Evaluation of radioactive contamination in soil samples from the Diyala Bridge area, Baghdad/Iraq: gamma spectroscopy and radon inhalation dose estimation

Abstract

This study evaluates the specific activity levels of Ra-226 (186 keV), Bi-214 (609 keV), Cs-137 (662 keV), Ac-228 (969 keV), and K-40 (1460 keV) in soil samples from the Diyala Bridge/Baghdad area using a NaI(Tl) scintillation detector for gamma-ray spectroscopy. Key parameters calculated include Radium Equivalent Activity, Gamma Dose Rate, External and Internal Hazard Indices, and the Gamma Index. In the results, the calculated Excess Lifetime Cancer Rate due to exposure to gamma ray were varied from 0.460×10⁻⁶ in sample (9) to 2.721×10⁻⁶ in sample (5), with an average of 1.236×10⁻⁶ across all samples. Also in this paper the concentration of Rn-222 in the air was estimated based on radium data, and doses from radon gas consumption and inhalation were calculated. The average inhalation dose from radon in soil samples was 47.941×10⁻⁹ Sv/y. All radionuclide activity levels were below permissible limits except in sample (5), located near the Iraqi Atomic Energy facility in Al-Twetha city.