Radioactivity Levels and dose evaluation in Some Environmental Rock Samples from Taiz, Yemen

The specific activities of 226 Ra, 232 Th and 40 K in a variety of rock samples from Taiz region, Yemen were investigated using gamma ray spectroscopy technique to estimate the associated radiation hazard impacts. Furthermore, the X-ray fluorescence technique has been applied to detect the natural elements that may have industrial importance. The mean activity concentrations of 226 Ra, 232 Th and 40 K were found to be 65.58±1.38, 82.93±0.93 and 976.40± 6.11 Bq Kg -1 respectively. These values exceed the maximum international limits. Radium equivalent (Ra eq ), the external hazard index (H ex ), the internal hazard index (H in ), the representative level index (I γ ), dose rate, annual effective dose, excess lifetime cancer risk (ELCR), annual gonadal dose equivalent (AGDE), emanation factor (F) and mass exhalation rate of radon (E Rn ) were estimated and discussed. Additionally, the X-ray analysis showed that there are considerable concentrations of Fe, Al, Zr and Ti have been observed.