1. 1) UNSCEAR, United Nations Scientific Committee on the Effect of Atomic Radiation, Report to the General Assembly with scientific annexes: United Nations, New-York (2000)
2. 2) Picat, Ph., Calmet, D., Louvat, D., Vray, F., et al., Radioactivité d’origine naturelle dans l’environnement en France: niveaux non perturbés par l’homme, Radioprotection, 37, 283–327 (2002)
3. 3) Issa, S., Uosif, M. and Elsaman, R., Gamma radioactivity measurements in Nile River sediment samples, Turkish J. Eng. Env. Sci., 37, 109–122 (2013)
4. 4) Fares, S. S., Korna, A. H., Elsaeedy, H. I., Alshahrani, B. E., et al., Environmental impact assessment due to natural radioactivity in the mountain rocks of the Red Sea coast., Egypt, Radiat. Pro Environ., 40, 60–68 (2017)
5. 5) UNSCEAR, UNSCEAR 1993 Report, Effects of ionizing radiation Annex A: Exposures from natural sources ofradiation (1993)