Deposition of 137Cs in Rokkasho, Japan and its relation to Asian dust

J Environ Radioact. 2007;95(1):1-9. doi: 10.1016/j.jenvrad.2007.01.007. Epub 2007 Mar 23.

Abstract

Biweekly atmospheric depositions of (137)Cs were measured in Rokkasho, Aomori, Japan from March 2000 to March 2006 to study recent (137)Cs deposition. Although the deposition level was generally lower than the detectable limit, deposition samples collected in spring occasionally had measurable levels of (137)Cs. The annual (137)Cs deposition from 2001 to 2005 was 0.04-0.69 Bq m(-2) with a mean value of 0.27 Bq m(-2). Depositions of insoluble Al, Fe and Ti were strongly correlated with the (137)Cs deposition, suggesting that suspension of soil particles was the main source of the recent (137)Cs deposition. Asian dust events were coincident with some of the significant (137)Cs depositions in spring. It was found that the ratios of (137)Cs/Al and Fe/Al could be used as indices for discriminating Asian dust from suspension of the local surface soil. Backward trajectory analysis suggested southern Mongolian and northeastern China regions as sources of the significant (137)Cs depositions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants, Radioactive / analysis*
  • Aluminum / analysis
  • Atmosphere / analysis
  • Cesium Radioisotopes / analysis*
  • Dust / analysis*
  • Iron / analysis
  • Japan
  • Radiation Monitoring*
  • Radioactive Fallout
  • Titanium / analysis

Substances

  • Air Pollutants, Radioactive
  • Cesium Radioisotopes
  • Dust
  • Radioactive Fallout
  • Aluminum
  • Titanium
  • Iron