Natural radioactivity levels and associated radiation hazards in Nile river sediments from Aswan to El-Minia, Upper Egypt

The natural radionuclides Ra-226, Th-232 and K-40 contents in the Nile river sediments at various locations in Upper Egypt from Aswan to El-Minia have been investigated using gamma spectrometric analysis. Determination and measurement of radionuclide concentration are of great importance for assessment of external radiation dose received by man. The range and mean values of Ra-226, Th-232 and K-40 activity concentrations are 13-42 (29), 10-67 (45) and 74-139 (123) Bq kg(-1), respectively. These results are found to be in agreement with those reported data for Egyptian soil as 17 (5-64), 18 (2-96) and 320 (29-650) Bq/kg dry weight (UNSCEAR, 2000). The mean radium equivalent (Ra-eq) and dose rates are 100.21 +/- 10.01 Bq kg(-1), 44.88 +/- 6.69 n Gy h(-1), respectively. The measured activity concentrations differ widely as their presence in the Nile river depends on the pertinent environmental situation such as the presence of dams, barrages and sediments type. The other factors controlling the distribution of the detected natural radioisotopes have been discussed.