Polychlorinated biphenyls (PCBs) are recognised reproductive and immune system toxicants in marine mammals mediated by endocrine-disrupting mechanisms. As with other predators, seals are exposed to elevated bioaccumulated concentrations of PCBs and other persistent organic pollutants (POPs). Cryopreserved plasma samples from adult ringed (Phoca hispida; n = 39) and grey (Halichoerus grypus; n = 38) seals, sampled between 1998 and 2002 from Baltic Sea, Svalbard, and Sable Island (Canada) were used to investigate relationships between PCB exposure and sex hormone concentrations (progesterone; P4, 17α-hydroxy progesterone; 17α-OH-P4, testosterone; T4, 17β-estradiol; E2, estrone; E3). Immunoassay methods were used for quantification of analytes due to the limited sample volumes available. PCB concentrations were found to be significantly higher in Baltic seals than other sampling locations and were classed as "Exposed" seals while Svalbard and Sable Is seal were classed "Reference" seals (sexes and species separate). Mean hormone concentrations in Exposed seal were lower than Reference seals, and this was statistically significantly for 17α-OH-P4 (both sexes and both species), E2 (ringed and grey seal females), and E3 (grey seal females). Regression analyses (PCB v hormone concentrations) for each sex and species revealed significant correlations for P4 (Sable Is. female grey seals and female ringed seals), 17α-OH-P4 (Sable Is. male grey seals and Svalbard male ringed seals), T4 (Svalbard male ringed seals), E2 (female ringed seals), and E3 (female ringed seals and Baltic female grey seals). Although significant correlations are not evidence of cause and effect, the potential impact of hormone changes on endocrine homeostasis and reproductive health for seal populations warrants further investigation given that PCB concentrations found here are in the same range as those currently reported in seals from these populations.

中文翻译：

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环状和灰色海豹中的多氯联苯（PCB）和性激素浓度：可能与内分泌干扰有关？

多氯联苯（PCB）是公认的海洋哺乳动物内分泌干扰机制介导的生殖和免疫系统毒物。与其他捕食者一样，海豹也暴露于较高的生物积累浓度的PCB和其他持久性有机污染物（POPs）中。1998年至2002年之间从波罗的海，斯瓦尔巴特群岛和加拿大黑貂岛采样的成年环状（Phoca hispida; n = 39）和灰色（Halichoerus grypus; n = 38）海豹的冷冻保存血浆样品用于研究PCB之间的关系暴露和性激素浓度（孕酮； P4，17α-羟基孕酮；17α-OH-P4，睾丸激素； T4，17β-雌二醇； E2，雌酮； E3）。由于可用的样品量有限，因此使用免疫分析方法定量分析物。发现波罗的海海豹中的PCB浓度明显高于其他采样地点，被归类为“裸露”海豹，而斯瓦尔巴群岛和黑貂海豹则被归类为“参考”海豹（性和物种独立）。暴露海豹中的平均激素浓度低于参考海豹，这在17α-OH-P4（性别和两个物种），E2（有环斑海豹和灰海豹雌性）和E3（灰海豹雌性）中具有统计学意义。每个性别和物种的回归分析（PCB v激素浓度）显示，P4（黑貂雌性灰海豹和雌性环状海豹），17α-OH-P4（黑貂雄性灰海豹和斯瓦尔巴德雄性环状海豹）具有显着相关性， T4（斯瓦尔巴特岛公型密封件），E2（母头环形密封件）和E3（母头环形密封件和波罗的海母灰色密封件）。