Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.
Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Science and Engineering, Woods Hole, Massachusetts 02543, United States.
Environ Sci Technol. 2020 Dec 1;54(23):15066-15075. doi: 10.1021/acs.est.0c05321. Epub 2020 Nov 10.
The Fukushima Dai-ichi Nuclear Power Plants (FDNPPs) accident in 2011 led to an unprecedented release of radionuclides into the environment. Particularly important are Sr and Cs due to their known health detriments and long half-lives ( ≈ 30 y) relative to ecological systems. These radionuclides can be combined with the longer-lived I ( = 15.7 My) to trace hydrologic, atmospheric, oceanic, and geochemical processes. This study seeks to evaluate Cs, Sr, and I concentrations in seawater off the coast of Japan, reconcile the sources of contaminated waters, and assess the application of Cs/Sr, I/Cs, and I/Sr as oceanic tracers. We present new data from October 2015 and November 2016 off the coast of Japan, with observed concentrations reaching up to 198 ± 4 Bq·m for Cs, 9.1 ± 0.7 Bq·m for Sr, and (114 ± 2) × 10 Bq·m for I. The utilization of activity ratios suggests a variety of sources, including sporadic and independent releases of radiocontaminants. Though overall concentrations are decreasing, concentrations are still elevated compared to pre-accident levels. In addition, Japan's Environment Minister has suggested that stored water from the FDNPPs may be released into the environment and thus continued efforts to understand the fate and distribution of these radionuclides is warranted.
2011 年福岛第一核电站（FDNPPs）事故导致放射性核素前所未有地释放到环境中。由于其已知的健康危害和相对于生态系统较长的半衰期（约 30 年），Sr 和 Cs 尤为重要。这些放射性核素可以与半衰期较长的 I（=15.7My）结合，以追踪水文学、大气、海洋和地球化学过程。本研究旨在评估日本沿海海水中的 Cs、Sr 和 I 浓度，协调受污染水的来源，并评估 Cs/Sr、I/Cs 和 I/Sr 作为海洋示踪剂的应用。我们提出了 2015 年 10 月和 2016 年 11 月日本沿海的新数据，观察到的浓度达到 Cs 的 198±4Bq·m、Sr 的 9.1±0.7Bq·m 和 I 的（114±2）×10Bq·m。放射性核素活度比的利用表明存在多种来源，包括放射性污染物的零星和独立释放。尽管总体浓度正在下降，但与事故前水平相比，浓度仍处于高位。此外，日本环境大臣已表示，可能将福岛第一核电站的储存水释放到环境中，因此有必要继续努力了解这些放射性核素的命运和分布。
