Optically stimulated luminescence properties of commercially available KCL dietary supplements as retrospective dosimeters.

In the case of an unexpected exposure to radiation in places where there is no access to standard dosimeters, materials that can act as detectors in methods of retrospective dosimetry are looked for. Such materials include, but are not limited to, medicines and dietary supplements that are found in households or in personal bags. This article presents the optically stimulated luminescence (OSL) dosimetric properties of dietary supplements, the main ingredient of which is a sensitive phosphor - potassium chloride (KCl). Three types of KCl dietary supplements were tested and compared to a selection of four common drugs in terms of their sensitivity. Basic dosimetric properties of dietary supplements such as signal repeatability, dose response and fading were determined. The dose recovery test was performed 2 and 7 days after exposure to radiation. The obtained dose values for the two supplements showed good compliance with the nominal dose values and the possibility of correctly assigning the doses to the levels of triage (low dose 0-1 Gy, medium dose 1-2 Gy and high dose > 2 Gy). The presented results show that dietary supplements with KCl have the potential to be used as emergency detectors in the dose recovery process.

Variations of plutonium isotopic ratios in Antarctic ecosystems.

The aim of the article was to verify the hypothesis concerning the diversification of plutonium sources in the natural environment of Antarctica. Plutonium activity and atom ratios were analyzed in two groups of biological samples: terrestrial and marine. Both isotopic ratios in the terrestrial set were consistent with global radioactive fallout ratios. The average activity ratio in the marine ecosystem was lower than global radioactive fallout. At the same time mass ratio values in this group turned out to be surprisingly varied. Analysis of the results showed statistically significant differences between the marine and terrestrial ecosystems.

The sources of high airborne radioactivity in cryoconite holes from the Caucasus (Georgia).

Cryoconite granules are mixtures of mineral particles, organic substances and organisms on the surface of glaciers where they decrease the ice albedo and are responsible for formation of water-filled holes. The contaminants are effectively trapped in the cryoconite granules and stay there for many years. This study evaluates the contamination level of artificial and natural radionuclides in cryoconite holes from Adishi glacier (Georgia) and identifies the sources of contamination based on activity or mass ratios among artificial radionuclides. Results revealed high activity concentrations of fallout radionuclides reaching 4900 Bq/kg, 2.5 Bq/kg, 107 Bq/kg and 68 Bq/kg for 137Cs, 238Pu, 239+240Pu and 241Am, respectively. The main source of Pu is global fallout, but the low 240Pu/239Pu atomic ratios also indicated local tropospheric source of 239Pu, probably from the Kapustin Yar nuclear test site. Also, high activity ratios of 241Am/239+240Pu could originate from Kapustin Yar. The natural radionuclides originate from the surrounding rocks and were measured to control the environmental processes. 210Pb in cryoconite granules comes predominantly from the atmospheric deposition, and its activity concentrations reach high values up to 12000 Bq/kg.

Determination of element composition and extraterrestrial material occurrence in moss and lichen samples from King George Island (Antarctica) using reactor neutron activation analysis and SEM microscopy.

Seven lichens (Usnea antarctica and U. aurantiacoatra) and nine moss samples (Sanionia uncinata) collected in King George Island were analyzed using instrumental neutron activation analysis, and concentration of major and trace elements was calculated. For some elements, the concentrations observed in moss samples were higher than corresponding values reported from other sites in the Antarctica, but in the lichens, these were in the same range of concentrations. Scanning electron microscopy (SEM) and statistical analysis showed large influence of volcanic-origin particles. Also, the interplanetary cosmic particles (ICP) were observed in investigated samples, as mosses and lichens are good collectors of ICP and micrometeorites.