Tissue Uptake, Distribution, and Elimination of Perfluoroalkyl Substances in Juvenile Perch through Perfluorooctane Sulfonamidoethanol Based Phosphate Diester Dietary Exposure

Abstract

Perfluorooctane sulfonamidoethanol based phosphate diester (SAmPAP) is a potential perfluorooctanesulfonate (PFOS) precursor. To examine whether SAmPAP exposure would result in fish contamination by perfluoroalkyl and polyfluoroalkyl substances (PFASs), juvenile Eurasian perch were dietarily exposed to this compound (dosed group) or exposed to the same tank water but fed control feed (control group). SAmPAP and metabolites were monitored in the muscle, liver, and serum during the 45-day exposure phase and 35-day depuration phase. SAmPAP was only detected in the dosed group and the absorption efficiency (0.04-2.25%) was very low, possibly related to its low bioavailability in the gastrointestinal tract, steric constraints in crossing biological membranes, and clearing by enterohepatic circulation. Although SAmPAP was biotransformed and eliminated at a slow rate (t > 18 days), its biomagnification factor was low. The observed metabolites in fish were N-ethyl perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamide, and PFOS. Considering that SAmPAP was the only source of PFASs in the tanks, the occurrence of metabolites indicates that SAmPAP could be biotransformed in fish and contribute to PFOS bioaccumulation. However, levels of metabolites were not significantly different in the dosed and control groups, indicating that metabolite excretion followed by re-exposure to these metabolites from water was the main uptake route.

Risk to human health related to the presence of perfluoroalkyl substances in food

“…Gaillard et al. () investigated the fate of EtFOSE in juvenile perch ( Perca fluviatilis ) dietary exposed for 45 days to EtFOSE‐based phosphate diester incorporated into feed at a concentration of 1.6 mg/kg feed. EtFOSE and metabolites, including PFOS, were monitored in fish tissues (muscle, liver, serum) to study the bioaccumulation.…”

A Toxicokinetic Framework and Analysis Tool for Interpreting Organisation for Economic Co‐operation and Development Guideline 305 Dietary Bioaccumulation Tests

“…Transformation of the chemical in the liver and other tissues of the fish body is included in k BM and not in k BG . It is possible that a metabolite(s) of the test chemical excreted in the bile is reconstituted into the parent chemical in the intestinal tract and then reabsorbed (Gaillard et al 2017). This particular contribution to enterohepatic recirculation of chemicals is not captured in the model.…”

Photochemical transformation of perfluoroalkyl acid precursors in water using engineered nanomaterials

“…Perfluorochemicals including perfluorooctylsulfonylfluoride (POSF) (Zhang et al, 2004), methyl perfluorooctane sulfonamide (MeFOSA) (Chu and Letcher, 2014), perfluorooctane sulfonamidoethanol (MeFOSE) (Avendano and Liu, 2015), N-ethyl perfluorooctane sulfonamide (EtFOSA), N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE) (Gaillard et al, 2017) are used as precursors for the formation of perfluorinated sulfonic acids (PFSAs).…”