Search

A study of the radiocaesium activity in fruitbodies of 54 mushroom species from 18 locations of Polis'ke Forestry complex was carried out with γ-spectrometry. In some mushroom samples, strontium was determined with a radiochemical method. However, the mushrooms accumulated 137Cs one to three orders of magnitude more actively than 90Sr. The highest levels of 137Cs activity, recorded in Lactarius rufus, Imleria badia, Paxillus involutus and Cortinarius praestans from the forest area at the settlement of Polis'ke in 1998 and 2000, exceeded 1 MBq/kg dry mass. By 2018, the activity of 137Cs in 60.0% and 37.84% of mushroom samples in the Zelenopolyans'ke and Steshchyns'ke Forestries, respectively, exceeded the maximum permissible level valid in Ukraine, 2,500 Bq/kg dry mass. Significant differences in the levels of contamination of the same species are noted not only at different locations, but also within the same sampling site, which is probably associated with a complex of factors which are difficult to assess, such as extremely heterogeneous nature of contamination, depth of mycelium in the soil layer, and microclimatic conditions in the place where individual fruitbodies grow. The data obtained indicate a persistent risk to the population due to internal exposure as a result of uncontrolled consumption of wild mushrooms in this region. In 2018, the potential equivalent dose per year (contribution of 137Cs only) reached maximum values of 0.239 mSv in Suillus spp. and 0.130 mSv in Imleria badia from Zelenopolyans'ke Forestry. [ABSTRACT FROM AUTHOR]

The decontamination properties of shampoos for cesium, strontium, and cobalt were determined. The method has been developed for determining the decontaminating properties of shampoos. The chemical part of the study includes the preparation of hair, which consists of forced pollution and subsequent washing. Stable isotopes were used in the work. This has increased the safety of staff during chemical hair research. The analytical part includes the quantitative determination of the cesium, strontium, and cobalt in the hair, which was carried out by the Particle-Induced X-ray Emission (PIXE) method using the analytical nuclear-physical complex “Sokol”. Various shampoos were analyzed, and their decontamination properties were determined. During the research, various samples of shampoos, which are presented on the market of Ukraine, were considered. It has been established that TM “Ringo” shampoo has the best deactivating properties for cesium (Kd - 574.0) and insignificant deactivating properties for strontium (Kd - 3.1) and cobalt (Kd - 3.6). It was determined that with multi-isotope contamination (a mixture of cesium, strontium, and cobalt isotopes) decrease in the deactivation coefficient for all isotopes was observed, which is due to the competition factor of the isotopes in the complexation process with shampoo. Reduction of decontaminating properties was observed on all samples of shampoos. [ABSTRACT FROM AUTHOR]

The active moss biomonitoring technique was applied to assess the environmental pollution in the Donetsk region and to compare the biomonitoring capacity of acrocarpous (Ceratodon purpureus) and pleurocarpous (Brachythecium campestre) moss transplants. Moss bags were exposed for 6 months in the surroundings of two steelworks, a power station, and two parks. The concentrations of 19 elements were determined in the moss transplants by neutron activation analysis and atomic absorption spectrometry. Various environmental indices—relative accumulation factor, contamination factor, pollution load index, enrichment factor, and ecological risk index—were used to quantitatively assess the degree of ambient contamination. The RAF values indicate that the most prevalent elements in Brachythecium campestre and Ceratodon purpureus were Na, Al, Ca, Fe, Ti, V, Cr, Mn, Co, Ni, Zn, Ba, Sr, Pd, and Cd. The results showed a significant difference between metal accumulation by Ceratodon purpureus and Brachythecium campestre indicating various mechanisms of uptake. All elements were highly correlated in Ceratodon purpureus. The main air pollution sources in the region are the Zuivska power station (Zuivska TES), Donetsk Metallurgical Plant, and Yenakiieve Iron and Steel Works. [ABSTRACT FROM AUTHOR]

Activity concentrations of 90Sr in fish in lakes located within the Chornobyl Exclusion Zone (ChEZ) reach 100 kBq kg−1, which is several thousand times higher than the permissible level in Ukraine (35 Bq kg−1). This study was conducted in the natural conditions of the ChEZ to determine the effectiveness of keeping radioactively contaminated fish in "clean" water to reduce the 90Sr content of their muscle tissue, as previously shown in short-term laboratory experiments. It was found that transferring tench (Tinca tinca (Linnaeus, 1758)) from Lake Glubokoye one of the most contaminated lakes in the ChEZ, to a cage in the "clean" Lake Starukha for 45 days did not lead to a significant decrease in 90Sr content in both bone and muscle tissues. Establishing permissible levels of 90Sr concentration only in fish fillet, and not in the whole fish body (with bone tissue), is appropriate for human radiation protection, since the retention factors of 90Sr treatment for boiled bone tissue of crucian carp from the Chornobyl exclusion zone are less than 0.01, and up to 97% of strontium is contained in bone tissue. [Display omitted] • No reduce of 90Sr content in contaminated fish when kept in "clean" water for 45 days. • Less than 1% of 90Sr is transferred to broth during boiling of fish bone tissue. • Current Ukrainian permissible levels of 90Sr in fish products need to be revised. • Long-term experiments are needed to study ways to remove 90Sr from fish tissues. [ABSTRACT FROM AUTHOR]

We examined 12- to 13-year-old children, inhabitants of industrial regions of Ukraine with high levels of environmental contamination; these children suffered from autonomic disorders. Conventional norms for the contents of lead and calcium were exceeded in samples of biologically stable tissues (hairs) of these children; strontium concentrations corresponded to reference values. The analysis of correlations of the absolute and relative spectral powers of EEG frequency components under conditions of rhythmic photoand phonostimulation with the contents of the above elements showed that there were both similarities and specificities of neurotropic effects of these elements at the systemic level. With higher lead concentrations, we observed lower, in general, values of the integral power of EEG activity, while the balance of excitatory and inhibitory neural processes was preserved. The patterns of effects of calcium and strontium were more similar to each other but were dissimilar in the levels of expression. The described effects were, to a great extent, found in EEG samples recorded under conditions of rhythmic photostimulation. We conclude that lead and calcium demonstrated relatively higher neurotropic activities within the examined group. [ABSTRACT FROM AUTHOR]

In 12- to 13-year-old children, inhabitants of regions of Ukraine with high levels of industrial contamination, we found higher contents of lead and calcium, as compared with the upper limits of the norm, in samples of biologically stable tissues (hairs). Concentrations of strontium were within the limits of reference values. Correlation analysis of the EEG frequency components vs levels of the above-mentioned metals demonstrated the existence of significant (or close to significant) relations between normalized spectral powers of the rhythms of background EEG recorded at different functional states (eyes open/closed, solving an arithmetic task) and concentrations of these elements. According to the number of the correlations found and their strength, the order of significance of the effects of the above elements with respect to the pattern of EEG activity was the following: Ca > Sr > Pb. The intensity of significant correlations varied from mild to moderately strong (0.41 < r < 0.70). The tightest correlations with the levels of all elements were observed under conditions of cognitive loading (solving an arithmetic task). High-frequency EEG components (β1 and β2 rhythms) were found to be the EEG components most sensitive to the contents of the mentioned elements. [ABSTRACT FROM AUTHOR]

Abstract: Results are presented for 137Cs, 90Sr and plutonium activity concentrations in more than 20 samples of terrestrial invertebrates, including species of beetles, ants, spiders and millipedes, collected in the highly contaminated area of the Chernobyl exclusion zone. The majority of samples were collected in Belarus, with some also collected in the Ukraine. Three other samples were collected in an area of lower contamination. Results show that seven samples exceed an activity concentration of 100kBq/kg (ash weight – a.w.) for 137Cs. The maximum activity concentration for this isotope was 1.52±0.08MBq/kg (a.w.) determined in ants (Formica cynerea). Seven results for 90Sr exceeded 100kBq/kg (a.w.), mostly for millipedes. Relatively high plutonium activity concentrations were found in some ants and earth-boring dung beetles. Analyses of activity ratios showed differences in transfer of radionuclides between species. To reveal the correlation structure of the multivariate data set, the Partial Least-Squares method (PLS) was used. Results of the PLS model suggest that high radiocesium activity concentrations in animal bodies can be expected mainly for relatively small creatures living on the litter surface. In contrast, high strontium activity concentrations can be expected for creatures which conduct their lives within litter, having mixed trophic habits and a moderate lifespan. No clear conclusions could be made for plutonium. [Copyright &y& Elsevier]

In this work a general, process-based mass-balance model for water contaminants for coastal areas at the ecosystem scale (CoastMab) is presented and for the first time tested for radionuclides. The model is dynamic, based on ordinary differential equations and gives monthly predictions. Connected to the core model there is also a sub-model for contaminant concentrations in fish. CoastMab calculates sedimentation, resuspension, diffusion, mixing, burial and retention of the given contaminant. The model contains both general algorithms, which apply to all contaminants, and substance-specific parts (such as algorithms for the particulate fraction, diffusion, biouptake and biological half-life). CoastMab and the sub-model for fish are simple to apply in practice since all driving variables may be readily accessed from maps or regular monitoring programs. The separation between the surface-water layer and the deep-water layer is not done as in most traditional models from water temperature data but from sedimentological criteria. Previous versions of the models for phosphorus and suspended particulate matter (in the Baltic Sea) have been validated and shown to predict well. This work presents modifications of the model and tests using two tracers, radiocesium and radiostrontium (from the Chernobyl fallout) in the Dnieper-Bug estuary (the Black Sea). Good correlations are shown between modeled and empirical data, except for the month directly after the fallout. We have, e.g., shown that: 1. The conditions in the sea outside the bay are important for the concentrations of the substances in water, sediments and fish within the bay, 2. We have demonstrated “biological,” “chemical” and “water” dilution, 3. That the water chemical conditions in the bay influence biouptake and concentrations in fish of the radionuclides and 4. That the feeding behaviour of the coastal fish is very important for the biouptake of the radionuclides. [Copyright &y& Elsevier]

This article discusses the aging of radionuclides in soil and the changes over time. The authors used drying and wetting cycles on soils contaminated with strontium and cesium radioisotopes from Chernobyl, Ukraine and Mediterranean areas. They found that aging was more relevant for cesium than for strontium. The fixed fractions were measured by an extraction test, but sorption could not be predicted from soil properties such as clay content. They concluded that the tests for aging will permit remediation design at contaminated sites to be improved.

The article focuses on the radiochemoecological monitoring of the salt lakes of Crimea, Ukraine. Topics discussed include Chernobyl nuclear power plant (NPP) accident, mercury (Hg), which is considered as the most dangerous chemical pollutants in marine ecosystem, and growth of anthropogenic impact and climate change in the region. Also mentioned are sediments, hydrobionts, and strontium (Sr).

• The Nikopol deposit is one of the world's largest deposits among the sedimentary Mn deposits. • The total REE contents are between 60 ppm and 197 ppm, with a mean of 108 ppm. • The Ce/Ce* values of manganese oxide-hydroxide ores vary from 0.88 to 1.43. • All data indicate that the Nikopol manganese oxide ores formed within oxic-suboxic seawater. • The metals formed to the Mn-oxide ores were syngenetically transported from deeper water depths. The Nikopol manganese deposit is situated in the west and north of Nikopol, Ukraine and one of the world's largest deposits among the sedimentary manganese deposits. The Nikopol Oligocene basin consists of two structural stages, Precambrian crystalline basement rocks and sedimentary cover rocks (Cretaceous to Quaternary). Nikopol Ore horizon is traced in a thickness varying from several cm to 4.5 m and a single stratum from the west to the eastwards to about 250 km. Nikopol manganese ore horizon was separated to three different units; carbonate ore, mixed carbonate-oxide ore, and oxide ore. The main minerals of supergene oxidation zone in Nikopol manganese deposits are: manganite, pyrolusite, todorokite, cryptomelane, birnessite, rancieite. The manganese oxide-hydroxide ores were analyzed for major oxides using ICP-AES and, trace and rare earth elements (REE) using ICP-MS. The mean major oxide contents of the manganese ores are 40.7 wt% MnO, 4.1 wt% Fe 2 O 3, 15.6 wt% SiO 2 , 4.17 wt% for Al 2 O 3 , and 7.1 wt% for CaO. The average Mn/Fe, Co/Ni, Co/Zn, and Zr/Hf ratios in the Nikopol manganese deposit are 25, 0.54, 1.15, and57, respectively. The total REE contents are between 60 and 197 ppm, with a mean of 108 ppm. The PAAS-normalized REE patterns of the Nikopol manganese oxide ores have similar trends and show MREE (middle rare earth element) and HREEs (heavy rare earth element) enrichments. The Ce/Ce* values of manganese oxide-hydroxide ores collected from the study area vary from 0.88 to 1.43, with the mean of 1.16. Most of manganese samples have positive Ce anomalies except for a few samples, indicating that ore-forming rocks were primarily marine chemical or biogenic deposit. The Eu/ Eu* anomalies of the manganese oxide-hydroxide ores are close to 1 with a range of 0.68 to 1.12 (mean: 0.96). The Y concentrations vary from 9.1 to 47.1 ppm, with an average of 18.2 ppm and show negative Y anomalies, except for three samples. The Pb isotope ratios are 19.0 for 206Pb/204Pb, 15.7 for 207Pb/204Pb and 39.4 for 208Pb/204Pb isotopes. All these data indicate that the Nikopol manganese oxide-hydroxide ores formed rapidly within oxic/suboxic seawater as reflected by Ce anomalies close to 1 in compared to similar environments, low-oxygen fugacity in source of the hydrothermal fluids, volcanogenic input or hydrothermal contributions to seawater, and high Co, Ni, Cu, Sr, Ba and As and low V, Rb, Nb, Hf, U, Th, Pb and Zn values. Also, our results point out that the metals were transported from both a hydrothermal source in deeper water (chemical discrimination diagrams) and terrestrial sources (Pb isotopic data). The metals formed to the Mn-oxide ores syngenetically likely came from water depths deeper than the area where the carbonate-ore deposits formed. [ABSTRACT FROM AUTHOR]