STILLBIRTH RATE AND INFANT MORTALITY RATE: STUDY IN THE REGIONS OF UKRAINE MOST INTENSIVELY RADIOCONTAMINATED UPON THE CHORNOBYL NPP ACCIDENT. / МЕРТВОНАРОДЖУВАНІСТЬ ТА МАЛЮКОВА СМЕРТНОСТЬ: ДОСЛІДЖЕННЯ РАЙОНІВ УКРАЇНИ НАЙБІЛЬШ РАДІОАКТИВНО ЗАБРУДНЕНИХ ВНАСЛІДОК АВАРІЇ НА ЧОРНОБИЛЬСЬКІЙ АЕС.

OBJECTIVE: to evaluate the time pattern peculiarities of stillbirth and infant mortality rates in the radiocontaminated territories of Ukraine in the post-accident period on the basis of the national State Statistics Service data. OBJECT OF THE STUDY: stillbirth and infant mortality rates of population of the most intensively radiocontaminated territories of Ukraine (Lughinskyi, Narodytskyi, Ovrutskyi and Olevskyi districts of Zhytomyrska oblast, Vyshgorodskyi, Ivankivskyi and Poliskyi districts of Kyivska oblast, Rokytnivskyi and Sarnenskyi districts of Rivnenska oblast, and Kozeletskyi and Rypkinskyi districts of Chernihivska oblast).Research materials and methods. Information resources of the State Statistics Service of Ukraine for 1986-2020 regarding the infant mortality and stillbirth rates were used in the study. Demographic, mathematical-statistical, graphical, and software-technological research methods were applies. RESULTS AND CONCLUSIONS: Parameters of infant mortality and stillbirth rates for the 1986-2020 period were studied retrospectively. Significant variations in values were revealed both between the territories and years of survey.

RADIOACTIVELY CONTAMINATED TERRITORIES OF CHERNIHIVSKA OBLAST OF UKRAINE: THE RADIATION-ECOLOGICAL AND MEDICAL-DEMOGRAPHIC PAST AND PRESENT. / RADIATsIINO ZABRUDNENI TERYTORIÏ ChERNIGIVS'KOÏ OBLASTI UKRAÏNY: RADIATsIINO-EKOLOGIChNE TA MEDYKO-DEMOGRAFIChNE MYNULE TA SUChASNE.

OBJECTIVE: 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. OBJECTS AND METHODS: 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. MATERIALS AND METHODS: 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 Ukraine¼ were used. General scientific, mathematicalstatistical, graphic, cartographic, and softwaretechnological research methods are applied. RESULTS AND CONCLUSIONS: 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.

SOME ISSUES OF LIFE ACTIVITIES OF POPULATION IN THE CHORNOBYL EXCLUSION ZONE IN UKRAINE. / DEIaKI ASPEKTY ZhYTTIeDIIaL'NOSTI NASELENNIa V ChORNOBYL'S'KII ZONI VIDChUZhENNIa UKRAÏNY.

BACKGROUND: Radiation accidents at the Chornobyl Nuclear Power Plant (USSR, 1986) and Fukushima-1 (Japan,2011) have shown that global environmental contamination is an intervention in normal human life making nega-tive effect on population health. These accidents highlighted a number of statutory and regulatory both with me-dical and social problems for individuals, who returned voluntarily for permanent residence in the ChornobylExclusion Zone i.e. a radiation-hazardous area (they are named the «self-settlers¼). OBJECTIVE: generalization of experience in the settlement of normative-legal, ecological-dosimetric and medico-social life issues of population living in the Chornobyl NPP (ChNPP) Exclusion Zone («self-settlers¼). OBJECT AND METHODS: The chosen problem is complex, necessitating the generalization of radiation-hygienic, med-ical-biological, socio-economic, demographic and sociological research results obtained by the national and foreignauthors. A set of theoretical research and analysis of empirical data methods on the principles of interdisciplinaryinteraction was used; the systematic, legal, economic, medical-biological, demographic and retrospective-dosimet-ric approaches of research were applied. RESULTS: It was shown that a part of population refused to evacuate or had returned for permanent residence to theradiation-hazardous lands after the ChNPP accident. In 1986-2009 the number of «self-settlers¼ ranged from 150to 2,000 in different years. In 2021 - the 101 people. Those were mainly people of working age, mostly females, single people or widows/widowers. Рrevious medical and dosimetric studies have shown that long-term residence inthe Exclusion Zone affects physical and mental health of «self-settlers¼ and causes atypical aging, includinginvolvement of the central nervous system. According to calculations, the average effective total radiation doseaccumulated by «self-settlers¼ for the first 3 years was 30 % of dose for the entire post-accident period, and thedose accumulated over 20 years was 54 % of the dose accumulated over 35 years. But the effective radiation dosesaccumulated in different periods after the accident differ significantly in residents of different Exclusion Zone settlements. This information needs further study in terms of the «radiation dose - health status¼ dependence. CONCLUSIONS: The effective radiation doses accumulated in different periods after the accident differ significantlyin the residents of different Exclusion Zone settlements. Тhe average effective total radiation dose accumulated by«self-settlers¼ for the first 3 years was 30 % of the dose for the entire post-accident period, and the dose accumulated over 20 years was 54 % of the dose accumulated over 35 years.

INTEGRATED ASSESSMENT OF THE DEMOGRAPHIC STATE OF RADIOLOGICALLY CONTAMINATED AREAS OF UKRAINE. / INTEGRAL'NE OTsINIuVANNIa DEMOGRAFIChNOGO STANU RADIOAKTYVNO ZABRUDNENYKh TERYTORII UKRAÏNY.

OBJECTIVE: Basing on the integrated assessment to conduct a comparative statistical analysis as of 2016 of thedemographic state of the areas of Ukraine that are recognized as those with the most intensive radiological con-tamination due to the Chornobyl NPP accident.Study object. The population of the regions of Ukraine with the most intensive radiological contamination due tothe Chornobyl NPP accident and the population of Ukraine as a whole (control). MATERIALS AND METHODS: The data of the State Statistics Service of Ukraine and its regional offices were used asinformation base in this study. Integrated assessment of the demographic situation in a oblast was conducted basedon the calculations of the territorial indices and multidimensional average variable on each region. Demographic,mathematical-statistical, graphic, software-technological methods were used in this study. RESULTS AND CONCLUSION: Radiologically contaminated regions of Ukraine differ significantly: both by the number ofpopulation (from 5800 people in the Poliske region to 105100 people in the Sarny region), and by the variability inthemedical and demographic indicators; bothone from another and compared to data for the country.The results of the calculations of 10 medical and demographic («positive¼ and «negative¼) territorial indices andmultidimensional average variable (P) as integrative assessment of the demographic state have revealed that thebest indicators of the demographic situation in 2016 were in Rokytne (P = 1.249) and Sarny (P = 1.112) regions ofthe Rivne oblast, while the worse indicators were in Kozelets (P = 0.363) and Ripky regions of the Chernihiv oblast.The demographic situation of the Olevsk region of the Zhytomyr oblast (P = 0.947)was the closest to the nationalaverage one. Poliske, Narodychi, Ovruch, Ivankiv and Korosten regions take intermediate position as comparedto theregions of Rivne and Chernihiv oblasts (P = 0.618-0.742).

STUDY OF SUICIDE BEHAVIOR IN JOINT FORCE OPERATION VETERANS IN EASTERN UKRAINE AND IN LIQUIDATORS OF THE CONSEQUENCES OF THE CHORNOBYL ACCIDENT. / DOSLIDZhENNIa SUÏTsYDAL'NOÏ POVEDINKY U VETERANIV OPERATsIÏ OB'IeDNANYKh SYL NA SKhODI UKRAÏNY I LIKVIDATORIV NASLIDKIV AVARIÏ NA ChORNOBYL'S'KII ATOMNII ELEKTROSTANTsIÏ.

The article is devoted to the problem of completed suicides among veterans of the Joint Forces for National Securityand Defense operation in Donetsk and Luhansk regions (JFO) and liquidators of the consequences of the Chornobylaccident (LCCA). The results of the analysis of surveys of families and close associates of JFO veterans who committed a completed suicide in the period 2014-2019 are presented. The survey was conducted as part of criminal proceedings initiated on the facts of suicide. OBJECTIVE: to analyze the current dynamics of suicidal behavior in veterans of JFO and the impact of psychosocialfactors on its development and compare with the relevant indicators among LCCA at the Chornobyl nuclear powerplant. MATERIALS AND METHODS: 175 questionnaires are presented, socio-demographic characteristics are compiled and psychosocial factors that influenced the development of suicidal behavior in environmental protection veterans areidentified. An analysis of the status of such studies among liquidators of the Chornobyl accidents. RESULTS: the data analysis of suicidal behavior in veterans of environmental protection, the impact on its development of psychosocial factors and comparison with the indicators among LCCA at the Chornobyl Nuclear PowerPlant. CONCLUSIONS: The results of the study show that in emergency situations, mostly men from all regions of the country, both professional servicemen and civilians, are involved in its elimination. It has been proven that while performing their official duties, the veterans of JFO and LCCA at the Chornobyl nuclear power plant experienced mental stress. But most of them, returning home, did not seek medical treatment, prevent the development of diseasesand their complications and remained for a long time without proper medical, social and psychological care.

ANALYSIS OF POPULATION SIZE AND COMPOSITION IN AREAS WITH THE MOST INTENSIVE RADIOLOGICAL CONTAMINATION IN UKRAINE AT DIFFERENT TIMES. / ANALIZ ChYSEL'NOSTI TA STRUKTURY NASELENNIa NAY̆BIL'Sh RADIOAKTYVNO ZABRUDNENYKh TERYTORIY̆ UKRAÏNY V RIZNI ChASY.

OBJECTIVE: To identify the existing demographic problems basing on the data of All-Ukrainian Population Census for 2011 and as at 01.01.2017 related to the population size and composition in the areas most radiologically contam- inated due to Chornobyl NPP accident.Study object. Population of the most intensively contaminated areas of Ukraine (areas of radiological contamina- tion - ARC), i. e. Narodychi, Ovruch and Olevsk regions of Zhytomyr oblast, Ivankiv and Poliske regions of Kyiv oblast, Rokytne and Sarny regions of Rivne oblast, Kozelets and Ripky regions of Chernihiv oblast. Entire population of Ukraine was the control. MATERIALS AND METHODS: The State statistical services of Ukraine and their regional offices related to the distribu- tion of permanent population by gender and age as at 01.01.2017, as well as data of All-Ukrainian Population Census for 2011, were the information base of the study. Demographic, mathematical and statistical, graphical and techno- logical software methods and tools were applied. RESULTS: There are significant differences in size and composition of the population of the ARC of Ukraine. Gender and age structure of the population living in the ARC, similar to that living in Ukraine in general, changes over time. The whole shape of demographic pyramid of Ukraine indicates that the share of over-60 age group in the popula- tion increased in 2017, whereas the population of the same age living in the ARC is rapidly disappearing. Also there is a significant regional variation of ageing levels of the population living in the radiologically contaminated areas. CONCLUSION: The analysis of pyramid slopes indicates that both in 2001 and in 2017 the most rapid change of pop- ulation size occurred in Rokytne and Sarny regions of Rivne oblast.

VARIABILITY OF POPULATION GENDER AND AGE COMPOSITION IN AREAS WITH THE MOST INTENSIVE RADIOLOGICAL CONTAMINATION IN UKRAINE. / VARIATYVNIST' STATEVO-VIKOVOÏ STRUKTURY NASELENNIa NAIBIL'Sh RADIOAKTYVNO ZABRUDNENYKh TERYTORII UKRAÏNY.

OBJECTIVE: Assay of contemporary structure and age composition of population in the areas of the country desig-nated as ones of the most intensive radiological contamination after the Chornobyl NPP accident.Study object. Population of the most intensively contaminated areas of Ukraine, i.e. Korosten, Narodychi, Ovruchand Olevsk regions of Zhytomyr oblast, Ivankiv and Poliske regions of Kyiv oblast, Rokytne and Sarny regions of Rivneoblast, Kozelets and Ripky regions of Chernihiv oblast. Entire population of Ukraine was the control. MATERIALS AND METHODS: The State statistical services of Ukraine and their regional offices were the study informa-tion base regarding the distribution of permanent population by gender and age as of 01.01.2017. Demographic,mathematical and statistical, graphical and technological software methods and tools we applied. RESULTS: An excess of males over females from birth up to 35 years old is found in Ukraine. Similar gender imbal-ance was observed only in Olevsk region. In other age groups, high or very high disproportion in age compositionbeing the most pronounced after 65 years old remains in favor of females, except villages in Sarny region. An aver-age age of population in Ripky (45.9 years), Kozelets (44.5 years), Korosten (42.5 years), Ovruch (42.3 years) andNarodichi (42.2 years) regions was higher vs. the entire Ukraine (41.1 years). The lowest age at that was in Rokytne(30.9 years) and Sarny (33.8 years) regions. The age difference between males and females was from 3.6 years inSarny region to 7.7 years in Ripky region.Сonclusion. There are some differences in age composition of population of the contaminated areas of Ukraine.Rokytne, Sarny, Olevsk and Poliske regions feature the best potential of demographic replacement in the foreseeablefuture. Areas of radiological contamination are different in patterns of population replacement, i.e. progressive, sta-tionary of regressive. The number of children under 15 years old exceeds there the size of population older thanworking age.

Information and statistical support for retrospective study of mortality among people exposed in childhood as a result of the Chornobyl accident and living in contaminated areas of Ukraine: assessment of feasibility. / INFORMATsIY̆NO STATYSTYChNE ZABEZPEChENNIa RETROSPEKTYVNOGO DOSLIDZhENNIa SMERTNOSTI OSIB, OPROMINENYKh U DYTIaChOMU VITsI VNASLIDOK AVARIÏ NA ChORNOBYL'S'KIY̆ AES TA PROZhYVAIuChYKh NA RADIOAKTYVNO ZABRUDNENYKh TERYTORIIaKh UKRAÏNY: OTsINKA PRAKTYChNOÏ MOZhLYVOSTI.

OBJECTIVE: Analysis of information from various sources for its use in epidemiological study on mortality of people (born in 1968-1986) who were children and adolescents at the time of the Chornobyl accident. OBJECT OF STUDY: Information and statistical sources for 1986-2011 on mortality among people who were children and adolescents at the time of the Chornobyl accident and lived on the most radioactive contaminated territories (RCT) of Ukraine (Ivankiv and Polisske regions of Kyiv oblast, Narodychi and Ovruch regions of Zhytomyr oblast). RESEARCH METHODS: theoretical, general scientific, documentary analysis, demographic. RESULTS AND CONCLUSIONS: The study is to determine the suitability of available information and statistical support for measuring and assessing mortality of people exposed in childhood as a result of the Chornobyl accident and liv ing in contaminated areas of Ukraine. A combination of information and statistical data provided by SRU, Ministry of Justice of Ukraine, State Statistics Service (SSS) of Ukraine and NNCRM makes it possible to successfully conduct retrospective cohort studies in any area and for any period.

Structural characteristics of children and adolescents at the time of the Chornobyl nuclear power plant accident residing in the most intensively contaminated territories of Ukraine. / STRUKTURNI VLASTYVOSTI KOGORTY MEShKANTsIV NAY̆BIL'Sh RADIOAKTYVNO ZABRUDNENYKh TERYTORIY̆ UKRAÏNY, IaKI BULY DIT'MY TA PIDLITKAMY NA ChAS AVARIÏ NA ChORNOBYL'S'KIY̆ ATOMNIY̆ ELEKTROSTANTsIÏ.

OBJECTIVE: Appraisal of trends in structure of characteristics in population of radiologically contaminated territo ries (RCT) born in 1968-1986 (children and adolescents at the time of the ChNPP accident).Study Object. Persons born since 1968 till 1986 i.e. children and adolescents at the time of the ChNPP accident, who lived on the most intensively contaminated territories of Ukraine (Ivankiv and Poliske regions of Kyiv oblast and Narodichi and Ovruch regions of Zhytomyr oblast) within 1986-2011. MATERIALS AND METHODS: The State Service of Statistics of Ukraine was a principal information base of the study. Specifically the statistical report forms R 11 «Distribution of residential population by gender and age in yearly intervals at a turn of the year¼ and A 1 «General totals of natural population development¼ were retrieved. Survey was conducted for the period of 1986-2012. Mathematical, statistical, demographic and software technological methods were applied. RESULTS AND CONCLUSIONS: Summarization of statistical data on population size, both with its gender and age pat terns in the most intensively contaminated territories of Ukraine, namely in Ivankiv and Poliske regions of Kyiv oblast and Narodichi and Ovruch regions of Zhytomyr oblast resulted in conclusion of 27,200 people living there who were born in 1968-1986. They are a critical group of the ChNPP accident survivors. At the beginning of 1987 the male generations of the same age were present in more even manner (4.53-5.82 %%) vs. females (3.04 6.02 %%). No significant change both in gender and year of birth was found in 2012 vs. 1987. Change in gender proportion in surveyed population within 1986 2011 requires some more precise evaluation.

Efficacy evaluation of managed population shift in Ukraine from zone of obligate (compulsory) resettlement as a measure of public radiation protection. / OTsINKA EFEKTYVNOSTI ORGANIZOVANOGO PERESELENNIa V UKRAINI ZhYTELIV IZ ZONY BEZUMOVNOGO (OBOV'IaZKOVOGO) VIDSELENNIa IaK ZAKhODU PROTYRADIATsIYNOGO ZAKhYSTU NASELENNIa.

OBJECTIVE: Evaluation of efficacy of the managed population transmigration from zone of obligate (compulsory) resettlement as a measure of civil protection after the Chernobyl NPP accident from the perspective of radiation biology. MATERIALS AND METHODS: Legislative and statutory tutorial documents that regulate the managed population shift from radiologically contaminated territories of Ukraine and data from the Ukrainian State Service of Statistics on time limits and scopes of population transmigration from contaminated settlements were the informational back ground of the study. Data on retrospective and expected/anticipated radiation doses in population of settlements exposed to radiological contamination in Ukraine after the Chernobyl disaster summarized for the 1986-1997 peri od and up to 2055 were the information source for calculation of averted doses due to population shift. Battery of basic research empirical evidence review methods was applied under the calculation, systemic, and biomedical approach. RESULTS AND CONCLUSIONS: Population shift from zone of obligate (compulsore) resettlement (hereafter referred to as Zone 2) to stop the radiation exposure as a tool of civil protection from emergency ionizing radiation after the Chernobyl NPP accident was scientifically substantiated and expedient from the perspective of radiation biology. Estimability of a managed population shift from "dose effect" perspective and "benefit/harm" principle is worse because of data absence on individual radiation doses to migrants in the country. Public shift in 1990 and 1991 was most effective from the viewpoint of level of averted lifetime dose. Due to transmigration the averted lifetime dose to the most vulnerable group of the Chernobyl disaster survivors i.e. children aged 0 years varied from 11.2 to 28.8 mSv (calculated for the Perejizdiv village council of Zhytomyr province). Since 2000 there was almost no public shift being not accomplished in the scheduled scope. Delay and incompleteness of transmigration have diminished the efficacy of this measure in the framework of radiological protection of population.