Radioactivity of some rock and soil samples from Yemen

Levels of natural radioactivity of rock and soil environmental samples have been evaluated. The 226Ra, 232Th series and 40K are the main objective of the current study. These samples were collected from Yafea town in Yemen (south west Asia) and measured by gamma ray spectrometer using HPGe detector with specially designed shield. The specific average radioactivity of 226Ra, 232Th and 40K were determined and expressed in Bq kg-1. The obtained results show that the average values of the specific activities of 226Ra, 232Th and 40K for rock samples are 31.79±2.55, 13.8±1.63 and 196.46±8.34 Bq/kg respectively. The corresponding values for soil samples are 16.02±1.11, 10.14±0.93, 155.72±4.84 respectively. The dose rate, radium equivalent, external hazard, internal hazard, and annual effective dose rate were evaluated and compared with the international data. Further investigations of the samples have been performed using X-ray fluorescence and remarkable concentrations of Fe, Al and Ti have been observed.