Measurements of the ¹³⁷Cs content in the bodies of residents of the territories radioactively contaminated due to the Chernobyl accident using a whole body counter (spectrometer) provide the most accurate assessment in determining the levels of radiation exposure to the population. The object of this study was analysis of results of ¹³⁷Cs measurements with a whole body counter. Materials and methods: In 2019-2022 measurements of the ¹³⁷Cs content in the bodies of more than 10 thousand residents of the southwestern territories of the Bryansk region were carried out. Research results and discussion: The results of measurements of the ¹³⁷Cs content in the bodies of residents of the surveyed settlements are presented. The highest levels of ¹³⁷Cs were measured in residents whose diet included such natural products as wild meat and wild mushrooms. It is shown that the average levels of ¹³⁷Cs in the bodies of residents of small settlements (up to 100 residents) are higher than that for residents of other settlements. Conclusion: Analysis of the obtained results allowed us to conclude that it is necessary to separate settlements with a population of less than 100 people into a specific category. Analysis of the distribution characteristics of the normalized values of specific activity of ¹³⁷Cs in the body of preschool children who do not attend child care institutions confirmed the justification for separating this category in dosimetric models.

Despite significant progress in the field of chemoradiation antitumor therapy, the introduction of new pharmacological agents and radiation response modifiers aimed at increasing the therapeutic index of radiation therapy remains one of the priority tasks of experimental oncology and radiobiology. Objective of the study is evaluation of the antitumor effects of the combined use of ionizing radiation (electrons, protons) and a new derivative of indole-3-carboxylic acid – 1-methyl-2-bromomethyl-3-ethoxycarbonyl-5-methoxy-6-bromindole. Materials and Methods: The study was conducted on female F1(CBA×C57Bl/6j) F1(CBAЧC57Bl/6j) mice with Ehrlich carcinoma transplanted into the right hind limb. The compound was administered intraperitoneally at a dose of 30 mg/kg on the day of irradiation and 48 hours after the first injection. The experimental methods included toxicometric and morphometric analyses. Results and Discussion: The median lethal dose of the compound was determined for intraperitoneal administration to mice, LD₅₀ = 60 mg/kg. Double injections in the monotherapy mode caused stable inhibition of tumor growth, which developed to 30 %. The combined use of radiation exposure and the studied compound led to significant increasing of therapeutic efficacy indicating the presence of synergistic interaction: the tumor growth inhibition index increased by 19 % with single electron irradiation, by 32 % with fractionated electron irradiation, and by 27 % with single proton irradiation. In addition, the experimental combination therapy, along with significant suppression of tumor growth, increased the survival of tumor-bearing animals without causing significant toxic effects. Conclusion: The obtained results indicate the prospects for further study of combined regimens of radiation therapy and indole-3-carbinol derivatives. Further studies of the mechanisms of interaction of these compounds and ionizing radiation should include an assessment of the effect on the main pathophysiological mechanisms of neoplasia development, key pathways of DNA repair and apoptosis.

Radiation exposure of pregnant women can not only increase the likelihood of stochastic effects for both the mother and the unborn child, but lead to the development of various birth defects as well. Revision of Rospotrebnadzor's regulations on radiation protection from medical and emergency exposure requires updating requirements for radiation protection of pregnant women. They should be based on modern scientific epidemiological and radiobiological data. The aim of this study was to develop requirements for radiation protection for pregnant women in various exposure situations. Materials and Methods: This study was based on a systematic review of Russian and international regulatory documents governing radiation protection for pregnant women during medical and emergency exposure, as well as epidemiological studies. Results and Discussion: The results of the analysis indicated that exposure of the fetus or embryo to ionizing radiation is associated with less than 2 % of congenital malformations identified in newborns. A threshold value of 100 mGy of absorbed dose in the fetus (embryo) is accepted as the threshold below which it is impossible to reliably determine deterministic effects associated with exposure to ionizing radiation. To ensure a conservative approach to radiation protection of pregnant women in Russian practice, it has been proposed to establish a dose constraint for pregnant women of 50 mGy of absorbed dose in the fetus (embryo) for the period from the moment of detection of pregnancy until delivery for situations involving routine medical care. Conclusion: This will prevent the development of malformations in the child and minimize the likelihood of radiation-induced cancer after birth. A value of 500 mGy of absorbed dose in the fetus (embryo) has been proposed as the criterion for radiation accidents. This approach will be implemented in the new edition of the Norms of Radiation Safety and the Basic Sanitary Rules for Radiation Safety.

The study of smoking probability and intensity in the Ural region is for the subsequent analysis of combined smoking and radiation effect on lung cancer risk. The smoking dose - number of cigarettes per day smoked by a conditional cohort member of a certain sex and age (the product of smoking probability and an average smoking intensity) was introduced. The study purpose is developing a sex- and age-specific smoking dose model. Materials and Methods: The smoking information register was used (48,694 records for 24,587 Ural residents born in 1889–1997). Smokers are the people who had ever smoked. The probability theory, distribution analysis and regression analysis were used. Results and Discussion: The smoking intensity increases up to 40 years, and then becomes constant and equal to 17.5 and 10 cigarettes per day for men and women, respectively. The smoking probability increases with age up to 30 years, and then it decreases. The smoking probability in men over 18 years exceeds 40%. For women, the smoking probability is ≤ 5% at any age. Smoking doses of a conditional men and women aged 35 years are 12.2 and 0.3 cigarettes per day, respectively. An algorithm for smoking dose assigning was formulated to analyze the effects in the South Urals Population Exposed to Radiation cohort. The results should be extrapolated to other territories and generations with caution. Conclusion: The proposed method of smocking dose assigning can be used in other epidemiological cohorts with insufficient individual data. Evaluation of model uncertainly and model impact on the joint analysis of radiation and non-radiation risks is the further directions of the study.

The paper considers modern approaches to the use of ionizing radiation to ensure microbiological safety of food products. In international practice, the issues of ensuring radiation safety in the processing of food products by ionizing radiation are well developed. On the contrary, the Russian Federation and the Eurasian Economic Union do not have hygienic standards and state control in the field of radiation biotechnologies, as well as special sanitary standards that set maximum permissible radiation doses for various categories of food products. Aim of the study: to analyze domestic and international regulatory documents establishing requirements for radiation treatment of food and agricultural products, in order to develop a set of requirements for hygienic standardization of such products in the Russian Federation. Materials and Methods: The study was based on the analysis of regulatory documents of the IAEA, WHO, and FAO, as well as the national legislation of countries that actively use methods of radiation treatment of food products. Results and Discussion: The analysis of international standards is carried out, and existing gaps in the regulatory framework of the Russian Federation are identified. It is shown that the lack of special sanitary standards and methods for identifying irradiated products complicates control and reduces market transparency. Conclusion: The necessity of developing a system of hygienic rationing and state control to ensure the quality and safety of products treated with ionizing radiation is emphasized.

Circulatory diseases are the leading cause of death all around the world. Even a small increase in radiogenic risk would lead to a significant increase in incident cases and deaths as the number of individuals exposed to radiation for different purposes increases constantly. The aim of the study was a comparative analysis of radiogenic risk of incidence and mortality from ischemic heart disease and cerebrovascular diseases in the cohort of Mayak Production Association workers based on several dosimetry systems. The first analysis of studied incident cases and death causes was performed using dosimetry system “Doses-2005” which included data on occupational histories as well as external and internal radiation exposure doses for workers employed at one of the main facilities during 1948–1972. The subsequent dosimetry systems, “MWDS-2008” and “MWDS-2013”, additionally included data for workers employed in the later years (1973–1982). The necessity to improve the external dose estimates was conditioned by a number of factors, i.e. using different types of dosimeters during all monitoring period, lack of accounting for individual radiation exposure specificities for separate workers etc.; whereas discrepancies between plutonium activities in some organs/tissues estimated by the systems and the ones measured in autopsy samples made for improvements in internal dosimetry system. Conclusion: The excess relative risk estimate for ischemic heart disease incidence and mortality was the most significantly affected by the improvements in dosimetry system for the internal exposure due to incorporated plutonium.

The widespread use of nuclear and radiation technologies necessitates preparedness for response to radiological emergencies. The application of medical countermeasures aimed at mitigating the adverse effects of ionizing radiation is a key element of risk management and reduction strategies, particularly during the early phases of large-scale radiation accidents among emergency response personnel. Medical agents for radiation protection are used for preventive and therapeutic purposes in cases of external, internal, or combined exposure. The aim of this study is to substantiate the choice of modern medical countermeasures for radiological protection and their protocols for application across various radiation accident scenarios. Materials and Methods: A review of Russian and international scientific publications, normative and methodological documents, and official guidelines for the period 2010–2025 was conducted. Results and Discussion: The main scenarios requiring the use of medical countermeasures for radiation protection were identified. The principal groups of drugs, their mechanisms of action, and roles within the medical radiation protection system were determined. A comparative analysis of domestic and foreign nomenclature of radiation protection agents was performed. Conclusion: It was established that the Russian nomenclature of medical countermeasures is more universal and covers a wider range of radiological emergency scenarios compared with foreign systems. The choice of specific preparations should be determined case by case, depending on the type of accident, radiological conditions, and radionuclide composition of releases. Expansion of the range and stockpiling of medical countermeasures should be given particular attention as part of emergency preparedness activities.

The pituitary gland exposure can lead to increase the risk of hormone-dependent cancers, such as breast cancer. The pituitary gland is located in the pituitary fossa of the sphenoid bone and can be exposed due to bone-seeking radionuclides such as 90Sr. The Commission on Radiological Protection does not distinguish the pituitary gland as a separate organ for absorbed dose calculating from incorporated radionuclides. In this regard, an urgent task is to create a dosimetric model that simulates the geometry of the source-tissues – the bones of the skull, and the target-tissue – the pituitary gland and adjacent tissues. This model will allow us to calculate the dose factors converting the activity concentration of radionuclide in the bone to the absorbed dose rate in the pituitary gland. To develop such a model, it is necessary to provide a systematic review of data on the size of the pituitary gland and surrounding tissues. Objective: to evaluate the morphometric characteristics necessary for constructing a computational dosimetric phantom of the pituitary gland and its adjacent tissues for people of the following age groups: newborn, 1-year-old, 5-year-old, 10-year-old, 15-year-old, adults. Materials and methods: The dosimetric model is supposed to include anatomical structures located within 1.5 cm around the pituitary gland. Therefore, the characteristics of the following tissues were evaluated based on published data: part of the brain, content of the sphenoid sinus, vessels around pituitary gland, pituitary gland, the sphenoid bone. Results and Discussion: The characteristics of the simulated objects were evaluated for all age groups, for the sella turcica they ranged from 3.4-13.3 mm, and for the pituitary gland – 3.8-13.6 mm. These values are based on studies of ~5,000 people. The size of the vascular sinuses is estimated at 1-1.7 mm, the thickness of the membranes of the pituitary gland is 0.57 mm. The thickness of the cortical bone was 0.75 mm, and the bone volume to total bone volume ratio was 39 %. Conclusion: The results of this work will be used for creating of three-dimensional computational dosimetric phantoms of the pituitary gland and its surrounding tissues for different age groups.

The new accreditation system has created rather stringent conditions for laboratories and necessitated strict adherence to a number of provisions to ensure accredited entities meet accreditation criteria. Testing laboratories or testing laboratory centers that perform radiation control conduct testing for the mandatory confirmation (assessment) of compliance. Accreditation in the national accreditation system, Rosaccreditation, is a prerequisite for the operation of testing laboratories performing such work. This article lists the laws and regulations governing the activities of laboratories accredited in the national accreditation system, presents the accreditation criteria requirements applicable to radiation control laboratories, and describes optimal methods for ensuring laboratories meet these requirements. It also lists documents that can be included in a testing laboratory's quality management system. Approaches to developing certain elements of a quality management system in light of the requirements of new Rosaccreditation documents are described. Aspects of the risk-based approach required for accredited testing laboratories in today's environment are explained. Examples of personnel supervision and competency monitoring procedures are provided. It was noted that in today's environment, special attention should be paid to improving the qualifications and competence of personnel. Currently, numerous training platforms exist, including free webinars, dedicated to approaches to ensuring testing laboratories' compliance with specific accreditation criteria. These platforms provide information on amendments to laws and regulations regarding requirements for accredited entities, answers to questions that arise during the practical implementation of testing laboratories' own approaches to building their quality management system as a whole and its individual components, and the opportunity to gain new knowledge and competencies.

Absolute transparency and control are required to ensure the safety of radiation biotechnologies that change product properties. Currently, the Russian Federation has not implemented regulatory control over the activities of radiation treatment centers in terms of compliance with sanitary and epidemiological requirements for the treatment process, as well as the safety and quality of irradiated products. The purpose of the work is to scientifically substantiate and develop the basis of a national system of rationing, control and traceability in the field of radiation biotechnologies based on the analysis of modern approaches to regulating the radiation technology industry and experiments conducted to study the effects of radiation on the properties of food and agricultural products. To ensure traceability of turnover, quality and safety of food and agricultural products treated with ionizing radiation. The paper considers modern approaches to the regulation of the radiation technology industry based on state regulation, remote monitoring and conformity assessment of treatment services and irradiated products. Based on the analysis, priority types of food and agricultural products for ionizing radiation treatment, methods of identification, quality control and safety of irradiated products, and methods for determining the radiation dose absorbed by products have been established. Based on the conducted scientific research, the experimental algorithms and procedures have been developed to establish maximum and minimum radiation levels. The optimal technological modes and radiation levels have been established for a number of priority types of products. A special Radurization hardware and software complex based on modern remote control and artificial intelligence tools has been developed, as well as a system of voluntary certification of ionizing radiation treatment centers and irradiated products "Good Practices", their key role and the need for industrial implementation as the basis of the Rospotrebnadzor monitoring and traceability system in the field of radiation biotechnologies have been substantiated.

In conditions of plutonium processing production, despite the achieved improvement of the radiation situation in the workplace, the probability of emergency situations leading to acute inhalation of radionuclides or their entry through damaged skin cannot be ruled out. In such cases, chelates are used to prevent radiation injuries or reduce the risk of their occurrence. The aim of this study was to examine domestic and foreign methodological documents and to determine the degree of completeness and sufficiency of the recommendations contained therein for the decorporation of plutonium and americium with chelate. General recommendations for the use of chelate complexes presented in Publication No. 96 of the International Commission on Radiological Protection, documents of the International Atomic Energy Agency, as well as documents of the National Council on Radiation Protection and Measurements of the United States, and domestic Methodological Guidelines 2.6.1.034-2014 “Order of Interaction between enterprises of State Atomic Energy Corporation “Rosatom” and organs and organizations of FMBA of Russia in case of non-standard (wound) and accidental inhalation intake of plutonium and americium-241 isotopes” were reviewed. Uniform requirements for the procedure for performing decorporation in terms of the frequency of drug administration and the duration of the decorporation course are not established by these documents; also, a uniform approach to determining the criterion for making a decision on the use of a chelate and the end of the decorporation course has not been developed. At present, until uniform criteria for making a decision on the initiation of decorporation therapy have been established, it is proposed to be guided by the principle of promptness and to begin decorporation as soon as possible after the expected or known intake. Then, decorporation tactics should be determined as information on dosimetric assessments becomes available, taking into account the health status of the affected worker, without excluding the possibility of delayed use of the chelate.

The purpose of this study was to analyze the radiation doses of personnel of radiation facilities in the Russian Federation in 2024 and for the period from 2019 to 2024.Data on radiation doses in 2024 were used for 239,743 personnel of group A and 22,490 personnel of group B working at 20,359 radiation facilities, of which 15,883 (78 %) were medical institutions. The average annual effective dose of technogenic industrial irradiation to Group A personnel in 2024 was 1.08 mSv, and to Group B personnel - 0.58 mSv. The average doses are quite stable for the period 2019-2024: those ranged from 1.08 to 1.19 mSv for the personnel of group A and from 0.58 to 0.66 mSv for the personnel of group B. About 10 % of the personnel of group A and about 2 % of the personnel of group B received annual individual doses of technogenic industrial radiation of more than 2 mSv. Four cases of exceeding the annual individual dose of 50 mSv for the personnel were registered in Group A in 2024. Over the past 6 years, the number of exceedances of the average annual dose limit for Group B personnel (91) has almost doubled the same amount for Group A personnel (50), although the number of group B personnel for whom individual dosimetric monitoring is carried out is significantly less than the number of Group A personnel. This is mainly the case for the personnel of group B medical institutions involved in X-ray-controlled operations. It is necessary to make individual dosimetric monitoring mandatory for this category of Group B personnel. In general, the Russian Federation ensures  socially acceptable level of radiation safety for personnel at radiation facilities.

The paper presents an assessment of the current state of the system of ensurance of public radiation safety in the Russian Federation related to exposure to natural sources of ionizing radiation. Summary: The regulatory and methodological documents regarding exposure to natural sources in force within the framework of the Russian sanitary legislation were analyzed. It is shown that for more than 20 years, the country has been operating a unique system for collecting, recording and analyzing data on the levels of all major natural sources of public exposure. The Federal databank of radiation doses to the public from exposure to natural and technologically enhanced radiation background contains the results of 2 549 785 ambient gamma dose rate measurements indoors in residential and public buildings and 3 742 296 measurements outdoors, 854 525 measurements of radon concentration indoors in residential and public buildings, and 270 026 measurements of activity concentration of natural radionuclides in drinking water, all taken in 20012024. It is shown that the average individual annual effective dose of public exposure to natural sources in the Russian Federation is 3.33 mSv, of which 1.97 mSv is the dose from inhalation of radon, thoron and their progeny. These results are consistent with the new global average data from the upcoming 2024/2025 UNSCEAR report. The paper also outlines the prospects for the development and modernization of the Russian regulatory and methodical documents related to public exposure to natural sources. Conclusion: The current regulatory system is a reliable tool for ensuring public radiation safety related to all regulated natural sources. The improvement of the regulatory framework, taking into account the standards and recommendations of international organizations, will make it possible to raise the Russian sanitary legislation to the level of modern global trends, while maintaining the achieved high levels of public radiation safety related to natural sources of radiation.

During the implementation of the "Nuclear Explosions for the National Economy" program between 1965 and 1985, 82 peaceful nuclear explosions were conducted on the territory of the Russian Federation. Monitoring of the explosion sites is crucial due to the potential risk of radioactive contamination spreading from the epicenter into groundwater and surface waters, and onto the land surface, which could lead to environmental contamination. In accordance with SanPiN 2.6.1.2819-10, the results of radiation monitoring at peaceful nuclear explosion sites must be included into the Radiation-Hygienic Passports of the territories. The aim of this work is to analyze the completeness of information presentation regarding the radiation situation at peaceful nuclear explosion sites in the Radiation-Hygienic Passports of the constituent entities of the Russian Federation for the period from 2010 to 2023. Materials and Methods: The study used data from the Radiation-Hygienic Passports for 2010-2023 of those constituent entities of the Russian Federation where peaceful nuclear explosions were conducted. The computer program FBD-RGPt MR 2.6.1.0257-21 was used as the tool for working with the territorial passports. Results and Discussion: The analysis revealed significant differences between regions in the quality and completeness of the provided data. A formalistic approach and data duplication were noted in the completion of the Radiation-Hygienic Passports. Regions that did not account for peaceful nuclear explosions when filling out the Radiation-Hygienic Passports for the entire study period were identified. These subjects include Stavropol Krai, Nenets Autonomous Okrug, Yamalo-Nenets Autonomous Okrug, the Republic of Kalmykia, and the Republic of Komi. Murmansk Oblast included information on peaceful nuclear explosions in its territorial radiation-hygienic passport only once, in 2019. The Republic of Sakha (Yakutia) ceased providing data on peaceful nuclear explosions in the Radiation-Hygienic Passports from 2017 onwards. Conclusion: The obtained results highlight the necessity of continuing the monitoring of peaceful nuclear explosion sites and the importance of interagency cooperation in the preparation of Radiation-Hygienic Passports for the territories.

The X-ray and gamma radiation dosimeter DKS-AT1123, designed for dosimetry of pulsed photon 

radiation with an energy of up to 10 MeV, is widely used for radiation monitoring of medical electron accelerators. Since the maximum energy of the bremsstrahlung radiation of medical electron accelerators can significantly exceed this value, the main purpose of this work was to calculate correction factors to compensate for the energy dependence of the sensitivity of the DKS-AT1123 dosimeter. It makes possible to obtain correct results of radiation monitoring of medical electron accelerators with an electron energy of up to 30 MeV. Materials and Methods: For this purpose, the authors calculated the energy spectra of bremsstrahlung radiation generated by electrons with energies of 10, 15, 20, 25 and 30 MeV behind concrete shield with a thickness of 0.5, 1.0, 1.5, and 2.0 m. Calculations were performed using the Monte Carlo method. Using the data obtained, correction coefficients to compensate for the energy dependence of the DKS-AT1123 dosimeter for all considered electron energies and concrete shield thicknesses were calculated. Results and Discussion: An analysis of the results showed that the correction factors are weakly dependent on the thickness of the concrete shield. For thicknesses from 0.5 to 2.0 m, the differences in the correction coefficients do not exceed 8 %. Numerical values of correction coefficients equal to 1.29; 1.44; 1.50; 1.56 and 1.60 were obtained for the maximum bremsstrahlung radiation energy of 10, 15, 20, 25 and 30 MeV, respectively. Conclusion: The use of these correction factors makes it possible to conduct radiation monitoring of medical electron accelerators using the DKS-AT1123 dosimeter.

Radiation dose monitoring and recording serve as an effective tool for ensuring the radiation safety of the population of the Russian Federation. The informational foundation for this monitoring and recording is provided by the Unified system of individual dose control of the citizens and radiation-hygiene passportization of organizations and territories. The software for these systems was developed in the early 2000s and is now obsolete, both morally and technologically. The aim of this work is to identify possible approaches to improving the software. Materials and Methods: An analysis of the shortcomings of the existing software was conducted, and promising directions for its redesign were identified, taking into account economic, material-technical, and time constraints. Results and Discussion: A software prototype was developed using Python and SQLite. Conclusion: The developed prototype provides cross-platform compatibility, portability, the capability for integration with regional and federal databases, and a high level of information security.

This overview article examines the key milestones in the development of an effective system for radiation safety in Russia covering all aspects of modern life, including through the establishment of independent scientific organizations. Evolvement of nuclear industry and the development of radiation safety requirements proceeded in parallel drawing both on national research and development and, of course, global trends and recommendations in the field of standardization. Today, it can be confidently stated that Russia operates a reliable system providing radiation safety of people. Actual doses, even when estimated conservatively, are much lower than the regulatory limits. However, certain revision of some key regulations in line with the latest international approaches is required to enhance the competitiveness of nuclear industry, which is hindered by the requirements of the Federal Law No. 3-FZ On Radiation Safety of January 9, 1996 no longer corresponding to present day developments. Despite numerous publications and studies, some issues remain unresolved regarding both the establishment of derived radiation safety indicators and the fundamental dose limits. Another persisting problem is related to the lack of clearly defined criteria based on which the necessity of site remediation can be declared, as well as end-state criteria for decommissioned nuclear legacy facilities. Russia still adheres to the principle of dose limits that are stricter than the basic dose limit even in case of existing exposure. This article addresses the problem of the annual effective dose limit set for the critical group of population in the context of radioactive waste disposal; the limit is between 500 and 10,000 times lower than the one recommended by international organizations. This, in turn, hinders the development of an effective waste disposal system, slows down the construction of disposal facilities and the decommissioning of legacy facilities.