Assessment of Natural Radioactivity Levels and Radiological Hazards of Cement in Iraq

Eight samples of cement were collected from different commercial factories (Al-Koufa, Al-Basra, Al-Najaf and Kerkouk factories) located in Iraq. They were analyzed using a gamma ray spectroscopy system. The activity concentrations of 226Ra, 232Th and 40K were ranged from 5.8 to 43.17 Bq kg-1, from 0.99 to 55.79 Bq kg-1 and from 53.28 to 185.34 Bq kg-1, respectively. The potential radiological hazards were assessed by calculating the radium equivalent activity (Raeq), the indoor absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the alpha index (Iα), the gamma index (Iγ), and the external hazard (Hex) and internal hazard (Hin) indices. The highest value of Raeq is estimated of 101.36 Bq kg-1, which is significantly less than the upper limit of 370 Bq kg-1. The estimated maximum value of the absorbed gamma dose rate of 54.71 nGy h-1 is within the world average value of 55 nGy h-1, and the annual effective dose equivalent in the studied samples were 0.05 (outdoor), 0.18 (indoor) mSv y-1, which is lower than the recommended limit reported in the UNSCEAR (2000). The values of the hazard indices were below the recommended levels; therefore, the study shows that the measured radioactivity for cement does not pose as significant source of radiation hazard and is safe for use in the construction of dwellings.