Use of Fertilizers in Agriculture: Individual Effective Dose Estimate

Natural radioactivity might be present in fertilizers above ordinary levels, in particular for K-40 and for the radionuclides of the U-238 series. A modeling evaluation of the individual effective dose deriving from the use of fertilizers in agriculture is presented here. Dose assessment is useful in the transposition of Directive 2013/59/Euratom, which rules the individual exposure to commodities containing radionuclides of natural origin, such as fertilizers. The following input data have been considered for this study: the amount of fertilizers used in the region of Veneto and in Italy; the utilized agricultural area (to estimate the density of spread fertilizers); and, the average values of activity concentrations in fertilizers for K-40 and U-238 series radionuclides, derived from scientific literature. The individual effective dose was evaluated while using the Resrad calculation model, making assumptions on the characteristics of the interested soil. This study is focused on the region of Veneto, where the use of fertilizers is higher with respect to the rest of Italy, such providing a more conservative estimate of the individual effective dose to the population. The results show that the estimated individual effective dose values do not exceed few mu Sv per year. The category that most contributes to the dose is that of compound fertilizers and radon and K-40 are the most significant radionuclides.