Assessment of natural radioactivity and its radiological hazards in several types of cement used in Senegal

In this study, the activity concentrations of Ra-226, Th-232 and K-40 in twenty cement samples of four types (CEM, CEM II, CEM III, and CEM IV) collected from building material suppliers in Senegal were measured using a low-background digital gamma-ray spectrometer equipped with broad energy germanium detector. The activity concentrations of Ra-226, Th-232 and K-40 varied from 7.1-150.3 Bq kg(-1), 3.7-16.1 Bq kg(-1), and 48.7-133.9 Bq kg(-1), respectively. Also, possible radiological risks from the usage of these materials were assessed by estimating external and internal index, indoor absorbed gamma dose rate and the corresponding annual effective dose, effective dose rate to different body organs and tissus, and excess lifetime cancer risk. The estimated radiological hazard indices were revised in light of the relevant national and international legislation and guidance. The values of the radiological hazard indices were found to be within relevant all limit values for structural building materials.