Gamma ray measurements of naturally occurring radioactive materials in various types of Egyptian rocks in Al-Qusair area

Thirty rock samples from Al-Qusair area in Egypt have been investigated. The naturally occurring radionuclide contents have been measured by gamma-ray spectrometry employing a shielded HpGe detector. The activities of 238 U, 232 Th and 40 K have been determined in Bq Kg -1 . The activity concentrations of 238 U, 232 Th and 40 K were ranged from (15.41±1.67) to (326.94±4.40), (2.05±0.98) to (25.58±3.40) and (39.02±3.98) to (654.94±14.42) Bq Kg -1 respectively. Radium equivalent activities, absorbed dose rate and the values of hazard indexes were calculated for the studied rock samples to determine the radiation hazards arising from those samples. The absorbed dose rate values were found to vary from 31.26 to 149.72 nGy h -1 . The radium equivalent values for the investigated samples are less than the international average value 370 Bq Kg -1 . The present results have revealed that the radiological parameters are normal and within the international levels. This study provides a base line map of radioactivity background levels in the Egyptian environment and could be used as reference information to assess any changes in the radioactive background level due to the geological process. Keyword: NORM; Absorbed dose; Hazard index; Radium equivalent -------------------------------------------------------------------------------------------------------------------------------------Date of Submission: 27-12-2019 Date of Acceptance: 11-01-2020 -------------------------------------------------------------------------------------------------------------------------------------