| 1. |
- Bogdal, Christian, et al.
(författare)
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Emissions of polybrominated diphenyl ethers (PBDEs) in Zurich, Switzerland, determined by a combination of measurements and modeling
- 2014
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 116, s. 15-23
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants but they are of concern and are currently being phased-out because of their environmentally hazardous properties and their potential to cause adverse health effects. We analyzed PBDEs in Zurich, Switzerland, and applied a multimedia environmental fate model to back-calculate the rate of PBDE emission to air. PBDE concentrations in ambient air were measured in summer 2010 and winter 2011 in the city center of Zurich. Concentrations were higher in summer (sum PBDEs 118-591 pg m(-3)) than in winter (sum PBDEs 17-151 pg m(-3)), and are on the upper end of concentrations reported in literature for urban sites with no point sources of PBDEs. The emissions derived from our measurements (summer: 53-165 mu g capita(-1) d(-1), winter: 25-112 mu g capita(-1) d(-1)) and extrapolated to annual emissions for Switzerland (114-406 kg a(-1)) lie in the middle of ranges reported on the basis of substance flow analyses and emission inventories. The difference between summer and winter emissions is small compared to the difference that would be expected from the temperature dependence of PBDE vapor pressure, which would be consistent with emissions occurring to a large extent from flame-proofed materials located indoors under nearly constant temperature conditions and/or emissions to air occurring by suspension of particles containing PBDEs. Compared to previous studies in Switzerland, concentrations and emissions of PBDEs appear to have increased during the last five years with an increasing contribution of decabromodiphenyl ether, despite the addition of PBDEs to national and international regulations.
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| 2. |
- Bogdal, Christian, et al.
(författare)
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Emissions of Polychlorinated Biphenyls, Polychlorinated Dibenzo-p-dioxins, and Polychlorinated Dibenzofurans during 2010 and 2011 in Zurich, Switzerland
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:1, s. 482-490
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human health relevance, but their emissions into the environment are still poorly known. In this study, concentrations of selected POPs were measured in ambient air in Zurich, Switzerland, and interpreted with a multimedia mass balance model. The aim of the combination of measurements and modeling was to back-calculate atmospheric emission rates of POPs. Measurements were performed in summer 2010 and winter 2011 and target analytes included polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Estimated emissions were higher in summer than in winter. Emission estimates for Zurich can be extrapolated to annual averages for Switzerland of 312 kg·a–1 (39 mg·capita–1·a–1), 53 kg·a–1 (7 mg·capita–1·a–1), and 3 kg·a–1 (0.4 mg·capita–1·a–1, 94 g WHO98-TEQ·a–1, 65 g I-TEQ·a–1) for the six indicator PCBs (iPCBs), the twelve coplanar dioxin-like PCBs (dlPCBs), and the 17 2,3,7,8-chlorosubstituted PCDD/Fs, respectively. The emission rates of iPCBs are in agreement with existing emission inventories, whereas for PCDD/Fs the emissions are five times higher than the estimates from the Swiss national emission inventory. Emissions of dlPCBs in Switzerland are presented here for the first time. Our study also provides the first seasonally resolved emission rates of POPs, which were determined with our combined measurement and modeling approach. These findings highlight the relevance of ongoing sources of POPs, even decades after regulations aiming to reduce or eliminate sources were established.
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| 3. |
- Scheringer, Martin, et al.
(författare)
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Helsingor Statement on poly- and perfluorinated alkyl substances (PFASs)
- 2014
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 114, s. 337-339
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Tidskriftsartikel (refereegranskat)abstract
- In this discussion paper, the transition from long-chain poly- and perfluorinated alkyl substances (PFASs) to fluorinated alternatives is addressed. Long-chain PFASs include perfluoroalkyl carboxylic acids (PFCAs) with 7 or more perfluorinated carbons, perfluoroalkyl sulfonic acids (PFSAs) with 6 or more perfluorinated carbons, and their precursors. Because long-chain PFASs have been found to be persistent, bioaccumulative and toxic, they are being replaced by a wide range of fluorinated alternatives. We summarize key concerns about the potential impacts of fluorinated alternatives on human health and the environment in order to provide concise information for different stakeholders and the public. These concerns include, amongst others, the likelihood of fluorinated alternatives or their transformation products becoming ubiquitously present in the global environment; the need for more information on uses, properties and effects of fluorinated alternatives; the formation of persistent terminal transformation products including PFCAs and PFSAs; increasing environmental and human exposure and potential of adverse effects as a consequence of the high ultimate persistence and increasing usage of fluorinated alternatives; the high societal costs that would be caused if the uses, environmental fate, and adverse effects of fluorinated alternatives had to be investigated by publicly funded research; and the lack of consideration of non-persistent alternatives to long-chain PFASs.
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| 4. |
- Wang, Zhanyun, et al.
(författare)
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Atmospheric fate of poly- and perfluorinated alkyl substances (PFASs) : II. Emission source strength in summer in Zurich, Switzerland
- 2012
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 169, s. 204-209
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Tidskriftsartikel (refereegranskat)abstract
- Fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamides (FOSAs) are present in consumer products and are semi-volatile precursors of persistent perfluoroallcyl acids (PFAAs). The high variability of levels of FrOHs and FOSAs in products makes it difficult to derive FTOH- and FOSA-emissions from urban areas based on emission factors. Here we used a multimedia mass balance model that describes the day-night cycle of semi-volatile organic chemicals in air to interpret measurements of 8:2 FTOH, 10:2 FTOH, MeFOSA and EtFOSA from a sampling campaign in summer 2010 in Zurich, Switzerland. The estimated emission source strength of the four substances follows the sequence: 8:2 FTOH (2.6 g/h) > 10:2 FTOH (0.75 g/h) > MeFOSA (0.08 g/h) > EtFOSA (0.05 g/h). There is no FTOHs- or FOSAs-related industry in Zurich. Accordingly, our estimates are representative of diffusive emissions during use and disposal of consumer products, and describe noticeable sources of these PFASs to the environment.
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| 5. |
- Wang, Zhanyun, et al.
(författare)
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Fluorinated alternatives to long-chain perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their potential precursors
- 2013
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 60, s. 242-248
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Tidskriftsartikel (refereegranskat)abstract
- Since 2000 there has been an on-going industrial transition to replace long-chain perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic adds (PFSAs) and their precursors. To date, information on these replacements including their chemical identities, however, has not been published or made easily accessible to the public, hampering risk assessment and management of these chemicals. Here we review information on fluorinated alternatives in the public domain. We identify over 20 fluorinated substances that are applied in [i] fluoropolymer manufacture, [ii] surface treatment of textile, leather and carpets, [iii] surface treatment of food contact materials, [iv] metal plating, [v] fire-fighting foams, and [vi] other commercial and consumer products. We summarize current knowledge on their environmental releases, persistence, and exposure of biota and humans. Based on the limited information available, it is unclear whether fluorinated alternatives are safe for humans and the environment. We identify three major data gaps that must be filled to perform meaningful risk assessments and recommend generation of the missing data through cooperation among all stakeholders (industry, regulators, academic scientists and the public).
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| 6. |
- Wang, Zhanyun, et al.
(författare)
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Global emission inventories for C-4-C-14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, Part I : production and emissions from quantifiable sources
- 2014
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 70, s. 62-75
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Forskningsöversikt (refereegranskat)abstract
- We quantify global emissions of C-4-C-14 perfluoroalkyl carboxylic acid (PFCA) homologues during the life-cycle of products based on perfluorooctanoic acid (PFOA), perfluorononanoic add (PFNA), perfluorooctane sulfonyl fluoride (POSF), and fluorotelomer compounds. We estimate emissions of 2610-21400 tonnes of C-4-C-14 PFCAs in the period from 1951 to 2015, and project 20-6420 tonnes to be emitted from 2016 to 2030. The global annual emissions steadily increased in the period 1951-2002, followed by a decrease and then another increase in the period 2002-2012. Releases from fluoropolymer production contributed most to historical PFCA emissions (e.g. 55-83% in 1951-2002). Since 2002, there has been a geographical shift of industrial sources (particularly fluoropolymer production sites) from North America, Europe and Japan to emerging Asian economies, especially China Sources differ between PFCA homologues, sometimes Considerably, and the relative contributions of each source change over time. For example, whereas 98-100% of historical (1951-2002) PFOA emissions are attributed to direct releases during the life-cycle of products containing PFOA as ingredients or impurities, a much higher historical contribution from PFCA precursor degradation is estimated for some other homologues (e.g. 9-78% for PFDA). We address the uncertainties of the PFCA emissions by defining a lower and a higher emission scenario, which differ by approximately a factor of eight.
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| 7. |
- Wang, Zhanyun, et al.
(författare)
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Global emission inventories for C-4-C-14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, part II : The remaining pieces of the puzzle
- 2014
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 69, s. 166-176
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Tidskriftsartikel (refereegranskat)abstract
- We identify eleven emission sources of perfluoroalkyl carboxylic adds (PFCAs) that have not been discussed in the past. These sources can be divided into three groups: [i] PFCAs released as ingredients or impurities, e.g., historical and current use of perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA) and their derivatives; [ii] PFCAs formed as degradation products, e.g., atmospheric degradation of some hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs); and [iii] sources from which PFCAs are released as both impurities and degradation products, e.g., historical and current use of perfluorobutane sulfonyl fluoride (PBSF)- and perfluorohexane sulfonyl fluoride (PHxSF)-based products. Available information confirms that these sources were active in the past or are still active today, but due to a lack of information, it is not yet possible to quantify emissions from these sources. However, our review of the available information on these sources shows that some of the sources may have been significant in the past (e.g., the historical use of PFBA-, PFHxA-, PBSF- and PHxSF-based products), whereas others can be significant in the long-term (e.g., (bio)degradation of various side-chain fluorinated polymers where PFCA precursors are chemically bound to the backbone). In addition, we summarize critical knowledge and data gaps regarding these sources as a basis for future research.
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| 8. |
- Wang, Zhanyun, et al.
(författare)
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Using COSMOtherm to predict physicochemical properties of poly- and perfluorinated alkyl substances (PFASs)
- 2011
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Ingår i: Environmental Chemistry. - 1448-2517 .- 1449-8979. ; 8:4, s. 389-398
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Tidskriftsartikel (refereegranskat)abstract
- Recently, there has been concern about the presence of poly- and perfluorinated alkyl substances (PFASs) in the environment, biota and humans. However, lack of physicochemical data has limited the application of environmental fate models to understand the environmental distribution and ultimate fate of PFASs. We employ the COSMOtherm model to estimate physicochemical properties for 130 individual PFASs, namely perfluoroalkyl acids (including branched isomers for C(4)-C(8) perfluorocarboxylic acids), their precursors and some important intermediates. The estimated physicochemical properties are interpreted using structure-property relationships and rationalised with insight into molecular interactions. Within a homologous series of linear PFASs with the same functional group, both air-water and octanol-water partition coefficient increase with increasing perfluorinated chain length, likely due to increasing molecular volume. For PFASs with the same perfluorinated chain length but different functional groups, the ability of the functional group to form hydrogen bonds strongly influences the chemicals' partitioning behaviour. The partitioning behaviour of all theoretically possible branched isomers can vary considerably; however, the predominant isopropyl and monomethyl branched isomers in technical mixtures have similar properties as their linear counterparts (differences below 0.5 log units). Our property estimates provide a basis for further environmental modelling, but with some caveats and limitations.
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