Circumpolar Study of Perfluoroalkyl Contaminants in Polar Bears (Ursus maritimus)

Abstract

Perfluoroalkyl substances were determined in liver tissues and blood of polar bears (Ursus maritimus) from five locations in the North American Arctic and two locations in the European Arctic. Concentrations of perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate, heptadecafluorooctane sulfonamide, and perfluoroalkyl carboxylates with C8−C15 perfluorinated carbon chains were determined using liquid chromatography tandem mass spectrometry. PFOS concentrations were significantly correlated with age at four of seven sampling locations, while gender was not correlated to concentration for any compound measured. Populations in South Hudson Bay (2000−2730 ng/g wet wt), East Greenland (911−2140 ng/g wet wt), and Svalbard (756−1290 ng/g wet wt) had significantly (P < 0.05) higher PFOS concentrations than western populations such as the Chukchi Sea (435−729 ng/g wet wt). Concentrations of perfluorocarboxylic acids (PFCAs) with adjacent chain lengths (i.e., C9:C10 and C10:C11) were significantly correlated (P < 0.05), suggesting PFCAs have a common source within a location, but there were differences in proportions of PFCAs between eastern and western location sources. Concentrations of PFOS in liver tissue at five locations were correlated with concentrations of four polychlorinated biphenyl congeners (180, 153, 138, and 99) in adipose tissue of bears in the same populations, suggesting similar transport pathways and source regions of PFOS or precursors.

Brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears (Ursus maritimus)

“…The overall dominance of PFOS in the brains of the present study (35.2 AE 2.0 ng/g wet wt) is consistent with other reports for East Greenland polar bear liver studies. However, the PFOS concentrations in the brain are roughly 100-fold lower than previously reported liver concentrations (3,000-4,000 ng/g wet wt) for bears collected in the same geographical location and/or the same year (2006) [4,7,37,38].…”

“…Harbor porpoise (1997-1998) [21] Harbor seal (2007) [17] Glaucous gull (2004) [24] Brown pelican (2004) [22] Fig been reported for polar bear liver, where the major PFCA was PFNA (C 9 ) [37,38]. This is a more pronounced shift than what was found in harbor seals [17], where there was a slight shift from C 9 being dominant in the liver to C 10 being dominant in the brain.…”

“…The present study is one of a select few that has shown PFCA (PFTrDA) concentrations approaching levels of PFOS in any tissue of any wildlife. In the East Greenland polar bear liver PFOS has always been the dominant PFAA, with the next most abundant PFAA (PFNA) typically in the range of 10 to 20 times lower [7,37,38]. However, the dominance of PFOS relative to PFTrDA is statistically negligible ( p > 0.26) in the whole brain (PFOS 35.2 AE 2.0 vs PFTrDA 31.4 AE 1.5 ng/g wet wt) as well as in each of the eight individually analyzed brain regions.…”

Perfluorinated compounds in red-throated divers from the German Baltic Sea: new findings from their distribution in 10 different tissues

“…[12][13][14] Perfluorooctane sulfonate (PFOS) is usually the dominating compound followed by perfluorononanoate (PFNA). [12,15] The highest concentrations of PFCs have been detected in liver and kidney tissues. [13,16,17] Investigations concerning seabirds reveal different compositions.…”

Brominated Flame Retardants in Polar Bears (Ursus maritimus) from Alaska, the Canadian Arctic, East Greenland, and Svalbard

“…Organochlorine pesticides (OCPs) and PCBs were first reported in polar bear tissues from Canada (5) and Greenland (6) nearly 30 years ago. Subsequently, PCBs, a wide range of OCPs and their metabolites (7), as well as PCB and PCB methyl sulfones (8), hydroxylated PCBs (9), chlorinated dioxin/furans (10), chlorinated naphthalenes (11), and perfluorinated acids (12,13), have been determined in polar bear populations.…”