest sites from northern, central and southern Norway across four summers (2013–2016). Additionally, two museum-archived feathers from 1979 to 1989 were included. Stable carbon (δ13C) and nitrogen isotopes (δ15N) were used as dietary proxies. In total, 11 PFAS (sum range 8.25–215.90 ng g−1), 15 PCBs (4.19–430.01 ng g−1), 6 OCPs (1.48–220.94 ng g−1), 5 PBDEs (0.21–5.32 ng g−1) and 3 OPEs (4.49–222.21 ng g−1) were quantified. While we observed large variation in the values of both stable isotopes, suggesting a diverse diet of the eagle-owls, only δ13C seemed to explain variation in PFAS concentrations. Geographic area and year were influential factors for δ15N and δ13C. Considerable spatial variation was observed in PFAS levels, with the southern area showing higher levels compared to northern and central Norway. For the rest of OHCs, we observed between-year variations; sum concentrations of PCBs, OCPs, PBDEs and OPEs reached a maximum in 2015 and 2016. Concentrations from 1979 to 1989 were within the ranges observed between 2013 and 2016. Overall, our data indicate high levels of legacy and emerging OHCs in a top predator in Norway, further highlighting the risk posed by OHCs to wildlife.
|
|
| 5. |
- Reardon, Anthony J. F., et al.
(författare)
-
Neurodevelopmental and Metabolomic Responses from Prenatal Coexposure to Perfluorooctanesulfonate (PFOS) and Methylmercury (MeHg) in Sprague-Dawley Rats
- 2019
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 32:8, s. 1656-1669
-
Tidskriftsartikel (refereegranskat)abstract
- Methylmercury (MeHg) and perfluoro-octanesulfonate (PFOS) are major contaminants of human blood that are both common in dietary fish, thereby raising questions about their combined impact on human development. Here, pregnant Sprague-Dawley rats ingested a daily dose, from gestational day 1 through to weaning, of either 1 mg/kg bw PFOS (PFOS-only), 1 mg/kg MeHg (MeHg-only), a mixture of 0.1 mg/kg PFOS and 1 mg/kg MeHg (Low-Mix), or of 1 mg/kg of PFOS and 1 mg/kg MeHg (High-Mix). Newborns were monitored for physical milestones and reflexive developmental responses, and in juveniles the spontaneous activity, anxiety, memory, and cognition were assessed. Targeted metabolomics of 199 analytes was applied to sectioned brain regions of juvenile offspring. Newborns in the High-Mix group had decreased weight gain as well as delayed reflexes and innate behavioral responses compared to controls and individual chemical groups indicating a toxicological interaction on early development. In juveniles, cumulative mixture effects increased in a dose-dependent manner in tests of anxiety-like behavior. However, other developmental test results suggested antagonism, as PFOS-only and MeHg-only juveniles had increased hyperactivity and thigmotaxic behavior, respectively, but fewer effects in Low-Mix and High-Mix groups. Consistent with these behavioral observations, a pattern of antagonism was also observed in neurochemicals measured in rat cortex, as PFOS-only and MeHg-only juveniles had altered concentrations of metabolites (e.g., lipids, amino acids, and biogenic amines), while no changes were evident in the combined exposures. The cortical metabolites altered in PFOS-only and MeHg-only exposed groups are involved in inhibitory and excitatory neurotransmission. These proof-of-principle findings at relatively high doses indicate the potential for toxicological interaction between PFOS and MeHg, with developmental-stage specific effects. Future mixture studies at lower doses are warranted, and prospective human birth cohorts should consider possible confounding effects from PFOS and mercury exposure on neurodevelopment.
|
|
| 6. |
- Akhdhar, Abdullah, et al.
(författare)
-
The use of high resolution graphite furnace molecular absorption spectrometry (HR -MAS) for total fluorine determination in extractable organofluorines (EOF)
- 2020
-
Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 209
-
Tidskriftsartikel (refereegranskat)abstract
- The determination of total fluorine content using high-resolution graphite furnace continuum source molecular absorption spectrometry (HR- MAS) has been employed in a variety of samples for over 10 years. However, most of the samples analysed by HR-MAS are rich in fluoride, with negligible levels of organic fluorinated species. With an increase in concern surrounding per- and polyfluoroalkyl substances (PFASs), new methods to measure total fluorine of organofluorine using different techniques have been developed. However, no studies focused on PFASs behaviour in HR-MAS have been performed. As these compounds encompass a wide range of different structures, boiling points, decomposition temperatures and matrix interactions, a loss of accuracy can occur when an aqueous external calibration is performed using only one compound. To overcome this issue, an investigation into permanent modifiers for the graphite furnace was performed. After optimisation similar sensitivity for different PFCA was achieved when 400 mu g of W was used as a permanent modifier together with an optimised temperature program. The relative deviation between the different PFCA standard slopes relative to the PFOA slope was lower than 15%. The instrumental limit of detection and quantification (LOD and LOQ, respectively) of total fluorine as total PFCA was 0.1 mg L-1 and 0.3 mg L-1, respectively, while the method LOD and LOQ (using solid phase extraction) was 0.3 mu g L-1 and 1.0 mu g L-1, respectively. The developed method gave satisfactory recoveries for the spiked PFCA into seawater, river water and effluent using PFOA calibration standards. The optimised method is useful for measuring extractable organofluorines (EOF) when only ionic PFASs such as PFCA are expected. When other organofluorines are expected, the results using HR GF-MAS should be taken with caution.
|
|
| 7. |
- Awad, Raed, et al.
(författare)
-
Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China
- 2020
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2050-7887 .- 2050-7895. ; 22:10, s. 2023-2030
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty per- and polyfluoroalkyl substances (PFAS) were determined in human milk from residents of three Chinese cities (Shanghai, Jiaxing, and Shaoxing; [n = 10 individuals per city]), sampled between 2010 and 2016. These data were compared to a combination of new and previously reported PFAS concentrations in human milk from Stockholm, Sweden, collected in 2016 (n = 10 individuals). Across the three Chinese cities, perfluorooctanoate (PFOA; sum isomers), 9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS; also known as 6:2 Cl-PFESA or by its trade name "F53-B"), and perfluorooctane sulfonate (PFOS; sum isomers) occurred at the highest concentrations among all PFAS (up to 411, 976, and 321 pg mL-1, respectively), while in Stockholm, PFOA and PFOS were dominant (up to 89 and 72 pg mL-1, respectively). 3H-Perfluoro-3-[(3-methoxy-propoxy)propanoic acid] (ADONA) was intermittently detected but at concentrations below the method quantification limit (i.e. <10 pg mL-1) in Chinese samples, and was non-detectable in Swedish milk. The extremely high concentrations of F53-B in Chinese milk suggest that human exposure assessments focused only on legacy substances may severely underestimate overall PFAS exposure in breastfeeding infants.
|
|
| 8. |
- Awad, Raed, et al.
(författare)
-
Emerging Per- and Polyfluoroalkyl Substances (PFAS) in Human Milk from Sweden and China
- 2020
-
Ingår i: Environmental Science. - 2050-7887 .- 2050-7895. ; 19:22
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Twenty per- and polyfluoroalkyl substances (PFAS) were determined in human milk from residents of three Chinese cities (Shanghai, Jiaxing, and Shaoxing), sampled between 2010 and 2016. These data were compared to a combination of new and previously reported PFAS concentrations in human milk from Stockholm, Sweden, collected in 2016. Across the three Chinese cities, perfluorooctanoate (PFOA; sum isomers), 9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS; trade name F53-B), and perfluorooctane sulfonate (PFOS; sum isomers) occurred at the highest concentrations among all PFAS (up to 411, 976, and 321 pg/mL, respectively), while in Stockholm, PFOA and PFOS were dominant (up to 89 and 72 pg/mL, respectively). 3H-perfluoro-3-[(3-methoxy-propoxy) propanoic acid (ADONA) was intermittently detected but at concentrations below the method quantification limit (i.e. <10 pg/mL) in Chinese samples, and was non-detectable in Swedish milk. The extremely high concentrations of F53-B in Chinese milk suggest that human exposure assessments focused only on legacy substances may severely underestimate overall PFAS exposure in breastfeeding infants.
|
|
| 9. |
- Awad, Raed, et al.
(författare)
-
Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China (vol 22, pg 2023, 2020)
- 2021
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2050-7887 .- 2050-7895. ; 23:1, s. 188-188
-
Tidskriftsartikel (refereegranskat)abstract
- Correction for ‘Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China’ by Raed Awad et al., Environ. Sci.: Processes Impacts, 2020, 22, 2023–2030, DOI: 10.1039/D0EM00077A.
|
|
| 10. |
- Betterle, Andrea, et al.
(författare)
-
Hyporheic exchange in recirculating flumes under heterogeneous bacterial and morphological conditions
- 2021
-
Ingår i: Environmental Earth Sciences. - : Springer Science and Business Media LLC. - 1866-6280 .- 1866-6299. ; 80:6
-
Tidskriftsartikel (refereegranskat)abstract
- Hyporheic exchange (HE) contributes to the biogeochemical turnover of macro- and micro-pollutants in rivers. However, the spatiotemporal complexity and variability of HE hinder understanding of its role in the overall functioning of riverine ecosystems. The present study focuses on investigating the role of bacterial diversity and sediment morphology on HE using a multi-flume experiment. A fully coupled surface–subsurface numerical model was used to highlight complex exchange patterns between surface water and the underlying flow field in the sediments. Under the experimental conditions, the surface water flow induced by bedforms has a prominent effect on both local trajectories and residence time distributions of hyporheic flow paths, whereas mean hyporheic retention times are mainly modulated by average surface flowrates. In case of complex bedform morphologies, the numerical model successfully reproduces the HE estimated by means of salt dilution tests. However, the 2D numerical representation of the system falls short in predicting HE in absence of bedforms, highlighting the intrinsic complexity of water circulation patterns in real scenarios. Finally, results show that higher bacterial diversities in the stream sediments can significantly reduce hyporheic fluxes. This work provides a framework to interpret micropollutants turnover in light of the underlying physical transport processes in the hyporheic zone. The study emphasizes the importance of better understanding the tradeoff between physically driven transport processes and bacterial dynamics in the hyporheic zone to quantify the fate of pollutants in streams and rivers.
|
|
