Australian Nuclear Science and Technology Organisation, Sydney, Australia.
Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; Symbiotic Systems Science and Technology, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan.
Sci Total Environ. 2021 Feb 1;754:141890. doi: 10.1016/j.scitotenv.2020.141890. Epub 2020 Aug 23.
Plutonium (Pu) has been released in Japan by two very different types of nuclear events - the 2011 Fukushima accident and the 1945 detonation of a Pu-core weapon at Nagasaki. Here we report on the use of Accelerator Mass Spectrometry (AMS) methods to distinguish the FDNPP-accident and Nagasaki-detonation Pu from worldwide fallout in soils and biota. The FDNPP-Pu was distinct in local environmental samples through the use of highly sensitive Pu/Pu atom ratios. In contrast, other typically-used Pu measures (Pu/Pu atom ratios, activity concentrations) did not distinguish the FDNPP Pu from background in most 2016 environmental samples. Results indicate the accident contributed new Pu of 0.4%-2% in the 0-5 cm soils, ~0.3%-3% in earthworms, and ~1%-10% in wild boar near the FDNPP. The uptake of Pu in the boar appears to be relatively uninfluenced by the glassy particle forms of fallout near the FDNPP, whereas the Cs uptake appears to be highly influenced. Near Nagasaki, the lasting legacy of Pu is greater with high percentages of Pu sourced from the 1945 detonation (93% soils, ~88% earthworm, ~96% boar). The Pu at Nagasaki contrasts with that from the FDNPP in having proportionately higher Pu and was distinguished by both Pu/Pu and Pu/Pu atom ratios. However, compared with the contamination near the Chernobyl accident site, the Pu amounts at all study sites in Japan are orders of magnitude lower. The dose rates from Pu to organisms in the FDNPP and Nagasaki areas, as well as to human consumers of wild boar meat, have been only slightly elevated above background. Our data demonstrate the greater sensitivity of Pu/Pu atom ratios in tracing Pu from nuclear releases and suggest that the Nagasaki-detonation Pu will be distinguishable in the environment for much longer than the FDNPP-accident Pu.
钚（Pu）在日本是由两种截然不同的核事件释放的 - 2011 年福岛事故和 1945 年长崎的 Pu 芯武器爆炸。在这里，我们报告了使用加速器质谱法（AMS）来区分 FDNPP 事故和长崎爆炸的 Pu 与全球土壤和生物群中的沉降物。通过使用高度敏感的 Pu/Pu 原子比，FDNPP-Pu 在当地环境样本中是独特的。相比之下，在大多数 2016 年的环境样本中，其他常用的 Pu 测量方法（Pu/Pu 原子比、活度浓度）无法区分 FDNPP Pu 与背景。结果表明，事故导致 FDNPP 附近的 0-5 厘米土壤中新增 Pu 约为 0.4%-2%，蚯蚓中新增 Pu 约为 0.3%-3%，野猪中新增 Pu 约为 1%-10%。野猪对 Pu 的吸收似乎不受 FDNPP 附近玻璃状颗粒形式的沉降物的影响，而 Cs 的吸收似乎受到很大影响。在长崎，由于源自 1945 年爆炸的 Pu 百分比较高，Pu 的遗留问题更为严重（土壤中约 93%，蚯蚓中约 88%，野猪中约 96%）。长崎的 Pu 与 FDNPP 的 Pu 形成鲜明对比，其 Pu 比例更高，Pu/Pu 和 Pu/Pu 原子比均可区分。然而，与切尔诺贝利事故现场的污染相比，日本所有研究地点的 Pu 数量都要低几个数量级。FDNPP 和长崎地区的生物体和野猪肉消费者的 Pu 剂量率仅略高于背景水平。我们的数据表明，Pu/Pu 原子比在追踪核释放 Pu 方面具有更高的灵敏度，并表明长崎爆炸的 Pu 将在环境中可区分的时间比 FDNPP 事故的 Pu 长得多。
