Chernobyl Accident Research Articles

A study of particle dry deposition parameterizations in an atmospheric radioactive preparedness model: Application to the Chernobyl case

Parameterization of dry deposition is key for modelling of atmospheric transport and deposition of radioactive particles. Still, very simple parameterizations are often encountered in radioactive preparedness models such as the SNAP model (SNAP=Severe Nuclear Accident Program) of the Norwegian Meteorological Institute. In SNAP a constant dry deposition velocity (=0.2 cm/s) neglecting aerodynamic and surface resistances, is presently used. Therefore, two new dry depositions schemes (the Emerson scheme and the EMEP (European Monitoring and Evaluation Programme) scheme) have been implemented in SNAP to evaluate the benefits of including aerodynamic and surface resistances codes with respect to model prediction skills. The three dry deposition schemes are evaluated using 137Cs total deposition from soil sample data (n = 540) for a 60 km radial zone out from the Chernobyl Nuclear Power Plant (ChNPP) collected during the months after the accident. The present study capitalizes on high resolution meteorological data (2.5 km horizontal resolution), a detailed land-use data set with 273 sub-classes and the hitherto most comprehensive source term description for the Chernobyl accident. Based on our findings it is recommended to replace the present simple SNAP scheme with the Emerson or EMEP dry deposition scheme.

Optimal sizing of a proposed stand-alone hybrid energy system in a remote region of southwest Egypt applying different meta-heuristic algorithms

Hybrid energy system (HES) is considered a solution to the energy supply issue, particularly in rural areas to achieve their sustainable development goals. The rise in energy consumption has increased the appeal of renewable resources, because of their potential to supply consumers with competitive, carbon-free electricity. This paper suggests strategies for managing energy and the most recently published optimizers for designing a stand-alone HES positioned in a remote region of southwest Egypt. This HES includes two green energy sources (wind and solar) and a storage system for energy (battery) as the first backup in addition to a second backup (diesel). The most recent sizing techniques employing the Chernobyl disaster optimizer, dynamic control cuckoo search (DCCS), and gold rush optimizer have been suggested to obtain the optimal design of the utilized HES. Furthermore, an in-depth evaluation of the applied optimization approaches has been achieved based on a comparative study. A detailed analysis of the studied algorithms aims to identify the optimum algorithm that provides the lowest possible cost at the highest level of reliability for the proposed HES. The simulation results verified that, the DCCS algorithm outperformed other algorithms, indicating its potential for achieving promising solutions.

From crisis to recovery: scientific endeavors of the Institute of Agroecology and Environmental Management of the NAAS of Ukraine in minimizing the consequences of the Chornobyl accident

The participation of scientists from the Institute of Agroecology and Nature Management of the National Academy of Agrarian Sciences of Ukraine in mitigating and minimizing the consequences of the Chornobyl disaster during 1986–2024 is elucidated. It is demonstrated that the history of the development of radioecological research at the Institute originates from the early days following the Chornobyl Nuclear Power Plant accident. Actually, from this time onwards, the monitoring of radiation in agricultural lands affected by accidents has begun. One of the most crucial directions of work during this period was conducting of aerial and ground radiation reconnaissance. Active efforts were made in radioecological monitoring and dosimetric control of the population. The radioactive contamination of the territory was analyzed based on landscape, basin, and landscape-geochemical principles, upon which maps of radiation contamination of the territory for 137Cs, 90Sr, and 94Pu were compiled. During the remote period of Chornobyl disaster aftermath, the team of the unit was engaged in developing countermeasures for various types of economic activities in conditions of radioactive contamination, taking into account modern trends in the development of the natural-economic complex and new economic conditions based on landscape-ecological approach. Analysis of the results of scientific activities of the institution’s staff indicates that during the post-accident period, the team of radioecologists gathered and systematized significant volumes of information, which were transformed into various databases, cartographic materials, mathematical models, methodological recommendations, regulations, drafts of normative documents, and so forth. Information was provided on the contribution of the Institute’s employees to the development of radioecology, restoration of agricultural production on radioactively contaminated lands, and rehabilitation of territories affected by the Chornobyl Nuclear Power Plant accident. Furthermore, contemporary radioecological problems and threats posed by the full-scale military aggression of Russia against Ukraine were outlined, including its violation of all seven principles of radiation safety, as well as potential radiation-related hazards in the future.

37 years after the chernobyl: the current radiation status in Kocaeli, Turkey

This study aims to assess the artificial and natural radiation dose levels in certain districts of Kocaeli province within the Marmara region, 37 years after the Chernobyl nuclear accident, and evaluate the current status prior to potential nuclear leakage events from Zaporijya or other nuclear power plants. Radioactive concentrations of 232Th, 238U, 40K and 137Cs were determined using HPGe gamma spectrometry in 26 soil samples collected from the region of interest. The average concentrations were found to be 22.35 Bqkg−1 for 238U, 26.36 Bqkg−1 for 232Th, 368.34 Bqkg−1 for 40K, and 2.44 Bqkg−1 for 137Cs. Furthermore, the study revealed an absorbed dose rate of 41.73 nGyh−1, an annual effective dose equivalent of 51.18 µSvy−1, and an excess lifetime cancer risk of 0.00018.

Ecological and Aesthetic Potential of Works about Chornobyl: Technogenic Disaster as a Literary Problem

ABSTRACT This article is aimed at revealing the theme of the Chornobyl disaster as an apocalypse in the lyrical works of Ukrainian poets. The prerequisites for the development of the phenomenon of the “post-Chornobyl library” are revealed, the works of outstanding sixtiers (Ivan Drach, Lina Kostenko, Borys Oliynyk, and Dmytro Pavlychko) are considered, the elements that are called to the accident at the Chornobyl nuclear power plant are highlighted, and an imagery analysis of the selected works is carried out. Discourses about the catastrophe, apocalypse, and postapocalypse are highlighted to demonstrate Chornobyl, in lyrics and lyrical epic, as the largest man-made environmental and humanitarian tragedy. The connection between the Chornobyl discourse in literature and criticism of the Soviet regime as a manifestation of inhumanity and totalitarianism is revealed. An array of ecological poetry of lesser-known authors is processed and their contribution to the poetry of the paradigm is indicated, and a detailed analysis of the ecological lyrics of the late twentieth and early twenty-first centuries by authors Nina Hnatiuk, Tetiana Yakovenko, and Valentyna Storozhuk is carried out.

Association between radiation dose, thyroid hormone, and IQ levels in children exposed to radiation in utero after the Chernobyl accident.

Few studies have explored the effects of n utero radiation exposure on human health and cognition and none have taken into account thyroid hormone levels (T3), which have shown to affect cognitive performance. We investigated mechanisms of possible radiation effects on IQ in two cohorts of 250 persons each: exposed n utero after the Chernobyl accident: a 'higher exposure group (HEG)', whose mothers resided in more heavily contaminated territories at the time of the Chernobyl accident, and a 'lesser exposure group (LEG)' whose mothers resided in less contaminated areas. The dataset included information on estimated prenatal thyroid radiation dose, gestation week at the time of the accident (ATA); thyroid hormones: T3 (triiodothyronine) and T4 (thyroxine) levels measured at age 11-12 years and general IQ measured at three time points: t1: 6-7 years old; t2: 11-12 years old and t3: 15-16 years old. Descriptive and inference analyses were used to explore the dynamic of changes through time and the associations between key variables at the three time points. Estimated radiation doses to the thyroid gland were substantially higher in the HEG than in the LEG (mean 391 vs 25 mGy respectively). Significant differences in thyroid hormones levels were observed between the two groups, with lower values in T3 (higher in T4) in the LEG. At t1, the general IQ, as well as verbal and non-verbal IQ scores, were lower in the HEG than in the LEG. In the HEG, analyses adjusting simultaneously for radiation dose, gestational week ATA and T3 levels suggest that all three variables are associated with IQ, with the latter being highest among those exposed later during gestation and decreasing with increasing level of dose and of T3. No significant association was observed between IQ and T4 levels. No effect of exposure on IQ was seen in the LEG. Further investigation of this hypothesis will be important to understand the relation between n utero exposure radiation dose to thyroid, thyroid hormone levels and IQ, taking into account effects of potential confounding factors (physiological stress, maternal anxiety related evacuation).

RADIATION AND ECOLOGICAL STUDIES OF VEGETATION OF LUTSK DISTRICT OF VOLYN REGION

Abstract. The content of radionuclides of 137Сs, 90Sr and heavy metals in vegetation and agricultural products was found out in the settlements of Lutsk district of Volyn region. The results of our own field expeditionary research, as well as the results of generalization of stock materials of the Laboratory of Ecological Land Safety and Product Quality of the Volyn branch of the state institution “Institute for Soil Protection of Ukraine” (Lutsk) are the basis of the research. The plant products contain a small content of radioactive elements in the settlements of the Lutsk district of the Volyn region. The greatest pollution of plant products was found in the settlements of Sytnytsia and Omelіano. The content of the 137Сs, 90Sr does not exceed the maximum permissible concentrations. Exceeding the maximum permissible concentrations for the content of heavy metal salts was found in potatoes in the villages of Pozharky, Vesele. The results of the radiation-ecological study can be taken into account for the optimization of nature management and are necessary for state emergency management bodies of natural-technogenic content, for the possibility of reasonable planning and effective implementation of measures and projects for strengthening ecoenvironmental safety. The data obtained are important for the development of the National Concept to overcome the consequences of the Chernobyl disaster on the contamination of agricultural products with radionuclides and heavy metals.

Dimensions of freedom of Ukrainian art in the late 80s and early 90s of the 20th century and their manifestation in artistic associations of that time

The relevance of the research topic lies in the insufficient study of such a period of Ukrainian art as the turn of the 1980s and early 1990s, when banned artists came out of the underground, taking advantage of the weakening of the ideological pressure of the Soviet system, and led powerful artistic movements involved in the formation of dimensions of free creativity. The purpose of the work is to clarify the conditions for the development of Ukrainian art at the turn of the 80s and 90s of the 20th century, and to highlight the importance of creative associations in the process of artists’ realisation of new tasks in the emerging continuum of freedom (on the example of the associations “The Way” and “The Strontium-90”). The methodological apparatus of the study consists of three stages (preparatory, research and synthesising) using the following methods: analysis of literary and scientific sources, dialectical method in the emergence of a new phenomenon, method of logical analysis, method of critical and comparative analysis, synergistic method, generalisation, method of hypothesis and forecasting. The study found that at the end of the 1980s, under the influence of the Chornobyl disaster, Ukrainian “unofficial” art left the status of marginal, and its representatives became the forerunners of a new free creative continuum. The artists of the new generation, using the neo-avant-garde experience of their colleagues and the factor of freedom of expression, strive to use the latest creative practices, which has connected them to the global artistic space. The study argues that neo-mythologism, as one of the main principles of world art of the second half of the 20th century, at the turn of the 1980s and 1990s became decisive in the process of creating a free artistic continuum. This principle led to the most individualised figurative system of expression of Ukrainian artists of the new generation. The paper examines two artistic associations, “The Way” and “Strontium-90”, and their role in shaping the Ukrainian free creative continuum. The practical significance of the study lies in the use of the results in the creation of recommendations and methodological guides on the history of Ukrainian art of the 20th and 21st centuries and gallery business

Wpływ katastrofy elektrowni atomowej w Czarnobylu na raka tarczycy – przegląd najnowszych doniesień

Wpływ katastrofy elektrowni atomowej w Czarnobylu na raka tarczycy – przegląd najnowszych doniesień

Epidemiology of stroke in the Left bank area of Kyiv region on the eve of the 38th anniversary of the man-made Chernobyl disaster: implementing international experience into practice (modern view of the problem and own research)

The article highlights the global problems of stroke. Most of them are associated with three groups of risk factors for stroke: well-known pathogenetic, psychogenic, and ecological factors of environmental pollution. The authors draw attention to this on the eve of 38th anniversary of the man-made Chernobyl disaster (April 26, 1986) comparing data on the stroke in Japan after the Fukushima nuclear accident (March 11–12, 2011) due to the earthquake, which led to the reactor core melting at three power units. Issues of improving the provision of specialized medical care to patients with stroke, risk factors for stroke are considered to minimize the consequences, optimize treatment, prevention of risk factors, especially in areas where the population is exposed to incorporated radiation damage through food, water, milk, fish, meat, berries, mushrooms, as well as the issues of improving the specialized stroke care, creation of stroke centers in regions of Ukraine. Studies conducted show that there are many causes of strokes, and they are not yet fully understood. The features of the clinical course of strokes in the Chernobyl liquidators are their development in the middle (40–49 years) and advanced age, long vascular history characterized by vascular dystonia transformation into dyscirculatory (postradiation) encephalopathy during the onset, the predominance of ischemic stroke over hemorrhagic one, lesions mainly of the carotid system, the relative benignity of clinical course, progressive nature of mental disorders, concomitant somatic pathology, the presence of stable pathomorphological substrate from both vascular endothelial dysfunction and cerebral liquor system. The obtained information complements the data on the pathogenesis, clinical picture, diagnosis of cerebral strokes in Chernobyl liquidators and is of practical interest. Raised issues of optimizing the provision of specialized care in stroke units, centers and further rehabilitation, their sufficient supply, both in terms of staffing and equipment, are becoming a cornerstone in overcoming the stroke epidemic. Based on the above, there is still a need to continue substantial research in this area, promptly develop and implement a scientific concept on the prevention, early detection of major modifiable risk factors for stroke together with family medicine doctors, specialist physicians, proper stroke treatment, which will undoubtedly improve quality of life of patients and their relatives.

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.

Current status of reference location in the basic model for assessment of external radiation doses to the population living in radioactively contaminated areas after the Chernobyl accident

An open plot of virgin land is the reference location in the basic model used to date to estimate the effective dose of external exposure to the population living in a radioactively contaminated area. As our field observations in the Bryansk region of Russia have shown, at present it is very difficult to find truly reference plots of virgin land due to the fact that many virgin meadows were plowed or reclaimed for more than 30 years after the Chernobyl accident. Without special instrumental survey, such disturbed meadow areas can easily be confused with areas of virgin soil. Therefore, the situation with the use of open areas of virgin soil as the reference location has changed dramatically since the first years after the Chernobyl accident. It requires a change in the approach to choosing such a location for the model and/or some revision of the structure of the model itself. Firstly, we propose and justify the use of a permanently cultivated kitchengarden plot as the reference location. The second way to resolve the current difficult situation with the presence of a sufficient number of the virgin soil sites could be excluding the very concept of “reference location” from the model. In this case, when calculating the effective dose of external radiation, it is proposed to directly use the values of the gamma radiation dose rate in the air normalized to the 137Cs contamination density of soil. The values of the normalized dose rate should be experimentally determined in the required time period for each of the locations taken into account in the model.

The Role of City Partnerships in the Reconstruction of Ukraine

In 2015, there were around 80 city partnerships between Germany and Ukraine. In addition to the major partnerships between Berlin, Munich, and Leipzig with Kyiv or Berlin and Nuremberg with Kharkiv1, these were mostly partnerships between smaller municipalities with fewer than 50,000 inhabitants. Many of these partnerships were very old and had their basis in the old structures between the Soviet Union and the former Germand Democratic Republic (GDR). Only a few new partnerships were formed after the fall of the Berlin Wall and Ukraine’s independence in 1991. Others resulted from the old peace movement in the West, which organized active support after the Chornobyl accident with vacation stays for Ukrainian children in Germany in conjunction with direct humanitarian and medical support.

Chromosomal disorders in Triticum aestivum subject to prolonged radionuclide pollution of soil from the Exclusion Zone of the Chornobyl Nuclear Power Plant

Due to the large number of nuclear power plants around the globe and the growing threat of radioactive accidents, a complex assessment of the biological consequences of the Chornobyl disaster is a relevant issue. Study of mutagenic activity of prolonged and chronic action of radionuclide pollution of soil in the Chornobyl Exclusion Zone long after the accident will allow us to identify the current level of threat they pose to the human genome and can reveal specific cytogenic markers of radionuclide environmental pollution. For this purpose, we germinated seeds of wheat of soft winter varieties Smuhlianka and Bohdana in soil samples from the Chornobyl Exclusion Zone 35 years after the disaster. Specific activity of Cs-137 and Sr-90 accounted for 4.5–28.2 kBq/kg. To determine the frequency and range of chromosomal aberrations, we used the anaphase-telophase method. In aberrant cells, we studied extracellular distribution of chromosomal disorders. The frequency of aberrant cells was 3.53–7.55 times above the spontaneous level. High mutagenic activity remained in the conditions of the lowest density of radionuclide pollution of soil. The range of chromosomal disorders mostly included paired fragments and bridges and containd chromosomal acentric rings, binding of chromosomes, myocardium, and lagging and leading chromosomes. Radionuclide pollution in the Chornobyl Exclusion Zone induced multiple cellular aberrations in the rhizome meristem, the share of which was the highest in case of low specific radionuclide pollution of soil, and exhibited a tendency towards decrease against the background of the highest density of radionuclides. Pollution of the environment with radionuclides as a result of disasters at nuclear energy objects poses a threat to the human genome and is a global problem, requiring state support to solve through systematic genetic monitoring in readionuclide-polluted territories and areas adjacent to them.

Long-term radiological assessment of a Mediterranean freshwater ecosystem surrounding a nuclear power plant.

The radionuclide concentration of man-made radionuclides on non-human biota in freshwater ecosystems has been extensively studied in environments affected by the Chernobyl and Fukushima accidents, in both humid continental and subtropical climates, respectively. However, there are very few studies that assess the long-term effects of operating nuclear facilities in Mediterranean environments. In the present study, a temporal analysis of the impact on carp, cattail, and bulrushes in the cooling pond of the currently operating Almaraz nuclear power plant was investigated for the period 2000-2020. The results do not show a general trend in man-made radionuclide concentrations. Instead, depending on their availability and the type of organism, trends decrease over time. This is also reflected in the effective half-lives obtained, which are lower than the physical half-life for some radionuclides. Transfer coefficients for the main man-made radionuclides detected were obtained, and it was found that these were significantly lower than the typical ranges found for benthic fish and vascular plants in freshwater ecosystems. Finally, the internal and external doses received by the carp have been evaluated using ERICA tool, and it has been observed that the main contribution to the total dose is due to the internal dose (0.65-7.04) × 10-4µGy/h.

A Revised System of Radiological Protection Is Needed.

The system of radiological protection has been based on linear no-threshold theory and related dose-response models for health detriment (in part related to cancer induction) by ionizing radiation exposure for almost 70 y. The indicated system unintentionally promotes radiation phobia, which has harmed many in relationship to the Fukushima nuclear accident evacuations and led to some abortions following the Chernobyl nuclear accident. Linear no-threshold model users (mainly epidemiologists) imply that they can reliably assess the cancer excess relative risk (likely none) associated with tens or hundreds of nanogray (nGy) radiation doses to an organ (e.g., bone marrow); for 1,000 nGy, the excess relative risk is 1,000 times larger than that for 1 nGy. They are currently permitted this unscientific view (ignoring evolution-related natural defenses) because of the misinforming procedures used in data analyses of which many radiation experts are not aware. One such procedure is the intentional and unscientific vanishing of the excess relative risk uncertainty as radiation dose decreases toward assigned dose zero (for natural background radiation exposure). The main focus of this forum article is on correcting the serious error of discarding risk uncertainty and the impact of the correction. The result is that the last defense of the current system of radiological protection relying on linear no-threshold theory (i.e., epidemiologic studies implied findings of harm from very low doses) goes away. A revised system is therefore needed.

Ангелина Константиновна Гуськова (к 100-летию со дня рождения)

Angelina Konstantinovna Guskova, Doctor of Medical Sciences, Professor, Corresponding Member of the Russian Academy of Medical Sciences, Laureate of the Lenin Prize, Honoured Scientist of the RSFSR, Laureate of the Sievert Prize, worked for 50 years at the A.I. Burnazyan FMBC. She was born on 29 March 1924 in the family of doctor Konstantin Vasilievich and pianist Zoya Vasilievna Guskov. In 1941, she entered the Sverdlovsk State Medical Institute, Faculty of Medicine, and successfully graduated in 1946. A.K. Guskova did her residency at the Clinic of Nervous Diseases and Neurosurgery. After her graduation, Angelina Konstantinovna was sent to Chelyabinsk-40 (Ozersk), where she started working in medical institutions serving the operating personnel of Plutonium Combine No. 817. There she gained her first experience in treating patients with acute and chronic radiation sickness. In 1957, A.K. Guskova became a senior researcher at the Institute of Biophysics in Moscow, from 1961 she headed the Radiology Department of the Institute of Occupational Hygiene and Occupational Diseases of the USSR Academy of Medical Sciences. In 1974 she returned to the Institute of Biophysics of the Ministry of Health of the USSR as Head of the Clinical Department. Under the leadership of A.K. Guskova in the Clinical Department of the Institute of Biophysics a number of methods of diagnostics and prediction of severity of radiation syndromes, as well as their treatment were developed and introduced into practice. This allowed the staff of the Department to successfully cope with the most difficult task of treating a large group of victims of the Chornobyl accident in 1986. A.K. Guskova is the author of more than 200 publications, 11 monographs (co-authored), and sections in monographs and manuals (independent). The most important of them are: «Human Radiation Disease» (1971), «Medical Assistance given to personnel of the Chernobyl N.P., after 1986 Accident». (1996). (editor and co-author), «Guidelines for Organisation of Medical Care for Persons Exposed to Radiation» (1986), «Guidelines for Radiation Medicine» (2001).

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.

Changes in radioactive contamination of living ground cover plants in black alder stands since the Chornobyl accident in the forests of Zhytomyr Polissia

The results of research conducted over the past 30 years in the forest ecosystems of Zhytomyr Polissia, in the areas affected by radioactive contamination as a result of the Chornobyl accident. In the course of the research carried out at the Poliskyi Branch of the Ukrainian Research Institute of Forestry and Forest Melioration named after G. M. Vysotsky, methods of forest radioecology, botany, and forestry were used, and the results were processed using statistical analysis. The peculiarities of radioactive contamination of the most common herbaceous and dwarf-shrub plants in the stands of black alder in damp fairly fertile site types were studied. As indicators characterizing these features, we used 137Cs specific activity in the aboveground part of plants and the transfer factor of radionuclide to plant phytomass from the soil. It was found that the highest values of the transfer factor of 137Cs from the soil to the aerial part of the plant phytomass in 1999 are characteristic of ferns: for Dryopteris cristata (L.) A. Gray (276.9 m2∙kg-1∙10-3), Dryopteris carthusiana (Vill.) H. P. Fuchs (236.5 m2∙kg-1∙10-3), Thelypteris palustris Schott (171.2 m2∙kg-1∙10-3), and Athyrium filix-femina (L.) Roth (164.0 m2∙kg-1∙10-3). It was found that among the higher plants, the highest values of this indicator are for the Agrostis stolonifera L. (263.5 m2∙kg-1∙10-3), Galium uliginosum L. (155.8 m2∙kg-1∙10-3) and Maianthemum bifolium (L.) F. W. Schmidt (155.4 m2∙kg-1∙10-3). It was found out that the previously noted trends and interspecific differences in radionuclide accumulation persist after 22 years. It is shown, using the example of three plant species (Lysimachia vulgaris L., Galium uliginosum, and Maianthemum bifolium), that during the observation period (1991-2021) there is a gradual decrease in radioactive contamination of living ground cover plants and the intensity of 137Cs intake into them. This is explained by the decay of the radioactive element, its entry into various perennial components of forest ecosystems, some fixation in the soil, and, possibly, its removal beyond their borders. The established decrease in 137Cs specific activity in the aboveground part of plants is described by linear equations: for Lysimachia vulgaris – Am = –605.34a + 3745.6; R² = 0.98; Galium uliginosum – Am = –5107.5a + 30698; R² = 0.99; Maianthemum bifolium – Am = –4661.6 a + 28280; R² = 0.98. The identified peculiarities of radioactive contamination of various plant species, changes in 137Cs specific activity in them, and transfer factors of the radionuclide from the soil in stands of black alder in damp fairly fertile site types can be used in scientific works to predict possible changes in its redistribution within the ecosystem, as well as in the practice of harvesting medicinal plants in areas contaminated with radionuclides.

Dynamics of state of former agricaltural lands taken out of agricatrure after the Chernobyl accident, according to remote sensing data

Results of assessment of condition (overgrowth of woody and shrubby vegetation), for example, of former agricultural land, taken out of agriculture, in western area of the European part of the Russian Federation (Bryansk region) using algorithms for automated detection of changes in multi-time multi-zone space images are presented. To perform the work, data from TM radiometers (Landsat 5) were selected from available data for study area, and two images of different times (2011 and 2018) were formed. Automated processing included following stages: preliminary processing of satellite images; determination of difference vegetation index (NDVI) based on index images assessment of changes in multi-time images by principal component method (РСА) based on formation of more informative combinations of source images obtained in different spectral zones and reduction of set of analyzed data; identification of changes by difference method based on difference in brightness of each pixel of first image and brightness of corresponding pixel of second image combined with first. Evaluation of use of algorithms for automated detection of changes in multi-time satellite images has shown that joint image processing makes it much better to assess the processes of changes that have occurred on former agricultural land, derived from agricultural turnover.