Comparative study of natural radioactivity concentrations in soil samples from the newly developed Tushki and Giza Regions in Egypt

Abstract

Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it was felt necessary to study the natural radioactivity in soil to assess the dose to the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. The natural radionuclide (²³⁸U, ²³²Th, and ⁴⁰K) contents were determined for 21 locations over the whole Giza area and Tushki area using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for calculating the absorbed dose rate of gamma radiation. The absorbed dose rates resulting from those concentrations ranged from 5.35 ± 0.54 to 53.95 ± 1.61 nGy h⁻¹ for major Giza and 34.21 ± 2.76 to 103355.69 ± 927.14 nGy h⁻¹ for the Tushki area. The radium equivalent (R _eq) and the external hazard index (H _ex), which resulted from the natural radionuclides in soil, are also calculated and tabulated. The radium equivalent was from 11.47 ± 1.15 to 113.25 ± 3.53 Bq kg⁻¹ and 73.38 ± 5.92 to 223331.64 ± 2008.2 Bq kg⁻¹ for the major Giza and Tushki areas, respectively. The assessment of natural radioactivity reveals a high background radiation in the north Tushki region, which fortunately is distant from the habitant and cultivated regions. The results of this study can be used as a data baseline for preparing a radiological map of the Tushki area, especially at the chosen settlement sites.

Keywords:

• Gamma spectroscopy
• Radionuclides in soil
• Uranium
• Thorium
• Potassium