Zone Of Radioactive Contamination Research Articles

Experience of using the portable gamma spectrometer MKS AT6101D for in situ measurements of the density of <sup>137</sup>Cs soil contamination in the Bryansk region of Russia

We have tested applicability of the commercially available portable spectrometer-dosimeter MKS AT6101D (the manufacturer: ATOMTEX, Belarus) to measure the density of 137Cs soil contamination (inventory of 137Cs in soil) in situ. The study was performed in 2015–2020 at the territories of the Bryansk region of Russia contaminated due to the Chernobyl accident. The in situ measurements were performed in the 17 ground plots (7 grasslands and 10 kitchengargens) for which the 137Cs inventory and the mean migration depth of the radionuclide in soil was available from laboratory (ex situ) measurements of soil samples. It was found that the in situ data obtained with the method that was provided by the manufacturer of the instrument required additional correction on the vertical distribution of 137Cs in the soil. The correction procedure was developed; in 2020–2021, it has been successfully tested in 114 kitchengarden plots located at the settlements in the zones of radioactive contamination in the Bryansk region.

Peculiarities of the exposure dose formation on the population in the most affected regions of Russia after the Chernobyl NPP accident

The paper presents an analysis of the current radiation situation in the settlements of the Russian Federation located on the most radioactively contaminated territory after the Chernobyl accident. The assessment of 137Cs content in local agricultural (milk, beef, pork, potatoes), natural (mushrooms) foodstuffs, doses of external, and internal irradiation of residents was carried out. 37 years after the Chernobyl NPP accident, 72 settlements with a total number of residents of 63869 remain in the zone of radioactive contamination whose average effective radiation doses exceed 1 mSv/year. All these settlements are located in five southwestern districts of the Bryansk region and are rural except for Novozybkov. In the private sector of settlements, potatoes and pork fully comply with radiological standards for the content of 137Cs. In milk, the content of the radionuclide can exceed the standards up to 3, in beef up to 5, in mushrooms up to 8–17 times. Over the past 30 years, the number of settlements exceeding the legally established standard for the total exposure dose to the population (1 mSv/year) has decreased by 7.5 times. Due to the decrease in the levels of 137Cs contamination of local foodstuffs and the volume of their consumption, the role of internal exposure dose has been decreasing in recent years. It was noted that in addition to a comprehensive assessment of the radiation situation in settlements, agricultural and natural ecosystems, when planning the rehabilitation of settlements with average annual radiation doses of residents above 1 mSv, it is important to take into account the current diets of residents and the real demographic situation in the territories affected by the Chernobyl accident.

CURRENT RADIOLOGICAL STATUS OF CONTAMINATED MEADOWS AND PASTURES AND ASSESSMENT OF THE POSSIBILITY OF THEIR RETURN TO USE

Meadows and pastures are the fodder base for milk and meat production. The rehabilitation and return to economic use of the radionuclide-contaminated meadows and pastures is an important and urgent national economic task. The criterion of returning radionuclide-contaminated meadows and pastures to economic use may be individual doses to residents who consume milk and meat produced on these lands. Values that determine the doses are the terrestrial density of soil contamination and permissible levels of radionuclides in food products (PL-2006). Considering abandoned agricultural lands, it is necessary to note the time that passed after the accident. The contamination of the territory by 137Cs and 90Sr decreased in more than 2 times due to radioactive decay only. The decreasing due to radioactive decay and self-remediation processes (fixation of radionuclides by soil, their redistribution in the root layer of the soil, etc.) resulted in declining of radioactive contamination of products. This allows us to consider the issue of returning reclaimed lands to use in accordance with the current radiological criteria and existing legal acts. Agricultural lands are a territorial resource and the main means of agricultural production, therefore the rehabilitation of the lands will contribute to the development of both individual producers and settlements as a whole. After the Chornobyl accident, in accordance with the Law of Ukraine "On the Legal Regime of the Territory Exposed to Radioactive Contamination Due the Chornobyl Catastrophe", the territory exposed to radioactive contamination had been divided into zones. However, the belonging of the lands to a zone does not guarantee that the products produced there will meet the requirements of PL-2006. Therefore, in 1998, taking into account the type of soil, the UIAR assessed the maximum permissible levels of soil contamination which ensure the fulfillment of the requirements of PL-2006 in terms of the content of 137Cs in produced products. However, in the 25 years that have passed since the establishment of these levels and the cesium transfer factors into plants have decreased significantly. Therefore, the values of the maximum permissible levels of soil contamination are conservative and their use leads to conservative conclusions. The current radiological state of meadows and pastures contaminated with radionuclides and the possibility of returning them to use were assessed. It is shown that most of the considered abandoned lands actually belong to the third zone of radioactive contamination. Some of the lands belong to the second zone of radioactive contamination - radiation-hazardous lands. It was found that the restrictions set in the recommendations for conducting agriculture in the conditions of radioactive contamination for the production of milk and meat are very conservative. Assessment of the possibility of using contaminated meadows and pastures for milk and meat production requires more precise and targeted forecasting methods.

Influence of different diets and sorbents on the accumulation of Cd in the muscle tissue of young cattle and pigs

The article, based on scientific research, examines an important problematic issue regarding the quality and safety of beef and pork during their production in the Polissia zone of Ukraine, affected by the Chornobyl accident. The purpose of the research was to evaluate the effect of different diets and saponite sorbent on the level of Cd accumulation in the muscle tissue of young bulls and pigs kept in the territory belonging to the third zone of radioactive contamination. Two scientific and economic experiments were conducted. When growing Ukrainian black and white dairy young bulls, the influence of different silages (4-component cereal-bean mixture and Echinоchloa frumentаcea silage) on the content of Cd in the longest back muscle was studied (experiment 1), and optimization of the protein nutrition of animals was carried out at the expense of various feeds with a high protein content (narrow-leaved lupine and fodder beans) (experiment 2). In the third experiment, young pigs were fed various amounts of the natural mineral saponite as part of their diet, and its influence on the ecological quality of products was studied. Since different types and amounts of feed components were used when feeding the animals of the studied groups, it was necessary to balance the rations according to the content of nutrients for each of the presented groups. Regulation and verification of the nutritional value of the rationed feed was carried out monthly. When changing rations for animals, their growth, live weight, zootechnical analysis of feed, their nutritional value and feeding rates were taken into account. Sample preparation of fodder and muscles was carried out according to GSTU 7670:2014 with the help of dry mineralization, the concentration of the toxicant was determined by the atomic absorption method. The transition coefficient of Cd in the chain «diet – muscle tissue» in this study is within the established standards. At the same time, feeding by Echinоchloa frumentаcea silage contributed to a decrease in the coefficient of transition of Cd into the muscle tissue of young bulls by 0.68 % (absolute). The introduction of 30 % (by mass) of fodder beans into the grain mixture instead of a similar amount of lupine for young cattle (cattle) for fattening in the territory of radioactive contamination (the third zone) contributed to a significantly lower accumulation and transition of Cd into the muscle tissue of animals – on 25.0 % and 0.71 % (absolute), respectively. The inclusion of the natural sorbent mineral saponite in the amount of 3–7 % by mass of concentrated feed in the diet of growing and fattening pigs contributed to a reduction of Cd in the longest muscle of the back by 21.8– 37.9%, while at the same time it was better in terms of the sorption efficiency for excretion of Cd, which turned out to be a saponite dose of 7 %. Key words: young bulls, pigs, nutrition, different diets, saponite, accumulation of Cd.

THE MODEL OF INFORMATION MESSAGE OF MONITORING RESULTS IN CASE EMERGENCIES OR EMERGENCY THREATS IN THE BORDER ZONES OF RADIOACTIVE CONTAMINATION IN RUSSIA AND BELARUS

The article describes model of the structure of the interstate information message is presented task is prompt and detailed transfer of information on emergency situations and their consequences through the automated systems of data exchange between the regional departments of the EMERCOM of Russia (Bryansk region) and the EMERCOM of the Republic of Belarus of border areas (Gomel and Mogilev regions).The digital representation of the data in the message is based on the use of joint electronic directories: on the settlements in Gomel and Mogilev regions of the Republic of Belarus, Bryansk region of the Russian Federation; on interstate standards on radiation remedial measures and electronic exchange of information; on emergencies and their scale; on weather conditions. The structure of an electronic message has been developed on the basis of a number of joint electronic directories designed to support information exchange procedures, provided that the volume of transmitted data is minimized and the level of detail about emergencies and/or their threats in the zones of radioactive contamination of the border areas of Russia and Belarus is expanded.

Оцінка наслідків застосування тактичної ядерної зброї на населення та інфраструктуру в районах ядерного вибуху

The article analyzes the process of formation and establishes the characteristics of the striking factors of a nuclear explosion of tactical nuclear ammunition with a power of 0.1 to 10 kt when damaging military facilities and the accompanying damage to the population of civilian communities and personnel of infrastructure facilities. Calculated are data on the parameters of air shock wave action zones, penetrating radiation flow, light pulse energy beam flow, and the dimensions of the zone of radioactive contamination of the area, which can create a negative impact on the population, residential buildings, personnel, and critical infrastructure facilities in the area of application of tactical nuclear weapons. It is shown that the zone affected by an air shock wave, depending on the type of explosion of tactical nuclear ammunition and its power, can reach a radius of up to 3100 m. Dangerous light pulse damage to the population and personnel located in the open area will be observed at a distance of 440 to 3700 m from the epicenter of the nuclear explosion. The negative impact of the penetrating radiation of a nuclear explosion on the population and personnel of critical infrastructure facilities will be observed at distances from 560 to 1300 m, depending on the type of explosion and the power of the tactical nuclear ammunition. The dimensions of the zone of radioactive contamination, in the case of the explosion of tactical nuclear ammunition, in which the most severe degree of radiation damage to the population and personnel of critical infrastructure objects will be observed, with their open location in the area, depending on the power and type of explosion, can reach from 1400 to 2600 m. And the zone in which it is necessary to carry out the priority immediate evacuation of the population can be from 3.4 to 44.0 km in the direction of the average wind. It was determined that the scale of radioactive contamination of the area will have the greatest values of the size of the areas of negative impact relative to other types of impressive factors of the nuclear explosion of tactical nuclear ammunition. In large areas of the regions adjacent to the area of application of the specified ammunition, a significant negative radiation effect will be created, which will require measures of radiation protection and evacuation of the population.

OSCILLATORY PATTERN OF DISTRIBUTION CS-137 IN THE BARK OF SCOTCH PINE

The paper studies the vertical distribution of Cs-137 trees in the bark of two model trees of Scots pine (Pinus sylvestris L.), selected in the zone of radioactive contamination of the Bryansk region. Each tree was divided into 10 centimeter bars from a length of up to 17 meters, after which the bark along with the bast was separated from each bar into a separate sample. In addition to Cs-137, the content of natural radionuclide K-40 was measured in the bark of model tree No.2 from a comline to 6.5 meters. Measurement of specific activity of technogenic radionuclide Cs-137 and natural radionuclide K-40 by gamma-spectrometric method. For the first time, it was found that in the bark of the studied trees, the vertical distribution of Cs-137 has a wave-like character and can be represented as harmonic oscillations with a period of 1 m. The distribution of potassium also has an oscillatory character similar to caesium, which is consistent with a similar mechanism of behavior of potassium and caesium in woody plants. The correlation coefficient between the values of specific activity of Cs-137 in model trees No.1 and No.2 was 0.80, and between Cs-137 and K-40 in model tree No. 2 was 0.45. Thus, Cs-137 can be used as a radiotracer to assess the intake and distribution of chemical elements in the tissues of scots pine. The found oscillatory nature of the vertical distribution of caesium and potassium in the pine bark has no analogues in the world literature.

GIS-BASED LANDSCAPE MANAGEMENT OF THE UZH RIVER BASIN: A STRATEGY TO ENHANCE RIVER WATER QUALITY

The article includes the findings of a study on the Uzh River basin’s surface water’s quality. This region is extremely important because a fraction of it is radioactively contaminated because of the Chornobyl nuclear power plant accident. Considering this, the goal of this work was to conduct a geo-informational analysis of the state and structure of the landscapes of the Uzh River basin, to identify the surface water quality parameters of this region, and to identify potential correlations between these parameters. For this purpose, we spatially divided the territory of the basin into separate massifs, in each of which, using the method of automatic decoding, we determined the ratio of the structural components of landscapes, their disturbance by erosion processes, and compared them with ground data on the quality of surface water of the massifs. According to the salt composition, all the investigated massifs have good quality conditions. The Uzh River and its tributaries should be categorized as 4 (slightly polluted) based on the average values of the trophosaprobological state, but the extreme values in some places shifted to 5 (moderately polluted). Most of the listed toxic substances were present at average levels and, for the most part, did not exceed the permitted concentrations for category 4-slightly polluted. Extreme concentrations frequently reached category 6 (polluted), which was primarily brought on by anthropogenic activity and the buildup of radioactive materials. It was found that the degree of erosive landscape destruction and the degree of landscape stabilization significantly influence the value of the integrated water quality index. Since the collected data, a three-dimensional model was developed, allowing for accurate evaluations and projections of changes in the quality of surface water based on the structural characteristics of the land shafts. Considering that some of these territories are currently in the zone of radioactive contamination, the planning of changes in the landscape structure should be coordinated with the potential risks of surface water quality deterioration, and the model proposed in this article will have significant applied value in addressing this issue.

Assessment of secondary radioactive contamination of a decontaminated land plot located on the territory of a recreation base in a wooded area

The article presents results of a long-term (1998–2021) radiological monitoring survey of a recreation base located in a wooded area in the zone of radioactive contamination after the accident at the Chernobyl nuclear power plant. Local mechanical decontamination of the soil had been made on the territory of the base in 1997. The evaluation of the secondary radioactive contamination of the decontaminated territory was performed by comparing dynamics of the radiological situation at the treated plot and the control, nondecontaminated, part of the base according to four main criteria: 1) dose rate of gamma radiation in the air from cesium radionuclides; 2) inventory of 137Cs in soil; 3) vertical distribution of 137Cs in soil; 4) activity concentration of 137Cs in plants and fungi. In 1998, the value of the 137Cs inventory in the upper 20 cm of soil in the control part of the territory of the base and in the decontaminated plot was 930 kBq/m2 and 143 kBq/ m2, respectively. By 2015, the value of the 137Cs inventory in the control area and the decontaminated plot had significantly decreased: by 35% and 36%, respectively. A decrease in the dose rate of gamma radiation in the air at the decontaminated plot and control area proceeded at the same rate, which is currently mainly determined by the decay of 137Cs. There was a gradual self-restoration of the forest ecosystem at the plot subjected to decontamination. Activity concentration of 137Cs in biota (pine, edible mushrooms) in the treated plot was many times lower than that in the control part of the recreation base. In general, there was no significant secondary radioactive contamination of the decontaminated plot in the 24 years after the intervention.

The role of mouse-like rodents in the Chornobyl Exclusion Zone in the spread of blood-borne diseases

A feature of the conducted research is the study of a topical issue – the influence of external and internal factors on the prevalence of pathogens of blood-parasitic diseases. One of the most important external factors of influence is the exposure dose of γ-radiation, since the catching of mouse-like rodents was carried out at the landfills of the drained bed of the cooling reservoir of the Chernobyl Nuclear Power Plant. Therefore, the aim of the work was to study mouse-like rodents for the presence of causative agents of blood-parasitic diseases in natural populations under the influence of radioecological conditions of man-made transformation of the cooling reservoir of the Chernobyl Nuclear Power Plant. Mouse-like rodents of the genera Apodemus and Myodes were studied from three different locations of the cooling pond using parasitological methods. Radiological methods were used to determine the level of contamination of the specified three places where mouse-like rodents were caught using the γ- and β-dosimeter Pripyat RKS 20.3. Examination of blood smears of mouse-like rodents from three experimental polygons of the cooling reservoir of the Chernobyl Nuclear Power Plant revealed the presence of pathogens of blood-parasitic diseases in 93.8% of animals. In particular, such pathogens as Rickettsia spp., Ehrlichia spp., Bartonella spp., Babesia spp., Hepatozoon spp., Haemobartonella (Mycoplasma) spp., were identified. and spirochetes. The prevalence of zoonotic agents among mouse-like rodents of the Chernobyl Zone of radioactive contamination, as well as its dependence on the level of radioecological pollution of the respective landfills, was established. Therefore, according to the results of the conducted research, the presence of causative agents of blood-parasitic diseases among mouse-like rodents, which are both intermediate and their definitive hosts, including those from dangerous zoonoses, which, subject to the application of timely and complex preventive measures, will prevent human infection

Оценка мощности амбиентного эквивалента дозы на лесных участках в юго-западных районах Брянской области

The large areas of forests in the Bryansk region are still contaminated with radionuclides released due to the accident at the Chernobyl NPP in April, 1986. The recovery of the economic and ecosystems potentials in the contaminated areas is the need to create a favorable living conditions for the population. This involves a full range of remediation activities in the contaminated areas aimed at the forests protection and regeneration. The aim of the work is to assess the ambient dose equivalent rate (ADER) in forest sites located in the zone of radioactive contamination. More than 1 thousand forest sites in the south-western part of the Bryansk region were surveyed from 2019 to 2022. The ADER and the density of the soil contaminated by Cs-137 for every surveyed forest site are available. The relationship between the ADER and the density of the soil radioactive contamination in various sites was analyzed. The dose rates were normalized with respect to the density of soil contamination. The ADER rates in the Bryansk forest areas ranged from 0.07 to 3.15 mSv/h. No reliable difference between the ADER in the areas of coniferous and deciduous forests was observed. There was reliable linear relationship between ADER and the density of soil contaminated by Cs-137. During forestry operations in radioactive contaminated areas the maximum permissible external radiation effective dose was the dose accumulated for the whole period of work in the forest sites with the average density of soil contaminated by Cs-137 of 450 kBq/m2.

Дозы облучения населения Беларуси вследствие аварии на Чернобыльской атомной электростанции на 2021-2025 гг.

In accordance with the Laws of the Republic of Belarus «On the social protection of citizens affected by the accident at the Chernobyl NPP» dated January 6, 2009 and «On the legal regime of territories exposed to radioactive contamination due to the accident at the Chernobyl NPP» dated May 26, 2012, the value of the average annual effective dose of exposure to residents is one of the indicators of the radiation situation in settlements contaminated with radionuclides as a result of the Chernobyl accident. The objective: to update the method for assessing the exposure doses to the population in the situation of existing exposure after the Chernobyl accident and, on its basis, to assess the average annual effective exposure dose to residents of settlements of the Republic of Belarus due to the Chernobyl accident for the period 2021-2025. The method for estimating the average annual effective doses due to external and internal irradiation to residents of radioactively contaminated settlements of the Republic of Belarus has been improved taking into account international recommendations in the field of radiation protection, changes in the radiation situation in the long-time period after the Chernobyl accident and the new data on individual dosimetry of internal exposure to the population based on the results of whole-body counter (WBC) measurements. An assessment of the average annual effective exposure doses to the population of the Republic of Belarus residing in the territory of radioactive contamination was carried out, and based on its results, the Catalog of average annual effective exposure doses to residents of 2193 settlements for the period 2021-2025 was compiled. According to the compiled Catalog of average annual effective exposure doses to residents of settlements located on the territory of radioactive contamination of the Republic of Belarus, in 29 settlements out of 2193, the total effective exposure dose can exceed 1 mSv/year, in addition, it is about 1 mSv/year in 5 settlements. In none of the settlements, the average annual effective radiation dose can exceed 5 mSv/year. Valid for the period 2021-2025 Catalog of average annual effective exposure doses to the residents of settlements located on the territory of radioactive contamination of the Republic of Belarus, along with data on the density of contamination of the territories of the Republic of Belarus with long-lived radionuclides, was used to compile the List of settlements and objects located in the zones of radioactive contamination, and to adopt a Resolution of the Council of Ministers of the Republic Belarus on designation of settlements to the corresponding zones of radioactive contamination.

The concentration of heavy metals in the energy crops phytomass when grown in the conditions of Zhytomyr Polissia

The high level of anthropogenic pressure on agro-landscapes recently leads to an increased level of their contamination with heavy metals, which are among the most harmful chemical pollutants for the environment. Heavy metals are transmitted through trophic chains with a pronounced cumulative effect, in connection with which their toxicity can appear suddenly on individual links of trophic chains. The danger from heavy metals is determined by the fact that, unlike organic pollutants, they do not break down, but change from one form to another. Based on the results of the study, it was established that the accumulation of heavy metals by energy plants depended on the type of crop. Thus, it was proved that the concentration of heavy metals in energy crops plants when grown in the territory of radioactive contamination was within the limit of permissible concentrations. The lowest concentration of toxicants was noted when all energy crops were grown without fertilizers. The subject of the study was energy crops (Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G.), heavy metals in plants, sod-podzolic sandy soil, mineral fertilizers. Therefore, the purpose of our research was to determine the phytomass of energy crops grown in areas contaminated with radionuclides as a result of the accident at the Chernobyl Nuclear Power Plant to determine the concentration of toxic substances. When performing the work, both general and special research methods were used: field – for conducting stationary and short-term field experiments, analytical – for determining the content of heavy metals in plants crops (Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G.). The research was conducted during 2017−2020 on sod-podzolic soils in the territory of the village. Khrystynivka, Zhytomyr region, which belongs to the zone of unconditional (mandatory) resettlement (2nd zone of radioactive contamination). Prospects for further research will be aimed at establishing patterns of distribution of heavy metals in soil layers when growing energy crops. Key words: Silhium perfoliatum L., Sorghum almum Parodi, Bunias orientalis L., Sida hermaphrodita Rusby, Miscanthus giganteus G., lead, cadmium, copper, zinc.

Peculiarities of the woodworking industry development in Ukraine and its regions

The article reveals the woodworking industry as a component of the wood processing complex and a perspective export-oriented sector of the Ukrainian economy. The purpose of the research is to identify the main trends and results of the development of the woodworking industry in the Ukraine regions in the pre-war period, to identify problems and to substantiate possible ways of solving them in the post-war period. The role and importance of the woodworking industry in the formation of the country's GDP was studied. The prerequisites for the formation and formation of the woodworking industry in Ukraine are characterized, namely, the level of forest cover in the country is analyzed, which directly affects the provision of raw materials for enterprises in the industry. Regional differences in natural conditions are determined, which is the reason for significant interregional differentiation of the development of the woodworking sector. The amount of produced forest products in the regions of Ukraine in the pre-war period was analyzed. It has been proven that the lack of raw materials remains a problem for the woodworking industry. It has been established that the forestry of Ukraine is characterized by a relatively low level of forest cover in the country, significant regional differentiation of forests, and a high proportion of ecologically significant forests; individual forests are provided for permanent use by enterprises; a significant area of forests grows in the zone of radioactive contamination; half of Ukraine's forests are artificially created and require increased care. It has been found that there is a dynamic and constantly growing demand for woodworking products. This attracts capital to the industry, increasing competition, which was quite high in the market for wood and wood products in Ukraine before the war. The woodworking industry market of Ukraine meets the conditions of effective competition, where small enterprises prevail. It was established that about 40% of the products of the woodworking industry are sold abroad. The most promising areas of industry are the manufacture of wood products, its processing and furniture production. Sawmill and planing production are the most export-oriented. At the same time, it was found that Ukraine will continue to be an exporter of mainly raw materials and products with a low share of added value. This reduces the efficiency of export activities and additionally creates pressure on the development of enterprises with a complex production cycle, increasing the shortage of wood raw materials. The article describes the current state and problems of the development of the woodworking industry during the war. The main directions of restoration of the woodworking sector of Ukraine in the post-war period are outlined.

Ambient dose equivalent rate from <sup>137</sup>Cs and natural radionuclides in one-story residential buildings in settlements of the Bryansk region in 2020–2021

Method of in situ gamma-ray spectrometry was used to discriminate contributions of 137Cs and natural radionuclides to ambient dose equivalent rate indoors in settlements located in the zones of radioactive contamination after the Chernobyl accident. The measurements using a portable scintillation gamma spectrometer-dosimeter were carried out in 115 individual one-story residential buildings in 46 settlements of the Bryansk region of Russia in the summer period of 2020–2021. According to official data, the average density of soil contamination with 137Cs in the settlements ranged from 27 to 533 kBq/m2. Based on the type of building materials that had been used to construct the walls, the surveyed houses were divided into three large groups: wooden (walls made of logs) – 51 buildings, stone (walls built of bricks and/or concrete panels) – 34 buildings, and frame-panel – 30 buildings. The latter had walls constructed of wooden panels with the inclusion of heat-insulating material. Outside, the walls of the frame-panel houses were lined with a layer of silicate (white) bricks. 70 houses were built before the accident and 37 – after the accident. In eight cases it was not possible to reliably estimate the period of construction. The total ambient dose equivalent rate ranged from 42 to 228 nSv/h (average = 77 nSv/h). The values of the ambient dose equivalent rate from natural radionuclides were in the range 27–122 nSv/h. The average values of the ambient dose equivalent rate from natural radionuclides in the groups of wooden, frame-panel, and stone houses were 42, 42 and 58 nSv/h, respectively. The difference between stone houses and panel houses was statistically significant (P < 0.01). The same difference was found between stone houses and wooden houses (P < 0.01). The average values of the ambient dose equivalent rate from 137Cs, normalized to the density of soil contamination with 137Cs, were 0.13, 0.16, and 0.05 (nSv/h)/(kBq/m2) in wooden, frame-panel, and stone houses, respectively. The normalized ambient dose equivalent rates from 137Cs in the group of stone houses were statistically significantly (P < 0.01) lower compared to the corresponding values for the groups of wooden houses and frame-panel houses. The small differences between frame-panel and wooden houses turned out to be statistically significant (P < 0.05). The median and mean values of the normalized ambient dose equivalent rate from 137Cs for houses built before the accident were lower compared to those for houses built after the accident. These differences were statistically significant (P < 0.01) for all groups of houses. The mean values of the normalized ambient dose equivalent rate from 137Cs and the ambient dose equivalent rate from natural radionuclides obtained in this study can be used to estimate the external effective dose to a person staying inside a one-story residential building. In this case, one should take into account not only the type of building materials used to construct the house, but also the time period of the construction: before or after the Chernobyl accident.

The influence of microelements cobalt, copper, manganese, zinc on the mineral composition of milk of cows in the zone of radioactive contamination

The influence of microelements cobalt, copper, manganese, zinc on the mineral composition of milk of cows in the zone of radioactive contamination

Ambient dose equivalent rate and soil contamination density with 137Cs in kitchen gardens in settlements of the Bryansk region, Russia in 2020–2021

The article provides results of application of the field (in situ) gamma spectrometry method for carrying out mass monitoring measurements of ambient dose equivalent rate and soil contamination density with 137Cs in kitchen garden plots located in the zone of radioactive contamination after the Chernobyl accident. In 2020 and 2021, 115 private farmsteads in 46 settlements of the Bryansk region were surveyed. At the time of the survey, the officially established average density of soil contamination with 137Cs in the settlements ranged from 27 to 533 kBq/m2 . The field spectra were measured using a portable scintillation gamma-spectrometer-dosimeter. Results of the field measurements and subsequent calculations of soil contamination density with 137Cs in the kitchen gardens were in good agreement with official data on the average soil contamination density with 137Cs in the surveyed settlements. The mean value of the ratio of the experimental data to the official data was 1.04. Individual values of experimental data deviated from corresponding official values by no more than two times. The use of the gamma spectrometry method in situ made it possible: 1) to determine separately values of the ambient dose equivalent rate from 137Cs and from natural radionuclides in the soil, and 2) to estimate the effective external doses to a person who worked in the kitchen gardens. The measured values of ambient dose equivalent rate varied from 17 to 53 nSv/h (mean ± standard deviation = 35 ± 9 nSv/h) for natural radionuclides and from 8 to 432 nSv/h (mean ± standard deviation = 125 ± 91 nSv/h) for 137Cs. The ambient dose equivalent rate from 137Cs normalized to the soil contamination density with 137Cs in the same kitchen garden was in the range of 0.41–0.84 (nSv/h)/(kBq/m2 ) with a mean value of 0.55 (nSv/h)/(kBq/m2 ). If a person stayed in kitchen garden for 840 hours per year, the estimated effective external doses from natural radionuclides and 137Cs were respectively in the range of 0.008–0.025 mSv/year and 0.004–0.20 mSv/year.

Assessment of the radiation safety of drinking water and surface water bodies used for recreational purposes in the Voronezh region

AIM: This study aimed to assess the radiation safety of surface water bodies used for recreational purposes and drinking water used by the population of the Voronezh Region (VR).
 MATERIALS AND METHODS: The fond materials of the Rospotrebnadzor Administration in VR in 20152019 were used. The following parameters were analyzed: total and activities and specific activity of radioactive substances in the water of open reservoirs (137Сs, 210Po, 226Ra, and 228Ra) and in the sources of drinking water (210Po and 222Rn). The annual effective dose was calculated on the basis of the probable consumption of drinking water from the centralized drinking water supply systems. The content of radionuclides in the water of open reservoirs was analyzed in three control points and in drinking water found in 2,036 water intake artesian wells of the centralized drinking water supply systems. Then, 100% of the sources were surveyed in terms of total and activities. The radiation safety of bottled drinking water from nine manufacturers was assessed on the basis of the data of the Federal State Sanitary and Epidemiological Surveillance. Water in open reservoirs and drinking water, including water packaged in containers, were laboratory controlled on the basis of an accredited testing laboratory center (Center for Hygiene and Epidemiology in the VR) by using MKS-01A Multirad spectrometric installation (Akvilon, Russia). UMF-2000 - and -radiometers were utilized to measure small activities (NPP, Doza, Russia).
 RESULTS: According to the regional databases of Rospotrebnadzor Administration regarding water from open water bodies for the population (three monitoring points: Tikhaya Sosna, Sukhaya Khvorostan, and Usman rivers) in 20152019, values did not exceed the intervention limit that was registered in terms of the content of the controlled radioactive substances (210Ро, 234U, 222Rn, and 137Сs) and the total and activities. Water from artesian wells used for drinking and domestic purposes fully met the requirements of radiation safety. The average annual effective radiation doses (AAERD) of the population in the VO in 74 settlements within the zones of radioactive contamination due to the Chernobyl disaster ranged from 0.05 mSv/year to 0.12 mSv/year, which was significantly lower than the threshold value (1 mSv/year). The analyzed drinking water samples, water packaged in containers, and the samples produced in the region were in compliance with sanitary and epidemiological requirements, including those for 90Sr and 137Cs radionuclide contents.
 CONCLUSION: Radiation monitoring in the VR revealed that the content of technogenic radionuclides (137Cs and 90Sr) and other standardized parameters of radiation safety in water of open reservoirs and drinking water did not exceed the threshold values.

Накопичення Pb і Cd у м’язовій тканині та печінці бугайців за їх годівлі різними силосами

Goal. To assess the effect of feeding calves with silage from a 4-component mixture of spring legumes (oats + field peas + lupine + vetch) compared to silage from Echinochloa frumentacea on the level of Pb and Cd accumulation in their muscle tissue and liver. Methods. 2 groups of experimental calves were formed: Group I (control) — fed with leguminous silage; Group II (experimental) — received experimental silage from Echinochloa frumentacea. Preparation of samples of plant and animal origin for the establishment of heavy metals in their composition was carried out by the method of dry mineralization, analysis — on the atomic absorption spectrophotometer “Kvant-2A». Results. The concentration of heavy metals in the feeds of the diets of experimental animals was determined. It was found that the presence of Pb and Cd in feed led to their accumulation in the longest muscle of the back and liver of calves. Feeding young cattle with different silage affected the accumulation of heavy metals in the products. The concentration of Pb and Cd in the longest muscle of the back and liver of calves was found to be lower than the maximum allowable concentration. Conclusions. Replacement in the rations of multicomponent silage from legumes (oats + field peas + lupine + vetch) for silage from Echinochloa frumentacea for fattening calves in the III-rd zone of radioactive contamination hurt the environmental quality of products, increasing the content of heavy metals in a muscle on 5 4–33.3%. At the same time, the rate of transition of Cd to the longest back muscle was lower by 0.68% abs. in young animals of the II-nd (experimental) group in comparison with the control.

Triticale diets and pork quality in the zone of radioactive contamination

The study is devoted to the substantiation of the use of grain mixtures with different amounts of triticale in the diets of store pigs of large white breeds and to determine their impact on the quality and safety of pig products during its production in III zone of radioactive contamination caused by the Chernobyl accident. Based on the study, fodder grain mixtures for fattening of store pigs in Ukrainian Polissia have been developed. These mixtures make it possible to replace partially or entirely wheat with triticale in the diets of animals. It has been found that when 20-40% (by weight) of wheat groats in the grain mixture is replaced with a similar amount of triticale groats, the concentration of radiocaesium in muscle tissue of pigs in the experimental groups reduces by 9.6-9.8 Bq/kg or 30.7-31.3% compared to the control group. At the same time, the multiplicity of accumulation of 137Cs in the musculus longissimus dorsi of piglets was 0.233-0.325 and was higher by 4.2-39.5% in animals which received grain mixture No. 1 without triticale, compared with the use of grain mixtures No. 2 and No. 3 (20-40 % of triticale by weight). The concentration of Pb, Cu, and Zn in the products of experimental store pigs was significantly lower than MAC, while the level of contamination of muscle tissue (groups I and II) and liver (groups I and III) with Cd exceeded the regulatory requirements by 2.0-2.4 times and by 24.7-28.7%, respectively. Replacement of 20-40% (by weight) of wheat groats in the grain mixture with a similar amount of triticale groats for fattening store pigs in III zone of radioactive contamination contributed to a much smaller transition of Pb, Cd, Cu, and Zn into musculus longissimus dorsi – by 3.27 (group III), 0.55-8.96, 1.15-1.27 and 0.52-7.86% absolute), respectively.