The present work evaluates the natural radioactivity of soils from the Najaf Sea area by determining the activity concentrations of U-238, Th-232, and K-40. A total of twenty soil samples were collected from different locations, prepared under laboratory conditions, and examined using a NaI(Tl) gamma-ray spectrometry system. The measured activity of U-238 varied from 21 to 33 Bq/kg, with a mean value of 26.9 Bq/kg, while Th-232 ranged between 15 and 28 Bq/kg, with an average of 21.2 Bq/kg. The highest activity values were recorded for K-40, which ranged from 260 to 420 Bq/kg and had a mean concentration of 332 Bq/kg. The obtained data were compared with internationally accepted reference levels, and no exceedance was observed. The spatial differences between the samples are mainly associated with the geological structure, sediment composition, and mineral content of the area. The results indicate that the investigated soils reflect normal natural background radiation and do not represent a considerable radiological hazard. The data may therefore serve as a reference basis for subsequent environmental radiation surveys in the Najaf Sea region.
Al-Kareem et al. (Tue,) studied this question.