Evaluation of natural radioactivity levels in soil samples of Al-Hindiya District, Karbala, Iraq

Using a NaI(Tl) detector and the gamma spectrometry technique, 18 soil samples were taken from the Al-Hindiya District in Karbala, Iraq, in order to measure the activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th. The results demonstrated that these radionuclides’ activity concentrations in the soil samples varied from 329 to 498 Bq/kg, 18.9 to 28.2 Bq/kg, and 8.2 to 13.1 Bq/kg, respectively. These levels, especially for ²²⁶Ra and ²³²Th, were lower than the global median values published by UNSCEAR (2000) and comparable to those in nearby locations. In order to carry out a more thorough investigation, a sample of dates, water from the Euphrates River, and sandy soil from dredging were also gathered and their inherent radioactivity examined. The sandy soil contained activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th of 271 Bq/kg, 13.1 Bq/kg, and 7.3 Bq/kg, respectively. The values in the water samples were, respectively, 2.13, 0.06, and less than the minimum detectable activity (MDA) in Bq/L. The readings for the date sample were, respectively, 380, 1.5, and MDA Bq/kg. With an average of 41 μSv/y, the outdoor annual effective dose caused by these radionuclides in the soil varied between 34.6 μSv/y and 48.6 μSv/y, which is consistent with values found in the literature and international regulations. Thus, it can be said that the natural radioactivity levels in this area do not pose a threat to the inhabitants.