Naturally Occurring Radon Levels: The Outcomes of Environmental Assessments in Kadhimiya (Baghdad, Iraq) Soil Samples

In the present study, radon concentrations were measured in soil samples collected from different sites in Kadhimiya district center in Baghdad, Iraq. A CR-39 passive nuclear track detectors was used to assess the radon concentrations through the sealed can technique. This study include an assessment of various radiation hazard parameters in 25 soil samples, including the annual effective dose, excess lifetime cancer risk, radium activity, uranium concentration, as well as surface and mass exhalation rates. The mean values were found to be 282.29 ± 3.83 Bq m⁻³ for radon concentration, 7.12 ± 0.096 mSv y⁻¹ for annual effective dose, 24.93 for excess lifetime cancer risk, 0.39 ± 0.002 Bq kg⁻¹ for radium activity, 135.75 ± 1.84 mBq m⁻²h⁻¹ for surface exhalation rate, 3.14 ± 0.04 mBq kg⁻¹h⁻¹ for mass exhalation rate, and 5.91 ± 0.079 PPb for uranium concentration. Consequently, the mean radon concentration exceeded the suggested limits, typically ranging between 200 and 600 Bq m⁻³, and the annual effective dose exceeded the recommended threshold of 1 mSv y⁻¹. However, the radium content was below the recommended limit of 30 Bq kg⁻¹. A significant direct correlation was observed between the radium concentration and both the surface and mass exhalation rates. It is recommended to expand this study to measure radon and thoron gas concentrations within buildings of the study area to enhance the understanding of indoor exposure risks. Additionally, it would be beneficial to estimate the concentrations of other radionuclides, such as ²³²Th and ⁴⁰K, as well as the major cations and anions in the soil to elucidate their potential impact on radon levels. Further actions to control radon exposure in the community to prevent lung cancer is important.