Radiometric Characterization of Sand in Northeast Sinai

Thirty-eight locations covering an area of 350 km2 in northeast Sinai were investigated by gamma-ray spectroscopy using a 50% HPGe detector. The limits of area are Al-Arish North, El-Hasana South, El-Oga East, and El- Gifgafa West. The range of activity concentrations of 238U, 234Th, 226Ra, 232Th and 40K are 0.6-35.2, 3.9-22.6, 4.7-29.6, 4.7-23.9, and 108-295 Bq/kg for sands, respectively. 137Cs in the region ranged from 0.1-8.0 Bq/kg. No major difference between the studied area and that previously investigated in the costal area in North Sinai. Reliable correlations (R2 = 0.8-0.9) among 238U, 234Th, and 226Ra isotopes was obtained. On the other hand, low correlation (R2 = 0.6-0.7) was obtained from the analysis of the isotopes of 238U-seies and 232Th. No evidence of correlation between the concentrations of radioisotopes and pH contents, TOM, and grain size were found. The soil-plant transfer factor are <0.2, <0.2, 1.5, and 0.7 for 226Ra and 232Th, 40K, and 137Cs, respectively. The wild vegetations collected from the studied area have average concentrations of 1.9, 1.4, 1.3, 254, and 0.3 for 234Th, 226Ra, 232Th, 40K, and 137Cs, respectively. The average concentrations of 226Ra, 232Th, and 40K in water samples collected from five wells are 0.02, 0.02, and 1.1 Bq/l, respectively. The average absorbed dose rate for the sand samples were calculated to be 19.4 n Gy h-1. The Raeq activities of the sands are lower than the recommended maximum value of 370 Bq kg-1 criterion limit of Raeq activity for building materials