Environmental assessment of gamma-radiation levels in stream sediments around Sharm El-Sheikh, South Sinai, Egypt.

Abstract A total surface area of ∼170 km 2 including 28 localities around Sharm El-Sheikh, South Sinai, were investigated by γ-ray spectroscopy. The concentrations of NORM were found to be five to seven-fold that in dune sands in different regions in Sinai. While relatively higher levels of 238 U, 234 Th, 226 Ra, and 232 Th are associated with the existing monzo-syenogranite, the concentration of 40 K is more uniformly distributed in the studied area. Locations with higher concentrations of 137 Cs are mainly located in the northern part. The 238 U, 234 Th and 226 Ra isotopes in the 238 U-series are in secular equilibrium. The absorbed dose rates and gamma-radiation hazard indices in all locations were higher than the world average value and unity, respectively. Properly regulated land use is recommended for a buffer zone in the northern part of the study area.