Natural radioactivity in soil samples of Najaf City, Iraq

This work presents a study of natural radioactivity in soil samples in Najaf districts — Iraq using a scintillation of NaI(Tl) detector and spectroscopy system. The specific activity for 238U series (214Bi), 232Th series (208Tl), and non-series 40K were obtained. Ten hazard indices had been calculated. The results of the distribution of the specific activity of 238U, 232Th, 40K, and 235U, as well as the radium equivalent activity (Raeq) and the external hazard (Hex), have been drawn using a geographic information system (GIS). The results show that the average values of the specific activity for 238U, 232Th, 40K, and 235U were 18.01±1.24, 13.4±0.91, 256.9±12.23, and 0.83± 0.44 Bq/kg, respectively. The results of 238U, 232Th, and 40K have been compared with the average worldwide values reported by UNSCEAR 2008 and were found to be lower than the allowable worldwide values for most samples.