According to the annual information packet “Radiation exposure doses to the population of the Russian Federation”, internal exposure to radon has been the main contributor to the annual dose for the population for many years. The paper presents results of a comparative assessment of doses and health risks for students (pupils) and employees of four educational institutions in the Kingiseppsky district of the Leningrad region due to exposure to radon and its progeny. Evaluation of the doses and risks was based on results of instant and long-term measurements of indoor radon concentrations published earlier. Individual annual effective doses to students (pupils) and employees due to exposure to radon while in the building of an educational institution, calculated on the basis of the results of instant measurements of radon EEC, ranged from 0.34 to 4.87 mSv/year for different institutions. However, calculation on the basis of the results of long-term measurements of radon concentration resulted in the dose values 2-4 times higher (from 1.40 to 14.79 mSv/year). These results do not reflect the real exposure scenario, since solid-state nuclear track detectors were exposed continuously, including nights, weekends and holidays (i.e. periods of actual absence of people in the buildings of the educational institutions). Based on the results of instant measurements of radon EEC, the contribution of radon and its progeny to the individual annual effective dose due to all natural sources of ionizing radiation to students (pupils) and employees was 59% (2.21 mSv/year) in the kindergarten of Opol’e, 61% (2.41 mSv/year) in the kindergarten of Falileevo, 82% (6.81 mSv/year) in the school of Falileevo, and 82% (7.11 mSv/year) in the school of Bol’shaya Pustomerzha. According to the classification established in sanitary rules and norms OSPORB 99/2010, the exposure of students and employees of the surveyed schools is classified as “increased” (from 5 to 10 mSv/year) when using the results of instant measurements of radon EEC, and is classified as “high” when using the results of long-term measurements of radon concentration (more than 10 mSv/year). The average individual lifetime risk of radon-induced lung cancer death (based on the results of instant measurements of radon EEC) for students (pupils) and employees was 3.8∙10^–4 in the kindergarten of Opol’e, 4.1∙10^–4 in the kindergarten of Falileevo, 1.2∙10^–3 in the school of Falileevo, and 1.2∙10^–3 in the school of Bol’shaya Pustomerzha. However, calculation on the basis of the results of long-term measurements of radon concentration resulted in the risk values from 1.5 to 2.4 times higher. The results obtained can be used to improve the method of monitoring of indoor radon concentration in existing operated public buildings in the Russian Federation, which in turn will make it possible to obtain correct values of doses and health risks.

Radioactive waste management is a modern-day issue in terms of radiation safety due to the development of radionuclide therapy, the emergence of new radiopharmaceuticals, radionuclides, and treatment methods, which allow for radionuclide therapy in a day hospital. According to the current domestic regulatory and methodological support biological wastes generated during the patient’s metabolic activity after injection of the radiopharmaceuticals for the therapy refer to the liquid radioactive waste. These wastes must be collected and kept for decay in hospitals to the safe levels before being spilled into the municipal sewerage. It requires additional expenses to the hospital for making the special sewerage. To increase the availability of radionuclide therapy, it is necessary to update the requirements of the liquid radioactive waste management in nuclear medicine departments, considering the volume activities of different diagnostic and therapeutic radionuclides in wastes generated after the injection of radiopharmaceuticals to the patients. On the basis of findings, it is possible to evaluate the feasibility of the binding requirement for the availability of special sewerage in the departments of the radionuclide therapy. In this work, excretion of the radiopharmaceuticals used in therapy: ⁸⁹Sr-dichloride, ²²³Ra-dichloride, ¹³¹I-MIBG, ¹⁷⁷Lu-PSMA, and ²²⁵Ac-PSMA was studied based on published data to determine the activity levels of radionuclides in waste of patients. As a results of preliminary computations, some nuclear medicine procedure will not lead to generation of liquid radioactive waste from biological waste of patients in sewerage system in usual operating condition and special sewerage is not strictly necessary. For example, estimations of radionuclide activity in wastes showed the volume of current sewerage system in a small hospital with a limitation of 50 beds can be enough to reduce the level of specific activity of radionuclides in wastewater from one patient a day after radionuclide therapy with ⁸⁹Sr-chloride and ²²³Ra-dichloride. In order to revision of requirements to special sewerage in each department of radionuclide therapy and to development of differentiated approach to the management of biological waste of patient in nuclear medicine departments, which ensure environment protection and radiation safety of people, it is necessary to continue the research including development and modeling of realistic scenario of staff and patient radiation exposure confirmed experimental results.

The aim of this study was to demonstrate how the severity of radiation damage in the case of bone marrow syndrome due to acute irradiation depends on the non-uniform irradiation of the body. We used the calculation method that involves the evaluation of organism mortality as a function of bone marrow cells colony survival vs dose for different radiation profiles. It was presumed that the probability of the death for the organism is the same for the same value of survival level of the bone marrow cells regardless of the dose distribution by mass of the organ. The dose of uniform irradiation that is equivalent to the dose for the L-th case of non-uniform irradiation is calculate based on the survival level of the total marrow cells. After that the probability of the death of the organism is estimated according to the dose response curve. Dose distribution in bone marrow of computational MIRD-5-type stylized model adult man for different geometries of exposure by point source of ¹³⁷Cs was evaluated. Larger non-uniformity of the dose distribution in the bone marrow at the same dose in free air in the site of human location causes a greater probability of survival due to a greater proportion of bone marrow cells that have preserved the possibility of reproduction. The values of mean 50% lethal dose for cases of approximately uniform irradiation of the body surface (point source at a distance 10m) and sharply non-uniform irradiation (point source at a distance of 0.5 m) differ approximately by the factor of 1.7 – 2.5 depending on direction of irradiation. Additionally the values of conversion coefficients from the reading of an individual dosimeter to the value of an effective dose for various geometries of irradiation of emergency workers from the ¹³⁷Cs point source were calculated. The average value of the conversion coefficient from personal dose to effective dose for the considered exposure situations is 0.7 Sv Cy^-1 and the 90% confidence interval is 0.49 – 0.99 Sv Gy^-1.

The article deals with the issues of normative and methodological support of radiation survey of buildings and structures to be demolished. It is noted that with the intensive growth of construction of dwellings and public buildings in large cities, former industrial territories with a significant number of facilities to be demolished are being included into the development zone. The radiation monitoring and sorting of industrial waste generated after the demolition of buildings is not feasible in practice. The expediency of radiation survey of buildings and structures to be demolished at the stage preceding their dismantling, as well as the need to develop and approve at the federal level the methodology of its implementation is substantiated. Recommendations for the assessment of radiation safety indicators of buildings and structures to be demolished are given. It is shown that if the value of ambient equivalent gamma dose rate in the buildings and structures to be demolished does not exceed 0.6 μSv/h, industrial waste generated after demolition of buildings and structures and containing only natural radionuclides are not a subject to any restrictions related to the radiation factor, since the value of effective activity concentration of natural radionuclides is guaranteed not to exceed 1500 Bq/kg and therefore the waste is classified as Category I in accordance with the Basic sanitary rules for the provision of radiation safety (OSPORB 99/2010).

The objective of the work was to study the prevalence of undifferentiated oligophrenia in the offspring of antenatally exposed parents. The analysis included 2,908 offspring of the Techa River antenatally exposed residents within Chelyabinsk Oblast born in the period 1974-1992. 1,705 of them were born to an antenatally exposed mother, 1,668 – to an antenatally exposed father, and 368 – to both antenatally exposed parents. Mean in-utero dose for the cohort of in-utero exposed population was 5.8 mGy, while the mean dose of mothers of oligophrenic persons was 12.6 mGy, and that of antenatally exposed fathers – 5.3 mGy. It was found that the prevalence of oligophrenia of different degrees of severity compared to the control group, which included the offspring of unexposed persons of the same age, ethnicity and living in adjacent territories, tends to increase More than 20% of cases of moderate oligophrenia in both main and control groups were of familial nature. All cases of severe oligophrenia in the compared groups were sporadic. There was an increase (p<0.05) in the prevalence of severe oligophrenia when compared to the control group in the offspring cohort of antenatally exposed individuals, 0.45% and 0.24%, respectively, which was 0.59%, p<0.01, in the offspring of exposed mothers. The corresponding rates for the offspring of antenatally exposed fathers were 0.42% and 0.24% in the main and control groups, respectively, p>0.05. No dependence of the prevalence of oligophrenia on the maternal and paternal in-utero dose has been detected.

Risk communication is one of the stages of health risk analysis and is an interactive process of exchange of information and opinions about risks, including medical risks, between risk assessment specialists, decision makers, the media, stakeholder groups and the public. In organizing interaction with stakeholders in the risk communication process, sociological research helps to explore the attitudes of the actors. One of risk communication situations in the field of radiation protection is information provision to patients and their legal representatives about radiation health risks due to the medical radiology examinations. The aim of this study was to assess the radiation risk perception among parents and legal representatives of children undergoing radiological examinations. Parents and legal representatives of children undergoing hospital treatment from November 2021 to March 2022 were interviewed in a large pediatric infectious diseases hospital. A questionnaire designed at St. Petersburg Research Institute of Radiation Hygiene was used for the interviews. In total, 125 people were interviewed. The study showed that there were no significant differences in the perception of radiation risks among parents and legal representatives of children undergoing inpatient treatment with different socio-demographic characteristics. The level of knowledge was not identified as a factor shaping a tolerant attitude toward medical radiation risks. Parents and legal representatives of children undergoing hospital treatment show high rates of trust in the attending physicians and medicine in general. The study results show that those who have been informed about the risks generally have lower risk perception for radiological medical examinations than those who have not been informed about the risks.

The article presents the results of a sociological survey of the population of three regions of the Northwest region of the Russian Federation: the Leningrad, Murmansk, and Arkhangelsk regions. The survey was conducted in 2016-2018 and investigated the population’s knowledge about radiation and sources of knowledge in view of the further development of nuclear power, the construction of radioactive waste storage facilities, and the increasingly widespread use of ionizing radiation sources in medicine and industry. The aim of the study was to examine how the degree of trust in certain sources of information and preferred ways of obtaining information depends on the gender, age, and educational level of respondents. Generalization of such materials makes it possible to optimize means and ways of improving public knowledge on radiation safety issues so that the population could adequately (without panic) treat reports concerning the development of nuclear power, construction of radioactive waste storage facilities, and the increasing use of ionizing radiation sources in medicine and industry. The study revealed that, regardless of gender, age, and education, respondents in all three surveyed regions want to receive information about the radiation situation only in the event of an emergency. A high percentage of the population, especially in the Leningrad and Murmansk regions, unreasonably characterize the level of radioactive contamination of their places of residence as strong, dangerous, and extremely dangerous, which indicates a poor level of knowledge of radiation safety issues. Age and education have no practically significant influence on this assessment. The respondents consider TV and the Internet to be the most popular sources of information about the radiation situation. At the same time, it is logical that older people prefer to receive information through traditional mass media, while younger people prefer the Internet.

The review dwells upon the problematic issues, uncertainties and prospects of establishing causal relationship between diseases and radiation exposure. The review discusses the challenges, uncertainties and prospects of establishing causation between exposure to radiation and diseases. The criteria that could be used to assess the radiation-induced health damage are considered. The existing practice of recognizing certain categories of citizens of the Russian Federation as people affected by radiation exposure, which is based on the establishing causal relationship between disease, invalidity, death with radiation exposure by Interdepartmental expert councils, is analyzed. Experts of Interdepartmental expert councils in taking the decision rely on to the list of diseases that should be updated consistently based on the findings of radio-epidemiological studies. To make the decision-making process objective, advanced scientific studies focused on individualization of the radiation risk and search for the biomarkers of radiation-induced effects, both deterministic and stochastic ones, are discussed.

Method of in situ gamma-ray spectrometry was used to discriminate contributions of ¹³⁷Cs and natural radionuclides to ambient dose equivalent rate indoors in settlements located in the zones of radioactive contamination after the Chernobyl accident. The measurements using a portable scintillation gamma spectrometer-dosimeter were carried out in 115 individual one-story residential buildings in 46 settlements of the Bryansk region of Russia in the summer period of 2020–2021. According to official data, the average density of soil contamination with ¹³⁷Cs in the settlements ranged from 27 to 533 kBq/m2. Based on the type of building materials that had been used to construct the walls, the surveyed houses were divided into three large groups: wooden (walls made of logs) – 51 buildings, stone (walls built of bricks and/or concrete panels) – 34 buildings, and frame-panel – 30 buildings. The latter had walls constructed of wooden panels with the inclusion of heat-insulating material. Outside, the walls of the frame-panel houses were lined with a layer of silicate (white) bricks. 70 houses were built before the accident and 37 – after the accident. In eight cases it was not possible to reliably estimate the period of construction. The total ambient dose equivalent rate ranged from 42 to 228 nSv/h (average = 77 nSv/h). The values of the ambient dose equivalent rate from natural radionuclides were in the range 27–122 nSv/h. The average values of the ambient dose equivalent rate from natural radionuclides in the groups of wooden, frame-panel, and stone houses were 42, 42 and 58 nSv/h, respectively. The difference between stone houses and panel houses was statistically significant (P < 0.01). The same difference was found between stone houses and wooden houses (P < 0.01). The average values of the ambient dose equivalent rate from ¹³⁷Cs, normalized to the density of soil contamination with ¹³⁷Cs, were 0.13, 0.16, and 0.05 (nSv/h)/(kBq/m2) in wooden, frame-panel, and stone houses, respectively. The normalized ambient dose equivalent rates from ¹³⁷Cs in the group of stone houses were statistically significantly (P < 0.01) lower compared to the corresponding values for the groups of wooden houses and frame-panel houses. The small differences between frame-panel and wooden houses turned out to be statistically significant (P < 0.05). The median and mean values of the normalized ambient dose equivalent rate from ¹³⁷Cs for houses built before the accident were lower compared to those for houses built after the accident. These differences were statistically significant (P < 0.01) for all groups of houses. The mean values of the normalized ambient dose equivalent rate from ¹³⁷Cs and the ambient dose equivalent rate from natural radionuclides obtained in this study can be used to estimate the external effective dose to a person staying inside a one-story residential building. In this case, one should take into account not only the type of building materials used to construct the house, but also the time period of the construction: before or after the Chernobyl accident.

In 2020 Federal Service for surveillance on consumer rights protection and human well-being organizes a series of events devoted to the 100th anniversary of the day of establishment of the state sanitary-epidemiological service of Russia. St-Petersburg research institute of radiation hygiene, as other scientific-practical institutions of the Rospotrebnadzor, summarizes its contribution to practical activities in the field of radiation hygiene. Since the foundation of the Institute in December 1956 and up to current time the results of the research on many aspects of this significantly young discipline formed the basis for the development of one of the main problems of radiation hygiene – protection of the public health from hazardous effects of ionizing exposure. One of the important practical aspects of the performed research in the assistance to the institutions providing sanitary surveillance on the radiation safety on the territories of the USSR and regions of the Russian Federation.