The emission of per- and polyfluoroalkyl substances (PFAS) from functional textiles was investigated via an outdoor weathering experiment in Sydney, Australia. Polyamide (PA) textile fabrics treated with different water-repellent, side-chain fluorinated polymers (SFPs) were exposed on a rooftop to multiple natural stressors, including direct sunlight, precipitation, wind, and heat for 6-months. After weathering, additional stress was applied to the fabrics through abrasion and washing. Textile characterization using a multiplatform analytical approach revealed loss of both PFAS-containing textile fragments (e.g., microfibers) as well as formation and loss of low molecular weight PFAS, both of which occurred throughout weathering. These changes were accompanied by a loss of color and water repellency of the textile. The potential formation of perfluoroalkyl acids (PFAAs) from mobile residuals was quantified by oxidative conversion of extracts from unweathered textiles. Each SFP-textile finish emitted a distinct PFAA pattern following weathering, and in some cases the concentrations exceeded regulatory limits for textiles. In addition to transformation of residual low molecular weight PFAA-precursors, release of polymeric PFAS from degradation and loss of textile fibers/particles contributed to overall PFAS emissions during weathering.
7 September 2020 in Environmental Science: Processes & Impacts
Emerging per- and polyfluoroalkyl substances (PFAS) were investigated in human milk from Stockholm (Sweden), and the cities of Shanghai, Jiaxing, and Shaoxing (China).
10 September 2021 in Environmental Science: Processes & Impacts
The high proportion of unidentified extractable organofluorine (EOF) observed globally in humans and the environment indicates widespread occurrence of unknown per- and polyfluoroalkyl substances (PFAS). However, efforts to standardize or assess the reproducibility of EOF methods are currently lacking. Here we present the first EOF interlaboratory comparison in water and sludge. Three participants (four organizations) analyzed unfortified and PFAS-fortified ultrapure water, two unfortified groundwater samples, unfortified wastewater treatment plant effluent and sludge, and an unfortified groundwater extract. Participants adopted common sample handling strategies and target lists for EOF mass balance but used in-house combustion ion-chromatography (CIC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. EOF accuracy ranged from 85–101% and 76–109% for the 60 and 334 ng L−1 fluorine (F) – fortified water samples, respectively, with between-laboratory variation of 9–19%, and within-laboratory variation of 3–27%. In unfortified sludge and aqueous samples, between-laboratory variation ranged from 21–37%. The contribution from sum concentrations of 16 individual PFAS (∑PFAS-16) to EOF ranged from 2.2–60% but extended analysis showed that other targets were prevalent, in particular ultra-short-chain perfluoroalkyl acids (e.g. trifluoroacetic acid) in aqueous samples and perfluoroalkyl acid-precursors (e.g. polyfluoroalkyl phosphate diesters) in sludge. The EOF-CIC method demonstrated promising accuracy, robustness and reporting limits but poor extraction efficiency was observed for some targets (e.g. trifluoroacetic acid).
4 December 2021 in Environmental Science & Technology Letters
Given their extensive production volumes and potential to form persistent perfluoroalkyl acids (PFAAs), there is concern surrounding the ongoing use of side-chain fluorinated polymers (SFPs) in consumer products. Targeted SFP quantification relies on matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which can suffer from poor accuracy and high detection limits. Alternatively, total fluorine (TF)-based methods may be used, but these approaches report concentrations on a “fluorine equivalent” basis (e.g., fluorine per square meter in the case of textiles) and are incapable of elucidating structure or chain length. Here a new method for comprehensive characterization of SFPs is presented, which makes use of the total oxidizable precursor assay for fingerprint-based structural elucidation and combustion ion chromatography for TF quantification. When used in parallel, quantitative determination of SFPs (in units of mass of CnF2n+1 per square meter of textile) is achieved. Expressing SFP concentrations in terms of the mass of the side chain (as opposed to fluorine equivalents) facilitates estimation of both the structure and quantity of PFAA degradation products. As a proof of principle, the method was applied to six unknown SFP-coated medical textiles from Sweden. Four products contained C6-fluorotelomer-based SFPs (concentration range of 36–188 mg of C6F13/m2), one contained a C4-sulfonamide-based SFP (718 mg of C4F9/m2), and one contained a C8-fluorotelomer-based SFP (249 mg of C8F17/m2).
22 June 2018 in Environmental Science: Processes & Impacts
Inter-individual, inter-city, and temporal trends of 19 per- and polyfluoroalkyl substances (PFASs) were investigated in human milk collected in Stockholm (1972–2016) and Gothenburg (2007–2015), Sweden. The concentrations of perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnDA), and perfluorotridecanoate (PFTrDA) in human milk from Stockholm increased significantly over the entire monitoring periods, whereas branched (Br) and linear (L) isomers of perfluorooctane sulfonamide (FOSA) decreased. In human milk from Gothenburg, significant downward trends were detected for perfluorododecanoate (PFDoDA), PFHxS and Br-perfluorooctane sulfonate (Br-PFOS) over the last decade. This declining trend was also observed for perfluorohexanoate (PFHxA), PFHxS, perfluorooctanoate (PFOA) and Br-PFOS in Stockholm over the same time period. No significant differences were observed in concentrations or relative PFAS profiles between Stockholm and Gothenburg. However, a comparison of the PFAS profile in Stockholm milk revealed distinct profiles for the time periods 1972–1996, 2000–2012, and 2013–2016, reflecting a shift in exposure over time. The lower bound estimated daily intake (EDI) for ∑PFAS concentrations in infants ranged from 7.1–40 ng per kg body weight per day (ng/kg bw/d) in Stockholm and from 5.2–25 ng/kg bw/d in Gothenburg over the studied time period, consistent with other European countries. Overall these data indicate that exposure to some legacy PFASs via breastmilk is declining, presumably as a result of regulation and phase-out initiatives. However, increasing concentrations for other PFASs and a shift in the overall PFAS profile in recent years may pose an ongoing health risk to infants.
2 August 2023 in Environmental Science: Processes & Impacts
Identification of novel PFAS, updating spatiotemporal trends and providing a framework for understanding white-tailed sea eagle PFAS exposure in Sweden.