Environmental impact assessment due to natural radioactivity in the mountain rocks of the Red Sea coast, Egypt

The mountains' composition, especially the granitic mountains, contains a certain amount of natural radioactivity due to the decay of uranium, thorium, and potassium isotopes. As a part of the impact assessment study, thirty rock samples were collected from natural mountains in the Red Sea coast, Egypt, considered as the most popular ones, and were measured for their natural radioactivity to assess the radiological impact when they are used as building materials. Rock samples were examined by high-resolution γ-spectrometry. The average activity concentration of 238U, 226Ra, 232Th, and 40K were 192 ± 24, 178 ± 27, 66 ± 7 and 193 ± 23, and 287 ± 31 Bq/kg, respectively. The annual effective dose rate (mSv/y), the mean of the absorbed dose rates (D), radium equivalent (Raeq), the external hazard index (Hex) and the internal hazard index (Hin) and the representative level index (Iγr, Iαr) were; 0.25 mSv/y, 205.64 nGy/h, 286.9 Bq/kg, 0.81, 1.33, 1.97 and 0.89, respectively. The specific activity ratios of 226Ra/238U and 232Th/238U were evaluated to analyze the behavior of these radionuclides.