This study aimed to evaluate the radiological impacts in Khanaqin, located in the Diyala Governorate, Iraq. The specific activities of natural radionuclides of ²³⁸U, ²³²Th, and ⁴⁰K in soil samples were investigated by collecting thirty composite soil samples from different locations in the area. Measurements were performed using a NaI(Tl) gamma-ray spectrometry system to acquire the data and analyses were conducted using the UCS-20 program. From the results, the average specific activities of ²³⁸U, ²³²Th, and ⁴⁰K were 25.15 ± 3.65 Bq kg⁻¹, 12.27 ± 2.28 Bq kg⁻¹, and 300.09 ± 14.50 Bq kg⁻¹, respectively. These results were lower than the global average recommended by UNSCEAR. The radiological risk criteria were estimated based on the specific activities of radionuclides to assess any radiological risks that may be associated with the soil of the study area under investigation. The radiological risk criteria included radium equivalent activity (Ra_eq), absorbed dose rate (D_R), annual effective dose (AEDE), annual gonadal equivalent dose (AGDE), excess lifetime cancer risk (ELCR), external hazard index (H_ex), internal hazard index (H_in), representative gamma index (I _γ ) and effective dose rate to different body organs (D_organ). They were compared with the international safe limits. Overall, all the radiological risk criteria had values lower than the worldwide average recommended by UNSCEAR. This work employed statistical techniques to understand and explain the statistical characteristics of measured radionuclide-specific activities and the associated radiological risk criteria , including skewness, kurtosis, correlation coefficients, and K-means cluster analysis.

The essential variables used to measure radiological pollution and related human health concerns include radionuclides’ distribution and transfer factors (TFs) in plants. The TF is the radionuclide’s specific activity (Bq kg⁻¹) ratio in the plant to its dirt equivalent (in dry weight). This research aimed to determine the radionuclides’ soil-to-plant TF, to evaluate natural radionuclides’ transfer level from soil to a selected cultivated crop (wheat) in the Shaqlawa district of Erbil Province, Iraq. The study randomly collected soil and cultivated plant samples from various locations. The collected samples were analyzed using HPGe gamma spectroscopy. The ²²⁶Ra, ²³²Th, and ⁴⁰K radionuclides, the average TFs from soil to plant root were 0.032, 0.033, and 0.405, respectively. TF values indicate that approximately 3.2%, 3.3%, and 40.5% of ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively, were transferred from the soil to the wheat, following the order of ⁴⁰K (0.40) > ²³²Th (0.033) and ²²⁶Ra (0.032). All TFs were below the global standard of unity. A positive Pearson correlation was found among the three radionuclides in soil and plant samples. The three radionuclides were detected in soil and wheat samples, and the positive correlation among them suggested they originated from a common source in each environmental matrix. The results confirmed that the TF values from soil to wheat are safe for agricultural lands in the Shaklawa district, with no immediate radiological health implications.