Perfluorinated compounds in the plasma of loggerhead and Kemp's ridley sea turtles from the southeastern coast of the United States

Perfluorinated compounds (PFCs) have been measured in blood of humans and wildlife and are considered globally distributed contaminants. We examined 12 PFCs in the plasma of 73 loggerhead sea turtles (Caretta caretta) and 6 Kemp's ridley sea turtles (Lepidochelys kempii) captured from inshore waters of Core Sound, North Carolina (NC), and offshore waters of South Carolina, Georgia, and Florida (SC-FL). Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the dominant compounds, with respective mean concentrations of 11.0 ng/mL and 3.20 ng/mL for loggerhead turtles and 39.4 ng/mL and 3.57 ng/mL for Kemp's ridley turtles. Mean PFOS concentrations were 2- to 12-fold higher than typical mean Sigma PCB concentrations (similar to 5 ng/g wet mass) measured previously in sea turtle blood. More than 79% of the samples had detectable levels of perfluorocarboxylates (PFCAs) with 8-12 carbons, whereas only 17% or less of samples had detectable levels of PFCAs with 6 or 7 carbons. No samples had detectable levels of PFCAs with 4 or 5 carbons. In loggerhead turtles, Sigma PFC concentrations were not influenced by sex p > 0.05), but were higher in turtles captured from inshore waters of NC than in turtles from offshore waters of SC-FL (p = 0.009). A backward stepwise multiple regression model showed that Sigma PFC concentrations were (1) significantly higher in Kemp's ridley turtles than loggerhead turtles (p < 0.0001), (2) higher in larger turtles (p = 0.018; carapace length used as a proxy for age), and (3) higher in turtles captured toward the north (p=0.006). These findings suggest that bioaccumulation of PFCs in sea turtles is influenced by species, age, and habitat.