Leukemia incidence in the cohort of Russian male recovery operation workers (liquidators) was estimated at 78110 people for the follow-up period 1986-2014. The average age of the liquidators at the time of entry into the zone of works for liquidation of the Chernobyl accident was 34 years. Radiation risk of leukemia incidence (with the exception of chronic lymphocytic leukemia) was analyzed for liquidators who had official data on the individual dose of external gamma radiation of the entire body accumulated over the period of work. During the follow-up period, 157 cases of leukemia were detected (with the exception of chronic lymphocytic leukemia). Collection and verification of data of hemoblastoses cases among persons exposed to radiation exposure was carried out according to a specially developed algorithm. The average dose of the liquidators was 108 mGy. During the period 1986–1997 was established a statistically significant (p<0.05) linear dose dependence of the leukemia incidence with an excess relative risk of ERR/Gy=4.17 (90% CI: 0.18, 13.24). From 1998 until the end of the follow-up period, as well as for the entire follow-up period (from 1986 to 2014), no statistically significant estimates of excess relative risk were found. For mortality, no statistically significant estimates of excess relative risk and relative risk were found for any of the observation periods. The obtained estimates of the radiation risk of morbidity indicate that a statistically significant excess leukemia incidence of liquidators, which may be associated with external gamma irradiation, is manifested in the first decade after exposure.

In 2017, the specialists of the radiation safety laboratory of JSC «VNIPIpromtekhnologii» conducted a radioecological examination of the «Buranny», «Severny» and «Yuzhny» sites in the Tomtorskoe rare metal deposit (the northern part of the Olenek ulus of the Sakha Republic (Yakutia)). By this time, exploration work was completed at the field with an assessment of the radiation situation. Due to the fact that the amount of information received was not sufficient for a comprehensive analysis and prediction of the radiation situation, it was decided to conduct an additional radioecological survey at the field and in the adjacent area. The research program included field and laboratory work: gamma surveying of the territory, measuring the flux density of alpha and beta particles, gamma spectrometric measurements, environmental sampling, residues of drill cuttings and core, conducting research on the content of natural and man-made radionuclides, as well as individual chemical elements in the selected samples. According to the results of the research, a conclusion was drawn about the normal radiation situation in general in the field. Certain sites of the radioactive contamination was associated with an anthropogenic impact on the ecology of the field during exploratory drilling with the extraction of core from the ore body to the surface of the sites.

The purpose of this paper is to assess the compliance of criterion A, adopted in NRB-99/2009 as emergency level of dose intervention, to permissible values of specific activity of ¹³⁷Cs, ⁹⁰Sr and ¹³¹I in food products in the first year after the accident. Assessments are made on the basis of comparison of the conservativeness coefficients by dose and the magnitude of the risk. The results of the evaluation showed that estimates of the doses and risks for ¹³⁷Cs, ⁹⁰Sr, calculated on the basis of weighting by the number of age groups, are equally conservative. For ¹³¹I, the conservative factors for dose and risk vary significantly, which indicates that it is not appropriate to use an effective dose to optimization of radiation protection for the given radionuclide. The ratios of the risk-weighted average weighted by the number of individual age groups to the weighted average effective dose values for ¹³⁷Cs and ⁹⁰Sr are close to the nominal risk of death from malignant neoplasms for the population of 5×10^-5, which confirms that nominal risk factors can only be used for the general population. Two variants of the criteria for optimization of the radiation protection of the population are proposed: 1) by the value of the average weighted by the number of individual age groups, the value of the effective dose, or 2) the value of the average weighted by the number of individual age groups of risk. It is shown that to optimize the protection of individual age groups, the more preferable criterion is the risk value calculated for a given age group, since the maximum effective dose of some age group does not always correspond to the maximum risk.

The paper presents an analysis of the dynamics of individual doses of external exposure among the population living for almost 20 years in the territories affected by the radioactive contamination due to the Chernobyl NPP accident. The dynamics of the average effective dose of the external exposure of the inhabitants in the period of 5 to 20 years after the Chernobyl fallout is well described by processes that consider the radioactive decay of cesium radionuclides and their natural migration. The distribution of individual doses of external exposure among residents, normalized to the average dose in the settlement corresponds to a logarithmically normal law with the time-stable parameters: the geometric mean ~ 0.9 and geometric standard deviation ~ 1.5, which allows, in particular, predicting the dose for the critical group of population or for a representative person. Comparison of the mean effective doses of external exposure of the settlement residents estimated based on the results of two different measurement technologies (using TLD-method and measurements of dose rates in air in various settlement locations) indicated their good agreement for the 17 years period after the fallout. For two settlements, where measurements were performed in 2003, the relative differences in mean effective doses did not exceed 12%. It allows using the previously developed model of external exposure for dose estimation to the population residing on the territories contaminated after the Chernobyl accident.

Up to now there is no clear understanding of health risk and type of dose dependence for the population chronically exposed within a range of low and average dose levels (to 1Gy). In this respect studies performed in cohorts with a sufficient number of persons can have a significant potential in providing necessary information. Objective: to study peculiarities of lens opacity in exposed persons at later time after chronic radiation exposure with due account for dose impact and nonradiation factors. The study includes patients from the URCRM registry of exposed population examined by an ophthalmologist in the period 2016-2018 (total 1,377 persons). The same technique of medical examination with photofixation of lens opacity was applied to all examined individuals. A case-control technique was used to conduct the study. Individual exposure doses to lens were calculated on the basis of TRDS-2016 for the first time within the framework of the present study. As a result of the performed study among persons exposed to long-term ionizing low-dose radiation we have determined an exposure dose impact on risk growth of opacity in the posterior capsule and lens nucleus. No reliable statistical dependence of lens change with an increasing exposure dose in anterior capsule and cortical layers as well as colour change of the lens nucleus was obtained. Belonging to different ethnical groups showed no impact on priority opacification development in any lens layers.

In the case of radiation accident on a board of ships and vessels with nuclear power units, radioactive substances can be released into the environment and absorbed by the human body. The radioactive contamination is associated with a complex and rapidly disintegrating composition of radionuclides, which are products of nuclear fission and induced radioactivity. Therefore, the need for prompt post-accident control of internal exposure is justified. In the article, radiation accidents are classified in relation to ships and vessels with nuclear power units. As an example, one of the most severe accidents that occurred when nuclear fuel was transshipped on a nuclear-powered submarine in the Chazhma Bay in 1985 is considered. Methods for determining the incorporated radioactivity are described. Direct measurement of radionuclide content in a human body or an organ using human radiation spectrometers is shown to be the most accurate. The hardware-methodical support and the main measures for the postemergency individual control of the internal exposure of personnel of vessels with nuclear power plants are proposed.

The aim of the study was to study and evaluate the clinical and morphological characteristics of the pathology of the gastroduodenal zone of the digestive tract in the population of the radioactively contaminated areas in the immediate and remote observation periods after the Chernobyl accident. Methods: esophagogastroduodenoscopy, cytological examination of gastrobioptate, micronucleus test, dosimetric evaluation of gastrobioptates. To solve the problems of the interrelation of the accident factors at the Chernobyl and the state of the mucous membrane of the upper digestive tract, a medical statistical evaluation of the frequency dependence of the pathology of the upper gastrointestinal tract and environmental factors of the accident in the near and distant period was carried out. Results: it has been established that the main morphological types describing the state of the gastric and duodenal mucosa in the examinees are: erosive, edematic, fibrotic changes on the background of Hp infection, as well as the development of inflammatory cell infiltration. The frequency of occurrence of micronuclei in mucosal mucosa does not depend on the frequency of infection of Helicobacter pylori, as well as the total alpha and beta activity of biopsy specimens of the gastric mucosa, the density of contamination of the territory at ⁹⁰Sr and ¹³⁷Cs. The relationship between the frequency of gastroduodenal pathology and the levels of contamination of the territory of permanent residence by ⁹⁰Sr and ¹³⁷Cs, as well as statistical regularities of the evaluation of the total alpha and beta activity of gastrobioptates in residents of the radiation contaminated areas for a long period of observation are not statistically significant. Conclusions: the nature and clinical picture of the pathology of the upper digestive tract, the dynamics of the pathological process from inflammatory-dystrophic to atrophic changes in the gastric mucosa, the absence of a connection between this pathology and the indicators of ecological problems according to the isotope composition of the territories, I testify that the reason for the above-mentioned regularities may be the effect complex of factors of the Chernobyl accident.

A review of the complex of health protection and medical measures ensuring the prevention of deterministic and reducing the probability of stochastic effects of irradiation during radiation accidents is presented. It is shown that the most effective methods of ensuring radiation safety at radiation accidents are protection by time, protection by distance and shielding of the irradiated object. Medical means of anti-radiation protection are used in addition to collective and individual technical means when it is impossible to avoid over-standard radiation exposure. Classification of antiradiation medicines, including radioprotectors, means for stimulating the radioresistance of the organism, means for preventing and stopping the primary reaction to irradiation, means for preventing and treating injures from irradiation by incorporated radionuclides, means for treating acute bone marrow syndrome, and means for treating local radiation injures of the skin and mucous are given. The list of medical means of antiradiation protection registered in the Russian Federation is presented. Characteristics of first-aid kits, medical bags, medical equipment kits, medical evacuation devices intended for the first aid and medical assistance in the outbreak of a radiation accident and at the stages of medical evacuation are given. The nomenclature of medicines and volumes of the reserve of the Ministry of Health of the Russian Federation intended for liquidation of consequences of emergency situations of radiation nature are given. It is concluded that the Russian Federation has developed and implemented a modern strategy to protect personnel, rescuers and the population in emergency situations of radiation nature, including organizational, technical, hygienic and medical measures in the outbreak of a radiation accident and at the stages of medical evacuation.

This paper presents the experience and features of the organization and provision of specialized and hightech medical care to victims of the Chernobyl accident in the framework of the activities of the Union State in the Nikiforov Russian Center of Emergency and Radiation Medicine EMERCOM of Russia. It reveals the features of the morbidity, disability and mortality of the injured in the accident at the Chernobyl nuclear power plant. The paper presents the data on the types and amount of medical assistance provided to victims of the Chernobyl accident for the period from 2007 to 2018 as well as the features of the organization of rendering specialized, including hi-tech, medical assistance and medical rehabilitation to participants of liquidation of consequences of the Chernobyl accident and inhabitants of the radioactively contaminated territories.

The article presents the results of the generalized analysis of the data on staff, patient, and public doses from ionizing radiation obtained from the Unified System of Individual Dose Control for 2017. The analysis is conducted on the basis of the annual data from the forms of Federal State Statistical. Observation No.1-DOZ (staff individual doses), No.2-DOZ (doses from radiation accidents), No.3-DOZ (patient doses) and No.4- DOZ (public doses from natural and technogenically impacted background). The information is submitted by the organizations and territories under the supervision of the Rospotrebnadzor and FMBA of the Russian Federation. The article is based on the data obtained within the framework of Radiation-Hygiene passportization. In 2017, 18 324 organizations working with the artificial radiation sources submitted the form No.1-DOZ. The form No.1-DOZ contains data on 235 271 staff individual doses, 215 290 of the staff group A and 19 981 the staff group B with individual monitoring. In 2017, the average individual dose for the staff group A was 1,23 mSv, the staff group B – 0,67 mSv. In 2017, 13 036 healthcare organizations submitted the form No.3- DOZ. According to the No.3-DOZ data, more than 286 mln. X-ray procedures were conducted in the Russian Federation in 2017. An average dose per capita from medical exposure was 0,55 mSv/year and a mean dose per an X-ray examination was 0,28 mSv. In 2017, the form No.4-DOZ contained data on 8 130 measurements of gamma-radiation dose rate in wooden houses, 1 557 measurements in one-storey stone houses, 126 550 measurements in multi-storey stone houses and 178 138 measurements on the open ground As well as the results of 4 417 measurements of radon concentration levels in wooden houses, 5 971 measurements in one-storey stone houses, 57 461 measurements in multi-storey stone houses. The public average effective dose from natural ionizing radiation sources corresponded to 3.34 mSv/year, the average values for the subjects of the Russian Federation fall in the range from 2,15 mSv/year (Nenets Autonomous Okrug) to 8,9 mSv/year (Altai republic). The article includes the Annexes with the final generalized forms of the Unified System of Individual Dose Control in 2017 based on the forms of statistical observations No. 1-, 3- and 4-DOZ of the subjects of the Russian Federation.