Concentrations of 45 Per- and Polyfluoroalkyl Substances in North American River Otters (Lontra canadensis) from West Virginia, USA

Abstract

North American river otters (Lontra canadensis) are top predators in riverine ecosystems and are vulnerable to per- and polyfluoroalkyl substance (PFAS) exposure. Little is known about the magnitude of exposure and tissue distribution of PFAS in river otters. We measured 45 PFAS in various tissues of 42 river otters collected from several watersheds in the state of West Virginia, USA. The median concentrations of ∑All (sum concentration of 45 PFAS) varied among tissues in the following decreasing order: liver (931 ng/g wet weight) > bile > pancreas > lung > kidney > blood > brain > muscle. Perfluoroalkylsulfonates (PFSAs) were the predominant compounds accounting for 58–75% of the total concentrations, followed by perfluoroalkyl carboxylates (PFCAs; 21–35%). 8:2 fluorotelomer sulfonate (8:2 FTS), 10:2 FTS, and 6:2 chlorinated polyfluoroalkyl ether sulfonate were frequently found in the liver (50–90%) and bile (96–100%), whereas hexafluoropropylene oxide dimer acid (HFPO-DA) was rarely found. The hepatic concentrations of ∑All in river otters collected downstream of a fluoropolymer production facility located along the Ohio River were 2-fold higher than those in other watersheds. The median whole body burden of ∑All was calculated to be 1580 μg. PFOS and perfluorooctanoic acid (PFOA) concentrations in whole blood of some river otters exceeded the human toxicity reference values, which warrant further studies.

Persistence of PFOA Pollution at a PTFE Production Site and Occurrence of Replacement PFASs in English Freshwaters Revealed by Sentinel Species, the Eurasian Otter (Lutra lutra)

“…Three fluorotelomer sulfonates (FTSs) were analyzed in this study; 8:2 FTS was detected in 19/20 otters, 6:2 FTS in 2 otters, and 4:2 FTS was not detected. These are similar to detection frequencies to those found in the liver of American river otters (Lontra canadensis, 79%, 12%, and 0%, respectively) . 8:2 FTS had the third highest median concentration and the highest maximum concentration of the replacement compounds (median: 0.817 μg/kg ww, maximum: 70.3 μg/kg ww, Figure d); this is higher concentrations seen in Eurasian otters from Europe (maximum: 14.5 μg/kg ww) and American river otters (maximum: 1.87 μg/kg ww) .…”

“…These are similar to detection frequencies to those found in the liver of American river otters ( Lontra canadensis , 79%, 12%, and 0%, respectively). 32 8:2 FTS had the third highest median concentration and the highest maximum concentration of the replacement compounds (median: 0.817 μg/kg ww, maximum: 70.3 μg/kg ww, Figure 3 d); this is higher concentrations seen in Eurasian otters from Europe (maximum: 14.5 μg/kg ww) 23 and American river otters (maximum: 1.87 μg/kg ww). 32 FTSs have been used as PFOS replacements in a wide variety of products 17 , 20 , 65 but are probably excreted quickly, 32 and FTSs degrade to PFCAs in the environment and biota.…”

“…8:2 FTS had the third highest median concentration and the highest maximum concentration of the replacement compounds (median: 0.817 μg/kg ww, maximum: 70.3 μg/kg ww, Figure d); this is higher concentrations seen in Eurasian otters from Europe (maximum: 14.5 μg/kg ww) and American river otters (maximum: 1.87 μg/kg ww) . FTSs have been used as PFOS replacements in a wide variety of products ,, but are probably excreted quickly, and FTSs degrade to PFCAs in the environment and biota. , The rate of degradation increases with decreasing fluoroalkyl chain length under ultrasound thermolysis experiments, and this may explain the higher detection frequency of 8:2 FTS compared with 6:2 and 4:2 FTS.…”

“…F-53B is formed of two components: F-53B major and F-53B minor; in our study, F-53B major was detected in 19 of the 20 otters with concentrations up to 1.33 μg/kg ww, and F-53B minor was detected in 6 otters with concentrations up to 0.13 μg/kg ww. F-53B major has been previously reported in surface water and sediment samples in the UK , and in one otter from the UK at a concentration of 3.3 μg/kg ww and in American otter liver at a maximum concentration of 0.06 μg/kg ww . F-53B is not manufactured in the UK or EU, usage of the chemical is not known, and it is not registered under the EU or UK REACH Regulations, so no single company can be importing it in quantities exceeding 1 tonne/year .…”

“…Liver was selected as the optimum tissue for comparability with previous studies, 23 , 24 , 32 and because detection in liver has been shown to be higher than other tissues and therefore more likely to be of a detectable concentration. 32 Otter selection was restricted to a transect running east away from the PTFE manufacturing facility on the Fylde coast, North England. A sample of 20 livers from otters which died between 2015 and 2019 were selected for analysis ( Figure 1 ).…”