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 ²³⁸U, ²³⁵U, ²³²Th, and ⁴⁰K was estimated. Concentrations ranged between 36.5-177.4, 50-397.5 and 56.1-168.9 Bq.kg^-1 for ²³⁸U, ²³²Th and ⁴⁰K respectively. Activity concentration of ²³⁵U and the variation in uranium isotopic ratio ²³⁵U/²³⁸U was calculated. External hazard indices (H_ex) (or radium equivalent activity Ra_eq), activity concentration indices (I), alpha index (I_α), 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_α) 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).