2010 Fiscal Year Final Research Report

Study of provenance identification of Moshio by environmental radioactivity

Research Project

Project/Area Number	20700662
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Cultural property science
Research Institution	Kyoto University
Principal Investigator	OHTA Tomoko Kyoto University, 原子炉実験所, 助教 (30373020)
Project Period (FY)	2008 – 2010
Keywords	環境放射能 / 塩 / 海水 / 海藻
Research Abstract	The origin of the substance that adhered to the wooden tub at salt-production site was attempted to be determined by examining the environmental radioactivity in the substance by environmental radioactivity and isotopes. It was suggested that the adhesion could originate from not only seawater but also the seaweed and/or seagrass. Furthermore, the base that judged provenance identification of Moshio was obtained from some trace elements of the seaweed. In addition, iodine isotopes, ^<127>I and ^<129>I, were isolated from marine algal samples to obtain ^<129>I/^<127>I ratios. The ^<129>I/^<127>I ratio in algae collected from 1987 was 100-1000 times as high as the ratio measured in algae from before 1945. This dramatic increase in ^<129>I/^<127>I ratio after 1945 was attributed to human activity.