Comparative Assessment of Radiation Background Due to Natural and Artificial Radionuclides in Soil in Specific Areas on the Territories of State of Washington (USA) and Lithuania

摘要

Activity concentrations of Ra-226, Th-232, K-40, and Cs-137 in soil samples collected at Mount Rainier National Park and Satsop Nuclear Power Plant zone in State of Washington (USA) and Curonian Spit National Park and Ignalina Nuclear Power Plant zone in Lithuania have been measured by gamma spectrometry. The results have been compared with the worldwide measured average values reported by the UNSCEAR. Higher activity concentrations of Cs-137 were found in Curonian Spit National Park due to Chernobyl accident fallout. The radium equivalent activity (Ra-eq), the external hazard index (H-ex), the internal hazard index (H-in), the absorbed dose rate (D), and the annual effective dose rate (AEDR) were also calculated and compared with the international recommended values. These calculated hazard indices used to estimate the potential radiological health risk in soil and the dose rate associated with it are below their permissible limit.