To commemorate the 90th anniversary of the birth of doctor of medical sciences, professor, honored worker of science of the Russian Federation P.V. Ramzaev.

The article describes the main areas of scientific and administrative activities of professor P.V. Ramzaev during his work in the Research Institute of Radiation Hygiene. In particular, the results of a study of global radioactive fallout in the Far North of the USSR, as well as a study of the radiation situation and an assessment of the doses to the public after the accident at the Chernobyl NPP, are presented in a systematic way. The leading role of P.V. Ramzaev in the development of hygienic regulation and in the development of the theory of health is shown. The activities of P.V. Ramzaev in the International Commission on Radiological Protection are discussed in detail. The role of P.V. Ramzaev in the development of the law «On Radiation Safety of the Population» is shown.

The protective actions which were carried out with the purpose to reduce public exposure to radiation derived from the accidents at Chernobyl and Fukushima-1 nuclear power plants have caused negative consequences of social – psychological both social-economic character and medical nonradiological consequences. The corresponding damage put to the population of involved territories and to the entire society has considerably exceeded hypothetical benefit of aversion of radiation exposure. In the present study some possible ways of aprioristic maintenance of mitigation of the social damage accompanying realization of anti-radiation protective actions at large-scale radiation accident are considered. For the characteristic of total amount of the damage caused by protective actions, the scale of radiation and social protection in terms of a population of officially involved territories is accepted. The analysis of decisions on protection of the population in the Russian Federation against consequences of Chernobyl accident shows that at concrete radiation situation scales of protective actions differ more than on the order of magnitude, depending on criteria of decision-making and their administrative realization. Another factor that determines the scale of the accident is the degree of conservatism in the assessment of the radiation situation. The analysis of results of individual dosimetric examination of inhabitants of the western districts of the Bryansk region has shown steady values of statistical characteristics of distribution of the individual doses of an external and internal radiation caused by Chernobyl accident, according to which the value of 95% quantile of distribution in 2–3 times exceeds the average value at an examined sample of the population. Thus, application of the concept of “representative person» leads to overestimation of projected doses concerning to those corresponding to stochastic radiation effects. The results of such overestimation are expansion of scales of protective actions, prolongation of emergency, increase in accompanying social damage. As one of the ways to maintain aprioristic mitigation of social damage accompanying protective actions, the following position is offered. At a stage of an emergency, when there is enough information to consider, that the maximal public exposure to radiation will not achieve thresholds of deterministic effects, the decisions on protective actions violating normal human beings and socioeconomic functioning of territory is justified to accept on the basis of doses for the average person, instead of those for the most exposed people.

Purpose: to assess the radiation situation on the industrial site of the PA “Mayak” during the accident in 1957 and the radiation doses of the participants in the liquidation of consequences of this accident. Materials and methods: on the basis of the archival documents analysis, radiation situation data for 1957 – 1960, IDC data and calculated doses of the Mayak workers, as well as supporting organizations personnel and military units involved in the liquidation of the accident consequences and covered by individual monitoring are presented. Results: in 1957 – 1959 about 38,5 thousand people took part in the works on the territory of the PA “Mayak” industrial site for liquidation of consequences of the accident, including persons exposed at the time of the accident: employees of “Mayak”, military and civil builders. Radiation doses from 25 to 30 R received about 10,5 thousand people, while there were single cases of exposure in doses up to 100 R. Conclusion: the collective dose received during the accident and liquidation of its consequences in 1957 was about 820 000 person-R. Collective doses recorded in 1958 and 1959 amounted to 250 000 person-R and 54 000 person-R, respectively.

The results of monitoring of ²¹⁰Po and ²¹⁰Pb isotopes in water of artificial lake (former uranium mine) of Istiklol city of the Republic of Tajikistan and their bio-accumulation are given. Fish living in this area is using as a food by local population. It has been found that the level of210Po isotope in the liver of fish, in particular of carаs fish, was relatively high. It has been defined that the annual effective radiation dose from gamma radiation and isotopic activity in water for human in the Istiklolcity exceeds the recommended annual threshold dose level (10 mSv). 

The purpose of this work was to assess the influence of the Rostov NPP (consisting of 4 units with VVER1000 reactors) on the radioecological situation in the region of the station location within 18 years from the start of the first power reactor. Based on the results of observations at the radioecological monitoring network established in 2001, which included seven control sites and five control points, the content of natural and artificial radionuclides in environmental objects, agricultural products and foodstuffs was analyzed. It was shown that over the entire period under consideration, the average content of 90Sr in the soils of agroecosystems of the 15-km zone of influence of the Rostov NPP varied within 1.7-7.4 Bq/kg, and 137Cs – 7.5-14.9 Bq/kg. It was not detected any trends to increase in the concentrations of artificial radionuclides in the soil throughout the considered territory. The variation range of the average content of natural radionuclides in soils was 561-634 Bq/kg for 40K, 23.4-27.5 Bq/kg for 226Ra and 32.7-35.9 Bq/kg for 232Th. The average concentration of 90Sr in the grain was in the range of 0.1-0.68 Bq/kg, and 137Cs – 0.23-0.54 Bq/kg. Even the maximum specific activity values of artificial radionuclides in food grain were below the SanPiN standards 55 times for 90Sr and 65 times for 137Cs. The maximum levels of 137Cs in vegetables and potatoes and vine crops were 80 times lower than the SanPiN standards. The maximum levels of specific activity of 90Sr in milk were more than 400 times lower than the SanPiN standard (25 Bq/kg), and for 137Cs (standard 100 Bq/kg) this difference was 600 times. Vegetable crops were characterized by minimal transfer factors (TFs) of radionuclides. TFs of 90Sr in vegetables, depending on the product type, was in the range of 0.04-0.17, and for 137Cs it was in the range of 0.008-0.2 (Bq/kg)/(kBq/m2 ). Maximum TFs of radionuclides were noted in grasses. TF of 90Sr in natural and perennial grass was 0.75-2.2, and for 137Cs it was 0.28-0.86 (Bq/kg)/(kBq/m2 ). The differences in transition factors between vegetables and grass reached 50 times, and on average, they were 10-20 times. It was noted that all types of crops accumulated 90Sr on average 2-5 times more in comparison to 137Cs ac cumulation. It was shown that the content of artificial radionuclides in the water of the Tsymlyansk reservoir is 163 and 183 times lower than the permissible level for 90Sr and 137Cs, respectively. The analysis of 18-year results of observations of the radioecological situation in the vicinity of the Rostov NPP allows to conclude that the operation of this NPP in normal mode and the commissioning of new power-generating units did not lead to a recorded increase in the content of artificial radionuclides in agricultural products, foodstuffs and environmental objects.

An article is devoted to the peculiarities of exposure doses forming of adult population due to the main dose-forming foodstuffs in the remote period after Chernobyl accident. On an example of the Bryansk and Tula regions, we carried out the assessment of the effective purification half-periods of the main dose-forming food products (milk and mushrooms) from ¹³⁷Cs due to its radioactive decay and natural self-purification and the assessment of the periods of half-reduction of the average annual effective internal doses for the population of the Bryansk region divided on the ¹³⁷Cs soil surface activity actual in the corresponding year (based on whole body measurements data). Obtained results allowed fulfilling the prognosis of the internal doses for the population of the Bryansk region for the time period up to 2056.

²⁴¹Am is the only radionuclide of Chernobyl radioactive fallout the content of which until 2058 continues to increase. The purpose of this work is to assess the ²⁴¹Am internal exposure doses of residents of settlements on the territory adjacent to the resettlement lands of the Chernobyl nuclear power plant. To achieve this goal the current levels of ²⁴¹Am and accompanying 137Cs content in the soil and foodstuffs were determined at the private settlements of the Bragin district of Gomel region of Belarus. ²⁴¹Am (Eγ 59.6 keV) content in soil samples and 137Сs (Eγ 661 keV) content in soil/food samples were determined by gamma spectrometry. Determination of ²⁴¹Am specific activity in food samples was performed by the radiochemical method using selective extraction-chromatographic resins. With an average level of 1.3 kBq/m2 , the maximum soil contamination density of ²⁴¹Am can reach 3.6 kBq/m2 , and for 137Cs it is one or two orders of magnitude higher and ranges from 50 kBq/m2 to 350 kBq/m2 . The maximum specific activity of ²⁴¹Am in products is determined in samples of leafy parsley – 33 mBq/kg, and in samples of potatoes, beets, onions per feather – not exceed 5 mBq/kg. The content of accompanying ¹³⁷Cs in samples of plant products is in the range of 3-12 Bq/kg. In estimation of the internal dose of exposure by the food chain it is conservatively assumed that the population receives all the main components of the diet in their own farmstead. Calculation of the dose of internal exposure during inhalation is made under the assumption that the population performs work in the garden 4 hours a day for 7 months. The total expected dose of internal exposure from ²⁴¹Am residents of settlements is dominated by the inhalation component, while the oral route is dominant in the formation of the total dose of internal exposure from concomitant ¹³⁷Сs, which is 20 or more times higher than ²⁴¹Am.

Today, Russia is implementing a national program for the remediation of legacy sites, resulting from the activities of the nuclear industry, the use of nuclear energy for military purposes, and due to radiation accidents and emergencies. Main priority is given to the health care provision issues of the workers and the population living in the vicinity of the targeted facilities. These tasks are under the regulatory responsibility of the FMBA of Russia. Since the beginning of the development of the nuclear industry in the country, the Institute of Biophysics, technical supporting organization of the FMBA of Russia (now the State Research Center – Burnasyan Federal Medical Biophysical Center Federal Medical Biological Agency (SRC-FMBC)), has been a leading institute in the scientific and methodological support of public radiation safety in the vicinity of radiation hazardous facilities serviced by the FMBA of Russia. In this regard, radiation-hygienic monitoring has always served as the main regulatory tool for more than 60 years. The paper describes the results of long-term monitoring (2005-2018) at the former coastal technical bases of the Russian Navy ( now – sites for temporary storage of SNF and RW in the Russian Northwest and Far East (nuclear legacy sites); sites of the uranium mining and milling facilities: Priargun Mountain Chemical Association and former Production Association “Almaz” (Lermontov, Stavropol Krai); and at uranium legacy sites of the Central Asia (Republic of Tajikistan and Kyrgyz Republic). The peculiarities of radiation situation at the sites are discussed, current challenges identified, and further regulatory improvements presented based on the gained experience.

The authors share their experience and represent the historical overview of activities on public radiation protection against radon and other natural sources of radiation in Russia. Special attention is paid to the country’s first national radon program - Federal Target Program “Radon” (FTP “Radon”, 1994-1996). Organization, structure, main goals and objectives of the FTP «Radon» are discussed. In particular, it was noted that in a short period of time the country’s regulatory and methodological framework was developed. The scientific basis for identification of the radon prone areas and regulatory support for building construction at the sites was developed. The national SSND equipment was produced and QA/QC system implemented. The national and regional radon surveys have been performed. Unfortunately, the economic situation of those years did not allow to fully implement the planned set of measures at the federal and regional levels. Nevertheless the accumulated experience served as a scientific and technical basis for further improvements in this field and to be consistent with the modern radon regulatory issues and approaches developed by the international organizations (ICRP, IAEA, WHO).

The fundamentals of the state policy in the field of nuclear and radiation safety of the Russian Federation for the period up to 2025 and the further perspective have determined that one of the objectives of the state policy in the field of radiation safety is to maintain the risk of radiation exposure of the nuclear workers as low as possible. To achieve this goal, efforts and resources should be focused on solving a number of tasks, including: protection in accordance with the principle of acceptable risk for nuclear workers; improvement of the state management and state regulation of safety in the field of nuclear energy using; radiation safety assurance during the decommissioning of nuclear legacy facilities, management of spent nuclear fuel, remediation of radioactively contaminated sites of the Russian Federation. Today, federal authorities responsible for monitoring and supervising the health and epidemiological welfare of workers in some industries with especially hazardous working conditions, and research institutions involved in scientific and methodological support of these authorities are faced with the task of solving the following urgent problems in the field of radiation safety: to improve regulatory and methodical support of the state radiation safety regulation; to assure safety and protection of workers and the population during the decommissioning of radiation hazardous facilities and remediation of radioactively contaminated sites; to assure radiation safety during the management of spent nuclear fuel.

Aim of the study: analysis of the results of the radiation-hygienic monitoring of the territories of the Tula region, contaminated due to the Chernobyl NPP accident; concentration of 137Cs and 90Sr in the locally produced food products and analysis of the annual effective dose of the public. Materials and methods: the study was performed in the Tula region in 1997-2018. It included the evaluation of the indicators of the radiation safety of more than 50 thousand samples of the main food products, sampled in the areas of the radioactive “Chernobyl” contamination of the region with the simultaneous measurement of the external gamma-radiation dose rate in the stationary control points. Additionally, it included the assessment of the dynamics of concentration of 137Cs and 90Sr in food products, maximal values of mean annual effective doses of the public and contribution of the collective dose from medical exposure into the structure of the annual collective dose of the public. Results: The study allowed estimating the concentration of 137Cs and 90Sr in the main local food products. Estimated values of gamma radiation dose rate were stable and laid in the range of normal variations specific to the middle latitudes of the European part of Russia. The values of maximal mean annual effective doses of the public indicate the stable radiation environment and do not exceed 1 mSv. It should be mentioned that the contribution of collective dose from medical exposure into the annual collective dose of the public as well as the values of mean individual effective doses from medical exposure are reducing with the increase in the number of X-ray examinations. Conclusions: The lack of exceedances of the permissible levels of 137Cs and 90Sr in the locally produced food products and the reduction of the mean annual effective dose of the public indicates the possibility of the transfer of the settlements affected by the Chernobyl NPP accident into the normal living conditions within the program of the transfer of the settlements from the “Chernobyl” zone.

The aim of the work is to develop control levels of specific total alpha-activity of water samples for a number of sources of centralized drinking water supply in the Republic of Khakassia on the basis of the results of long-term laboratory studies. Materials and methods. The analysis is carried out on the basis of the results of laboratory studies of water sources of centralized drinking water supply of the population of the Republic of Khakassia, performed by accredited testing laboratories of institutions of the state sanitary and epidemiological service of the Republic for the period from 2001 to 2018, using alpha-beta radiometric, alpha-spectrometric methods with radiochemical preparation of counting samples, gamma-spectrometric method. The control levels of specific total alpha-activity of water samples from the sources of centralized drinking water supply in the Republic of Khakassia were established by the statistical maximum – the sum of the average value with a doubled standard deviation, with the volume of research more than 30, and the maximum value with the volume of research less than 30. Results. About half of the studied water samples from the sources of the centralized drinking water supply of the Republic of Khakassia, annually, are noted with exceeding the control level of specific total alpha-activity (0,2 Bq/kg). The values obtained in the studied samples vary up to 5,57 Bq/kg. During the observation period, samples of water exceeding the reference level of specific total alpha-activity (0.2 Bq/kg) were identified in settlements of the Altai, Askizsky, Beysky, Bogradsky, Ordzhonikidzevsky, Tashtypsky, Ust–Abakansky, Shira districts and the city of Sorsk, smt. Prigorsk (Chernogorsk). In previous studies, it was found that high levels of specific total alpha-activity in the country are mainly due to natural radionuclides uranium-238 (²³⁸U), uranium-234 (²³⁴U). In a number of settlements of the Republic, the sum of the ratio of specific activities of natural radionuclides to the corresponding levels of intervention exceeds 1,0. Average annual individual effective doses of internal exposure to natural radionuclides of drinking water, at or above 0,1 mSv/year (values in the range of 0,1-0,2 mSv/year), which does not require urgent radiation protection measures. At the same time, monitoring of indicators of radiation safety of water sources of water supply should be carried out in accordance with the established requirements. In this connection, in order to improve control, for the rapid assessment of the radiation situation and making timely decisions to ensure radiation safety of the population, the calculation of control levels of specific total alpha-activity was carried out. As a result of calculations, specific values of control levels for each of water source were obtained. The calculated values range from 0,2 to 2,6 Bq/kg. Conclusion. The control levels are “site standards” and are calculated for each of the source of water supply. Their excess will be considered as a signal of “negative change” of the radiation situation”, which may be associated with an increase of the specific activities of ²³⁴U, ²³⁸U, or the appearance of highly radiotoxic radionuclides: ²²⁶Ra, ²¹⁰Po, ²²⁸Ra.