Assessment of radioactivity and the associated hazards in local and imported cement types used in Sudan.

Activity concentration of 232Th, 226Ra and 40K in local (Atbra and Rabak) and imported cement types (Jordanian, Indonesian and Seabulk) has been measured using high-resolution gamma-spectrometry. The average values obtained for 232Th, 226Ra and 40K activity concentrations in different cements are lower than the corresponding global values reported in UNSCEAR publications. The radium-equivalent activity (Raeq) of the samples was calculated and compared with similar data reported in the literature. The comparison has revealed that Raeq values obtained fall far below the criterion limit specified for building materials. The potential radiological hazard of the different samples was estimated using different approaches: representative level index and annual dose limit (dose due to gamma radiation inside the room and inhalation of radon). The estimated representative level index for all the samples is less than unity (the upper limit) indicating that the associated gamma radiation level is low. The annual dose limit falls within 0.19 to 0.30 mSv, which is an order of magnitude below the criterion limit specified for building materials in the literature.