The present study discusses the natural radioactivity in the uraniferous two-mica granites and their
associated environmental impacts at El Sela area. Exposure rate (ER), dose rate (DR), radium equivalent
activity (Raeq), external hazard index (Hex), internal hazard index (Hin) and radio activity level index (I!)
were calculated. These rocks are dissected by microgranite and dolerite dikes which affected by different
alteration process such as ferrugination, kaolinitization, illitization and flouritization which responsible
about presence of some secondary uranium minerals. The radiometric investigations revealed that the
uranium average contents up to 102.6 in microgranite dike, and reach to 194 in dolerite dike respectively.
All the studied rocks had low values of eTh and K content. The exposure and dose rates exceeded the public
permissible values in these dikes but they were within the safety range for workers and the public in the
fresh two-mica granite. The expected environmental impacts may be low due to the limited occurrence of
U-mineralization and corresponding areas for radiation exposure. Some precautions and recommendations
were suggested to avoid any possible environmental impacts from areas and/or raw materials of high
intensity of natural radiation sources.