Wagemann R, Trebacz E, Boila G, Lockhart W L
Department of Fisheries and Oceans, Central and Arctic Region, Freshwater Institute, Winnipeg, Manitoba, Canada.
Sci Total Environ. 2000 Oct 16;261(1-3):21-32. doi: 10.1016/s0048-9697(00)00592-1.
Four types of mercury species, namely, methylmercury, organic mercury other than methylmercury, inorganic mercury, and insoluble mercury, deemed to be mercuric selenide (HgSe), were found in the liver of 45 ringed seals from the Canadian Arctic. On average, methylmercury, at 2%, made up the smallest fraction of the total mercury in the liver of these animals. Of the total mercury concentration in seal liver, 53% was insoluble mercury, estimated to be largely mercuric selenide. Other workers have found this compound to be present in mammalian liver and identified it to be HgSe. Organic mercury other than methylmercury made up 4%, and inorganic mercury 42% of the total mercury in the liver. The sum of the independently determined mercury species agreed well with the total mercury concentration in the liver. Species other than mercuric selenide are known to be toxic. Mercuric selenide, considered to be a stable end product of the demethylation process of methylmercury, although not readily eliminated from the liver, is inert and apparently non-toxic. Only approximately half of the total mercury in the liver was potentially toxic mercury. All four mercury species were positively correlated with the age of animals, the regression slope on age being 20 times larger for insoluble Hg (HgSe) than for methylmercury. A number of reported observations, such as the long half-life of Hg in liver (> or = 10 years), the dependence of Hg on age, and the often-observed one-to-one relationship between Hg and Se (on a molar basis), are readily explained by the temporal accumulation of HgSe in the liver. In the future, a more accurate assessment of the health risk to animals and humans from the consumption of contaminated animal tissues will be possible, by measuring all mercury species rather than just total mercury or methylmercury. Total mercury alone in the liver is an inadequate indicator of toxicity to animals. Methylmercury was analyzed by capillary gas-liquid chromatography with ECD detection, and the other species were operationally/experimentally defined using physical/chemical methods.
在来自加拿大北极地区的45只环斑海豹的肝脏中，发现了四种汞物种，即甲基汞、除甲基汞之外的有机汞、无机汞以及被认为是硒化汞（HgSe）的不溶性汞。平均而言，甲基汞占这些动物肝脏中总汞的比例最小，为2%。海豹肝脏中总汞浓度的53%是不溶性汞，估计主要是硒化汞。其他研究人员发现这种化合物存在于哺乳动物肝脏中，并确定其为HgSe。除甲基汞之外的有机汞占肝脏中总汞的4%，无机汞占42%。独立测定的汞物种总和与肝脏中的总汞浓度吻合良好。已知除硒化汞之外的其他物种具有毒性。硒化汞被认为是甲基汞脱甲基过程的稳定终产物，虽然不易从肝脏中排出，但它是惰性的，显然无毒。肝脏中总汞只有大约一半是潜在有毒汞。所有四种汞物种都与动物年龄呈正相关，不溶性汞（HgSe）与年龄的回归斜率比甲基汞大20倍。许多已报道的观察结果，如汞在肝脏中的长半衰期（≥10年）、汞对年龄的依赖性以及经常观察到的汞与硒（摩尔比）之间的一对一关系，都可以通过肝脏中HgSe的时间积累得到很好的解释。未来，通过测量所有汞物种而不仅仅是总汞或甲基汞，将有可能更准确地评估食用受污染动物组织对动物和人类的健康风险。仅肝脏中的总汞不足以作为对动物毒性的指标。甲基汞通过带电子捕获检测器的毛细管气液色谱法进行分析，其他物种则使用物理/化学方法进行操作定义/实验定义。
