Comparativein vitrotoxicity assessment of perfluorinated carboxylic acids

Abstract

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic fluorinated compounds that are highly bioaccumulative and persistent organic pollutants. Perfluorooctanoic acid (PFOA), an eight-carbon chain perfluorinated carboxylic acid, was used heavily for the production of fluoropolymers, but concerns have led to its replacement by shorter carbon chain homologues such as perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA). However, limited toxicity data exist for these substitutes. We evaluated the toxicity of PFOA, PFHxA and PFBA on a zebrafish liver cell line and investigated the effects of exposure on cell metabolism. Gross toxicity after 96 h of exposure was highest for PFOA and PFO , while PFHxA and PFBA exhibited lower toxicity. Although the structural similarity of these compounds to fatty acids suggests the possibility of interference with the transport and metabolism of lipids, we could not detect any differential expression of peroxisome proliferator-activated receptor (ppar-α, -β and -γ), fabp3 and crot genes after 96 h exposure to up to 10 ppm of the test compounds. However, we observed localized lipid droplet accumulation only in PFBA-exposed cells. To study the effects of these compounds on cell metabolism, we conducted fluorescence lifetime imaging microscopy using naturally fluorescent biomarkers, NADH and FAD. The fluorescence lifetimes of NADH and FAD and the bound/free ratio of each of these coenzymes decreased in a dose- and carbon length-dependent manner, suggesting disruption of cell metabolism. In sum, our study revealed that PFASs with shorter carbon chains are less toxic than PFOA, and that exposure to sublethal dosage of PFOA, PFHxA or PFBA affects cell metabolism. Copyright © 2016 John Wiley & Sons, Ltd.

Distribution and dry deposition of alternative and legacy perfluoroalkyl and polyfluoroalkyl substances in the air above the Bohai and Yellow Seas, China

“…Because of their (bio)degradation, n-PFASs are considered indirect sources of i-PFASs (Dassuncao et al, 2017;Ellis et al, 2004;Martin et al, 2006). Due to their toxicity and potential threat to ecosystems and human health (Giesy et al, 2010;Mahapatra et al, 2017;Trasande et al, 2017), the manufacture and application of 8-carbon groups (C 8 ), such as perfluorooctane sulfonic acid (PFOS) and their related compounds, have been regulated worldwide (UNEP, 2017a;. After the phase-out of C 8 homologues, shorter-chained substitutes, such as perfluorobutanoic acid (PFBA) and perfluorobutane sulfonate acid (PFBS) (Moeller et al, 2010), as well as other alternatives, such as chlorinated polyfluorinated ether sulfonate (Cl-PFAES) (Deng et al, 2018) and 3H-perfluoro-3-[(3-methoxy-propoxy) propanoic acid (ADONA) (Fromme et al, 2017), are more concerning because of their occurrence in the environment and in biota.…”

New Ionic Carbosilane Dendrons Possessing Fluorinated Tails at Different Locations on the Skeleton

“…Dendron topology was selected to control the homogeneity of the structure and particularly taking into account the possible dendronization processes over other platforms, such as nanoparticles, polymers or drugs. In addition, perfluorinated derivatives were chosen based on their well-known chain length-bioaccumulation relationship-the limit was established in six perfluorinated carbons to be considered as non-bioaccumulative compounds [19][20][21]. All employed fluorinated precursors for the dendron functionalization used in this work and are shown in Figure 1.…”

Associations of Maternal Serum Perfluoroalkyl Substances Concentrations with Early Adolescent Bone Mineral Content and Density: The Health Outcomes and Measures of the Environment (HOME) Study

“…PFAS have varying abilities to act as peroxisome proliferator–activated receptor ( or peroxisome proliferator–activated receptor ( agonists ( Fang et al. 2009 ; Mahapatra et al. 2017 ; Rosen et al.…”