Tissue distribution and bioaccumulation of a novel polyfluoroalkyl benzenesulfonate in crucian carp

Abstract

The emergence of novel per- and polyfluoroalkyl substances (PFASs) has enabled researchers to determine their bioaccumulation, which is important for understanding their internal doses and environmental risks. Here, for the first time, we report on the occurrence of a novel PFAS, p-perfluorous nonenoxybenzenesulfonate (OBS) in wild crucian carp and explore its tissue distribution and bioaccumulation. The highest levels of OBS were observed in blood (mean/median: 144/133 ng/ml) with the mean tissue/blood ratios (TBRs) consistently below 1, ranging from 0.090 (muscle) to 0.644 (liver). This followed the pattern of perfluorooctane sulfonate (PFOS), implying that their distributions were similar. The calculated tissue-specific LogBAF values, except for muscle, 3.78 (gill)-4.14 (blood) over the regulatory bioaccumulation criterion (Log value: 3.70) indicated its obvious bioaccumulative potency in crucian carp. Molecular docking with estimated binding energies at -8.5 and -9.0 kcal/mol corroborated the strong interactions of OBS with human serum albumin and liver fatty acid binding protein, even though the binding energies were lower than those of PFOS. This, to some extent, explained the lower bioaccumulation of OBS than PFOS. Considering its bioaccumulative potential, large production volume, and wide use, further investigation into the environmental risk and in vivo toxicology of OBS is required.

Keywords: Bioaccumulation factor; OBS; Tissue distribution.