Cross-sectional survey finds safe radionuclide levels alongside elevated transfer factors in agricultural soils and crops, highlighting potential food chain contamination.
Key Points
To evaluate the activity concentrations of naturally occurring radionuclides in cultivated soil and food crops and assess the associated radiological risks and soil-to-plant transfer factors.
Collected 45 total samples (30 soil samples and 15 food crop samples) from the extensively cultivated Teaching and Research Farm at Adeyemi Federal University of Education in Ondo, Nigeria.
Measured activity concentrations using gamma ray spectrometry and calculated radiological hazard indices alongside soil-to-plant transfer factors.
Average soil activity concentrations reached 3.74 Bq/kg for uranium-238, 10.03 Bq/kg for thorium-232, and 1021.59 Bq/kg for potassium-40.
Radiological indices—including a radium equivalent of 96.74 Bq/kg, annual effective dose equivalent of 53.10 µSv/y, and excess lifetime cancer risk of 1.86 × 10⁻⁴—fell below international public safety thresholds.
Soil-to-plant transfer factors were slightly greater than 1 for most crop samples, confirming radionuclide migration from soil into edible plants.