Distribution and effects of branched versus linear isomers of PFOA, PFOS, and PFHxS: A review of recent literature

Schulz, Katarina; Silva, Marcia R.; Klaper, Rebecca

doi:10.1016/j.scitotenv.2020.139186

Cited by 180 publications

(112 citation statements)

References 99 publications

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“…Compared with the more contaminated sediments, at the lightly impacted sites, the contribution of n‐PFOS to the ∑PFOS is variable, although n‐PFOS is still slightly dominant (Figures 1 and ). In recently and highly PFOS‐contaminated sediments, the PFOS isomer profile is dominated by n‐PFOS: n‐PFOS accounts for 70%–80% of the PFOS mixture produced by electrochemical fluorination (Buck et al, 2011; Schulz et al, 2020). It has also been suggested that n‐PFOS is more hydrophobic than branched isomers and preferentially adsorbs onto sediments, causing enrichment of n‐PFOS compared with br‐PFOS (Houde et al, 2008; Munoz et al, 2019; Schulz et al, 2020).…”

Section: Resultsmentioning

confidence: 99%

“…In recently and highly PFOS‐contaminated sediments, the PFOS isomer profile is dominated by n‐PFOS: n‐PFOS accounts for 70%–80% of the PFOS mixture produced by electrochemical fluorination (Buck et al, 2011; Schulz et al, 2020). It has also been suggested that n‐PFOS is more hydrophobic than branched isomers and preferentially adsorbs onto sediments, causing enrichment of n‐PFOS compared with br‐PFOS (Houde et al, 2008; Munoz et al, 2019; Schulz et al, 2020). In the absence of direct sources of PFOS in weathered sediments, other processes can occur that could lead to enrichment of br‐PFOS content, such as biotransformation or preferential absorption and retention of n‐PFOS in biological systems leading to enrichment of emissions of br‐PFOS from wastewater treatment plant effluents (Benskin et al, 2009; Schulz et al, 2020).…”

Section: Resultsmentioning

confidence: 99%

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Sediment quality assessment framework for per‐ and polyfluoroalkyl substances: Results from a preparatory study and regulatory implications

Casado-Martínez¹,

Pascariello

Polesello

et al. 2021

Integr Envir Assess & Manag

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A preparatory study was performed to develop a sediment quality and risk assessment strategy for Switzerland, addressing the following questions: the sediment fraction to be analyzed chemically (< 63 µm, or alternatively < 2 mm); the suitability of using perfluorooctanesulfonic acid (PFOS) as an indicator of per‐ and polyfluoroalkyl substances (PFAS) contamination in sediments; the availability of data for the derivation of sediment quality guidelines; and the suitability of normalization to total organic carbon (TOC). The results confirmed PFOS as a suitable indicator of PFAS contamination in sediments from small streams, being the most detected and on average with the highest concentrations among the analyzed PFAS. The fine fraction (< 63 µm) was more appropriate to screening for possible sources and studying the compound profiles at the study sites, but the analysis of the < 2 mm fraction and the normalization to a sample consisting of 100% of the < 63 μm fraction was, in principle, feasible for PFOS. Sediment quality guidelines for PFOS aiming to protect benthic invertebrates from generic adverse effects could be derived, but the available toxicity database is still too sparse. It was only possible to derive preliminary values. Sediment quality guidelines to protect wildlife and human health from secondary poisoning, using the equilibrium partitioning approach and simple trophic web models, were also derived. The use of food web models to derive sediment quality guidelines has not been validated, and the available database of Biota‐Sediment Accumulation Factors and Trophic Magnification Factors for PFOS remains limited. However, it is still larger than the effect concentrations database based on sediment studies using benthic invertebrates. Normalization to TOC content in the field (0.2%–12.9%) was decisive in the quality assessment outcome. This is a widely accepted practice for hydrophobic organic contaminants, but its endorsement for PFOS would also benefit from validation. Integr Environ Assess Manag 2021;17:716–725. © 2021 SETAC

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Sediment quality assessment framework for per‐ and polyfluoroalkyl substances: Results from a preparatory study and regulatory implications

Casado-Martínez¹,

Pascariello

Polesello

et al. 2021

Integr Envir Assess & Manag

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“…A sixth hypothesis, which is not exclusive of the others mentioned here, is included in the theory of ecological stoichiometry (Sterner and Elser 2002). Ecological stoichiometry is concerned with the effects of an imbalance between available resources, in the current context food resources, and the physiology of an organism, in this case, the physiology of reproduction.…”

Section: Introductionmentioning

confidence: 93%

Linking field and laboratory studies: Reproductive effects of perfluorinated substances on avian populations

Custer

2021

Integr Envir Assess & Manag

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Although both laboratory and field studies are needed to effectively assess effects and risk of contaminants to free‐living organisms, the limitations of each must be understood. The objectives of this paper are to examine information on field studies of reproductive effects of perfluorinated substances (PFASs) on bird populations, discuss the differences among field studies, and then place those results in context with laboratory studies. Hypotheses to explain the divergences between field studies and between laboratory and field studies will be discussed. Those differences include mixture issues, misattribution of the mechanism or the specific PFAS causing impairments, as well as other possible reasons. Finally, suggestions to better link laboratory and field studies will be presented. Integr Environ Assess Manag 2021;17:690–696. Published 2021. This article is a US Government work and is in the public domain in the USA.

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“…However, this may not be an advantage under all circumstances: it could conceivably prove to be a limitation when branched PFAS isomers come into play. It should be noted that technical PFAS products can be mixtures of linear and branched isomers [5] . According to the mechanistic considerations in [1] and the derived hypotheses, it remains to be seen whether the “favorable steric factors” and the “tight packing of PFOA in the Beta pores” will apply on the branched isomers.…”

Section: Conflict Of Interestmentioning

confidence: 99%

Comments on “Highly Selective Removal of Perfluorinated Contaminants by Adsorption on All‐Silica Zeolite Beta”

Kopinke

2021

Angew Chem Int Ed

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Distribution and effects of branched versus linear isomers of PFOA, PFOS, and PFHxS: A review of recent literature

Cited by 180 publications

References 99 publications

Sediment quality assessment framework for per‐ and polyfluoroalkyl substances: Results from a preparatory study and regulatory implications

Sediment quality assessment framework for per‐ and polyfluoroalkyl substances: Results from a preparatory study and regulatory implications

Linking field and laboratory studies: Reproductive effects of perfluorinated substances on avian populations

Comments on “Highly Selective Removal of Perfluorinated Contaminants by Adsorption on All‐Silica Zeolite Beta”

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