Risk assessment and natural radionuclide content in black-sand deposits of North Sinai coast, Egypt.

The radioactivity levels and risk factors have been assessed for twenty-eight positions of Black-Sand (BS) surface deposits along the Mediterranean Sea coast of north Sinai, Egypt. Twenty-eight surface samples were collected from six local cities: El Ressa, Abo Sakl, Ghornata, El Arish, El Masaed, and El Rommana. The activity concentration values of the nuclides of the Ra, Th, and K of the collected samples were measured using a P-type HPGe detector with a relative efficiency of ∼100% where it is defined at 1.