論文

査読有り
2018年5月1日

Radiocesium dynamics in the aquatic ecosystem of Lake Onuma on Mt. Akagi following the Fukushima Dai-ichi Nuclear Power Plant accident

Science of the Total Environment
  • Kyuma Suzuki
  • ,
  • Shun Watanabe
  • ,
  • Yumi Yuasa
  • ,
  • Yasunori Yamashita
  • ,
  • Hajime Arai
  • ,
  • Hideki Tanaka
  • ,
  • Toshihiro Kuge
  • ,
  • Masanobu Mori
  • ,
  • Kin-ichi Tsunoda
  • ,
  • Seiichi Nohara
  • ,
  • Yuichi Iwasaki
  • ,
  • Yoshitaka Minai
  • ,
  • Yukiko Okada
  • ,
  • Seiya Nagao

622-623
開始ページ
1153
終了ページ
1164
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.scitotenv.2017.12.017
出版者・発行元
Elsevier B.V.

Understanding ecosystem dynamics of radionuclides is necessary to ensure effective management for food safety. The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011 released large amounts of radiocesium (134Cs and 137Cs) and contaminated the environment across eastern Japan. In this study, we aimed to elucidate the temporal dynamics of 137Cs in the aquatic ecosystem of Lake Onuma on Mt. Akagi. The effective ecological half-life (Teff) of 137Cs in fishes, western waterweed (Elodea nuttallii), seston (phytoplankton and zooplankton), and lake water was estimated using survey data of 137Cs concentration collected from 2011 to 2016, and single- and two-component decay function models (SDM and TDM, respectively). The decay processes of 137Cs concentrations in wakasagi (Hypomesus nipponensis), pale chub (Zacco platypus), phytoplankton, and total 137Cs concentrations of the water column (WC) in the lake were well suited by the TDMs. The Teff in the fast component of the TDMs in these samples ranged from 0.49 to 0.74 years. The Teff in the slow component of the TDMs could converge towards the physical half-life of 137Cs. Nearly five and a half years after the FDNPP accident, we concluded that 137Cs concentrations approached a state of dynamic equilibrium between some aquatic organisms (wakasagi, pale chub, and phytoplankton) and the environment (lake water). However, the decay processes of 137Cs concentrations in Japanese dace (Tribolodon hakonensis), western waterweed, zooplankton, and particulate- and dissolved-forms in the WC were better predicted for the SDM. The total 137Cs concentrations in inflowing river and spring waters were one to two orders of magnitude lower than lake water under normal flow conditions. However, particulate 137Cs contamination level in the river water was high after heavy rains. Overall, 137Cs contamination levels have significantly decreased in Lake Onuma, but monitoring surveys should be continued for further understanding of the reduction processes.

Web of Science ® 被引用回数 : 10

リンク情報
DOI
https://doi.org/10.1016/j.scitotenv.2017.12.017
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/29890584
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000426349000115&DestApp=WOS_CPL

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