Abstract
The present study aims to assess Abu Rusheid and Um Naggat albite granite's natural radioactivity in the Central Eastern Desert, Egypt, using an HPGe laboratory spectrometer. A total of 17 albite granite samples were detected for this study. The activity concentrations were estimated for U-238 (range from 204 to 1127 Bq/kg), Ra-226 (range from 215 to 1300 Bq/kg), Th-232 (from 130 to 1424 Bq/kg) and K-40 (from 1108 to 2167 Bq/kg) for Abu Rusheid area. Furthermore U-238 (range from 80 to 800 Bq/kg), Ra-226 (range from 118 to 1017 Bq/kg), Th-232 (from 58 to 674 Bq/kg) and K-40 (from 567 to 2329 Bq/kg) for the Um Naggat area. The absorbed dose rates in the outdoor air were measured with average values of 740 nGy/h for Abu Rusheid albite granite and 429 nGy/h for Um Naggat albite granite. The activity concentration and gamma-ray exposure dose rates of the radioactive elements U-238, Ra-226, Th-232 and K-40 at Abu Rusheid and Um Naggat exceeded the worldwide average values that recommend the necessity of radiation protection regulation. Moreover, the corresponding outdoor annual effective dose (AED(out)) was calculated to be 0.9 and 0.5 mSv y(-1) for Abu Rusheid and Um Naggat albite granite, respectively, which are lower than the permissible level (1 mSv y(-1)). By contrast, the indoor annual effective dose (AED(in)) exceeded the recommended limit (3.6 and 2.1 for Abu Rusheid and Um Naggat, respectively). Therefore, the two areas are slightly saving for development projects concerning the use of the studied rocks. The statistical analysis displays that the effects of the radiological hazard are associated with the uranium and thorium activity concentrations in Abu Rusheid and Um Naggat albite granites.