Chernobyl Accident Research Articles

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.

Environmentalism or Sausages? Politicizing the Environment in the Late Soviet Union

This paper analyzes the politicization of the environment in the late Soviet Union based on a new perception of the interconnection between the human being and the ‘rest’ of nature. On the basis of previously ignored sources, it shows the emerging rise and ultimate decline of human subjectivity as a political force in the Soviet Union, and the Byelorussian Soviet Socialist Republic (BSSR) in particular. Experts, politicians, and the secret service had long understood the need to conserve natural resources and the ecological consequences of relentless industrialization or nature transformation projects, and they had at least partially attempted to counter them. However, the disclosure, in the late 1980s, of the extent and consequences of the Soviet Union's ecological legacies, particularly the Chernobyl disaster, triggered an unprecedented awareness of the vulnerability of the human body and the Soviet state's disregard of the dangers to human health. This new awareness mobilized Soviet citizens, including state functionaries who had previously seemed untouched by ecological issues, to call for a right to life in an unprecedented way. Despite some achievements, such as new protection laws and investments in health care, this ‘ecological revolution’ was short lived. The social and economic difficulties linked to the collapse of the Soviet Union allowed the concern for a healthy, livable environment to fade into the background again in the early 1990s.

Factors of the psychological status in victims of radiation accidents, which mitigate development of psychosomatic disorders in the long term

Relevance. In terms of environmental and social dimensions, the Chernobyl accident is the largest in the history of Russia. Radiation-hazardous incidents also occurred on nuclear submarines. The leading medical consequences of various radiation accidents in the remote period were the presence of psychosomatic pathology among the liquidators of the consequences of accidents. Intention. To determine the leading factors of psychological status among liquidators of the consequences of radiation accidents, which mitigate the development of psychosomatic disorders in the long term. Methodology. In 2019, a comprehensive in-hospital examination of 101 male liquidators of the consequences of the accident at the Chernobyl nuclear power plant was conducted. The examined persons were (65.2 ± 0.7) years old, the average radiation dose was 18 cSv. All surveyed liquidators had somatic pathology with an important contribution of psychogenic factors (hypertension, metabolic syndrome, diabetes mellitus, gastric/duodenum ulcer etc.). The psychological status was assessed using well-known tests. As a control, we used the reference indicators of the methods for similar gender and age groups. The information obtained was checked for normality of distribution. Arithmetic mean values and their errors (M ± m) are provided. Using the factor analysis with rotation of the array, the factors of psychological status were established. Results and Discussion. It turned out that the liquidators of the consequences of the accident have lowered indicators reflecting an active life position and quality of life. When the respective accident was mentioned, they showed irritability, a feeling of tension and alertness, which indicated their anxiety-phobic experience even in the remote period after the accident. Interest in life, its emotional saturation, and self-confidence were decreased. At the same time, indicators of manipulative and antisocial actions were lower vs the control group. In the factor analysis of psychological indicators using principal components with rotation, 5 factors were formed with a total variance of 58.6 %. Factors with higher association contained psychological signs that contributed to or mitigated psychosomatic disorders as follows: Factor 1, named as “Active life position”, accounted for 31.3 % of the total variance; Factor 2 “Negative socio-psychological consequences of a radiation accident” - 10.1%; Factor 3 “Quality of life” - 8.1 %; Factor 4 “Non-constructive models of behavior in a difficult life situation” - 4.9 %; Factor 5 “Mental health” - 4.1 %. Conclusion. The factor analysis of the results from liquidators of the radiation accident helped identify the leading positive qualities and maladjustment problems that can be targets for psycho-prophylaxis.

ASSESSMENT OF THE AVAILABILITY OF 137Cs AND 90Sr RADIONUCLIDES TO AGRICULTURAL PLANTS IN CHANGING CLIMATIC CONDITIONS

In field experiments conducted on sod-podzolic soils, it was found that 35 years after the Chernobyl accident, the largest share of 137Cs is in a strongly bound form, which determines the low transfer of 137Cs into crops. The share of easily available 137Cs forms (water-soluble + exchangeable) for plants is 10,9 % in sod-podzolic sandy soils – 5,1 % in sandy loam and – 3,9 % in loam of the total content in the soil. The share of easily available of 90Sr forms (water-soluble + exchangeable) is 67,2 % in sod-podzolic sandy soils 59,5 % sandy loam and 75,5 % loam of the total content in the soil. This fact determines the high transfer of 90Sr into crops. The research results show that for the studied crops there is a significant increase in the transfer of 90Sr to plants from sod podzolic sandy loam soil in warmer and drier growing seasons. It can be noted that with the warming of the climate on the territory of radioactive contamination, the problems with high transfer of 90Sr into crops will worsen.

Abstract 980: Genomic characterization of lymph node metastases in papillary thyroid carcinoma following the Chernobyl accident reveals an expression profile specific to metastatic process

Abstract Following the Chernobyl nuclear power plant explosion in Ukraine in 1986, increased childhood exposure to radioactive iodine (131I), which occurred primarily through contaminated food sources, has been consistently associated with increased risk of developing papillary thyroid carcinoma (PTC). Increased frequency of cervical lymph node metastases (LNM) is well recognized in pediatric PTC, including pediatric cases following the Chernobyl accident. We recently leveraged the collection of fresh-frozen tumor tissues from the Chernobyl Tissue Bank to conduct a genomic landscape analysis of 440 cases of PTC that provided new insights into radiation-related molecular characteristics of PTC occurring after the accident (Morton et al., Science 2021). Here, we extend that study to conduct a genomic landscape analysis of LNMs for a subset of 48 PTC cases to investigate the specific genomic alterations occurring in LNM. The analysis set comprised 144 samples, including fresh-frozen treatment-naïve primary and LNM PTC tumor samples as well as matched normal tissue or blood. Overall, the mutational load was highly concordant between primary and metastatic PTC. On average, 50% of somatic single nucleotide variants and 97% structural variants were shared between primary and metastatic PTCs. In contrast, the burden of somatic copy number alterations (SCNA) between primary tumor and LNM pairs was less concordant, particularly for copy number gains, whereas most of the copy number loss was found to be shared between matched pairs. PTC is usually driven by one driver mutation, most often involving the mitogen-activated protein kinase (MAPK) pathway. All driver mutations were shared between primary and metastatic PTC and were clonal; thus, no additional driver mutations were detected in metastatic PTC. Notably, however, the matched pairs in this study disproportionately had fusion drivers (77%), whereas only 23% of the drivers were BRAF V600E and none were RAS mutations. Transcriptome analysis revealed differentially expressed genes (DEGs) in metastatic PTC compared to primary PTC; three-quarters of the DEGs were overexpressed in metastatic PTC. Half of the LNM overexpressed DEGs were members of the HOXC family, which has been linked with epithelial-mesenchymal transition in cancer progression. There was also reduced expression in LNM for the DLX family, which relates to TGF-beta signaling. Our findings did not reveal a relationship between radiation dose and expression profiles in the LNM, comparable to our findings for the primary PTCs. We still observe that the efficiency of the radiation-induced PTC is paramount and subsequent events are directly related to the drivers in the MAPK pathway. For the cervical LNMs, we observed expression profiles not observed in the primary PTC that could give new insights into PTC local metastases. Citation Format: Olivia W. Lee, Danielle M. Karyadi, Chip Stewart, Tetiana I. Bogdanova, Jieqiong Dai, Stephen W. Hartley, Sara J. Schonfeld, Vidushi Kapoor, Marko Krznaric, Meredith Yeager, Amy Hutchinson, Belynda D. Hicks, Casey L. Dagnall, Julie M. Gastier-Foster, Jay Bowen, Mitchell J. Machiela, Elizabeth K. Cahoon, Kiyohiko Mabuchi, Vladimir Drozdovitch, Sergii Masiuk, Mykola Chepurny, Liudmyla Y. Zurnadzhy, Amy Berrington de González, Gad Getz, Gerry A. Thomas, Mykola D. Tronko, Lindsay M. Morton, Stephen J. Chanock. Genomic characterization of lymph node metastases in papillary thyroid carcinoma following the Chernobyl accident reveals an expression profile specific to metastatic process [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 980.

Comparative assessment of the state of the musculoskeletal system in children with different types of environmental pollution

In areas with three types of environmental pollution, the state of the musculoskeletal system was studied in 22,710 children aged from the first days of life to 17 years. In general, an increase in the incidence of diseases and injuries of the osteoarticular system was noted, which was most pronounced in areas with aluminum production, which indicates a direct dependence of the pathology of the musculoskeletal system on microelement disorders. In the zone of consequences of the Chernobyl accident with a period of radiation contamination calculated from 1986, static skeletal disorders are most frequent, in Kazakhstan, where the mixed type of contamination has been active for 30 years, the frequency of congenital deformities is increased, and in the zone of aluminum complexes, acquired diseases of the skeleton.

Contribution of transposable elements to transgenerational effects of chronic radioactive exposure of natural populations of Drosophila melanogaster living for a long time in the zone of the Chernobyl nuclear disaster

The accident at the Chernobyl Nuclear Power Plant (ChNPP) led to the negative impact of chronic radioactive contamination on populations of organisms associated with the transgenerational transmission of genome instability. When the destabilization of genome, different genetic damages occur, the accumulation of which leads to the formation of mutations, morphological anomalies, and mortality in the offspring. The mechanisms underlying the manifestation of transgenerational events in the offspring of irradiated parents are not well understood. In this study, for the first time, the features of the influence of transposable elements (TEs) on the long-term biological consequences of the ChNPP are considered. In this work, specimens of D. melanogaster obtained from natural populations in 2007 in the areas of the ChNPP with heterogeneous radioactive contamination were studied. The descendants from these populations were maintained in laboratory (inbred) conditions for 160 generations. A stable transgenerational transmission of dominant lethal mutations (DLMs) to the offspring of all studied populations was shown. The DLM frequencies strongly were correlated with the level of survival of offspring. The mean frequencies of recessive sex-linked lethal mutations varied at the level of spontaneous point mutations. The simultaneous presence of P, hobo and I elements indicates that the studied populations do not have a definite cytotype, their phenotypic status is unstable. The behavior of TEs in the genomes of offspring depends not only on parental exposure, but also on origin of population, distance to the ChNPP, and inbred conditions. The obtained results confirm the hypothesis that TEs are involved in transgenerational transmission and accumulation of mutations by the offspring of irradiated parents. The TEs pattern present in the Chernobyl genomes of D. melanogaster is a peculiar of epigenetic mechanism for the regulation of plasticity and adaptation of populations living for many generations under conditions of a technogenically caused radiation background.

Психоемоційний стан мешканців радіоактивно забруднених територій України, народжених до і після аварії на Чорнобильській атомній електростанції

Objectiv. Determining the attitude of residents from radiation-contaminated areas (RCA) born before and after the Chernobyl accident to the state of their health, their social and environmental factors. Materials and methods. Analysis of the psycho-emotional state of RCA residents under the age of 18 on the date of the Chernobyl accident and those born in the post-accident period from 1987 to 1997 was conducted during their medical examination according to the program of Clinical and Epidemiological Register (CER) for adults (over 18 years). The study results of the state of psychosomatic health of RCA residents (1534 people born before the accident and 1010 people after the accident) for the post-accident period (1993-2016) were obtained during the survey. Results: The majority of RCA residents born before the Chernobyl accident said (75.75%) that they already had a disease before the Chernobyl accident. In the period after the accident, 81.01% of respondents in this group reported deterioration and a severe deterioration in health. Of this group, 40.86% of respondents attributed the loss of their health to the impact of negative factors, including: 26.78% - social and professional and only 14.08% - with the Chernobyl accident. A significant number (39.43%) had answers "other factors" or "I do not know". Living on RCA as a factor in the development of anxiety, emotional tension, deteriorating health of the residents, their relatives, children, grandchildren now and in the future, indicated only 24, 57% of respondents and 21.99% of residents did not think that this factor affects the deterioration of their health. Among the measures that can prevent the deterioration of psychosomatic health, 44.45% of residents born before the accident considered effective - medical measures (regular inpatient and spa treatment, diet, physical therapy). The majority of residents born after the accident (62.64%) rated their current health status as "excellent" and "good". Some respondents (33.59%) indicated satisfactory health and 3.79% - poor health (against 60.10% and 26.86%, respectively, among those born before the accident). More than a half of those born after the accident said that living on RCA "does not affect" their health. Among the social measures that can improve health and prevent the development of diseases, half of respondents (50.0%) noted long vacations and physical activities, sports. Almost half of the residents in both groups did not know or pointed to other medical and social measures to restore and maintain their health.

Aging and mental health of the Chornobyl catastrophe survivors

IntroductionThe Chornobyl catastrophe (ChC) has impacted on depopulation and mental health of the survivors, however, the rate of demographic aging and mental health survey remain at issue.ObjectivesTo determine the rate of demographic aging of ChC survivors and to analyze the state of their mental health survey.MethodsInformation from the Ministry of Health and the State Statistics Service of Ukraine, Clinical and Epidemiological Register, the State Register of ChC survivors, and clinical neuropsychiatric data were analyzed.ResultsIn 2018, compared to 1995, the number of the ChC survivors decreased by 987 thousand with high level of aging: ChC clean-up workers – 59.0%; evacuees – 25.0%, and residents of radioactively contaminated territories (RCT) – 30.7%. There are negative tendencies in age parameters of survival of the RCT population. Long-term mental health disorders and neuropsychiatric effects in the ChC survivors have been identified, which may indicate an accelerated aging. Neurophysiological and molecular-biological atypia of aging processes under an exposure to low doses of and low dose rate of ionizing radiation have been found. Existing statistical and registry data underestimate the level of mental disorders in the population of Ukraine, including the ChC survivors by an order of magnitude.ConclusionsThe negative tendencies in age parameters of survival indicate the need to continue research to identify the factors “responsible” for such changes. Mental health disorders and neuropsychiatric effects in the ChC survivors are underestimated. It is necessary to create a national psychiatric registry of Ukraine and long-term (lifelong) monitoring of survivors.DisclosureNo significant relationships.

Radiation-associated cerebroophtalmic effects

IntroductionWe proposed to consider the brain and eye as a target of ionizing radiation exposure. Prevention of potential radiation-associated cerebroophtalmic effects are crucial for successful long-term space missions; interventional radiology; medical, occupational and accidental irradiationObjectivesDetermination of radiation-associated cerebroophtalmic effects in the long term after irradiation in adulthood and in utero.MethodsNeuropsychiatric, ophtalmological, neurophysiological and neuropsychological assessment of irradiated in adulthood (57 Chernobyl accident clean-up workers, liquidators), 52 persons exposed in utero as a result of the Chernobyl accident, comparison group (51 combatants of the Antiterrorist operation in Donbass), and 53 healthy people.ResultsRadiation-associated cerebroophthalmic pathology is characterized by high neuropsychiatric and ophthalmic comorbidity, which increases in proportion to the radiation dose, and is mainly represented by chronic vascular and degenerative diseases of the brain and retina, mild cognitive impairment (after irradiation in adulthood), as well as disorders of the autonomic nervous system; non-psychotic organic mental disorders; neurotic, stress-related and somatoform disorders; vascular and dystrophic processes in the retina (after in utero exposure). Characteristic of both radiological scenarios remains intellectual disharmony due to a decrease in the verbal IQ. The delay and attenuation of cerebral visual afferentation processing were observed in prenatally exposed.ConclusionsRadiation-associated cerebroophtalmic effects in the long term after irradiation in adulthood and in utero could be mainly classified as a “small vessel disease of the brain and eye” of vascular-degenerative nature and possible latent demyelination after irradiation in utero.DisclosureNo significant relationships.

Захворюваність на злоякісні новоутворення населення України у віддаленому періоді після аварії на ЧАЕС

There is performed a study of cancer incidence in the population affected by the Chornobyl accident. Analysis of demography situation has shown that unlike Western European countries with increasing life expectancy this index was notably decreased in Ukraine in 2005–2006 with slow growth during 2006–2019. Certainly this circumstance may influence on cancer incidence rate because the highest risk of malignant tumours is just in elderly age. Goal: to determine the frequency and risk of malignant neoplasms in groups of the population of Ukraine that were exposed to radiation as a result of the Chоrnobyl accident in the remote post-accident period. Materials and methods. The study was conducted on the basis of long-term monitoring of malignant tumours in the groups of victims – clean-up workers of 1986–1987, evacuees from the exclusion zone, residents of the territories most heavily contaminated with radionuclides. Results. There was a significant excess of the expected level of incidence of thyroid cancer among the participants in liquidation of the accident consequences (PLAC) - 4.5 times, evacuees - 3.8 times, residents of territories contaminated with radionuclides - 1.3 times. Leukaemia and lymphoma incidence rate in residents of contaminated territories increased sharply in the first years after the accident but decreased in the next years and not exceeded the level if Kyiv and Zhytomyr regions and Ukraine at whole. In a joint Ukrainian-American analytical epidemiological case-control study dose dependent excess relative risk of leukaemia (ERR/Gy) was proved in clean-up workers and defined at level 2.38 (0.49–5.87) in 1986–2006. A significant excess of the national level of incidence of breast cancer was determined only in women - PLAC in 1986–1987. In 1994–2019 SIR was 156.3% (95% CI: 141.0–171.5). Conclusions. Because latency period for different forms of radiation related malignancies might be very long further special attention should be paid not only to nosological forms mentioned above but also to cancers of the other sites.

Evaluation of 131I transfer in the environment based on the available measurements made in Belarus after the Chernobyl accident

This study evaluates the 131I transfer from ground deposition to the human thyroid gland after the Chernobyl accident using measurements of 131I concentrations in 1,252 soil, 124 grass, and 136 cow's milk samples as well as 131I thyroid activity measured in 3,100 individuals included in the Belarusian-American cohort. The following parameters of an 131I environmental transfer model used to calculate thyroid doses were evaluated in this study: (i) the interception factor of 131I by pasture grass, which was described by a purely empirical equation, (ii) the removal rate of 131I from pasture grass due to weathering and growth dilution, estimated to be 0.0676 d−1 (half-life of 10.3 d), (iii) the removal rate of 131I from cow's milk, estimated to be 0.0686 d−1 (half-life of 10.1 d), and (iv) the transfer coefficient of 131I from feed to cow's milk, arithmetic mean ± standard deviation of (6.7 ± 8.7) × 10−3 d L−1 (median = 4.0 × 10−3 d L−1). The individual model-based and measurement-based 131I thyroid activities for the Belarusian-American cohort members were calculated using different starting points of 131I transfer in the chain ‘ground deposition’ → ‘vegetation’ → ‘cow's milk’ → ‘human thyroid’, i.e., the measured 131I concentrations in soil, grass, and cow's milk. De novo thyroid doses from 131I for the 3,100 cohort members were calculated in this study using measured 131I activity concentrations in soil, grass, and cow's milk and were compared with those estimated previously for the same individuals using model-based 131I activity concentrations. It was shown that the use of measured instead of model-based 131I concentrations, in general, did not improve the measurement-based thyroid dose estimates. This is likely to be because there was already a good generic data base for the parameters used in this assessment. This finding indicates that, although the measurements of environmental samples are essential to estimate the parameter values of the 131I transfer model, the individual measurements of 131I thyroid activity are the most valuable information for estimating individual thyroid doses.

Cancer incidence in a male adult population in relation to estimated protracted colon dose – A nested case control study in Northern Sweden after the Chernobyl Nuclear Power Plant accident

IntroductionUncertainty in the dose-response of low dose radiation raised concern of an increased cancer incidence in Sweden after the Chernobyl Nuclear Power Plant (NPP) accident. Material and methodsA closed cohort was created of all males ≥18 years of age living in the Northern Sweden in 1986. In total 826,400 individuals were enrolled including 40,874 hunters. A nested case-control design was used with five controls randomly selected for each cancer case matched on year of diagnosis and year of birth. Individual absorbed colon dose was calculated 1986 to 2015. Allowing for a 5-year latency period Hazard Ratios (HR) per mGy with 95% Confidence Intervals (95% CI) were calculated in a conditional logistic regression adjusted by rural/non-rural living, length of education and pre-Chernobyl cancer incidence 1980 to 1985. A total of 127,109 cancer cases occurred from 1 January 1991 to 31 December 2015. Cancer was classified in: 1) Organ-specific (stomach, colon, liver, lung, prostate, urinary bladder, thyroid and leukaemia), 2) Other and 3) Not previously associated to ionizing radiation. ResultsThe average colon dose in cases was 1.77 mGy compared to controls 1.73 mGy. Hunters average colon dose was 2.32 mGy. Organ-specific cancers showed the highest HR per mGy both in the full cohort, adj HR 1.019 (1.014–1.024) and the hunter subcohort, adj HR 1.014 (1.001–1.027) during follow-up 1991 to 2015. Other cancer and Not previously associated with ionizing radiation showed lower HR per mGy. Therefore, the adj HR per mGy for Total cancer, 1.013 (1.009–1.017) was explained by Organ-specific cancer. Increased adj HR per mGy was seen in stomach, colon and prostate cancer, respectively in the full cohort and lung cancer in hunters. ConclusionsSome cancer sites previously associated with ionizing radiation showed a positive adjusted HR per mGy both in the full cohort and in the hunter subcohort.

SOCIO-GEOGRAPHICAL DIMENSION OF DEMOGRAPHIC PROCESSES IN UKRAINE IN THE PERIOD OF INDEPENDENCE (FROM 1991 TO 2022)

The article considers the formation of the demographic situation in Ukraine during its independence, namely - from 1991 to 2022. The authors analyzed the main demographic indicators - birth rate, mortality rate, natural increase, average life expectancy in the country over the past thirty years.
 In the first years of our country's acquisition of statehood, in addition to positive natural population growth, the increase in its number was also facilitated by a positive balance of migration due to a significant influx of immigrants. However, the deepening socio-economic crisis in 1992-1995 led to a sharp decline in birth rates, a deepening of natural population decline due to negative natural growth, and mass migration abroad in search of work. For the first time since this period, a negative balance of migration was recorded in Ukraine, and from that time until 2022, the volume of emigration exceeds immigration. Indicators of natural population movement have significant differences in the regions of Ukraine, urban and rural settlements. The highest values ​​are traditionally preserved in Volyn, Rivne and Zakarpattia oblasts, and the lowest ones are in Chernihiv and Sumy oblasts.
 The study allowed us to draw conclusions about the negative demographic phenomena - a rapid decline in population due to a significant decrease in birth rates, high mortality rates, the spread of the phenomenon of "aging" of the population. All this leads to the inevitable depopulation in the country, which confirms the demographic loss of about 10 million people during the study period (due to natural population decline and high migration in the mid-1990s and early XXI century). The demographic situation in rural areas remains particularly catastrophic. Negative demographic trends are exacerbated by the mass exodus of young people to study and work in the cities.
 Among the main factors that influenced the formation of the current demographic situation in Ukraine are: socio-economic (high unemployment, migration abroad, low level and quality of life compared to other countries in the European region), environmental (high level of industrial pollution) certain regions, uncontrolled application of mineral fertilizers to agricultural land, radiation emissions associated with the Chernobyl disaster), natural (Covid-19 epidemic), military (active phase of the Russian-Ukrainian war in 2022).
 The demographic catastrophe in Ukraine, connected with the beginning of the Russian-Ukrainian war in 2022, deserves special attention. The huge direct and indirect losses suffered by the country are due to the direct deaths during the hostilities, as well as the mass migration of people abroad since the beginning of the war. The losses will be assessed by demographers and statistical services after the war, but it is already worth considering the directions of a comprehensive demographic policy in Ukraine in the postwar period, which will restore the country's demographic potential. This work requires the coordinated work of demographers, geographers, economists and government and local government representatives. The authors outlined only the most important vectors of the formation of a new demographic policy in postwar Ukraine. They plan to pay more attention to these aspects by continuing further research.
 Keywords: population reproduction, birth rate, mortality, natural movement, life expectancy

ТHEORETICAL FUNDAMENTALS OF ECOLOGICAL AND ECONOMIC ESTIMATES OF WATER USE

Theoretical bases of modern water use, water resource potential, rational use, protection and reproduction of water resources of the region are considered. Changes in the ecological and economic system of water use in the Volyn region in market conditions are analyzed.
 Anthropogenically altered natural areas, progressive pollution of human habitat, caused a deterioration in quality of life, negatively affected the demographic characteristics of the inhabitants of the planet. Water, as an important natural resource, is used in all aspects of human life and in the spheres of the national economy, has become an important factor determining the development of society as a whole.
 The water management complex and especially its development must meet the socio-economic and environmental requirements of both society and the environment. The socio-economic aspect of these requirements is aimed at implementing measures and improving the territorial and sectoral structure and technologies of water use. Providing quality water to maintain the health of the population is the main goal of water use. International cooperation in the field of use and protection of water resources; taking into account environmental constraints and requirements in social and economic decisions should contribute to the stable development of regions. The Chernobyl catastrophe contaminated a large part of the territory of Volyn Polissya with radionuclides, which reduced the possibility of agricultural use of lands in the northern and north-western regions. Today it is becoming more and more important. acquires the need to develop the active use of environmental and economic tools to improve the process of water use. A number of proposals for solving an effective ecological and economic system of water use are presented
 A distinction is made between losses caused to fixed assets that lead to deterioration or reduction in the amount of resources such as soil, water, fish, wildlife, buildings and structures, and losses resulting from reduced output or profits from reduced productivity of these resources. The first type of loss is simultaneous, the second - current (deduction from production). To determine the value of the simultaneous damage to natural resources, it is necessary to use their economic evaluation: land and water, forests, mineral deposits. Current losses (reduction of output, reduction of its quality or reduction of profits) can be determined by direct calculation.
 Of particular importance are environmental losses of a social nature, which can only be partially measured by economic indicators: the cost of treatment, payment for sick leaves, loss of products due to illness and reduced productivity. Deterioration of health and reduced life expectancy are, of course, unacceptable and cannot be offset by any economic indicators. Damage to landscapes that worsen recreation conditions cannot be measured economically either.
 Economical rational use of natural resources largely depends on the comprehensive restructuring of the entire system of production and consumption. Organize control over the level of environmental pollution; correct determination of the costs necessary to overcome the harmful effects of irrational water use. In order to reduce the negative effects of radioactive contamination, to implement a set of organizational agrochemical, agrotechnical and technological measures.
 Given the great importance of water resources in the development of the national economy, not only Volyn region, but the state as a whole, the problem of balanced, scientifically sound, environmentally safe water use and dynamic development of the water complex of Ukraine is extremely important.
 Key words: water bodies, water use, urbanization, pollution, purification, water supply.

Dynamics of 137Cs Accumulation by Cranberry on Sphagnum Bogs of Polissia of Ukraine

Oligotrophic and mesotrophic bogs are common ecosystems in Polissia of Ukraine. After the Chernobyl accident, these ecosystems were contaminated with radionuclides. A common berry plant in these bogs is the cranberry, which is widely used in food industry. The aim of research is to establish dynamics of migration of 137Cs in cranberries during the last 30 years. The obtained results of monitoring studies are necessary for prognosis of radioactive contamination of cranberry. Investigation was conducted on stationary experimental plots (SEP) in Zhytomyr Polissia. 137Cs specific activity was measured on spectrum analyzers with scintillation and semiconductor detectors. Obtained results testify about intensive 137Cs migration on sphagnum bogs of Polissia of Ukraine. Results of investigation conducted after 34 years of Chornobyl accident showed low values of 137Cs specific activity in cranberry (Vaccinium oxycoccus L.) on all stationary experimental plots. This index in 2020 in fresh berries hesitate from 871±82.6 to 286±16.9 Bq/kg (at the permissible level 500 Bq/kg), and in dry shoots – from 1492 (SEP 15) to 6197 Bq/kg (SEP 12). It was found that in the first period (1991-1996) rather significant decreasing of 137Cs specific activity was observed in fresh berries of cranberry – from 3.8 times on SEP 11 to 2.2 times on SEP 12. In the next period (1996-2002) this decreasing was in the limits 1.4-2.9 times that is lower than in previous one. In the following period decreasing of 137Cs specific activity in berries was significantly lower. Revealed regularities of decreasing of 137Cs specific activity in berries during 1991-2020 also confirmed by decreasing of this index in the plant shoots. Total decreasing of this index in dry shoots on the whole period of investigation was: on SEP 11 – from 94590±4236 to 6099±366 Bq/kg (15.5 times), on SEP 12 – from 31800±2325 to 6197±242 Bq/kg (5.1 times), on SEP 15 – from 12120±898 to 1492±112 Bq/kg (8.1 times), on SEP 18 – from 14732±1126 to 1854±112 Bq/kg (7.9 times). Сontinuation of monitoring on stationary experimental plots will allow to predict levels of radioactive contamination of cranberry on the base of mathematical modeling

High-resolution records of cesium, plutonium, americium, and uranium isotopes in sediment cores from Swiss lakes

The Aare river system in Switzerland, with two nuclear power plants on the banks of the river, and its intermediate lakes and reservoirs, provides a unique opportunity to analyze the contribution of different sources to the radioactive contamination. Sediment cores were collected from two lakes and a reservoir, all connected by the river Aare. In order to study the influence of the Chernobyl accident, one sediment core was collected from a lake in the southern part of Switzerland. The sediment cores were sliced and analyzed with gamma ray spectrometry. Plutonium, americium, and uranium were extracted radiochemically, and their concentrations were measured with a sector field ICP-MS. The uranium isotope ratios were further measured with a multi collector ICP-MS. The maximum 137Cs activity from the Chernobyl accident and the Pu and 137Cs activities associated to the 1963 global fallout maximum were well identified in sediments from all three lakes. High-resolution records of plutonium isotopes in the zone of the sediments corresponding to the period of maximum fallout from the atmospheric nuclear weapon testing showed distinct fingerprints, depending on the different test activities. Pu isotope ratios could be used to detect non-global fallout plutonium. The ratio 241Am/241Pu was used to determine the age of the plutonium. Despite of very low 241Pu and 241Am concentrations, the calculated plutonium production dates seemed to be reasonable for the sediment layers corresponding to the NWT tests. The calculated production date of the plutonium in the upper most 15 cm of the sediment core seemed to be younger. The reason for this could be additional non-global fallout plutonium. For the lake sediments, natural ratios for 235U/238U and enriched or depleted ratios for 234U/238U were measured, depending on the lake. A small increase of the 236U/238U ratio could be recognized for the NWT zone in all three lakes and, for Lake Lugano, a further distinct increase in the Chernobyl layer.

Literatura, tożsamość i historia. Szkic o twórczości Liny Kostenko

The article concerns famous Ukrainian female poet, literary critic and writer Lina Kostenko (born 1930). It is a synthetic approach, which presents the important position of Kosteno in the life of Ukrainian literature and culture as well as politic life over the past 60 years as: 1. author of revealing lyrics and poems; 2. author of high-profile journalism on current topics, especially those related to the Chernobyl tragedy; 3. participant of the dissident movement in Ukraine; 4. author of the famous novel depicting the Ukrainian intelligentsia on the eve of the Orange Revolution of 2004 – Zapysky ukrajinskogo samashedshogo (2010); 5. a moral authority speaking on matters important for Ukrainian identity and historical heritage.

Clinicopathological Implications of the BRAF V600E Mutation in Papillary Thyroid Carcinoma of Ukrainian Patients Exposed to the Chernobyl Radiation in Childhood: A Study for 30 Years After the Accident.

With time after the Chernobyl accident, the number of papillary thyroid carcinomas (PTCs) driven by the BRAFV600E oncoprotein is growing in patients exposed to radiation at a young age. Clinicopathological associations of BRAFV600E in PTCs from patients with internal radiation history have not been sufficiently studied so far. This work analyzes the structural characteristics, proliferative activity, invasive features, clinical information, and dosimetric data in the BRAFV600E-positive and BRAFV600E-negative PTCs from the Ukrainian patients exposed to Chernobyl radiation and treated over 30 years after the accident. The study included 428 PTCs from patients aged 4–49 years at surgery who lived in the six northern regions of Ukraine most contaminated by 131I, were ≤18 years of age at the time of exposure, and were operated on from 1990 to 2017. Immunohistochemical staining for BRAFV600E was performed with the VE1 antibody. The probability of causation (POC) of a tumor due to radiation was determined using an interactive online NIH/NCI software. BRAFV600E was detected in 136/428 (31.8%) PTCs. In comparison with the BRAFV600E-negative PTCs, the BRAFV600E-positivity was associated with older patient age at the accident and at surgery, a longer period of latency, and lower POC. The BRAFV600E-positive PTCs were characterized by smaller tumor size, higher Ki67 labeling index, more frequent oncocytic changes, multifocality, and dominant papillary growth pattern. Tumor invasive features were less frequent in the BRAFV600E-positive PTCs and did not change with POC level. Despite a less aggressive tumor phenotype, BRAFV600E was a risk factor for recurrence, namely radioiodine-refractory (RAI-R) recurrent metastases. Multivariate models of RAI-R included BRAFV600E and/or histopathological parameters closely correlating with BRAFV600E such as tumor size, multifocality, dominant papillary growth pattern, or oncocytic changes. Thus, the BRAFV600E-positive PTCs from patients from a high-risk group for radiogenic thyroid cancer diagnosed in the 30 years after the Chernobyl accident did not display higher invasiveness regardless of POC level, but in view of the prognostic impact of this genetic alteration, knowledge of the BRAF status may be beneficial for middle-aged patients with radiogenic PTC considered for RAI therapy, and suggests more careful follow-up of patients with the BRAFV600E-positive tumors.

THE LATE XXth AND EARLY XXIst CENTURY WORLD LITERATURE AS A FACTOR IN SHAPING THE HISTORICAL MEMORY OF FUTURE TEACHERS

It is noted that fiction for various reasons loses its educational role among future teachers, and a certain educational potential of modern world literature is virtually unfamiliar to students. It has been proved that modern foreign literature, which actualizes Ukrainian issues, can become an effective means of educating spirituality, national-patriotic feelings and historical memory in future teachers. The interest of foreign authors in Ukraine, its historical past, raising of important issues of national identity, historical memory of Ukrainians is a stimulus for students to get acquainted with these literary works and to read them deeply. The object of study may be the novel "Chornobyl Prayer: A Chronicle of the Future" by the Nobel Prize-winning writer Svetlana Alexievich , as well as Taisa Bondar (the novel "In the Name of the Father and the Son"), Ivan Shamyakin (the novel "The Evil Star") , the American writer Irene Zabytko ("The Sky Unwashed"), representing diaspora literature, the novel by the Irish writer Darragh McKeon "All That is Solid Melts into Air", the literary work of the French illustrator Emmanuel Lepage "Springtime in Chernobyl", journalism of the American-English scholar Serhii Plokhy ("Chernobyl: The History of a Nuclear Catastrophe”) and others. These authors are thematically united by the Chernobyl accident, which they portray as a global catastrophe, as a national tragedy of Ukrainians, a huge psychological trauma for people. The writers emphasize that the Chernobyl explosion happened not only due to neglect of safety rules, problems with the construction of the reactor or staff errors, but also largely due to the socio-political system and the authoritarian regime of those times. Today, more than ever, these problems are urgent, especially taking into consideration the events that took place at the Chernobyl nuclear power plant as a result of the invasion of Russian troops. Unfortunately, there is a great threat of a repeat of this catastrophe. Therefore, the artistic and journalistic works of the “Chernobyl discourse” must be read carefully and in a new way, in order to prevent a recurrence of the Chernobyl disaster. The lessons of Chernobyl must not be forgotten and should never be allowed to happen today. Such issues are perhaps the most capable of shaping the national memory of youth, national consciousness and high spiritual values.
 Keywords: modern world literature, future teachers, historical memory, education, Chernobyl discourse, writers.