Assessment of natural and anthropogenic radioactivity levels in rocks and soils in the environments of Juban town in Yemen

The natural radioactivities of 40K, 226Ra, and 232Th and the fallout of 137Cs in rock and soil samples collected around Juban town in Yemen (south west of Asia) were measured. Concentrations of radionuclides in samples were determined by gamma-ray spectrometer using HPGe detector with specially designed shield. The average radioactivity concentrations of 226Ra, 232Th, and 40K were determined expressed in Bq/kg. The results show that these radionuclides were present in concentrations of (53.6±4, 127±6.7, and 1742.8±62 Bq/kg), (55±4, 121±6.6, and 2341±78 Bq/kg), (212.8±8.7, 109 ±5.5, and 32.4±4.7 Bq/kg), and (32.1±3, 22.3±2.9 and 190.9±15 Bq/kg) for granite, gneiss, siltstone, and sandstone rocks, respectively. For soil the corresponding values were 44.4±4.5, 58.2±5.1, and 822.7±31 Bq/kg. Low deposits of 137Cs were noted in investigation area, where the activity concentrations ranged from 0.1±0.1 to 23.2±1.2 Bq/kg. Also the radiological hazard of the natural radionuclides content, radium equivalent activity, total dose rates, external hazard index, and gamma activity concentration index of the (rocks/soils) samples in the area under consideration were calculated. The data were discussed and compared with those given in the literature.