Abstract
Measurements of the levels of radioactivity in beaches are of great interest during the last decades for many studies worldwide. Such investigations can be useful for mapping of radiation levels and recording reference data to ascertain potential environmental radioactivity changes due to nuclear, industrial, and other human activities. This study was conducted to determine the natural radioactivity concentration levels of 238U, and 232Th natural decay chains and 40K in 30 beach sand samples collected from different sites of the coast between Tajoura and Misrata, Libya. Representative sand samples have been analysed based on the gamma spectroscopy system using High Purity Germanium (HPGe) detector housed in the Nuclear Radiation Laboratory at the Department of Nuclear Engineering, University of Tripoli, Libya. The activity concentrations of 238U, 232Th and 40K based on the weighted mean values across samples were (6.728±0.385), (3.010±0.576) and (29.673±0.183) Bq/kg, respectively. The activity concentration of 238U, 232Th and 40K in the beach sand samples ranged from 3.668 ± 0.381 to 25.656 ± 2.405 Bq/kg, 0.755 ± 0.271 to 13.081 ± 1.231 Bq/kg and 15.935 ± 1.460 to 88.881 ± 6.20 Bq/kg for 238U, 232Th and 40K respectively. The annual effective dose equivalent in μSv/y ranged between 4.092 ± 0.494 and 21.694 ± 0.214 µSv/y while the world average annual effective dose equivalent (AEDE) from outdoor or indoor terrestrial gamma radiation is 290 µSv/y. The activity concentrations of 226Ra, 232Th, and 40k were below the global limit. Thus, there are no harmful radioactive effects resulting from sea sand. The achieved results will be used as reference information to track any change in the radioactivity background levels in this area and may provide good achievement for mapping the radioactivity background.