Natural radioactivity survey in Al-Jabal Al-Gharbi Mountain Region Libya


The measurement of natural radioactivity in a given region or country is essential to provide a reference base-line map to follow up a possible variation in future. In order to perform such measurement, the natural radioactivity was measured in different locations. The locations (50 sites) were distributed over Al-Jabal Al-Gharbi Mountain, starting from the city Al-Azeeziah in the eastern part to Wazen on the Tunisian border in the west. The measurements showed obvious variation from one site to another. The levels were fluctuating from (12.8 counts/minute) in Bir-Ayad to (45.7 counts/minute) in Gherian.In order to investigate the cause for such variation, samples were collected from (27) sites for detailed study. The levels of natural radioactivity were determined in the laboratory, and were ranging from (58.7 Bq/kg) in Bir-Ayad to (102.1 Bq/kg) in Gherian.The variation in measured radioactivity was related to the geological structures taken in six perpendicular sections, namely, Gharian, Yevren, Zintan, Nalut, Wazen and Al-Azeeziah taking the naturally occurred radioisotopes concentration of 40K, 232Th and 238U present in consideration.