Radiological risk assessment of phosphate fertilizer application on farmlands in Ondo State, Nigeria

This study assesses the radiological risks associated with phosphate fertilizer application on farmlands in Ondo State, Nigeria. Soil samples from ten agricultural towns were analyzed for radionuclide concentrations using gamma-ray spectrometry. Primordial radionuclides such as 238U, 232Th, and 40K were examined, with 40K showing the highest concentration due to the potassium-rich nature of phosphate fertilizers. Spatial variability in radionuclide concentrations was observed, attributed to agricultural activities. Despite variations, mean activity concentrations were below global averages, indicating low radiological risks. Hazard indices, radium equivalent concentrations, and absorbed dose rates were all within safe limits. The annual effective dose equivalent was significantly lower than recommended levels, and excess lifetime cancer risk estimates were below the global average. The study emphasizes the importance of educating farmers on the potential adverse effects of radionuclides and recommends reducing the use of inorganic fertilizers to promote eco-friendly agricultural practices.