Lujanienė Galina, Šilobritienė Beata, Tracevičienė Diana, Šemčuk Sergej, Romanenko Vitaliy, Garnaga-Budrė Galina, Kaizer Jakub, Povinec Pavel P
SRI Center for Physical Sciences and Technology, Vilnius, Savanorių Pr. 231, LT-02300, Lithuania.
Ministry of Environment, A. Jakšto g. 4, LT-01105, Vilnius, Lithuania.
J Environ Radioact. 2022 Aug;249:106892. doi: 10.1016/j.jenvrad.2022.106892. Epub 2022 May 4.
Distribution trends and temporal variations of Am and Pu isotopes in the south-eastern Baltic Sea during the study period of 1999-2001 and 2011-2015 were investigated with the aim to study temporal changes of radionuclide levels in seawater, suspended particles and sediment, to estimate Am and Pu levels in marine biota and to assess the radiation doses received by the biota. The activities of Am and Pu were measured by alpha spectrometry after radiochemical purification. Pu was determined radiometrically via the ingrown daughter Am after 10-12 years of storage, while the Pu/Pu atom ratio of was measured by accelerator mass spectrometry. The Pu activities in suspended particles collected in the coastal waters of the Baltic Sea decreased by a factor of ∼3 during the study period, while they decreased about fourfold in the Curonian Lagoon. This could indicate a decrease in the influx of particles containing Pu isotopes into the Baltic Sea. While in the Curonian Lagoon, the Pu activities in the sediment samples varied insignificantly during the study periods, in the Baltic Sea, the maximum activity decreased by a factor of 6, and the mean/median values decreased by ∼4 times. The assessment tool ERICA was used to calculate the dose rates for biota. The total dose rate from all analysed radionuclides was <0.1 μGy/h, therefore no risk to organisms was identified.
对1999 - 2001年以及2011 - 2015年研究期间波罗的海东南部海域镅（Am）和钚（Pu）同位素的分布趋势及时间变化进行了调查，目的是研究海水中、悬浮颗粒和沉积物中放射性核素水平的时间变化，估算海洋生物群中镅和钚的含量，并评估生物群所接受的辐射剂量。经放射化学纯化后，通过α能谱法测量镅和钚的活度。钚经过10 - 12年储存后，通过其生长出的子体镅进行放射性测量来确定，而钚的(^{239}Pu/^{240}Pu)原子比则通过加速器质谱法测量。在研究期间，波罗的海沿海水域采集的悬浮颗粒中的钚活度下降了约3倍，而在库尔斯沙嘴泻湖则下降了约4倍。这可能表明进入波罗的海的含钚同位素颗粒的流入量减少。在库尔斯沙嘴泻湖，沉积物样本中的钚活度在研究期间变化不显著，而在波罗的海，最大活度下降了6倍，平均/中值下降了约4倍。使用评估工具ERICA计算生物群的剂量率。所有分析的放射性核素的总剂量率<0.1 μGy/h，因此未发现对生物体有风险。
