Measurement of Natural Radioactivity in Sand Samples Collected from Ad-Dahna Desert in Saudi Arabia

Natural radioactivity is a source of continuous exposure to human beings. The natural radioactivity due to the presence of 226 Ra, 232 Th and 40 K in sand samples collected from Ad-Dahna was measured by means of HPGe. The measured activity concentrations of radionuclides were compared with the worldwide reported data. Mean measured activity concentrations of 226 Ra, 232 Th and 40 K varied between 16.2 -30.6, 15.8 -36.7 and 285.3 -533.2 Bqkg -1 respectively with a mean value of 23.4 4.3 Bqkg -1 , 29.7 5.9 Bqkg -1 and 380 65 Bqkg -1 respectively. Mean values of radium equivalent activity, absorbed dose rate and external radiation hazard index were 106 8 Bqkg -1 , 51.4 nGyh -1 and 0.29 respectively. The annual effective radiation dose was calculated to be 0.32 mSvy -1 . The Ra eq values of sand samples are lower than the limit of 370 Bqkg -1 , equivalent to a gamma dose of 1.5 mSvyr -1 .This study shows that the measured sand samples do not pose any significant source of radiation hazard and are safe for use in building materials.