[Show abstract][Hide abstract] ABSTRACT: Activity concentrations of 238U, 232Th and 40K in rocks and soil samples collected from Sannur cave, Beni Suef governorate, eastern desert of Egypt, were determined using the high-resolution gamma spectrometry technique. The results show that the concentrations of the naturally occurring radionuclides are the following: 238U ranged from 8.51 +/- 1.23 to 20.66 +/- 2.12 Bq kg(-1), 232Th ranged from 7.69 +/- 1.02 to 22.73 +/- 1.60 Bq kg(-1) and 40K ranged from 185.74 +/- 0.42 to 2084.70 +/- 23.30 Bq kg(-1). The radium equivalent activity (Raeq), the absorbed dose rate (D), and the external hazard index (Hex) were also calculated and compared to the international recommended values. The radon concentration and radon exhalation rate from the rock and soil samples were measured using the Can technique. The average value of annual effective dose for cave workers is 1.98 mSv y(-1), while for visitors it is 2.4 microSv per visit. The radon exhalation rate varies from 0.21 +/- 0.03 to 1.28 +/- 0.02 Bq m(-2) h(-1). A positive correlation has been observed between uranium content and radon exhalation rate.
[Show abstract][Hide abstract] ABSTRACT: The study of the radiation hazards from building materials is of interest in most countries. The measurements of natural radioactivity were verified for some Egyptian building materials to assess any possible radiological hazard due to their use. The measurements were performed by gamma-ray spectroscopy using a Hyper-Pure Germanium (HPGe) detector. A CR-39 track detector was used to measure the radon exhalation rates, and these were found to vary from 2.83 ± 0.86 to 41.57 ± 8.38 mBq m–2 h–1 for Egyptian alabaster. The absorbed dose rate in the air was lower than the international recommended value (55 nGy h–1) for all test samples.
Full-text · Article · Jun 2008 · International Journal of Low Radiation