Tissue-Specific Concentrations and Patterns of Perfluoroalkyl Carboxylates and Sulfonates in East Greenland Polar Bears

摘要

Several perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) of varying chain length are bioaccumulative in biota. However, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. In the present study, the comparative accumulation of C_6 to C_(15) PFCAs, C_4, C_6 C_8 and C_(10) PFSAs, and select precursors were examined in the liver, blood, musde, adipose, and brain of 20 polar bears (Ursus maritimus) from Scoresby Sound, Central East Greenland. Overall, PFSA and PFCA concentrations were highest in liver followed by blood > brain > muscle ≈ adipose. liver and blood samples contained proportionally more of the shorter/medium chain length (C_6 to C_(11)) PFCAs, whereas adipose and brain samples were dominated by longer chain (C_(13) to C_(15)) PFCAs. PFCAs with lower Iipophilicities accumulated more in the liver, whereas the brain accumulated PFCAs with higher Iipophilicities. The concentration ratios (±SE) between perfluorooctane sulfonate and its precursor perfluorooctane sulfonamide varied among tissues from 9 (±1):1 (muscle) to 36 (±7):1 (liver). PFCA and PFSA patterns in polar bears indicate that the pharmacokinetics of these compounds are to some extent tissue-specific, and are the result of several factors that may include differing protein interactions throughout the body.