Natural Radioactivity Assessment and Radiation Hazards of Pegmatite as a Building Material, Hafafit Area, Southeastern Desert, Egypt

El-Afandy H. Adel, Samia H. Taha, Osama A. Ebyan, Wafaa M. Rashed, Mohamed G. El-Feky, Mohammed S. Alqahtani, Korany A. Korany & Mohamed Y. Hanfi