~(226)ra, ~(232)th And ~(40)k Activities In Soils Of Cuihua Mountain National Geological Park, China

摘要

Gamma activity from the naturally occurring radionuclides namely, ~(226)Ra, ~(232)Th, the primordial radio-nuclide ~(40)K was measured in the soil of Cuihua Mountain National Geological Park, China using γ-ray spectrometry technique. The mean activity of ~(226)Ra, ~(232)Th and ~(40)K were found to be 27.2 ± 6.5, 43.9 ± 6.2 and 653.1 ± 127.6 Bq kg"1, respectively. The concentrations of these radionuclides were compared with the typical world values and the average activities of Chinese soil. The radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, and the external hazard index were evaluated and compared with the internationally approved values. All the soil samples have Ra_(eq) lower than the limit of 370 Bq kg~(-1) and H_(ex) less than unity. The overall mean outdoor terrestrial gamma dose rate is 66.3 nGy h~(-1) and the corresponding outdoor annual effective dose is 0.081 mSv.