Abstract
The radioactivity levels are poorly studied in non-coastal arid regions. For this reason, 38 locations covering an area of about 350 km
2
in northeast Sinai, Egypt, were investigated by γ-ray spectroscopy. Moderately significant correlations among
238
U,
234
Th, and
226
Ra isotopes and low significant correlations between the concentrations of
238
U-series and
232
Th in sand were obtained. No evidence of correlation was found between the concentrations of radioisotopes and pH, grain size, total organic matter content, bicarbonate or calcium carbonate concentrations of the sand samples. The mean values of soil-to-plant transfer factor were 0.15, 0.18, 1.52 and 0.74 for
226
Ra,
232
Th,
40
K, and
137
Cs, respectively. The range of concentrations of
226
Ra,
232
Th, and
40
K in water samples collected from five wells were<0.4-0.16,<0.4-0.13, and<0.15-1.62 Bq l
−1
, respectively. The mean absorbed dose rate in outdoor air at a height of 1 m above the ground surface for the sand samples was 19.4 nGy h
−1
. The Ra
eq
activities of the sands are lower than the recommended maximum value of 370 Bq kg
−1
criterion limit for building materials.