Studies on Background Radioactivity in Niigata City Area

—Identification of natural nuclide present in underground (well) water samples—

Abstract

Background radioactivity levels in Niigata city area were studied through the years of 1981-1984. As the results, it was found that the gross β-radioactivity in underground (well) water samples were comparatively higher than those of other ground water samples. Ion chromatographic and γ-ray spectroscopic determination revealed that this higher radioactivities were contributed by ⁴⁰K rather than radium or thorium series nuclides or fallout originated ⁹⁰Sr.