Assessment of radioactivity concentration of natural radionuclides and radiological hazard indices in coral reefs in the Egyptian Red Sea

Coral reef samples were collected from three areas; Quseir Harbour, Marsa Alam marine, and Quseir area (In-front of reject discharge of desalination plant) at the Egyptian Red Sea coast. Using the HPGe detector with a relative efficiency (100%), the radioactivity levels were determined by direct γ-ray spectrometry. The mean activity concentrations (Bq/kg) for natural radionuclides 226 Ra, 232 Th, and 40 K in coral reefs collected from the Quseir Harbour, Marsa Alam marine, and Quseir desalination plant were found to be 7.48 ± 0.15, 3.25 ± 0.15, and 21.17 ± 0.51, 11.18 ± 0.13 ± , 7.51 ± 0.15 and 28.35 ± 0.60 and 9.66 ± 0.26, 5.08 ± 0.23, and 18.84 ± 0.88, respectively. In contrast, the corresponding mean values for the radium equivalent activity are 13.76, 24.10, and 18.38 Bq kg −1 , respectively. The absorbed dose rate, the annual effective dose equivalent, the external and internal hazard indices, and the radioactivity level index were determined to assess the radiological hazard and risk indices of natural radionuclides. The radiological hazard parameters were much lower than the safety limits.