Determination of radiation doses to the skin due to 238U and 232Th series for the therapeutic application in the Merzouga sand baths

In this work, we used CR-39 and LR-115 type II solid-state nuclear track detectors to measure 238U, 232Th,222Rn and 220Rn concentrations in Merzouga sand. The measured concentrations of 238U and 232Th in the studied sand samples vary from (332.59±16.62) mBq·cm−3 to (335.54±20.13) mBq·cm−3 and (80.43±4.02) mBq·cm−3 to (84.75±5.08) mBq·cm−3, respectively. We evaluated the radiation doses to the skin from the application of different sand baths by the patients by using a model based on specific alpha-dose and alpha-particle residual energy concepts. The maximum total equivalent dose to the skin due to the 238U and 232Th series from the cutaneous application of different sand baths by patients was found equal to (148.12±11.85) µSv y−1cm−2

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. .