Dahlgaard Henning, Eriksson Mats, Nielsen Sven P, Joensen Hans Pauli
Risø National Laboratory, Radiation Research Department, NUK-204, DK-4000 Roskilde, Denmark.
Sci Total Environ. 2004 Sep 20;331(1-3):53-67. doi: 10.1016/j.scitotenv.2004.03.023.
Levels of radioactive contaminants in various Greenland environments have been assessed during 1999-2001. The source of 137Cs, 90Sr and (239,240)Pu in terrestrial and fresh water environments is mainly global fallout. In addition, the Chernobyl accident gave a small contribution of 137Cs. Reindeer and lamb contain the largest observed 137Cs concentrations in the terrestrial environment--up to 80 Bq kg(-1) fresh weight have been observed in reindeer. Due to special environmental conditions, 137Cs is transferred to landlocked Arctic char with extremely high efficiency in South Greenland leading to concentrations up to 100 Bq kg(-1) fresh weight. In these cases very long ecological half-lives are seen. Concentrations of 99Tc, 137Cs and 90Sr in seawater and in marine biota decrease in the order North-East Greenland and the coastal East Greenland current > South-West Greenland > Central West Greenland and North-West Greenland > Irmiger Sea-Faroe Islands. The general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean causes this. As the same tendency is seen for the persistent organic pollutants (POPs) DDT and PCB in marine biota, it is suggested that long-distance oceanic transport by coastal currents is a significant pathway also for POPs in the Greenland marine environment. The peak 99Tc discharge from Sellafield 1994-1995 has only been slightly visible in the present survey year 2000. The concentrations are expected to increase in the future, especially in East Greenland. The Bylot Sound at the Thule Airbase (Pituffik) in North-West Greenland was contaminated with plutonium and enriched uranium in a weapons accident in 1968. Biological activity has mixed accident plutonium efficiently into the new sediments resulting in continued high surface sediment concentrations three decades after the accident. Transfer of plutonium to benthic biota is low--and lower than observed in the Irish Sea. This is supposed to be caused by the physico-chemical form of the accident plutonium. A recent study indicates that 'hot particles' hold considerably more plutonium than previously anticipated and that the Bylot Sound sediments may account for the major part of the un-recovered plutonium after the accident, i.e. approximately 3 kg.
1999年至2001年期间，对格陵兰岛不同环境中的放射性污染物水平进行了评估。陆地和淡水环境中137铯、90锶和（239,240）钚的来源主要是全球沉降。此外，切尔诺贝利事故对137铯的贡献较小。在陆地环境中，驯鹿和羔羊体内的137铯浓度最高——在驯鹿中观察到的鲜重浓度高达80贝克勒尔/千克。由于特殊的环境条件，在格陵兰岛南部，137铯以极高的效率转移到内陆北极红点鲑体内，导致浓度高达100贝克勒尔/千克鲜重。在这些情况下，可以看到非常长的生态半衰期。海水和海洋生物群中99锝、137铯和90锶的浓度按照东北格陵兰岛和东格陵兰岛沿岸洋流＞西南格陵兰岛＞中西格陵兰岛和西北格陵兰岛＞伊尔明厄海-法罗群岛的顺序递减。这是由大规模的海洋环流、欧洲沿海排放以及北冰洋先前的污染共同造成的。由于在海洋生物群中持久性有机污染物（POPs）滴滴涕和多氯联苯也呈现出相同的趋势，因此有人认为，沿岸洋流的远距离海洋运输也是格陵兰岛海洋环境中持久性有机污染物的重要传播途径。1994年至1995年塞拉菲尔德核电站99锝的排放峰值在2000年的本次调查中仅略有显现。预计未来浓度会增加，尤其是在东格陵兰岛。1968年的一次武器事故导致格陵兰岛西北部图勒空军基地（皮图菲克）的拜洛特湾被钚和浓缩铀污染。生物活动已将事故钚有效地混入新沉积物中，导致事故发生三十年后表层沉积物浓度持续居高不下。钚向底栖生物群的转移率较低——低于在爱尔兰海观察到的水平。这被认为是由事故钚的物理化学形态造成的。最近的一项研究表明，“热粒子”所含的钚比先前预期的要多得多，拜洛特湾的沉积物可能占事故后未回收钚的大部分，即约3千克。
