The study of natural and artificial radionuclides incorporation in teeth and head bones of animals lived nearby Caetité uranium mine, Brazil

Assessment of internal radiation exposure to Antarctic biota due to selected natural radionuclides in terrestrial and marine environment

The present article introduces data on natural radioactivity (⁴⁰K, ^230,232Th, ^234,238U) in the Antarctic marine and terrestrial environment. Various biota samples were analysed due to internal exposure to ⁴⁰K, ^230,232Th, ^234,238U. Activity concentration of ⁴⁰K was the highest in both marine and terrestrial samples. Mean values of ⁴⁰K activity concentration are 1340 Bq/kg and 370 Bq/kg for the marine and terrestrial samples respectively. ²³⁴U/²³⁸U ratios analysis revealed that sea waters and sea spray are the main source of the uranium in the terrestrial samples. Average ^230,232Th, ^234,238U activity concentrations in the Antarctic biota do not exceed 6 Bq/kg. Weighted internal dose rates are relatively low; they range from approximately 0.1 to 0.6 μGy/h. Statistically significant differences in radionuclide accumulation were discovered between the mosses and lichens. It may point to various mechanisms of the nutrient absorption from the environment by these organisms.

Determination of natural radionuclides and some metal concentrations in human tooth samples in the Rize province, Turkey

The main purpose of this study was to identify the concentrations of naturally occurring radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) and some metals (Fe, Ni, Cu, Zn, Pb and Cd) in tooth samples collected from humans living in the Rize province of Turkey. It was found that the activity concentrations ranged from 8.1 to 114.51 Bq kg^-1 for ²²⁶Ra, from 10.44 to 97.3 Bq kg^-1 for ²³²Th and from 14.53 to 489.27 Bq kg^-1 for ⁴⁰K. The mean activity concentration values of ²²⁶Ra and ²³²Th in tooth samples were higher than the average world values for bones. Furthermore, when the metal concentrations were examined, there was no regular increase or decrease according to age or sex. The results of the metal analysis on the tooth samples were compared with the results of similar studies and were generally found to be consistent.