Perfluorooctanesulfonate and related fluorinated hydrocarbons in mink and river otters from the United States

Mink and otters are good integrators of their aquatic environments and useful sentinel species for determining exposure to environmental contaminants. In this study, perfluorooctanesulfonate (PFOS; C8F17SO3-), perfluorooctanesulfonamide (FOSA; C8F17SO2NH2), perfluorohexanesulfonate (PFHxS; C6F13SO3-), and perfluorooctanoate (PFOA; C7F15CO2-) were measured in livers of mink and river otters collected from various locations in the United States. PFOS was found in all mink livers analyzed. Frequencies of occurrence of FOSA, PFHxS, and PFOA were less. The greatest concentration of PFOS measured in liver of mink was 5140 ng/g, wet weight. Maximum concentrations of FOSA, PFHxS, and PFOA in mink livers were 590, 39, and 27 ng/g, wet weight, respectively. There were no significant positive relationships between concentrations of PFOS and PFHxS or PFOA in mink livers. Concentrations of PFOS were positively correlated with those of FOSA in mink livers from Illinois. There was no significant correlation between concentrations of PFOS and lipid content in mink livers. There were no age- or sex-related differences in the concentrations of fluorochemicals in mink livers. Greater concentrations are associated with those individuals collected near urbanized and/or industrialized areas. PFOS was detected in livers of all river otters collected from Washington and Oregon at concentrations ranging from 25 to 994 ng/g, wet wt.