Estimation of natural radioactivity in soil of primary schools at old city in Najaf

Abstract EN

The specific activity level of Uranium-238, Thorium-232, Potassium-40, and Uranium-235 in soil samples of selected primary schools in the old city of al-Najaf province, Iraq, was investigated for radiological hazards to determine children's and staff's safety in these schools.

fifteen (15) samples were collected from the soil of schools under study, prepared, and transported to the radiation detection and measurement laboratory for analysis with the use of gamma-ray spectroscopy detector NaI (Tl) with a "3 x 3" crystal.

the average specific activities of Uranium-238, Thorium-232, Potassium-40 and Uranium-235 were (17.18 ± 1.63, 24.24 ± 1.96, 318.23 ± 21.23 and 0.79 ± 0.07) Bq / kg respectively.

the concentrations levels for Uranium-238, Thorium-232, and Potassium-40 have been lower than the internationally recommended standard of (33, 45, and 420) Bq / kg.

the average values of radium equivalent activity, external hazard index, internal hazard index, gamma index, and alpha index were (76.35 ± 4.97, 0.206 ± 0.01, 0.252 ± 0.01, 0.569 ± 0.03, 0.086 ± 0.008) respectively.

furthermore, the average values of orbed dose rate, annual effective dose equivalent outdoor, annual effective dose equivalent indoor, and excess lifetime cancer risk (ELCR) were (35.85 ± 2.31) nGy / h, (0.043 ± 0.002) mSv / y, (0.175 ± 0.011) mSv / y, and (0.153 ± 0.009) respectively.

it is observed that all results of radiological hazard parameters due to a specific activity for Uranium-238, Thorium-232, Potassium-40, and Uranium-235 were within the world of safety limits.

therefore, the children and staff whose schools were assessed are deemed not exposed to any radioactive risks.