Radiological Investigation of High Background Radiation Areas

In this paper, we used the Hyper-Pure Germanium (HPGe) detector to measure 30 samples which are collected from north of Nile Delta near Rosetta beach in Egypt. The activity of primordial radionuclides, such as U-238, U-235, Th-232, and K-40 was estimated. Concentrations ranged between 36.5-177.4, 50-397.5 and 56.1-168.9 Bq. kg(-1) for U-238, Th-232 and K-40 respectively. Activity concentration of U-235 and the variation in uranium isotopic ratio U-235/U-238 was calculated. External hazard indices (H-ex) (or radium equivalent activity Ra-eq), activity concentration indices (I), alpha index (I-alpha), absorbed outdoor gamma dose rate (D-out), effective outdoor gamma dose rate (E-out) and Excess Lifetime Cancer Risk (ELCR) due to different samples are estimated. External hazard indices (H-ex) are ranged between 0.32-2.04, radium equivalent activity (Ra-eq) are ranged between 118.67-753.91, the activity concentration indices (I) are 0.42-2.61, and alpha index (I-alpha) are 0.18-0.89. External hazard indices (H-ex) in some samples more than unity then it exceeds the upper limit of exposure. Also, the radium equivalent activities (Ra-eq) are higher than the exemption limits (370 Bq. kg(-1)).