Dynamics of radiocesium in the river and lake environment around high air dose rate areas and mapping of radiocesium in the lake bottom sediment

2014 Fiscal Year Final Research Report

• Project/Area Number: 24510076
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Risk sciences of radiation/Chemicals
• Research Institution: National Institute for Environmental Studies
• Principal Investigator: TANAKA Atsushi 独立行政法人国立環境研究所, 環境計測研究センター, 主任研究員 (80171734)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 霞ヶ浦 / 放射性セシウム / 湖底堆積物

Outline of Final Research Achievements

After the accidents of Fukushima Daiichi Nuclear Power Plant, radioactive material deposited and formed locally contaminated area even in the underwater sediments. Sediment samples were collected in Dec. 2012, Sep. 2013 and Oct. 2014 from 77 sites which covers whole lake surface. Maps of radiocesium in the bottom sediment were provided in this study.
In the first observation, the concentration of radiocesium in the sediment was relatively high in the western part of the lake, and deposition at the river mouths whose watershed showed high air dose rate was found. In the second and third observations, concentrated radiocesium was mixed and moved toward the deeper layer of the sediment. Cumulated amount of radiocesium in the lake bottom was almost constant throughout the observation period.

Free Research Field

環境化学