Dissertation for the degree of Candidate of Medical Sciences (Doctor of Philosophy) in specialty 03.00.01 "Radiobiology". – State Institution “National Research Center for Radiation Medicine of The National Academy of Medical Sciences of Ukraine”, Kyiv, 2019. The dissertation devoted to the important scientific and practical problem in the field of radiobiology, optimization of medical expertise of establishing the causal relationship of arterial hypertension (AH) in the clean-up workers of the accident at the ChNPP with the effect of ionizing radiation in the remote post-accident period by developing of scientific recommendations. A retrospective analysis of the 26142 medical expert cases examined by the Central Interagency Expert Commission of the Ministry of Health of Ukraine for diseases, cause of disability and death causal relationship to CHNPP accident (CIEC) during 2013-2017 yy. was carried out. In an in-depth study of 16073 cases of ChNPP accident victims reviewed by the CIEC during 2014-2016 yy., 796 cases of AH in clean-up workers of ChNPP accident were selected. In the remote post-accident period, it was found that the pathology of the cardiovascular system occupies second place (39,62 %) in the structure of medical expertise of ChNPP accident victims, with the proportion of AH cases accounting for 28,4 % of the total number of cases clean-up workers considered. The proportion of AH cases leading to the death of clean-up workers of ChNPP accident represented 17,8 % of AH. A retrospective analysis of CIEC's medical expertise cases confirmed the early development and younger age of clean-up workers of ChNPP accident with AH associated with participation in works for liquidation of ChNPP accident consequences. Vegetative-vascular dystonia (VVD), which preceded the development of AH, for main group of clean-up workers develops 3,8 years earlier (3,5±3,3 years after participating in clean-up works) than in comparison group, in which AH is not associated with clean-up works for the ChNPP accident. Patients with AH associated with clean-up work at the ChNPP accident have developed complications such as acute cerebral circulation / transient ischemic attack and myocardial infarction (3,1-4,3 years earlier). In the clean-up workers of the main group, the course of AH is characterized by rapid progression: 3,7 years earlier there is a loss of capacity (after 23,1±6,9 years participation in clean-up work at the ChNPP accident), compared with clean-up workers in whom AH was not associated with liquidation consequences of ChNPP accident. The informative content of expert use of the following instrumental and laboratory indices was found: increase of the thickness of the interventricular septum and increase of the left ventricular myocardial mass index in the main group of clean-up workers of ChNPP accident compared to the group of clean-up workers of ChNPP accident in whom AH was not associated with liquidation of consequences of ChNPP accident; glucose level – hyperglycemia detection rate frequency among main group of clean-up workers of ChNPP accident was higher 2,5 times, triglycerides – triglyceridemia detection frequency – higher 2,2 times, decrease in kidney filtration function frequency – higher 2,37 times compared to a group of clean-up workers of ChNPP accident with AH not associated with works for liquidation of ChNPP accident. Radiation exposure is significant for the development of AH in clean-up workers of ChNPP accident: when the dose of external radiation exposure is greater than 0,05 Sv, the dependence of the causative relationship of AH with clean-up works at ChNPP accident increases in compare with clean-up workers of ChNPP accident who received a dose of external radiation exposure less than 0,05 Sv. For the clean-up workers of the Chornobyl NPP accident, whom received a dose of external radiation exposure above 0,25 Sv, the level of dependence of the causative relationship of AH development is increasing higher 4,2 times. For clean-up workers of ChNPP accident with a dose of external radiation exposure greater than 0,2 Sv dose dependence of the time of development of VVD and its transformation into AH, development of AH, date of the first hospital treatment for VVD or AH, realization of vascular events and crisis course of the disease were proved. Scientifically based recommendations and proposals for updating regulatory documents for establishing causal relationship of AH with clean-up works for ChNPP accident were developed. Keywords: ionizing radiation, arterial hypertension, clean-up workers of Chornobyl NPP accident, medical expertise, Chornobyl NPP accident.
