Investigation of natural radionuclide transfer from soil to wheat

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.