Transfer of Uranium and Radium-226 from soil to tubers and roots culture on the northern coast of Pernambuco State, Brazil

Tubers and roots are the most produced foodstuffs along the northern coast of Pernambuco State, Brazil. This region presents uranium anomalies in subsoil, with a radionuclide concentration mean of 150 ppm, due to phosphate mines. The phosphatic ore extraction activities, have produced a soil movement, so that more rich materials containing uranium and radium-226 have been transferred from subsoil to cultivation layers of the soil.These facts associated with intensive agricultural production of the region, has determined the performance of this study, which has the objective to measure uranium and radium-226 concentrations in soil, tubers and roots, cultivated in this area, as well as its partition in soil-to-plant system. The results found show that exchangeable fraction of uranium and radium-226 concentrations in soil ranged between 0.12 to 7.67+- 0.57 Bq/Kg of dry soil and 3.7 to 30.3+-1.4 Bq/Kg of dry soil, respectively. Otherwise, these radionuclide concentrations in tubers and roots ranged from 12.9 to 78.8+-8.0 Bq/Kg wet weight and 120 to 1607+-80 Bq/Kg wet weight, respectively. The transfer factor is defined as concentration of the nuclide in a plant organ at harvest divided by concentration of the nuclide in dry soil, and the mean values found to uranium and radium-226 transfer factors (8.5 and 3.2) have demonstrated that uranium, in spite of its lower soil concentration, is more absorbed by cultivars than radium-226