Burger Joanna, Gochfeld Michael
Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ 08854-8082, USA.
Environ Res. 2007 Oct;105(2):276-84. doi: 10.1016/j.envres.2007.05.004. Epub 2007 Jun 27.
While there has been considerable attention devoted to the risks to high level consumers from mercury in freshwater fish, relatively little attention has been devoted to saltwater fish. Although the U.S. Food and Drug Administration has issued advisories based on mercury for four saltwater species or groups of fish, there are few data on mercury levels generally, or on the risk these levels pose to the fish themselves or to consumers of marine fish. We examined total mercury levels in liver and muscle of Pacific cod (Gadus macrocephalus) collected from the northern Pacific and Bering Sea waters around Nikolski, Amchitka, and Kiska Islands in the Aleutian Chain (Alaska). We were interested in whether there were differences in mercury levels as a function of location, weight, length, and age of the fish, and what risk mercury posed to the food chain, including people. Fish were aged by examining otoliths, and we measured selenium because of its reported protective effects against mercury. Regression models indicated that 27% of the variation in levels of mercury was due to tissue examined and age, while 67% of the variation in levels of selenium was due to tissue, length, and age. Mercury levels were significantly higher in the muscle than the liver, and the reverse was true for selenium. Mercury levels were negatively correlated with selenium levels, and positively correlated with length, weight, and age. There were no gender differences in mercury or selenium levels. The mean levels of mercury in muscle (0.17 ppm wet weight) are within the range known to cause adverse effects in sensitive birds and mammals. Only 4% of the Pacific cod samples had mercury levels above 0.5 ppm, the action level promulgated by many states and countries, and none were above the 1 ppm action level of the U.S. FDA.
尽管人们相当关注淡水鱼中的汞对高摄入量消费者的风险，但对咸水鱼的关注相对较少。虽然美国食品药品监督管理局已针对四种咸水鱼品种或鱼群发布了基于汞含量的建议，但总体上关于汞含量的数据很少，关于这些汞含量对鱼本身或海鱼消费者构成的风险的数据也很少。我们检测了从阿留申群岛（阿拉斯加）的尼科尔斯基、阿姆奇特卡和基斯卡岛周围的北太平洋和白令海水域采集的太平洋鳕鱼（大头鳕）肝脏和肌肉中的总汞含量。我们感兴趣的是汞含量是否因鱼的位置、重量、长度和年龄而有所不同，以及汞对包括人类在内的食物链构成何种风险。通过检查耳石来确定鱼的年龄，并且由于据报道硒对汞有保护作用，所以我们对硒进行了测量。回归模型表明，汞含量变化的27%归因于所检测的组织和鱼的年龄，而硒含量变化的67%归因于组织、长度和年龄。肌肉中的汞含量显著高于肝脏，而硒的情况则相反。汞含量与硒含量呈负相关，与长度、重量和年龄呈正相关。汞和硒的含量不存在性别差异。肌肉中汞的平均含量（湿重0.17 ppm）在已知会对敏感鸟类和哺乳动物产生不良影响的范围内。只有4%的太平洋鳕鱼样本汞含量高于0.5 ppm（许多州和国家公布的行动水平），且没有样本高于美国食品药品监督管理局的1 ppm行动水平。
