الفهرس 
Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
The rock is a source of natural radionuclides and a source of natural radiation risk to humans. This study aims to measure the radioactivity concentrations, contributions, radiological hazards and to quantify the radiogenic heat productions in seventy seven rock samples having different lithology from the middle member of Um Bogma Formation in Gabal Um Hamd, and west Gabal Adediya (upper, middle, and lower), southwestern Sinai, Egypt. The concentration of natural radionuclides was determined using a p-type Hyper Pure Germanium (HPGe) detector. The average activity concentrations of uranium ((_^238)U ), radium ((_^226)Ra ), thorium ((_^232)Th ), and potassium ((_^40)K ) in Gabal Um Hamd were found to be 4909.58 ± 54.34Bq/kg, 5003.12 ± 17.56 Bq/kg, 79.04 ± 8.82 Bq/kg and 137.35 ± 8.64 Bq/kg respectively. While for west Gabal Adediya, the average activity concentrations of uranium ((_^238)U ), radium ((_^226)Ra ), thorium ((_^232)Th ), and potassium ((_^40)K ) were found to be 1016.31 ± 83.87 Bq⁄kg, 940.46 ± 8.48 Bq⁄kg, 87.39 ± 10.10 Bq⁄kg, and 804.53 ± 7.32 Bq⁄kg, respectively. Other hazard indices average values were measured, such as: absorbed dose rate, annual effective dose equivalent, radium equivalent activity, external and internal indices, annual gonad equivalent dose, and excess lifetime cancer risk. The radiologic hazards results, obtained in this study shows that the radiation levels are higher than the internationally approved values and the recommended safety limits. Furthermore, the results show that the radiogenic heat value ranged from 3.58 to 402.45 µW m-3 and from 1.38 ± 0.45 µW m-3 to 48.86 ± 2.44 µW m-3 with an average value of 60.11 ± 0.79 µW m-3, and 11.80 ± 1.00 µW m-3 in Gabal Um Hamd and west Gabal Adediya respectively, which is higher than previously reported averages. The calculated mass of (_^226)Ra was found to be 4434.14×〖10〗^(-12) gm, and 1172.31×〖10〗^(-12) gm out from 11510.00 gm, and 13019 gm, at Gabal Um Hamd and west Gabal Adediya respectively, which represent the total masses of seventy seven samples.