Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland.
J Environ Radioact. 2010 Apr;101(4):323-31. doi: 10.1016/j.jenvrad.2010.01.006. Epub 2010 Feb 20.
Sediment deposits are the ultimate sink for anthropogenic radionuclides entering the marine environment. The major sources of anthropogenic radionuclides to the Barents Sea are fallout from nuclear weapons tests, long range transport from other seas, and river and non-point freshwater supplies. In this study we investigated activity concentrations, ratios, and inventories of the anthropogenic radionuclides, 137Cs, 238Pu, 239,240Pu in dated sediment cores collected along a north-south transect in the northwestern Barents Sea. The data were used to evaluate the influence of different sources on the derived spatial and temporal patterns of anthropogenic radionuclides in seafloor sediment deposits. Activity concentrations of 137Cs ranged from <0.1 Bq/kg to 10.5 Bq/kg while 239,240Pu ranged from <0.01 Bq/kg to 2.74 Bq/kg and 238Pu activity concentrations ranged from <0.01 Bq/kg to 0.22 Bq/kg. Total inventories of 137Cs ranged from 29.5+/-1.5 Bq/m2 to 152.7+/-5.6 Bq/m2 and for 239,240Pu inventories (6 sediment layers only) ranged from 9.5+/-0.3 Bq/m2 to 29.7+/-0.4 Bq/m2. Source contributions varied among stations and between the investigated radionuclides. The 238Pu/239,240Pu ratios up to 0.18 indicate discharges from nuclear fuel reprocessing plants as a main contributor of plutonium. Based on 238Pu/239,240Pu ratio, it was calculated that up to 19-27% of plutonium is supplied from sources other than atmospheric global fallout. Taking into account Atlantic current flow trajectories and that both activity concentrations and inventories of plutonium negatively correlate with latitude, Sellafield is a major source for the Barents Sea. Concentrations and inventories of 137Cs correlate positively with latitude and negatively with distance from the Svalbard archipelago. The 137Cs concentrations are highest in an area of intensive melting of sea ice formed along the Siberian coast. Thus, sea ice and supplies from Svalbard may be important source of 137Cs to the Barents Sea seafloor.
沉积物是进入海洋环境的人为放射性核素的最终归宿。人为放射性核素进入巴伦支海的主要来源是核武器试验的沉降物、从其他海域的远距离传输以及河流和非点源淡水供应。在这项研究中，我们调查了沿巴伦支海南北向横剖面采集的年代沉积物芯中人为放射性核素 137Cs、238Pu、239,240Pu 的活度浓度、比值和库存。这些数据用于评估不同来源对海底沉积物中人为放射性核素的空间和时间分布模式的影响。137Cs 的活度浓度范围为 <0.1 Bq/kg 至 10.5 Bq/kg，而 239,240Pu 的活度浓度范围为 <0.01 Bq/kg 至 2.74 Bq/kg，238Pu 的活度浓度范围为 <0.01 Bq/kg 至 0.22 Bq/kg。137Cs 的总库存范围为 29.5+/-1.5 Bq/m2 至 152.7+/-5.6 Bq/m2，而 239,240Pu 的库存（仅 6 个沉积物层）范围为 9.5+/-0.3 Bq/m2 至 29.7+/-0.4 Bq/m2。来源贡献在站之间和研究的放射性核素之间有所不同。238Pu/239,240Pu 比值高达 0.18，表明核燃料后处理厂的排放是钚的主要来源。根据 238Pu/239,240Pu 比值，估计有 19-27%的钚来自大气全球沉降物以外的来源。考虑到大西洋海流轨迹以及钚的活度浓度和库存与纬度呈负相关，塞拉菲尔德是巴伦支海的主要来源。137Cs 的浓度和库存与纬度呈正相关，与斯瓦尔巴群岛的距离呈负相关。137Cs 浓度在西伯利亚沿海形成的密集海冰融化区域最高。因此，海冰和来自斯瓦尔巴群岛的供应可能是巴伦支海海底 137Cs 的重要来源。
