Estimation of radiation exposure in soils and organic (animal) and inorganic (chemical) fertilizers using active technique

摘要

In this study, activity concentrations of K-40, Ra-226 and Th-232 in fertilized soil samples and different organic and inorganic fertilizers used in agricultural soil were analysed using gamma-ray spectrometry NaI (Tl) detector in order to access the implications of extended use of fertilizers in 2-3 years. The concentrations of radionuclides in some granular fertilizer brands were discovered to be higher for K-40, Ra-226 and Th-232 than those obtained in leafy fertilizer, animal fertilizer and fertilized soil samples. From the results, the highest overall mean concentrations of the specific activities of K-40, Ra-226 and Th-232 were 2301.8 (granular fertilizer), 42.5 (leafy fertilizer) and 327.1 (animal fertilizer) in Bq kg(-1), while the lowest values observed in the specific activities of the same radionuclides were 357.7 (leafy fertilizer), 28.1 (animal fertilizer) and 36.5 (animal fertilizer). The radiological hazards of the radium equivalent (Ra-eq), normative value (NRN), outdoor radium equivalent (Raeq-out), external hazard index (H-ext), internal hazard index (H-in), dose rate, annual effective dose rate, activity utilization index and concentration accumulation index (CAI) and Ra-FZ due to the presence of these radionuclides in the investigated samples were calculated. Nevertheless, some of the fertilizer brands have higher concentration values than the recommended limit, and the values of hazard indices of fertilizer brands used in the selected teaching and research farms were within acceptable limit. Therefore, the fertilized soil samples in the studied farms are safe.