Use of Fertilizers in Agriculture: Individual Effective Dose Estimate

Natural radioactivity might be present in fertilizers above ordinary levels, in particular for 40K and for the radionuclides of the 238U 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 40K and 238U 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 µSv per year. The category that most contributes to the dose is that of compound fertilizers and radon and 40K are the most significant radionuclides.

Natural radioactivity of some spring and bottled mineral waters from several Central Balkan sites, as a way of their characterization

In this work, a study of the radioactive content of some spring and bottled mineral waters originating from metamorphic rock areas was carried out. A high content of radium isotopes (226Ra, 228Ra), was found by radiometric analysis in the spring waters: Studenica (226Ra: 289 mBq/L), Cibutkovica (226Ra: 92, 4 mBq/L, 228Ra: 610 mBq/L), and Crni Guber (226Ra: 120 mBq/L, 228Ra: 1170 mBq/L). On the other hand, the radiochemical results showed a higher concentration of 238U in the bottled mineral water samples (dissolved uranium concentrations were from 0.21 mBq/L, for "Kopaonik" to 71.5mBq/L fo "Skadarska") than in the spring water samples (dissolved uranium concentrations were very low ?10 mBq/L). The concentrations of all the present naturally occuring radionuclides: 238U, 234U, 232Th, 230Th, 228Th, 228Ra and 226Ra were determined by alpha/gamma spectrometric analysis. The activity ratios 234U/238U, 226Ra/230Th and 228Th/232Th, 228Ra/228Th were calculated and are discussed as an indication of the radioactive disequilibrium in bothe the 238U and 232Th radioactive series. The high contents of radium isotopes with respect to the equilibrium values expected from the respective parents 232Th/(232Th series) and 230Th (238U series) found in the spring water samples is the main evidence for the existence of significant radioactive disequilibrium in both the radioactive series. .