Chornobyl Nuclear Power Plant Accident Research Articles

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.

Psychological distress 35 years after the Chornobyl accident in the Lithuanian clean-up workers

ABSTRACT The adverse effects on the health of the Chornobyl nuclear power plant accident clean-up workers have been reported previously. However, there is a lack of studies on the mental health of Chornobyl clean-up workers. The current study explored psychological distress in a sample of Lithuanian clean-up workers 35 years after the accident. In total, 107 Lithuanian Chornobyl clean-up workers (Mage = 62.5) and 107 controls were included in the study. The Hospital Anxiety and Depression Scale (HAD) was used for the assessment of anxiety and depression. The depression symptoms were significantly higher in the clean-up workers compared to the control group. The prevalence of severe depression symptoms was 23.4% and 4.7% in the Chornobyl clean-up workers and control groups, respectively. The risk for severe depression was associated with Chornobyl clean-up work (adjusted OR = 5.9). No differences in the anxiety symptoms were found between clean-up workers and controls. The study revealed the deteriorated mental health of the Lithuanian Chornobyl clean-up workers 35 years after the disaster – in particular, high levels of depression. Psychosocial support programmes for clean-up workers should be provided to mitigate the adverse effects of the disaster.

Numerical simulation of the radioactive contamination of Ukraine after the Chornobyl disaster: the influence of the input meteorological data on the results uncertainty

In this article we assess the sensitivity of the numerical simulations of the radioactive 137Cs contamination of Ukraine caused by the Chornobyl nuclear power plant accident in 1986 to the input meteorological data. The atmospheric transport, dispersion, and deposition (dry scavenging and rain washout) of the radioactive aerosols was simulated using the CALPUFF dispersion model. The source parameterization of the 137Cs emissions during the active phase of the catastrophe (26 April—May 5 of 1986) was adopted from the previously published literature results. Seventeen different versions/realizations of the input meteorology for CALPUFF simulations were prepared with the regional prognostic meteorological model WRF by combining the available global atmospheric reanalyses for 1986 (NNRP, ERA-Interim, ERA5, CFSR) and the model’s physical parameterizations (microphysics, radiation processes, boundary/surface layer physics). The assessment of the simulation uncertainty was carried out in two different ways. In the first approach, the uncertainty was estimated as the width of the distribution of the calculated 137Cs surface concentrations (adjusted to the logarithmic scale), which were obtained with different versions of the input meteorology. The second approach was based on the statistical comparison of the calculated 137Cs contaminations and the corresponding measured values obtained during a complex assessment of the aftermath of the disaster made at the beginning of 1990s. Two statistical metrics were used: the geometric mean bias and the geometric mean variance. The results of our study demonstrate that even when using somewhat unified meteorological data (atmospheric reanalysis), the results of the radioactive contamination calculations at the same spatial locations can differ by several orders of magnitude. We find that the uncertainty depends not only on the distance to the source of the emissions but also on the physical mechanism (wet or dry deposition) responsible for the formation of the local contamination

Exposure to the Thyroid from Intake of Radioiodine Isotopes after the Chornobyl Accident. Report I: Revised Doses and Associated Uncertainties for the Ukrainian-American Cohort.

Thyroid doses from intake of radioiodine isotopes (131I, 132Te+132I, and 133I) and associated uncertainties were revised for the 13,204 Ukrainian-American cohort members exposed in childhood and adolescence to fallout from the Chornobyl nuclear power plant accident. The main changes related to the revision of the 131I thyroid activity measured in cohort members, the use of thyroid-mass values specific to the Ukrainian population, and the revision of the 131I ground deposition densities in Ukraine. Uncertainties in doses were assessed considering shared and unshared errors in the parameters of the dosimetry model. Using a Monte-Carlo simulation procedure, 1,000 individual stochastic thyroid doses were calculated for each cohort member. The arithmetic mean of thyroid doses from intake of 131I, 132Te+132I, and 133I for the entire cohort was 0.60 Gy (median = 0.22 Gy). For 9,474 subjects (71.6% of the total), the thyroid doses were less than 0.5 Gy. Thyroid doses for 42 cohort members (0.3% of the total) exceeded 10 Gy while the highest dose was 35 Gy. Intake of 131I contributed around 95% to internal thyroid exposure from radioiodine isotopes. The geometric standard deviation of individual stochastic thyroid doses varied among cohort members from 1.4 to 4.3 with an arithmetic mean of 1.6 and a median of 1.4. It was shown that the contribution of shared errors to the dose uncertainty was small. The revised thyroid doses resulted, in average, in around 40% decrease for cohort members from Zhytomyr Oblast and an increase of around 24% and 35% for the cohort members from Kyiv and Chernihiv Oblast, respectively. Arithmetic mean of TD20 doses for the cohort was around 8% less than that estimated in TD10, 0.60 Gy vs. 0.65 Gy, respectively; however, global median of TD20 doses somewhat increased compared to TD10: 0.22 Gy vs. 0.19 Gy, respectively. The difference between TD10 and TD20 was mainly due to a revision of the individual 131I thyroid activity measured in the cohort members.

Mode of Atmospheric Deposition in Forests Demonstrates Notable Differences in Initial Radiocesium Behavior.

The March 2011 Fukushima Dai-ichi Nuclear Power Plant accident in Japan released 520 PBq of radionuclides compared to a total release of 5300 PBq from the Chornobyl Nuclear Power Plant accident. Both nuclear accidents resulted in deposition of radiocesium throughout the northern hemisphere, and a plethora of studies have been performed regarding radiocesium (137Cs) behavior. However, few studies have assessed the impact of precipitation on 137Cs deposition in forests. Wide-scale environmental measurements from 2011 and 2016 were used to determine the differences in 137Cs deposition because of precipitation following the Fukushima accident. In areas where wet deposition processes were dominant, dense forests generally had lower ambient dose rates and levels of contamination on forest floors than other stands with fewer stems per hectare in 2011. Similar tendencies were not observed in areas that were primarily subject to dry deposition nor were any trends observed in 2016. 137Cs was retained in dense forest canopies for an extended period regardless of the deposition mode. Additionally, it was found that the initial retention of radionuclides by forest canopies is in general higher for areas with predominantly dry deposition. Incorporation of radiocesium into wood tissues was the same for both wet and dry deposition.

ASSESSMENT OF THE SEVERITY OF GINGIVITIS IN CHILDREN WITH DISORDERS OF TEETH FORMATION SUFFERED AFTER THE CHORNOBYL NPP ACCIDENT.

to determine the severity of gingivitis in children with teeth formation disorders - residents of the ter-ritories contaminated with radionuclides as a result of Chornobyl Nuclear Power Plant (ChNPP) accident. The object of the study is 1470 children aged 6-14 years with dental malformations, 528 amomg them are residents of areas contaminated with radionuclides as a result of the ChNPP with the identified types of disorders of teeth formation (DTF) (systemic enamel hypoplasia (SEH) and molar-incisor hypomineralization (MIH)), and different stages of the severity of gingivitis. Determining of the degree of severity of gingivitis in children with DTF indicates the presence of its lesion of a moderate degree of the severity with a prevalence in persons with SEH or MIH and chronic diseases of internal organs suffered after the ChNPP accident. In irradiated children with DTF, an average degree of severity of gingivitis was established (РМА = (43.03 ± 19.64) %, p > 0.001), which may be due to the effect of a complex of negative factors, in particular the influence of low doses of ionizing radiation, the peculiarities of the social status of the examined persons (imbalanced nutrition), unsatisfactory oral hygiene. In children suffered after the ChNPP accident with SEH, the indicators of the PMA index were reliable (p > 0.05) higher compared to individuals with MIH, which indicates a more pronounced degree of periodont damage. Revealed damage to periodont, in particular gingivitis, in children with DTF residents of the contaminated territories, probably caused by the action of a complex of negative environmental factors, in particular the influence of low doses of ionizing radiation, and the peculiarities of the social status of children, which requires a comprehensive approach to the prevention of complications of defects of hard tissues of the teeth.

COMPLEX ANALYSIS OF THE ROLE OF CYTOKINE GENE POLYMORPHISMS AS PROGNOSTIC FACTOR OF THE RISK OF PLASMA CELL MYELOMA IN PERSONS SUFFERED AFTER THE CHORNOBYL NPP ACCIDENT.

to provide a comparative characterization of the prevalence of polymorphic variants of cytokine genes in plasma cell myeloma (PCM) patients suffered after the Chornobyl disaster and patients who were in contact with ionizing radiation within the natural radiation background, based on comparison with population controls to determine their contribution as genetic markers of disease risk. Molecular genetic studies of polymorphism of cytokine genes (TNF-α, TGF-β1, IL-6, IL-10, IFN-γ) and complex frequency analysis of occurrence in three-, four-, and five-locus combinations of their allelic variants as prognostic markers of the risks of plasma cell myeloma was carried out in 102 patients - 56 victims of the Chornobyl nuclear power plant accident and 46 patients irradiated within the limits of the natural radiation background, in comparison with the control group (364 practically healthy people, residents of the Central geno-geographical region of Ukraine). The same probable increase in the prevalence of the TGF-β genotype codon10 T/T of the TGF-β1 gene was established in the groups of patients irradiated after the Chornobyl NPP accident and non-irradiated patients. In patients with plasma cell myeloma a protective effect for IL-10 -1082 A/G and an association with the risk of disease occurrence for IL-10 -1082 G/G were determined. Probable difference in the frequency of the TGF-β1 genotype codon10 T/T of the TGF-β1 gene in the observed groups relative to the control group provides grounds for considering this single-nucleotide polymorphism of the TGF-β1 gene as an immunogenetic factor of predisposition to the development of PCM independent of exogenous factors. The study of the contribution of multigene combinations of «gene-gene» interaction indicates their role in the mechanisms of plasma cell myeloma occurrence and confirms the presence of an additive interaction.

IONIZING RADIATION AND CYTOKINES: THE ROLE IN THE PATHOGENESIS OF PLASMA CELL MYELOMA (LITERATURE REVIEW).

The review presents literature data on the role of ionizing radiation as a negative environmental factor in the occurrence of plasma cell myeloma (PCM). The data of studies of various categories of irradiated persons regarding the incidence of PCM, in particular employees of nuclear enterprises and victims of the accident at the Chornobyl Nuclear Power Plant accident, are given. The effect of cytokines (interleukin-6 and interleukin-10) on PCM substrate cells was analyzed, including under conditions of combined action of IR and cytostatic agents in vitro.

Comparative assessment of the dynamics of the average annual deposition velocity of 90Sr and 137Cs for a long term period after the Chornobyl accident for the cities of Ukraine, Kyiv and Chornobyl

A reliable assessment of the radioactive aerosol spread is an environmental safety task of current interest and high priority. An important parameter, used to calculate the transport of radioactive fallout, is the deposition velocity of radioactive aerosol. Fluctuations in the deposition velocity, which according to experimental data are within several orders of magnitude, depend on a number of factors (including time), which requires a detailed analysis of the patterns of radioactive pollution fields formation of air and the underlying surface. In this radio- ecological study, the dynamics of the average annual values of the deposition velocity of 90Sr and 137Cs were evaluated and analyzed, based on the experimental data of the measurements of the volume activity and the depositional fluxes obtained in Ukraine for the cities of Kyiv and Chornobyl after the Chornobyl nuclear power plant accident, during 1987–2019. The deposition rates for 90Sr and 137Cs estimated over a long period of time (33 years) show different trends. The total deposition velocity of 90Sr tends to increase, while for 137Cs the deposition velocity decreases over time. This pattern is characteristic of the two studied sites (Kyiv and Chornobyl). Relevant trends in the dynamics of deposition velocity may indicate the transformation of aerosol carriers of these radionuclides, their aerodynamic and migratory capabilities. This study could be of use for an empirical parameterization of deposition velocities in air quality models.

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

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

Чорнобильська аварія та йодна недостатність як фактори ризику тиреоїдної патології у населення постраждалих регіонів України

Наслідком аварії на Чорнобильській атомній електростанції була негативна дія опромінення на здоров’я населення значних територій України та прилеглих країн, наслідки цієї дії будуть виявлятися протягом багатьох років. Дослідження, проведені у 2011–2014 рр. у Київській, Житомирській і Чернігівській областях, показали, що йодний дефіцит у харчуванні населення на цих територіях зберігається та негативно діє на здоров’я мешканців, які зазнали впливу факторів Чорнобильської аварії. Розв'язання проблеми профілактики йододефіцитних захворювань лежить в аспекті прийняття законодавчих актів щодо масової і групової йодної профілактики.

Аналіз поширеності тиреоїдної патології та захворюваності на неї серед населення Київської області та України за 2007–2017 рр.

Актуальність. В Україні чітко простежується збільшення кількості пацієнтів із різноманітною патологією щитоподібної залози. Показники поширеності та захворюваності відрізняються в різних регіонах країни залежно від впливу чинників зовнішнього середовища та їх комбінації. Одним із відомих факторів є аварія на ЧАЕС, але ріст тиреоїдної патології на незабруднених територіях свідчить про необхідність більш детального вивчення даної проблеми. Мета: провести аналіз поширеності тиреоїдної патології й захворюваності на неї серед населення Київської області за 2007–2017 роки. Матеріали та методи. Проведено аналіз даних щорічних звітів медичних закладів Київської області за 2007–2017 роки. Статистичний аналіз проводився за допомогою пакета програм Windows Office Exсel 2016 та IBM SPSS Statistics 23.0. Результати. У структурі тиреоїдної патології серед населення Київської області у 2017 р. частка тиреоїдитів становила 11,2 %, гіпотиреозу — 4,6 %, гіпертиреозу — 2,1 %. У жінок тиреоїдити траплялися в 9,7 раза частіше, гіпотиреоз — у 8,3 раза, а гіпертиреоз — у 5,3 раза частіше, ніж у чоловіків. Виявлені вірогідні дані щодо зростання поширеності тиреоїдитів — у 1,9 раза (р < 0,01), гіпотиреозу — у 2,1 раза (р < 0,01), гіперти­реозу — 1,7 раза (р < 0,01) по області. По Україні відбулося зростання поширеності тиреоїдитів у 2,5 раза (р < 0,01), гіпотиреозу — у 1,7 раза (р < 0,01), гіпертиреозу — у 1,5 раза (р < 0,01). Згідно з прогностичними моделями, протягом наступних п’яти років очікується збільшення поширеності тиреоїдитів, гіпо- та гіпертиреозу по області, що може бути спричинено негативним впливом екзо- та ендогенних факторів. Висновки. Неухильне зростання поширеності тиреоїдної патології й захворюваності на неї в забруднених і незабруднених після ЧАЕС регіонах України, збільшення частки тиреоїдитів, гіпо- та гіпертиреозу за останнє десятиріччя, прогнозоване зростання даної патології протягом наступних п’яти років свідчить про необхідність аналізу причин і заходів їх профілактики в практиці сімейних лікарів та ендокринологів.

Correlation between secondary hyperparathyroidism and comorbid disorders among the Chornobyl NPP accident survivors

Background. Endocrine comorbidity, a concomitant radiation injury of several endocrine glands, is a topical issue in radiation medicine. The purpose of the study was to establish a correlation of secondary hyperparathyroidism with thyroid and pancreatic disorders among the Chornobyl nuclear power plant (NPP) accident survivors. Materials and methods. A blind sample (n = 60) of subjects treated at the radiation endocrinology department in 2019 was selected for the study. Study sample included the Chornobyl NPP accident survivors (group 1, n = 40) and patients not exposed to radiation (group 2, n = 20). The average age of people was 60.2 ± 9.8 years. Decompensation of type 2 diabetes was the most common cause for hospital admission (48.3 %), decompensation of hypothyroidism was in second place (46.7 %). Research methods: clinical, instrumental, laboratory, statistical. Results. Incidence of the increased risk of vitamin D deficiency and excessive parathyroid hormone production in the Chornobyl NPP accident survivors was somewhat higher than in individuals not exposed to radiation (81.08 and 78.12 %; χ2 = 0.257, p = 0.612; 31.12 and 28.08 %; χ2 = 0.462, p = 0.319, respectively). Using a multivariate analysis, the reliable model was obtained confirming the relationship of increased parathyroid hormone level and early subclinical signs of the target organ damage (F = 4.294; p = 0.042), which proves the relevance of using clinical questionnaires. A reliable positive correlation was found between the vitamin D and free thyroxine levels (r = 0.729; p = 0.001), and negative one was found with the thyroid-stimulating hormone content (r = –0.803; p = 0.001). In the Chornobyl NPP accident survivors with type 2 diabetes, a decreased vitamin D concentration correlated with an increased duration of metformin therapy (r = –0.421; p = 0.001) and body mass index (r = –0.787; p = 0.001). It was found that the parathyroid hormone level increases along with the duration of type 2 diabetes and an increase in creatinine clearance (r = 0.724; p = 0.001, and r = 0.799; p = 0.001). Conclusions. Vitamin D deficiency has a negative effect on the course of comorbid disorders (type 2 diabetes and hypothyroidism) and excessive production of parathyroid hormone.

Patterns of liver disease formation in victims of the Chornobyl nuclear power plant accident

The aim of the study is to determine the mechanisms for the formation and progressivity of chronic diffuse liver diseases in victims of the Chornobyl Nuclear Power Plant accident with the development of a diagnosis criteria for fibrous changes in this pathology. The materials were the results of examination and treatment in the clinic of the State Institution "NRCRM of the NAMS of Ukraine" of victims of the Chornobyl Nuclear Power Plant accident, 57 of which, according to the criteria for switching on and off, were assigned to the main group. The research methods were: general clinical examination, instrumental studies (ultrasound diagnostics of abdominal organs), biochemical, medical statistics, analytical. According to the results of the study, it was proved that in the victims of the Chornobyl Nuclear Power Plant accident, the main liver pathology was non-alcoholic fatty liver disease. It has been shown that in patients affected by the Chernobyl disaster, NAFLD develops a pronounced violation of fat metabolism with a reliable decrease in cholesterol and beta-lipoproteins in cirrhosis – a sign of a long-term course of the disease, accompanied not only by the development of fibrosis, but also by a fatty rebirth of liver tissue with low cholesterol and beta-lipoproteins; this can be considered a marker of cirrhosis in the Chornobyl accident clean-up personnel with NAFLD.

ASSESSMENT OF QUALITATIVE CHANGES IN PERIPHERAL BLOOD CELLS IN CHILDREN - RESIDENTS OF RADIOLOGICALLY CONTAMINATED TERRITORIES IN THE LATE PERIOD AFTER THE ChNPP ACCIDENT.

to establish the relationship between quantitative and qualitative parameters of peripheral blood cells(lymphocytes, neutrophilic granulocytes, monocytes, platelets) depending on the type of somatic diseases andannual internal radiation doses from 137Cs in children - residents of radiologically contaminated territories in thelate period after the Chornobyl Nuclear Power Plant (ChNPP) accident. There were 175 children included in the study comprising residents of radiologically con-taminated territories (n = 79) aged from 4 to 18 years. Annual internal radiation doses in children from 137Cs rangedfrom 0.004 to 0.067 mSv. Certain blood parameters were assessed in a comparative mode in children having got theradiation doses up to 0.01 mSv and higher. The comparison group (n = 96) included children living in settlementsnot attributed to the radiologically contaminated ones. Incidence and type of somatic diseases and its impact onquantitative and qualitative changes in blood parameters (i.e. lymphocyte, neutrophilic granulocyte, monocyte, andplatelet count) were studied. The cell size, state of nucleus, membranes and cytoplasm, signs of proliferative anddegenerative processes were taken into account. Incidence and type of somatic diseases in children did not depend on the annual internal radiation dose.Number of cases of monocytosis was significantly higher among the children exposed to ionizing radiation than inthe comparison group (16.6 % vs. 7.3 %). There were, however, no correlation between these changes and radiationdoses. Number of activated blood monocytes with cytoplasmic basophilia and residues of nucleoli in nuclei washigher in individuals with internal radiation doses > 0.01 mSv. A direct correlation between the qualitative param-eters of monocytes and internal radiation doses was established (rs = 0.60; р < 0.001), as well as a direct correlationof different strength between qualitative parameters of blood cells, indicating their unidirectional pattern depend-ing on the somatic morbid conditions. Regardless of annual internal radiation dose, there was an increase in thenumber of degenerative and aberrant cells vs. the comparison group (р < 0.05), which could be due to the role ofnon-radiation factors. Results of the assessment of quantitative and qualitative parameters of peripheral blood cells reflect-ed the state of morbid conditions in children and are of a diagnostic value. The identified dose-dependent changesin monocyte lineage of hematopoiesis may be the markers of impact of long-term radionuclide incorporation withfood in children living in environmentally unfavorable conditions after the ChNPP accident.

Practice of research in mortality of the persons, which was children on the moment of accident on Chornobyl NPP and lived on the most radioactive contaminated territories of Ukraine

Introduction. Previous studies have revealed a fairly high level of premature mortality of the population in radioactive contaminated territories (RCT) of Ukraine, which led to the feasibility of further studies of children's health at the time of the Chornobyl Nuclear Power Plant accident (subjects born in 1968–1986) on mortality. Objective: to investigate retrospectively the mortality rate of subjects who were children during the CNPP accident and lived in 1986–2011 on the most radiation contaminated territories of Ukraine (Ivankivsky and Polissky districts of Kyiv region and Narodytsky and Ovrutsky districts of Zhytomyr region). Materials and methods. The combination of information bases of the State Statistics Service of Ukraine and the Ministry of Justice of Ukraine made it possible to form a study cohort (more than 31 thousand people who at the time of the CNPP accident were 0–17 years old and they lived in Ivankivsky, Polissky, Narodytsky and Ovrutsky districts) and collect anonymized information about 2.1 thousand deaths for 1986–2011. The control was the population of Ukraine of the corresponding age. Variables were calculated in accordance with the recommendations on population statistics. Documentary analysis, theoretical, general scientific, demographic, mathematical, statistical, software-technological and graphic (using the Microsoft Word, Microsoft Excel software package) research methods were applied. Results. For the first time, the methodological and practical issues of studying the differentiation of mortality in subjects born in 1968–1986 who lived in the RCT in 1986-2011 were worked out. Average chronological mortality rate for 1986–2011 for the cohort in RHT was (2.26 ± 0.37) ‰, in Ukraine – (1.74 ± 0.74) ‰. There was revealed a significant excess of mortality rates inn RTH in comparison with the population of the country and men in comparison with women. It was established that the studied cohort potentially lost 82.3 thousand years of life over 26 years. In premature mortality, the leading role (50.4%) belonged to exogenous causes, 43.1 % – to somatic pathology, 6.55 % – to symptoms, signs and vaguely defined conditions. The average age of death for both sexes is (27.7 ± 0.11) years, for men – (28.2 ± 0.12) years, for women – (25.9 ± 0.23) years. Conclusions. In terms of mortality rates, the state of health of subjects who were children at the time of the CNPP accident and lived in 1986–2011 in the most radiation contaminated territories of the country is recognized as worse than the population of Ukraine of the corresponding age. Key words: radioactive contaminated territories, children on the moment of accident on Chernobyl NPP, mortality.

Analysis of immunoglobulin heavy variable chain rearrangement in chronic lymphocytic leukemia patients among Chornobyl clean-up workers.

A number of epidemiological studies have shown an elevated radiation-associated risk for chronic lymphocytic leukemia(CLL). The aim of the paper was to analyze immunoglobulin heavy variable chain (IGHV) rearrangement and IGHV usage in CLL cases associated with ionizing radiation (IR) exposure. Samples of 76clean-up workers of Chornobyl Nuclear Power Plant accident of 1986 (the main group) and 194non-exposed patients (the control group) were analyzed. Two groups of CLL patients were comparable by gender (all patients were male), age, and place of residence (rural or urban). Some features of IR-associated CLL cases as compared to CLL cases in patients without history of IR exposure were revealed. Among unmutated IGHV sequences, IGHV1genes were less commonly used (29.4% vs 48.6%; p= 0.018), while the frequency of IGHD6genes was higher (23.5% vs 10%; p= 0.029). The unmutated IGHV sequences did not use IGHD3-16gene (0% vs 7.9%, p= 0.038). Mutated IGHV sequences were less frequently expressed IGHV3genes (44% vs 68.5%; p= 0.037) due low representation of IGHV3-21 (4% vs 11.1%) and IGHV3-23 (0% vs 11.1%) genes; did not use IGHD3-22gene (0% vs 18.5%, p= 0.025); and have signs of positive selection in the HCDR regions (Σ= 0.5029± 0.155vs -0.0539± 0.14; p= 0.013). The revealed differences in IGHV gene usage and B-cell receptor structure in the main and the control groups of CLL patients indirectly indicate a change in the spectrum of antigens associated with CLL under IR exposure. The possible antigenic drivers associated with CLL associated with IR exposure are discussed.

CHRONIC MYELOID LEUKEMIA COURSE IN PERSONS EXPOSED TO IONIZING RADIATION AS A RESULT OF THE CHORNOBYL ACCIDENT.

Describe and characterize the peculiarities of the chronic myeloid leukemia (CML) course and responseto treatment in patients irradiated as a result of the Chornobyl nuclear power plant (ChNPP) accident based on theassessment of clinical-laboratory and clinical parameters. The CML patients (n = 33) exposed to ionizing radiation as a result of the ChNPP accidentwere enrolled. The comparison group consisted of CML patients (n = 725) with no history of radiation exposure. Allpatients were in the chronic phase of the disease. Clinical, hematological and molecular genetic research methodswere applied. Patients exposed to ionizing radiation as a result of the ChNPP accident had no differences in CML manifestation, as well as in classical genetic markers at the onset of the disease compared with patients with no historyof radiation exposure. Reduction of tumor clone on imatinib therapy was significantly less effective in the patientsexposed to ionizing radiation than in cases of no history of radiation exposure. Cases of primary resistance were statistically significantly prevalent in the ChNPP accident consequences clean-up workers while in the residents ofradiologically contaminated areas a statistically significant increase in probability of loss of complete cytogeneticresponse (development of secondary resistance) to imatinib therapy was found. An association was found betweenthe radiation exposure and probability of loss of complete cytogenetic response to imatinib therapy in this group ofpatients. The radiation exposure in the history even many years before the onset of CML is an unfavorable exogenous factor responsible for the development of resistance to imatinib therapy.

The metabolic relationship of calcium and phosphorus to the state of genome of folate metabolism in children living in areas affected by the chornobyl nuclear power plant accident

The metabolic relationship of calcium and phosphorus to the state of genome of folate metabolism in children living in areas affected by the chornobyl nuclear power plant accident

Childhood leukemia in Ukraine after the Chornobyl accident

This population-based ecological study analyzes the prevalence of childhood leukemia in Ukraine before and after the Chornobyl nuclear power plant accident, based on the contamination status of the territory, time period, gender, and age. Three regions-Zhytomyr, Kyiv (except Kyiv city), and Chernihiv were included as areas contaminated by radioactive 137Cs from 1 to 15Ci/km2 with annual effective doses exceeding 1.0mSv, and Sumy region as the control (non-contaminated) area with 137Cs contamination less than 1Ci/km2 and effective doses less than 0.5mSv per year. The integrated database of the National Research Centre for Radiation Medicine used in the present study included 1085 childhood leukemia cases. Two aggregated periods were used for analysis: 1980-1986 (pre-accident) and 1987-2000 (post-accident). ICD-9 codes for leukemia (204-208.9) were used to perform analyses according to the extent of leukemic cells maturity (acute, chronic, and maturity unspecified leukemia), leukemic cell lineage (lymphoid, myeloid and lineage unspecified leukemia) and all leukemia cases in different age subgroups (1-4, 5-9, 10-14, and 15-19years). Standard methods of descriptive epidemiology were used to calculate the prevalence of disease and frequency ratio in regression models. A statistically significant increase in frequency ratio for acute leukemia (1.44; 95% confidence interval (CI), 1.22-1.71), myeloid leukemia (2.93; 95% CI, 1.71-5.40), cell lineage unspecified leukemia (II) (1.48; 95% CI, 1.18-1.87) and all forms of leukemia (1.59; 95% CI, 1.36-1.86) was found for the post-accident period in highly contaminated areas. The results indicate that the frequency of childhood leukemia (and of some of its types) increased in contaminated areas during the post-accident period, suggesting that radiation exposure after the Chornobyl accident might be the cause of the increase. However, further analytical studies, with individual or at least group dose estimates, are needed to confirm a link between childhood leukemia and the Chornobyl accident.