Assessment of radiological health risk and radiogenic heat production changeability of different sedimentary rocks at Gabal Um Hamd, Southwestern Sinai, Egypt

Soil 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 thirty two rock samples having different lithology from the middle member of Um Bogma Formation in Gabal Um Hamd, 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 U 238 , radium R 226 a , thorium T 232 h , and potassium K 40 in the interested area were found to be 4909.58 ± 54.34 B q k g − 1 , 5003.12 ± 17.56 B q k g − 1 , 79.04 ± 8.82 B q kg − 1 and 137.35 ± 8.64 B q kg − 1 respectively. Other hazard indices average values were measured, such as: 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 with an average value of 60.11 ± 0.79 μW m − 3 in the studied area which is higher than previously reported averages.