Investigating the OECD database of per- and polyfluoroalkyl substances – chemical variation and applicability of current fate models

Chelcea, I.; Ahrens, Lutz; Örn, Stefan; Mucs, Dániel; Andersson, Patrik L.

doi:10.1071/en19296

Cited by 16 publications

(9 citation statements)

References 54 publications

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“…Nonpolymeric PFAS comprise a large set of chemicals and chemical structures ( Buck et al , 2011 ; Chelcea et al , 2020 ; Wang et al , 2017 ). These PFAS encompass a broad range of Markush structures, with a wide array of chemical and physical properties.…”

Section: Resultsmentioning

confidence: 99%

Application of a Framework for Grouping and Mixtures Toxicity Assessment of PFAS: A Closer Examination of Dose-Additivity Approaches

Goodrum

Anderson

Luz

et al. 2020

Toxicological Sciences

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Environmental occurrence and biomonitoring data for per- and polyfluoroalkyl substances (PFAS) demonstrate that humans are exposed to mixtures of PFAS. This paper presents a new and systematic analysis of available PFAS toxicity study data using a tiered mixtures risk assessment framework consistent with U.S. and international mixtures guidance. The lines of evidence presented herein include a critique of whole mixture toxicity studies and analysis of dose-response models based on data from subchronic oral toxicity studies in rats. Based on available data to-date, concentration addition and relative potency factor methods are found to be inappropriate due to differences among sensitive effects and target organ potencies and noncongruent dose-response curves for the same effect endpoints from studies using the same species and protocols. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) lack a single mode of action or molecular initiating event and our evaluation herein shows they also have noncongruent dose-response curves. Dose-response curves for long chain perfluoroalkyl sulfonic acids (PFSAs) also significantly differ in shapes of the curves from short chain PFSAs and perfluoroalkyl carboxylic acids (PFCAs) evaluated, and additional differences are apparent when curves are evaluated based on internal or administered dose. Following well-established guidance, the hazard index (HI) method applied to PFCAs and PFSAs grouped separately is the most appropriate approach for conducting a screening level risk assessment for non-polymeric PFAS mixtures, given the current state-of-the science. A clear presentation of assumptions, uncertainties, and data gaps is needed before dose additivity methods, including HI, are used to support risk management decisions. Adverse outcome pathway(s) and mode(s) of action information for PFOA and PFOS and for other non-polymer PFAS are key data gaps precluding more robust mixtures methods. These findings can guide the prioritization of future studies on single chemical and whole mixture toxicity studies.

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Section: Resultsmentioning

confidence: 99%

Application of a Framework for Grouping and Mixtures Toxicity Assessment of PFAS: A Closer Examination of Dose-Additivity Approaches

Goodrum

Anderson

Luz

et al. 2020

Toxicological Sciences

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“…2). Chelcea et al [39] noted that the strong affinity of PFASs to proteins can lead to a discrepancy between K ow and bioconcentration factors in biological matrices. The increased hydrophobicity of these compounds and their affinity for proteins in the serum [21] may be stronger than the methanol used to elute the compounds from the WAX and HLB cartridges and further investigation to the strength of solvent used for elution is required.…”

Section: Methods Performance (Mass Recoveries)mentioning

confidence: 99%

“…The log octanol-water partition coefficient (log K oc ) for compounds was predicted by the EPI Suite v4.11 KOWWIN™ package [38] where mass-labelled internal standards were assumed to have the same value as the native compound. The KOWWIN™ model performed well in predicting log K ow against measured values from the literature [39]. Descriptive statistics, statistical tests and data visualisation were performed with R v4.0.2 using RStudio v1.2.5019 and the following packages: tidyverse v1.3.0.9000 [40], rstatix v0.060 [41] and RColorBrewer v1.1-2 [42].…”

Section: Statistical Analysesmentioning

confidence: 99%

Evaluation and validation of methodologies for the extraction of per- and polyfluoroalkyl substances (PFASs) in serum of birds and mammals

et al. 2022

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Advances in analytical techniques have allowed greater detection of environmental contaminants from small volumes of sample. Four methodologies were evaluated for the extraction of 53 per- and polyfluoroalkyl substances (PFASs) from eight classes in 200 µL of avian and mammal serum. Spiked serums at four concentrations (0, 0.5, 5.0 and 25 ng mL−1) were prepared by protein precipitation (PPT), enhanced matrix removal (EMR), weak anion exchange (WAX), and hydrophilic-lipophilic balance (HLB) solid-phase extraction cartridges. The extract from each methodology was analysed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS), and concentrations were compared with known concentrations in the spiked media. EMR performed the best overall, with 40 of 53 compounds effectively recovered at 5 ng mL−1. Furthermore, EMR was effective overall at concentrations ranging from 0.5 to 25 ng mL−1 for 39 out of 53. Similarly, PPT was effective for 35 of 53 compounds at all spiked serum concentrations. There was a negative correlation between internal standard recovery for compounds with increasing octanol–water coefficients (Kow) for WAX (R = − 0.65, p = 0.0043) and HLB (R = − 0.62, p = 0.0077) extractions, indicating methanol may not be a suitable solvent for long-chain PFAS extraction from protein-rich tissues. EMR and PPT represent fast and effective methodologies for the extraction of PFASs from low volumes of serum which allows greater accuracy and precision that can be applied to future human and wildlife biomonitoring programmes.

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“…Additionally, a common terminology for the nomenclature of PFASs has thus been agreed upon and saw PFASs divided in two classes, namely non-polymeric and polymeric PFASs [60], each with subclasses, groups and subgroups, as depicted on Table 1. For more details, there are various references therein [59][60][61][62][63][64]. In addition, it is currently estimated that more than 5000 known PFAS chemicals exist, with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) being the most manufactured; and their numbers are expected to increase as industries continue to invent and manufacture new substances [61,62].…”

Section: What Are Per-and Polyfluoroalkyl Substances?mentioning

confidence: 99%

Medicinal Plants Threatened by Undocumented Emerging Pollutants: The Sub-Saharan African Viewpoint

Mudumbi¹,

Itoba-Tombo²,

Ntwampe³

et al. 2022

Medicinal Plants

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The history of medicinal plants on the African continent is huge, the oldest and probably the most diverse, for there are thousands of spoken languages, in the sub-Saharan African region, that are used during the traditional practices that utilize medicinal plants for healing purposes. However, our lines of research have exhibited a potential unprecedented threat to this remarkable history of African medicinal plants by emerging pollutants, the per- and polyfluoroalkyl substances (PFASs), which are yet to be efficiently and sufficiently reported and documented on in this region. Accordingly, this review chapter reports on sub-Saharan African medicinal plants with the aim of highlighting how undocumented PFASs, in this region, present a huge threat to the extraordinary diversity of these plants and the therapy that they have assisted the low-income populations of this region with for centuries. Thus, we recommend appropriate and regular assessments and monitoring of PFASs, particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) the most studied of these substances and their substitutes, in medicinal plants of the region, for these chemicals have been scientifically proven to be associated to numerous health concerns. The region should also consider properly regulating these compounds.

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Investigating the OECD database of per- and polyfluoroalkyl substances – chemical variation and applicability of current fate models

Cited by 16 publications

References 54 publications

Application of a Framework for Grouping and Mixtures Toxicity Assessment of PFAS: A Closer Examination of Dose-Additivity Approaches

Application of a Framework for Grouping and Mixtures Toxicity Assessment of PFAS: A Closer Examination of Dose-Additivity Approaches

Evaluation and validation of methodologies for the extraction of per- and polyfluoroalkyl substances (PFASs) in serum of birds and mammals

Medicinal Plants Threatened by Undocumented Emerging Pollutants: The Sub-Saharan African Viewpoint

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