ASSESSMENT OF NATURAL RADIOACTIVITY LEVEL AND ASSOCIATED RADIOLOGICAL HAZARDS IN MARINE SEDIMENT SAMPLES COLLECTED FROM ABYAN BEACH, GULF OF ADEN, YEMEN

Abstract

Twenty three marine sediment samples taken from the side beach from the Abyan beach, Aden Gulf, Yemen to measuring the activity concentration of terrestrial radionuclides radium-226, thorium-232 and potassium-40 and its associated hazard indices using gamma spectrometer with High-Purity Germanium HPGe detector. The average activity concentration of natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰k in marine sediments samples under investigation were 16.25± 0.63Bqkg^-1, for Ra-226, 23.80± 1.46Bqkg^-1 for Th-232 and 518.54±44.61Bqkg^-1 for K-40 respectively. The radiation hazard indices which resulting from the presence of natural radionuclides in marine sediment samples were calculated and the obtained results indicate that the average value of radium equivalent activity was 90.21Bqkg^-1. The average value of External hazard index H_ex was 0.243 and the average values of internal hazard index H_in was 0.287. The average value of outdoor absorbed dose rate D_out was 43.66nGyh⁻¹ and indoor absorbed dose rate D_in was 83.13nGyh⁻¹. The average values of annual outdoor effective dose AED_out was 0.053mSvy^-1and the annual indoor effective dose AED_in was 0.407mSvy^-1. The average values of the annual gonadal dose equivalent AGDE were 312.52μSvy^-1. While the average values of outdoor excess life-time cancer risk ELCR_out was 0.187×10⁻³ and the indoor excess life-time cancer risk ELCR_in was 1.427×10⁻³. They are less than worldwide limits.