Abstract
It is well known that "black rain"containing FP radioactivity fell down in the Koi-Takasu area located 3 km west from the hypocenter in Hiroshima. Meanwhile, the radiological situation is yet unknown about black rain that fell down in other areas around Hiroshima, including the mountainous suburbs. In this symposium, the followings are reported: previous studies including black rain in Nagasaki, analysis of questionnaires on black rain experience, recent uranium isotope measurements with TIMS and AMS techniques, radioactivity measurement of soil samples under houses built during the period between A-bomb and global fallout. Then, a trial is presented to reconstruct radiation exposure from deposited radionuclides as well as a proposal of meteorological simulation for the black rain. The general discussion will be at the end of the symposium about future tasks to be tackled with.
