Quantifying Indirect Contribution from Precursors to Human Body Burden of Legacy PFASs Based on Paired Blood and One-Week Duplicate Diet

Abstract

The restriction on legacy perfluoroalkyl substances (PFASs) has led to increasing application and contamination of their precursors and novel alternatives. However, the indirect contribution from precursors has not been well characterized. In this study, 24 PFASs were measured in the paired human blood and urine from general volunteers (n = 20), as well as their corresponding exposure matrices (7 day duplicate diet, drinking water and dust). Perfluorooctanoic acid (PFOA) was predominant, followed by 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA), contributing 21.6–47.0 and 6.6–20.0% of the total concentrations, respectively. Total oxidable precursor (TOP) assay and isomeric analysis coupled with a toxicokinetic model suggested that around 19% of perfluorooctane sulfonate (PFOS) in human was contributed by its precursors. The strong correlation between the estimated daily intake (EDI) and human blood concentration for 6:2 Cl-PFESA suggested that it was mainly contributed by direct exposure. The bioavailability of 6:2 Cl-PFESA in the food matrices was estimated as 18.6% by comparing the estimated and measured blood concentrations, implying that human exposure might be overestimated if the bioavailability of PFASs in food was not considered. Assuming that they had a similar bioavailability, it was estimated that ca. 20% of PFOS body burden was from indirect exposure to its precursors, which was supported by TOP assay.

Per- and Polyfluoroalkyl Substances (PFASs) Impair Lipid Metabolism in Rana nigromaculata: A Field Investigation and Laboratory Study

“…PFASs are widely distributed in the environment and inevitably appear in locations that are accessible to animals and even humans . By revealing PFAS-impaired lipid metabolism in frogs, our study fills the gap in knowledge created by the limited data on the occurrence of PFASs in amphibians and their adverse effects in the environment.…”

“…PFASs are widely distributed in the environment and inevitably appear in locations that are accessible to animals and even humans. 77 By revealing PFAS-impaired lipid metabolism in frogs, our study fills the gap in knowledge created by the limited data on the occurrence of PFASs in amphibians and their adverse effects in the environment. This is the first comprehensive in situ, in vivo, and in silico study to confirm the lipid metabolic-disrupting effects of PFASs on frogs through both field and laboratory studies.…”

Nontarget Identification of Novel Per- and Polyfluoroalkyl Substances in Cord Blood Samples

“…Per- and polyfluoroalkyl substances (PFASs) have many unique physicochemical characteristics imparted by the fluorinated region, including amphiphobicity, surfactivity, and thermostability, making them suitable for numerous industrial and commercial applications. − The ubiquitous presence of PFASs has been observed in various environmental compartments (e.g., drink water, soil, and atmosphere) and biotas, even in humans. − Epidemiological and toxicological studies revealed that PFASs possessed hepatic and metabolic toxicity, reproductive and developmental toxicity, immunotoxicity, and so on . Several PFASs, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), are listed in Stockholm Convention to regulate their usage due to their persistence, long-range transport, bioaccumulation and potential toxicities .…”

Analysis of Specific Perfluorohexane Sulfonate Isomers by Liquid Chromatography-Tandem Mass Spectrometry: Method Development and Application in Source Apportionment

“…Figure S2. Mass spectra of chromatographic peaks A4, A5, and M4, presented in Figure 1 (A), Chromatographs of typical fragment ions of peak A5 and a : e sample points in brackets and treatment procedures, please refer to the literature [30,31] for details; b : Drinking water collection and treatment methods, see references for details [39]. N.D.: not detected.…”

“… a : The sample points in brackets and treatment procedures, please refer to the literature [ 30 , 31 ] for details; b : Drinking water collection and treatment methods, see references for details [ 39 ]. N.D.: not detected.…”