Department of Biology, Norwegian University of Science and Technology-NTNU, Høgskoleringen 5, NO-7491 Trondheim, Norway.
Environ Int. 2012 Nov 15;49:92-9. doi: 10.1016/j.envint.2012.08.004. Epub 2012 Sep 23.
Perfluoroalkyl substances (PFASs) are protein-binding blood-accumulating contaminants that may have detrimental toxicological effects on the early phases of mammalian development. To enable an evaluation of the potential health risks of PFAS exposure for polar bears (Ursus maritimus), an exposure assessment was made by examining plasma levels of PFASs in polar bear mothers in relation to their suckling cubs-of-the-year (~4 months old). Samples were collected at Svalbard in 1998 and 2008, and we investigated the between-year differences in levels of PFASs. Seven perfluorinated carboxylic acids (∑₇PFCAs: PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA) and two perfluorinated sulfonic acids (∑₂PFSAs: PFHxS and PFOS) were detected in the majority of the mothers and cubs from both years. In mothers and cubs, most PFCAs were detected in higher concentrations in 2008 than in 1998. On the contrary, levels of PFOS were lower in 2008 than in 1998, while levels of PFHxS did not differ between the two sampling years. PFOS was the dominating compound in mothers and cubs both in 1998 and in 2008. Concentration of PFHpA did not differ between mothers and cubs, while concentrations of PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFHxS, and PFOS were higher in mothers than in their cubs. Except from PFHpA, all compounds correlated significantly between mothers and their cubs. The mean cub to mother ratios ranged from 0.15 for PFNA to 1.69 for PFHpA. On average (mean±standard error of mean), the levels of ∑₇PFCAs and ∑₂PFSAs in cubs were 0.24±0.01 and 0.22±0.01 times the levels in their mothers, respectively. Although maternal transfer appears to be a substantial source of exposure for the cubs, the low cub to mother ratios indicate that maternal transfer of PFASs in polar bears is relatively low in comparison with hydrophobic contaminants (e.g. PCBs). Because the level of several PFASs in mothers and cubs from both sampling years exceeded the levels associated with health effects in humans, our findings raise concern on the potential health effects of PFASs in polar bears from Svalbard. Effort should be made to examine the potential health effects of PFASs in polar bears.
全氟烷基物质 (PFASs) 是一种与蛋白质结合的血液蓄积性污染物，可能对哺乳动物发育的早期阶段产生有害的毒理学影响。为了评估 PFAS 暴露对北极熊 (Ursus maritimus) 的潜在健康风险，通过检查北极熊母亲及其哺乳期幼崽（约 4 个月大）的血浆中 PFASs 水平进行了暴露评估。样本于 1998 年和 2008 年在斯瓦尔巴群岛采集，我们研究了这两年间 PFASs 水平的差异。在这两年的母亲和幼崽中，大多数都检测到了七种全氟羧酸（∑₇PFCAs：PFHpA、PFOA、PFNA、PFDA、PFUnDA、PFDoDA 和 PFTrDA）和两种全氟磺酸（∑₂PFSAs：PFHxS 和 PFOS）。在母亲和幼崽中，大多数 PFCAs 在 2008 年的浓度高于 1998 年。相反，2008 年的 PFOS 水平低于 1998 年，而 PFHxS 水平在这两年间没有差异。PFOS 是 1998 年和 2008 年母亲和幼崽中含量最高的化合物。PFHpA 在母亲和幼崽中的浓度没有差异，而 PFOA、PFNA、PFDA、PFUnDA、PFDoDA、PFTrDA、PFHxS 和 PFOS 的浓度在母亲中高于幼崽。除了 PFHpA 之外，所有化合物在母亲和幼崽之间均呈显著相关性。幼崽与母亲的比值平均值范围从 PFNA 的 0.15 到 PFHpA 的 1.69。平均而言（平均值±标准误差），幼崽中∑₇PFCAs 和∑₂PFSAs 的水平分别为母亲的 0.24±0.01 和 0.22±0.01 倍。尽管母体转移似乎是幼崽暴露的一个重要来源，但幼崽与母亲的低比值表明，与疏水性污染物（例如 PCB）相比，北极熊中 PFASs 的母体转移相对较低。由于来自这两年采样的母亲和幼崽中的几种 PFASs 水平超过了与人类健康影响相关的水平，因此我们的研究结果引起了对斯瓦尔巴群岛北极熊中 PFASs 潜在健康影响的关注。应该努力研究 PFASs 对北极熊的潜在健康影响。
