The artificial radioactivity data in the ocean, air, and soil were collected from around the world and a set of database was created. I estimated the total amount of 137Cs deposition in the Northern Hemisphere and distribution of 137Cs deposition by analyzing the collected data. The total amount of cesium-137 in the Northern Hemisphere was 765+-79 PBq and this was 40% higher than in previous reported 545 PBq by United Nations Scientific Committee on the Effects of Atomic Radiation. Spatial distribution of 137Cs deposition was also presented.
The ocean part of the constructed database was provided to the International Atomic Energy Agency's database of artificial radioactivity in the marine environment and contributed to the construction of a global scale database together with other sources. The Center for Research in Isotopes and Environmental Dynamics at the University of Tsukuba now manages a database site to publish environmental radioactivity data related to the Fukushima accident with a DOI, and also provide a search site to retrieve radioactivity data which already published outside of the site at Univ. of Tsukuba.