Folland William R, Newsted John L, Fitzgerald Scott D, Fuchsman Phyllis C, Bradley Patrick W, Kern John, Kannan Kurunthachalam, Remington Richard E, Zwiernik Matthew J
Department of Animal Science, Michigan State University, East Lansing, Michigan, USA.
Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA.
Environ Toxicol Chem. 2016 Mar;35(3):604-18. doi: 10.1002/etc.3201. Epub 2016 Feb 5.
Polychlorinated biphenyls (PCBs) from the commercial mixture Aroclor 1268 were historically released into the Turtle-Brunswick River estuary (southeastern Georgia, USA) from industrial operations. Sum PCBs (ΣPCBs) in blubber samples from Turtle-Brunswick River estuary bottlenose dolphins (Tursiops truncatus) have been reported at concentrations more than 10-fold higher than those observed in dolphins from adjacent regional estuaries. Given that toxicity data specific to Aroclor 1268 and applicable to marine mammals are limited, predicting the toxic effects of Aroclor 1268 in dolphins is uncertain, particularly because of its unique congener profile and associated physiochemical characteristics compared with other PCB mixtures. American mink (Neovison vison) were chosen as a surrogate model for cetaceans to develop marine mammalian PCB toxicity benchmarks. Mink are a suitable surrogate species for cetaceans in toxicity studies because of similarities in diet and taxonomic class, and a characteristic sensitivity to PCBs provides a potential safety factor when using mink toxicology data for cross-species extrapolations. Effects of dietary exposure to Aroclor 1268 on reproduction, growth, and mortality in mink were compared with both a negative control and a positive control (3,3',4,4',5-pentachlorobiphenyl, PCB 126). Aroclor 1268 dietary ΣPCB concentrations ranged from 1.8 µg/g feed wet weight to 29 µg/g feed wet weight. Whelp success was unaffected by Aroclor 1268 exposure at any level. Treatment mean litter size, kit growth, and kit survival were adversely affected relative to the negative control at dietary ΣPCB concentrations of 10.6 µg/g feed wet weight and greater.
历史上，来自商业混合物多氯联苯（PCBs）产品Aroclor 1268中的多氯联苯，因工业生产活动被排放到美国佐治亚州东南部的海龟-不伦瑞克河河口。据报道，海龟-不伦瑞克河河口宽吻海豚（Tursiops truncatus）脂肪样本中的总多氯联苯（ΣPCBs）浓度，比相邻区域河口的海豚高出10倍以上。鉴于特定于Aroclor 1268且适用于海洋哺乳动物的毒性数据有限，预测Aroclor 1268对海豚的毒性影响具有不确定性，尤其是因为与其他多氯联苯混合物相比，它具有独特的同系物分布和相关的物理化学特性。美洲水貂（Neovison vison）被选为鲸类动物的替代模型，以制定海洋哺乳动物多氯联苯毒性基准。在毒性研究中，水貂是鲸类动物合适的替代物种，因为它们在饮食和分类类别上具有相似性，并且对多氯联苯具有特征性敏感性，这在将水貂毒理学数据用于跨物种推断时提供了潜在的安全因素。将饮食中接触Aroclor 1268对水貂繁殖、生长和死亡率的影响，与阴性对照和阳性对照（3,3',4,4',5-五氯联苯，PCB 126）进行了比较。Aroclor 1268饮食中ΣPCBs浓度范围为每克饲料湿重1.8微克至29微克。在任何暴露水平下，Aroclor 1268暴露均未影响产仔成功率。当饮食中ΣPCBs浓度达到每克饲料湿重10.6微克及更高时，与阴性对照相比，处理组的平均窝仔数、幼崽生长和幼崽存活率均受到不利影响。
