137Cs Concentrations Research Articles

137Cs and 40K activity concentrations in edible wild mushrooms from China regions during the 2014–2016 period

Introduction. Contamination by radiocaesium of edible wild mushrooms after major nuclear accidents is a long-lasting process in some regions of the world. Following greater awareness of radioactive pollution in Asia, particularly after the Fukushima accident, this study investigated the radioactivity of 137Cs and 40K contamination in edible wild mushrooms in China.
 Study objects and methods. The objects of the research were edible wild mushrooms collected during 2014 to 2016, from the Inner Mongolian and Yunnan regions of China. To obtain an insight into any environmental impacts to distant regions of mainland Asia, the mushrooms were analyzed for 137Cs activity. In parallel, the natural activity of 40K was also determined and used to estimate the content of total K. The topsoil underneath the mushrooms was also investigated from a few sites in Bayanhushu in Inner Mongolia in 2015.
 Results and discussion. The results showed that in 4 to 6 mushrooming seasons after the accident, mushrooms from both regions were only slightly contaminated with 137Cs, which implied negligible consequences. The activity concentrations of 137Cs in dried caps and whole mushrooms in 63 of 70 lots from 26 locations were well below 20 Bq kg–1 dry weight. Two species (Lactarius hygrophoroides L. and Lactarius volemus L.), from Jiulongchi in Yuxi prefecture showed higher 137Cs activities, from 130 ± 5 to 210 ± 13 Bq kg–1 dw in the caps. 40K activities of mushrooms were around two- to three-fold higher. A composite sample of topsoil (0–10 cm layer) from the Bayanhushu site (altitude 920 m a.s.l.) in Inner Mongolia showed 137Cs activity concentration at a low level of 6.8 ± 0.7 Bq kg–1 dw, but it was relatively rich in potassium (40K of 595 ± 41 Bq kg–1 and total K of 17000 ± 1000 mg kg–1 dw).
 Conclusion. Wild mushrooms from the Yunnan and Inner Mongolia lands only slightly affected with radioactivity from artificial 137Cs. Lack of 134Cs showed negligible impact from Fukushima fallout. Ionizing radiation dose from 137Cs in potential meals was a fraction of 40K radioactivity. The associated dietary exposure to ionizing irradiation from 137Cs and 40K contained in mushrooms from the regions studied was considered negligible and low, respectively. Mushroom species examined in this study are a potentially good source of dietary potassium.

A comparative study of riverine 137Cs dynamics during high-flow events at three contaminated river catchments in Fukushima

This study presents the temporal variations in riverine 137Cs concentrations and fluxes to the ocean during high-flow events in three coastal river catchments contaminated by the Fukushima Daiichi Nuclear Power Plant accident. River water samples were collected at points downstream in the Niida, Ukedo, and Takase Rivers during three high-flow events that occurred in 2019–2020. Variations in both the dissolved and particulate 137Cs concentrations appeared to reflect the spatial pattern of the 137Cs inventory in the catchments, rather than variations in physico-chemical properties of water and suspended solid. Negative relationships between the 137Cs concentration and δ15N in suspended solid were found in all rivers during the intense rainfall events, suggesting an increased contribution of sediment from forested areas to the elevation of particulate 137Cs concentration. The 137Cs flux ranged from 0.33 to 19 GBq, depending on the rainfall erosivity. The particulate 137Cs fluxes from the Ukedo River were relatively low compared with the other two rivers and were attributed to the effect of the Ogaki Dam reservoir upstream. The percentage of 137Cs desorbed in seawater relative to 137Cs in suspended solids ranged from 2.8% to 6.6% and tended to be higher with a higher fraction of exchangeable 137Cs. The estimated potential release of 137Cs desorbed from suspended solids to the ocean was 0.022–0.57 GBq, and its ratio to the direct flux of dissolved 137Cs was 0.12–6.2. Episodic sampling during high-flow events demonstrated that the particulate 137Cs flux depends on catchment characteristics and controls 137Cs transfer to the ocean.

137Cs Concentration In Soils Collected From Bulgaria-Turkey Border Region

The Chernobyl accident caused artificial radioactive contamination, especially artificial 137Cs radionuclide contamination. Due to having long half-life, 137Cs still continues to remain in soils. In the present study, the surface soil samples were collected from various locations in Bulgaria-Turkey border. The activity concentrations of 137Cs in collected soil samples were determined. In order to investigate the radiological hazard; the dose rates and the annual effective dose rates were estimated. The activity concentrations of artificial 137Cs radionuclide in soils were found to range from 1.71±0.18 Bq kg−1 to 6.99±0.66 Bq kg−1. The mean values of absorbed dose rates, outdoor and indoor annual effective dose rates were found to be 0.10, 4.19, and 16.77 µSv y−1, respectively. The dose rates and the annual effective dose rates were below the worldwide limit values reported by UNSCEAR and ICRP. In addition, statistical data were estimated, frequency distribution and Q-Q plot were used to assess 137Cs distribution.

RADIATION SAFETY ASSESSMENT OF CARROT AND BEET PRODUCTS CULTIVATED IN THE BLACK EARTH ZONE OF RUSSIA IN THE OREOL OF THE EASTERN CHERNOBYL TRACE

On the territory of the Plavsky radioactive hotspot of the Tula region of Russia, formed as a result of the accident at the Chernobyl nuclear power plant in 1986, an assessment of the radiation safety of growing carrots and beets was carried out in 2019. It has been established that at present the content of 137Cs in arable leached chernozems of the surveyed lands is 90–170 kBq/m2 , which is 2.5–4.5 times higher than the permissible level of density of surface radioactive contamination of soils. However, the specific activity of the radionuclide in carrot and beetroot crops does not exceed 5 Bq/kg, which is significantly less than the maximum permissible level of 137Cs accumulation in vegetables (600 Bq/kg for absolutely dry weight). The accumulation coefficients of 137Cs in the total biomass of carrots and beets are 2.0·10−2 and 7.5·10−2, and in eaten root crops – 1.1·10−2 and 2.0·10−2, respectively, which is in good agreement with the IAEA estimate for the intensity of the transition 137Cs in the production of vegetable roots from loamy and clayey soils.

The role of Cs dopants for improved activation of molecular oxygen and degradation of tetracycline over carbon nitride

Molecular oxygen (O2) is activated to reactive oxygen species (ROS) by transferring energy and carriers in the photocatalytic process, which plays an important role in environmental remediation. Herein, Cs-doped carbon nitride (CN-xCs, x = 0.2, 0.8, 1) was prepared by CsCl directly inducing the structural reconstruction of carbon nitride (CN), which had obvious molecular oxygen activation ability to promote tetracycline (TC) degradation. Besides, we explored the influence of Cs doping concentration. As a consequence, the doping concentration of Cs was an important factor affecting the activation of O2, which could cause changes in the physical and chemical structure of CN, make O enter the CN structure, form N vacancy defects and cyano groups. In addition, a proper amount of Cs doping could reduce the band gap value, increase the light absorption range, have better charge separation and transfer performance, which could remarkably promote the activation of O2. Benefiting from these advantages, CN-0.8Cs could generate a higher concentration of superoxide radicals (•O2−, 179.30 µmol/L), which was much higher than CN (6.22 µmol/L). Therefore, it exhibited excellent TC degradation photocatalytic performance, and the rate constant k of TC degradation was 0.020 min−1, which was 6.7 times the degradation rate of CN (k = 0.0030 min−1). Furthermore, the possible degradation pathways of TC were proposed based on the results of HPLC-MS.

THRESHOLD LIMIT VALUES OF RADIONUCLIDES IN THE WATERBODIES

When the content of 90Sr and 137Cs in reservoir water is below the permissible level, even for drinking water, the specific activity of radionuclides in fish can be hundreds and thousands of times higher than the established hygienic standards of DR-2006. The purpose of this work was to determine the maximum permissible concentrations of 90Sr and 137Cs in the water of reservoirs depending on the content of calcium and potassium in the water based on the parameters of the metabolism of cesium and strontium in fish, which guarantee that the established hygienic standards of radionuclides in fish (DR-2006) are not exceeded with a probability of 95%. It is shown that in reservoirs with low water mineralization, the maximum allowable concentrations of 90Sr and 137Cs will be too low at the level of Bq units per cubic meter and difficult to measure, unlike radioactive contamination of fish, which makes them, even with minor radioactive contamination of reservoirs, a unique bioindicator for the purposes radiation protection of people and the environment.

Evaluation of the radiation effect on building highway subgrade using 137Cs slightly polluted soil after nuclear power plant accidents

After the accident at the Fukushima nuclear power plant in Japan, a large amount of radioactive contaminated soil was generated, which brought great challenges for treating and disposing of the soil. The recycling of slightly polluted soil can reduce the amount of contaminated soil. This paper analyzes the main exposed scenes of 137Cs polluted soil used in the construction of highway subgrade, soil bag handling and paving. The Monte Carlo algorithm (MCNP) and RESRAD-ONSITE program are used to simulate the two scenes respectively, and the concentration of 137Cs is derived in the soil at the effective dose of 1 mSv per year. It is concluded that: the annual effective doses of porter and paver are 0.41 mSv per year and 0.23 mSv per year respectively caused by 1 Bqg-1 137Cs contaminated soil; the activity of 137Cs are 2.44 Bqg-1 and 4.26 Bqg-1 respectively in the soil at 1 mSv per year for porter and paver; the calculated results are consistent with those reported by the Japan Atomic Research Agency. Also, they are lower than the activity concentration corresponding to the effective dose control level of 1 mSv per year under low-probability events in IAEA No. RS-G-1.7 slightly.

RADIOACTIVELY CONTAMINATED TERRITORIES OF CHERNIHIVSKA OBLAST OF UKRAINE: THE RADIATION-ECOLOGICAL AND MEDICAL-DEMOGRAPHIC PAST AND PRESENT.

to determine the current radiationecological and medicaldemographic parameters of the territories of Chernihivska oblast of Ukraine, which were recognized as radioactively contaminated as a result of the Chornobyl Nuclear Power Plant accident, and to assess their changes in the postaccident period. The parameters of contamination of natural environments (soil, food products), both with number, structure, natural and migratory movement of population of radioactively contaminated territories of Chernihivska oblast of Ukraine (Kozeletskyi, Koriukivskyi, NovhorodSiverskyi, Ripkynskyi, Semenivskyi, Sosnytskyi, and Chernihivskyi districts) were the study objects. Data from the Chernihiv Regional Office of the State Statistics Service of Ukraine,Department of Ecology and Natural Resources of the Chernihiv Regional State Administration, and CentralEnvironmental Dosimetry Register of the State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine» were used. General scientific, mathematicalstatistical, graphic, cartographic, and softwaretechnological research methods are applied. After the accident at the Chornobyl Nuclear Power Plant the largescale radioecological monitoring was conducted on the territory of Chernihivska oblast, where a significant improvement in the state of radioactively contaminated areas had been observed. The number of settlements where the soil contamination density with cesium isotopes exceeded the lower limit for the zone of guaranteed voluntary resettlement (185 kBq*m2) has decreased from 8 to 1. The average regional concentration of 137Cs in milk mostly did not exceed 50 Bq*l1. The average concentration of 137Cs in potatoes from private households over the entire observation period was 5-10 times lower than in milk. Analysis of medical and demographic data allowed concluding that the districts of Chernihivska oblast, which were most intensively contaminated after the Chornobyl accident, feature now some regional problems. There are trends towards population decline and birth rate decrease along with increase in mortality. The most intensive changes had occurred in Kozeletskyi and Ripkynskyi districts, where destructive processes in the age structure of population and a stable trend of increase of mortality rates were revealed. Research should be continued.

Reconstruction of the Arrival and Migration of 137Cs and 90Sr in the Ecosystem of the Barents Sea

Based on the analysis of data from long-term radioecological observations in the Barents Sea, the main migration flows of 137Cs and 90Sr in its ecosystem have been reconstructed. In the current (2010–2019) balance of technogenic radioactivity, the transboundary transfer of radioisotopes from the Norwegian Sea accounts for more than 90% of the total intake. Most of the incoming radionuclides are removed from the Barents Sea through its northern and northeastern borders in the process of water exchange. A significant decrease in the concentrations of radionu- clides in the components of the environment and biota in the “post-nuclear era” is shown. The content of 137Cs and 90Sr in the food web of the marine ecosystem was estimated in comparison with the reserve of their activity in water and bottom sediments. The biotas accumulate no more than 0.01% of the total isotope content in the ecosystem.

Nanoencapsulation of Cordycepin Induces Switching from Necroptosis to Apoptosis in Human Oral Cancer Cells (HSC-4) Through Inhibition of Receptor-Interacting Serine/Threonine-Protein Kinase 3 (RIPK3) and Autophagy Modulation

Human oral squamous carcinoma is considered the most common oral cancer; it imposes multiple oral and dental consequences as a result of oral cancer treatment. We previously found that the nanoencapsulation of cordycepin (CS) could inhibit oral cancer cells. However, the mechanism of action was not understood. The aim of this study was to investigate the signaling pathway by which CS and encapsulated nanoparticles (NPs) activate the inhibition of cancer cell growth. We demonstrated that human oral cancer (HSC-4) cells underwent necroptosis when incubated with high concentrations of CS, but not when incubated with either low concentrations of CS or encapsulated CS NPs. High concentrations of CS-induced necroptosis of HSC-4 cells, demonstrated by a reduction in apoptotic ( BAX, Caspase-3, Caspase-8, and Caspase-9) and autophagic genes ( LC3, Atg5, and Atg12). However, low concentrations of CS significantly induced the expression of autophagic gene LC3. Interestingly, encapsulated CS NPs induced a significant increase in apoptotic genes ( P53, BAX, Caspase-3, Caspase-8, and Caspase-9), but a significant decrease in autophagic ( P62, Atg5, and Atg12) and necroptotic genes ( receptor-interacting serine/threonine-protein kinase 3 [RIPK3]) . We also found that encapsulated CS NPs enhanced the accumulation of cellular protein and decreased secreted supernatant protein levels. Moreover, encapsulated CS NPs had higher efficacy in terms of reactive oxygen species (ROS) generation-mediated inhibition of autophagy compared to nonencapsulated CS, suggesting that nanoencapsulation of CS can switch the program of HSC-4 cell death from necroptosis to apoptosis. In conclusion, HSC-4 cells have a defense strategy against CS-induced cell apoptosis, but this problem can be solved through the use of encapsulation combined with nanotechnology.

Measurement of 226-Ra, 232-Th, 40-K and 137-Cs concentrations in sediment samples and determination of annual effective dose due to these radionuclides in vicinity of hot springs in Kerman Province

Measurement of 226-Ra, 232-Th, 40-K and 137-Cs concentrations in sediment samples and determination of annual effective dose due to these radionuclides in vicinity of hot springs in Kerman Province

Uncertainty in Aerosol Rainout Processes through the Case of the Radioactive Materials Emitted by the Fukushima Dai-ichi Nuclear Power Plant in March 2011

The process of an aerosol rainout in wet deposition induces large uncertainties among atmospheric aerosol simulations, especially for particles in the fine mode. In this study, we performed an intercomparison study of four different rainout schemes on the model (the nonhydrostatic icosahedral atmospheric model or NICAM) to simulate particulate Cs-137 in the emission scenario of the March 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant. The schemes include global climate models (GCMs) approach with a simple tuning parameter to determine the scavenging coefficient, and another optimized for cloud resolving models (CRMs) to account for prognostic precipitation and realistic vertical transport. The third approach was the conventional method under the assumption of a pseudo-first-order approximation based on the surface precipitation flux. The fourth approach was involved in offline chemical transport models (CTMs) with a simplified parametric analysis approach to clouds and precipitation flux. In most experiments, statistical metrics of the Cs-137 concentrations using in-situ measurements were calculated to be within ±30 % (bias), 0.6–0.9 (correlation), 67–112 Bq m−3 (uncertainty), and < 40 % (precision within a factor of 10). The CRM-type method yielded the best results but required a lower limit of tuning parameters to compensate for the results. Both the GCM-type and the conventional methods were also useful by setting proper tuning parameters. The CTM-type yielded better correlation and lower uncertainty but larger negative bias. These analyses suggest the overestimation of the conversion rate from cloud droplets into raindrops by the NICAM. However, this cannot be resolved by simply interchanging cloud microphysics schemes. It was found that the sensitivity of the rainout scheme has a stronger influence on the Cs-137 concentration than the different treatments of cloud microphysics. Thus, to replicate the observed Cs-137 distribution, it is essential to have a better meteorological field as well as a proper rainout scheme.

DETERMINATION OF RADIONUCLIDE CONCENTRATION IN MILK SAMPLES CONSUMED IN REPUBLIC OF NORTH MACEDONIA AND POPULATION DOSE RATE ESTIMATES

Milk is one of the most important food products in the human diet and contains all the macronutrients, that is, proteins, carbohydrates, fat, vitamins (A, D and B groups) and trace elements, especially calcium, phosphorus, magnesium, zinc and selenium. Milk contamination is largely due to the grazing of animals on contaminated grass and drinking water. Grass is a direct source or route of radionuclides to animals and humans through the consumption of meat and milk. One of the important tasks of the veterinary activity is veterinary-sanitary supervision of the production and sale of milk and dairy products, whose main goal is the provision of biologically good milk and dairy products from healthy animals.The purpose of this study was to determine the activity concentrations of 226Ra, 232Th 40K and 137Cs in milk samples most commonly used in daily consumption in the Republic of North Macedonia and based on the results, the risk of radiation to the population can be estimated. An instrument - gamma spectrometer (Canberra Packard) with a high purity germanium detector and GENIE 2000 program was used for measurement of the samples.On the basis of the performed tests, the mean activity concentrations of 226Ra, 232Th, and 40K were 1.76 ± 0.23; 1.05 ± 1.00; 31.9 ± 5.07 (Bq·kg-1), respectively. 40K has the highest value compared to other radionuclides due to the process of transfer from soil to grass and from grass and water to milk.The activity of 137Cs is below the detection limit for all tested milk types. This shows that there is no risk of radiation to the population, i.e., the safety limits are not exceeded, which points out the insignificant threat of radiation arising from radionuclides that are naturally or artificially present in the tested milk, and that reach humans through the food chain.

RADIOACTIVE CONTAMINATION AND DOSES OF INTERNAL IRRADIATION OF FISH IN THE DEEP LAKE OF THE CHORNOBYL EXCLUSION ZONE

After the accidents at the Chornobyl and Fukushima NPPs, the specific activity of radionuclides in fish in radioactively contaminated reservoirs reached hundreds of kBq kg-1. Over time, as the radiological situation improved, there was a decrease in radioactive contamination of fish, but even now there are cases of exceeding the permissible levels of radionuclides in food. This work aimed to determine in real conditions the content of 90Sr and 137Cs in different species of fish in one of the most radioactively contaminated reservoirs of the Chornobyl Exclusion Zone - Glubokoye lake. As a result of experimental studies conducted from 2016 to 2021, the values of the specific activity of 90Sr and 137Cs in different species of fish were obtained, which were hundreds of times higher than the permissible levels. It is shown that without the use of countermeasures, this situation will persist for several decades. The results show that the internal radiation doses of fish due to the level of their radioactive contamination do not exceed the permissible levels recommended by international organizations for radiation protection of the environment.

COMPLEX RADIATION AND HYGIENIC MONITORING OF POPULATION ON RADIOLOGICALLY CONTAMINATED TERRITORIES OF ZHYTOMYR OBLAST IN 2021.

the key factors identification in radiation dose formation in population of radiologically contaminatedareas of Zhytomyr oblast in the current period of accident through complex radiation and hygienic monitoring in reference settlements in 2021. For complex radiationhygienic monitoring in Zhytomyr oblast, 10 settlements were chosen - Narodychi, Selets, Bazar, Rudnya Bazarska, Khrystynivka - zone 2, Motiyki, Zalissya, Davydky, Radcha, Nova Radcha - zone 3 of Narodychi district, in which the highest radiation doses were recorded after the accident at the Chornobyl Nuclear Power Plant. The research was carried out in June 2021. In order to determine the doses of internal radiation, 645 measurements were performed on whole body counters (WBC) (478 adults and 167 children). The 44 samples of milk, 45 samples of potatoes and vegetables, and 38 samples of wild products were collected in local farms and measured for the 137Cs and 90Sr content. Residents of the studied settlements (n = 220, 175 adults, and 45 children) were interviewed about the levels of consumption of staple foodstuffs. External radiation doses were evaluated in all the studied settlements. Mathematical, dosimetry, and radiochemical methods were applied. Annual effective radiation doses of Zhytomyr oblast population in 2021 were formedmainly due to internal radiation ones that not exceeded 1.8 mSv * year-1 in adults and 0.5 mSv * year-1 in children against the radiologically contaminated territories (RCT) criterion of 1 mSv * year-1. Intake of 137Cs with milk and wild mushrooms, which traditionally occupy a significant part of diet in Zhytomyr oblast area and have consistently high levels of radioactive cesium contamination, remains a key factor of internal radiation dose forming in residents of the surveyed settlements of Zhytomyr oblast.

Radioecological studies of urban soils in the Arkhangelsk region

The aim of the study: to analyze the radioecological status of soils in the Mezen city and the Kamenka village (Mezensky district of the Arkhangelsk region) and to identify low-intensity anomalies in soil 137Cs, 226Ra, 232Th and 40K specific content on the studied territory. Location and time of the study. Field work was carried out in the summer of 2021 on the territory of the Mezen city and Kamenka village and their environs (Mezensky district of the Arkhangelsk region). Methodology. To accomplish the task, the soil from the upper 5 cm layer of Urbikvizems, Culturozems and Replantozems at 68 sites was sampled in the study area. Under laboratory conditions, the samples were air-dried and placed in Marinelli vessels to measure specific activity of isotopes by gamma spectrometry. The registration of gamma radiation from a soil sample, as well as the processing of the spectra, was carried out using the Progress-gamma software and hardware complex FVKM.412131.002-03. The energy calibration of the gamma spectrometer was carried out after each measurement using a combined control source OISN-137-1 in a 1-liter Marinelli vessel. The minimum exposure time for the counting sample was 3600 seconds. Results. The specific activity of 137Cs in the upper 5 cm layer varied from 1,6 to 24,2 Bq/kg in Mezen and from 2,4 to 26,1 Bq/kg in Kamenka, with an average value of 5,88 and 8,27 Bq/kg, respectively; higher specific activities of this radionuclide was observed in the Kamenka soils as compared with the Mezen soils. For 226Ra and 232Th higher activity was also observed in the Kamenka soils. The 40K specific content in the urban soils of the studied area was almost uniform. The specific activity of technogenic 137Cs and natural radionuclides 226Ra, 232Th and 40K in the upper 5 cm of soil layer on pastures and grasslands was comparable to the urban soils in Mezen and Kamenka. In forest soils the 137Cs specific activity was more than three times higher, reaching 65,4 Bq/kg. Analysis of the spatial distribution of the specific activity of technogenic 137Cs and natural radionuclides 40K, 226Ra and 232Th showed that small local anomalies (SLA) of 137Cs (T1/2=30.17 years) were confined to the park zone of the central and southern parts of Mezen, where 4 MLAs were recorded. The natural radionuclides 226Ra (T1/2=1590 years), 232Th (T1/2=1, 41*1010 years) and 40K (T1/2=1.3*109 years) were found mainly in meadow soddy soils on the western outskirts of the city, in areas of one-story buildings (private sector), along banks of the Tova River and also in the airport area. In the rest of the Mezen city, the measured concentrations of the studied radionuclides were minimal. The spatial distribution of the studied radionuclides, revealed in the upper soil layer in the Mezen city, was also typical for Kamenka, where SLA of 137Cs were found in the soils of park areas in the southwestern part of the village without intensive anthropogenic impact. 226Ra and 232Th were characterized by increased concentrations on the outskirts of Kamenka in the north and south. The distribution of 40K is almost uniform throughout the entire study area, including not only the outskirts, but also the central parts of the village. Conclusions. The content of natural and technogenic radionuclides in the urban soils of the Mezen city and Kamenka village do not exceed the maximum allowable concentrations and are typical for urban settlements in the Arkhangelsk region. Higher activity of 137Cs the Kamenka soils as compared with the one in the Mezen soils can be explained by varying degrees of anthropogenic impact on soils in the studied area. SLA of 137Cs in park soils are due to the minimal anthropogenic impact; moreover, the soddy soil layer firmly fixes the atmospheric input by humic acids. SLA of 226Ra and 232Th in the meadow soddy is soils closely associated with the underlying sandy quaternary deposits, concentrating the elements. The SLA of potassium in these areas can be explained by the dense herbaceous vegetation, which easily involves the element in the biological cycle, thus contributing to its accumulation in the upper soil horizon.

Selected aspects of caesium-137 contamination in wild boars (Sus scrofa)

Monitoring the activity of radionuclides in food is part of the monitoring system of foreign substances. A close correlation between gamma spectrometry determined by 137Cs activity concentration in the meat and stomach wall (r = 0.984) was found in monitored Slovak wild boars with a low activity of 137Cs . The transfer factors of the soil and the stomach content and the soil and the meat were approximately 0.07 at the median. The median transfer factor between the stomach content and the stomach wall is similar to that of the stomach wall and the meat (2.412 and 1.805). The mean value of 137Cs activity concentration in the muscles of wild boars from the Czech Republic was 46.7 Bq·kg-1. The mean value of 137Cs activity concentration in the stomach wall was 23.7 Bq·kg-1. The mutual correlation was r = 0.988. There was further correlation of 137Cs activity concentration between the heart and the diaphragm (r = 0.977), the heart and the tongue (r = 0.902), and the heart and the lungs (r = 0.906). Based on the results from Slovakia and the Czech Republic, there is hope that it will be possible to use a sample from the stomach wall to determine the activity concentration of 137Cs in meat, thereby replacing the commonly used and highly valued top side sample. In practice, monitoring soil contamination to predict the meat contamination of wild boars is more important than monitoring elements of the food chain. The potassium-caesium coefficient reached 5.57 in the muscles and 17.25 in the stomach wall.

MINERAL COMPOSITION AND ADSORPTION CAPACITY OF PRECIPITATES FORMED DURING OZONATION OF RADIOACTIVELY CONTAMINATED WATER FROM NUCLEAR POWER PLANTS TOWARDS 137Cs

The mineral composition and sorption properties of precipitates formed during ozonation of a model solution simulating nuclear power plant wastewater (total mineralization 7 g/dm3, pH = 11.5, T = 60°C, t = 2 hours) 137Cs were studied. The precipitate is represented by finely dispersed spherical particles of metal oxides ranging in size from 20 to 30 nm, forming microaggregates and their associates of various shapes. The composition of the precipitates, along with X-ray amorphous phases, includes Fe(II)-Fe(III) layered double hydroxides (Green Rust), as well as LDH of mixed composition, in particular Fe-Co, and iron oxyhydroxides — goethite and lepidocrocite. The precipitates also contain manganese-containing phases represented by manganese (IV) hydroxide and manganese (II) carbonate with an admixture of manganese oxides, such as Mn2O3∙H2O, MnO, Mn3O4 (gaussmanite). In the process of ozonation, organic compounds that are part of the solutions undergo destruction, co-precipitation with other components of the solution, which is accompanied by the sorption of 137Cs radionuclides on the surface of mineral particles. An increase in the concentration of Fe2+ and Mn2+ cations by 10 times (up to 50 and 100 mg/dm3, respectively) in wastewater reduces the concentration of 137Cs in the initial solution by 50.5%.

Distribution and influence of forest fires on the ecological and radiation situation in radioactively contaminated areas

The article discusses the main causes of forest fires in radioactively contaminated areas and the factors affecting the spread of fires and radioactive substances. It is certain that the main elements of influence on the ecological and radiation situation are the intensity and direction of migration of radioactive combustion products. It is proposed to use a model based on deflation parameters, such as radioactivity, maximum wind speed, using the results of experimental studies. The results obtained were verified by calculating the surface concentration of 137Cs released into the atmosphere after a forest fire in the Chernobyl exclusion zone. For the deflation intensity factor, graphical dependencies were obtained under various meteorological conditions.

RESULTS OF RESEARCH OF PERSONAL HYGIENE PRODUCTS FOR SUITABILITY FOR SPECIAL PROCESSING IN ZONES OF CHEMICAL, RADIOACTIVE CONTAMINATION AND IN COMBAT CONDITIONS.

The aim: Research of personal hygiene products with detoxification properties by evaluating their formulation composition, emulsifying and complexing ability to heavy metal ions and radionuclides. Materials and methods: The complex-forming ability of raw materials with heavy metal ions was determined in vitro, the content of heavy metals was determined by the method of atomic emission spectrometry with inductively coupled plasma (BS EN 13805:2014); determined the content of 137Cs, 232Th, 40K, 226Ra, 90Sr in washings from the surface of the skin of hands treated with personal hygiene products. The means were tested for compliance with the standard on scintillation spectrometers of gamma radiation energy «SEG-001» «AKP-S» and beta radiation (SEB-01-70); methods used: MI 12-04-099 and MI 12-05-099. Results: A high complexing ability of the pectin-containing «Liana» shampoo was found in relation to heavy metal ions (Co2+, Cu2+, Zn2+, Cd2+, Pb2+), as well as in their combined presence. It was established that the effectiveness of removing fatty impurities from the surface of the skin of the «Liana» product was 10.1 times higher than that of liquid soap (p<0.001). A high level of deactivating, degassing and antibacterialproperties of the personal care products «Bastion» and «Bastion-M» was revealed. Conclusions: Today, there is significant potential in the creation of formulations for special (sanitary) skin and hair surface treatment, containing natural complexing agents as detoxicants, and can be used in special professional activities associated with the risk of exposure to CBRN factors.