| 1. |
- Miaz, Luc T., et al.
(författare)
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Temporal trends of suspect- and target-per/polyfluoroalkyl substances (PFAS), extractable organic fluorine (EOF) and total fluorine (TF) in pooled serum from first-time mothers in Uppsala, Sweden, 1996–2017
- 2020
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Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 22:4, s. 1071-1083
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Tidskriftsartikel (refereegranskat)abstract
- A combined method for quantitative analysis, along with suspect and non-target screening of per- and polyfluoroalkyl substances (PFAS) was developed using ultra-high pressure liquid chromatography-ultra-high resolution (Orbitrap) mass spectrometry. The method was applied together with measurements of total- and extractable organofluorine (TF and EOF, respectively), to pooled serum samples from 1996–2017 from first-time mothers living in the county of Uppsala, Sweden, some of which (i.e. 148 of 472 women sampled 1996–2012) were exposed to drinking water contaminated with perfluorohexane sulfonate (PFHxS) and other PFAS until mid-2012. Declining trends were observed for all target PFAS as well as TF, with homologue-dependent differences in year of onset of decline. Only 33% of samples displayed detectable EOF, and amongst these samples the percentage of EOF explained by target PFAS declined significantly (−3.5% per year) over the entire study period. This finding corroborates prior observations in Germany after the year 2000, and may reflect increasing exposure to novel PFAS which have not yet been identified. Suspect screening revealed the presence of perfluoro-4-ethylcyclohexanesulfonate (PFECHS), which displayed declining trends since the year 2000. Non-target time trend screening revealed 3 unidentified features with time trends matching PFHxS. These features require further investigation, but may represent contaminants which co-occurred with PFHxS in the contaminated drinking water.
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| 2. |
- Miaz, Luc T, et al.
(författare)
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Temporal trends of suspect and target per/polyfluoroalkyl substances (PFASs), Extractable organic fluorine (EOF) and total fluorine (TF) in pooled serum from first-time mothers in Uppsala 1996-2017
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A combined method for quantitative, suspect, and non-target screening of per- and polyfluoroalkyl substances (PFASs) was developed using ultra-high pressure liquid chromatography-ultra-high resolution (Orbitrap) mass spectrometry. The method was applied together with measurements of total- and extractable organofluorine (TF and EOF, respectively), to pooled serum samples from 1996–2017 from first-time mothers living in the county of Uppsala, Sweden, some of which were exposed to drinking water contaminated with perfluorohexane sulfonate (PFHxS) and other PFASs until mid-2012. Declining trends were observed for all target PFASs as well as TF, with homologue-dependent differences in year of onset of decline. Only 33% of samples displayed detectable EOF, and amongst these samples the percentage of EOF explained by target PFASs declined significantly (−3.5% per year) over the entire study period. This finding corroborates prior observations in Germany after the year 2000, and may reflect increasing exposure to novel PFASs which have not yet been identified. Non-target time trend screening revealed 3 unidentified features with time trends matching PFHxS (Spearman’s ρ > 0.5). These features require further investigation, but may represent contaminants which co-occurred with PFHxS in the contaminated drinking water.
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| 3. |
- Muir, Derek, et al.
(författare)
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Spatial and Temporal Trends of Perfluoroalkyl Substances in Global Ocean and Coastal Waters
- 2021
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:14, s. 9527-9537
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFAS) have been widely detected in global surface waters since the early 2000s. Here, we have compiled and analyzed the published data for perfluorocarboxylates (PFCAs) and perfluorosulfonates (PFSAs) in surface waters of coastal seas, the Great Lakes, and open oceans to examine temporal and geospatial trends. Mass discharges from major rivers were also estimated. A large number of measurements of individual PFAS have been made in these surface waters (29 500 values), with seven C4-C10 PFSAs and nine C4-C12 PFCAs accounting for 83% of all data. However, most results (85% for PFSAs; 80% for PFCAs) were for the coastal seas of Western Europe, China, Korea, and Japan, while results were limited for coastal North America and lacking for South America and Africa. Highest median concentrations of PFCAs and PFSAs were reported in the Bohai and Yellow Seas region of China as well as in the North and Baltic seas in Europe. Significant declines in median PFSAs and C7-C12 PFCAs were also observed for the period 2012-2018 in these same regions, and for 2004-2017 in the Great Lakes. Mass discharge estimates indicated continued substantial riverine emissions of long chain (C7-C12) PFCAs in the period 2015-2019 for the coastal seas of China and reductions in emissions for Western European rivers compared to earlier time periods.
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| 4. |
- Tian, Run, 1994-, et al.
(författare)
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Influence of Season on Biodegradation Rates in Rivers
- 2024
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Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851.
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Tidskriftsartikel (refereegranskat)abstract
- Biodegradation plays a key role in the fate of chemicals in the environment. The variability of biodegradation in time can cause uncertainty in evaluating the environmental persistence and risk of chemicals. However, the seasonality of biodegradation in rivers has not yet been the subject of environmentally relevant testing and systematic investigation for large numbers of chemicals. In this work, we studied the biodegradation of 96 compounds during four seasons at four locations (up- and downstream of WWTPs located on two Swedish rivers). Significant seasonality (ANOVA, p < 0.05) of the first-order rate constant for primary biodegradation was observed for most compounds. Variations in pH and total bacterial cell count were not the major factors explaining the seasonality of biodegradation. Deviation from the classical Arrhenius-type behavior was observed for most of the studied compounds, which calls into question the application of this relationship to correct biodegradation rate constants for differences in environmental temperature. Similarities in magnitude and seasonality of biodegradation rate constants were observed for some groups of chemicals possessing the same functional groups. Moreover, reduced seasonality of biodegradation was observed downstream of WWTPs, while biodegradation rates of most compounds were not significantly different between up- and downstream.
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