The paper presents data on indoor radon concentrations in the buildings of children institutions in a number of regions of the Russian Federation. The results of detailed radon surveys in 132 buildings of children institutions in 85 settlements of six districts of the Leningrad Region conducted in 2018-2020 were analyzed. In 14 buildings of children institutions in the Leningrad region (10.5% of all surveyed buildings) the hygienic limit on the indoor radon EEC was exceeded, the maximum measured value of radon concentration in the premises of children institutions reached 2200 Bq/m³. It seems appropriate to extend the experience of cooperation between the Directorate of the Rospotrebnadzor for the Leningrad Region and the Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev in conducting detailed radon surveys in children institutions on other regions of the Russian Federation that face problems with indoor radon.

At present, the permissible atmospheric release levels of ²³⁸U are evaluated only on a basis of its radiation impact on population. At the same time, uranium belongs to the 1^st hazard class (extremely dangerous chemicals) by its toxic effect. Limitation of the ²³⁸U release to the atmosphere is calculated separately using two criteria – radiation protection (annual dose limits) and chemical toxicity of uranium. It is shown that the permissible release level of 238U by radiation criteria is 100 – 250 times higher than the maximum release level limited by chemical toxicity of uranium. Annual intake limit of ²³⁸U for population 8400 Bq/year, established by Radiation Safety Norms NRB-99/2009, under condition of its uniform intake is equal to 184 mkg/kg of body mass per day for the indicated age group. It is 306 times higher than the tolerable daily intake of uranium estimated by World Health Organization. Compliance with the public health regulations in radiation safety does not guarantee that the annual intake of uranium by population would not exceed the tolerable toxicity levels indicated by World Health Organization. Therefore, the established value of the annual intake limit of ²³⁸U for the population needs to be revised taking into account the recent World Health Organization publications and the research results in the field of chemical toxicity of uranium. The revised value could be incorporated to the system of establishing the permissible atmospheric releases levels of radioactive substances.

In the event of radiation accidents and incidents related to a possible threat to public health, one of the tools for forming health-saving behavior of the population, ensuring the social acceptability of protective measures and reducing social tension is crisis communication. Nuclear and radiation emergencies associated with the potential for radioactive contamination of large areas or the impact on the population can become the basis for the emergence of resonant information events. Properly organized crisis communication with the population in such situations is one of the necessary conditions for the effectiveness of emergency response. The article analyzes the impact on crisis risk communication of some features of nuclear and radiation events that have occurred in recent years. These events have had a significant impact on the possibility or impossibility of following the general principles of crisis communication, and provides examples of recommendations for adjusting information work if it is impossible to strictly follow the general principles of crisis communication in real circumstances. The study made it possible to identify the following features of the development of specific crisis situations that influenced the course of crisis communication and created a number of difficulties: 1) the latent nature of the early phase of the accident; 2) absence or deliberate concealment of information about a radiation accident; 3) the transboundary nature of the accident; 4) hidden (secret) nature of information about the accident; 5) an increase in the level of radiation anxiety among the population of the territories not affected by the accident; 6) the rapid formation and spread of myths; 7) projecting artistic images on a real accident. The analysis of the influence of the features of radiation accidents and incidents on the crisis communication allowed us to come to the following conclusions: 1) crisis communication is an important component of emergency response, affecting both the psychoemotional state of the population and the effectiveness of emergency measures related to the actions or inaction of the population; 2) the development of means of information interaction and methods of dissemination and consumption of information requires a revision of traditional methods of information work with the population; 3) the information should be timely, objective, consistent and understandable both for the public and for non-specialists in the field of radiation hygiene responsible for making management decisions; 4) information should not be presented in the form of short messages without explanations; 5) contradictory aggressive information received by the population from different sources may cause distrust of official sources of information; 6) if you do not provide up-to-date and objective information about the accident, the public’s trust is very easy to lose and very difficult to restore.

This paper demonstrates the shortcomings of the existing method of radiation control in the X-ray rooms and the interpretation of the results of the measurements to assess the compliance of the working conditions of various groups of exposed individuals with radiation safety requirements. A new method of interpretation of the measurement results is proposed, considering the relative time spent by certain categories of exposed persons in the corresponding rooms during the use of the X-ray units, as well as the use of personal protective equipment (lead aprons). The interpretation of the measurement results in the treatment room according to the new approach has demonstrated the compliance of the working conditions to the Norms and Rules of radiation safety, provided that the worker is wearing a protective apron. The proposed approach to the interpretation of the results of the measurements in adjacent rooms leads to both reduced and stricter requirements for the stationary shielding. The paper includes a special focus on the incorrect calculation of stationary shielding for the installation of several X-ray units in one X-ray room within the framework of the current approach.

The Republican Research Center for Radiation Medicine and Human Ecology in the Internal and External Emergency Plans of the Belarusian nuclear power plant is specified as an institution that provides specialized treatment for personnel, as well as persons from the population living in the emergency zone of the station. The plant is the first facility in the Republic that used nuclear energy. There is no experience in treating radiation injuries in Belarus. This is the first time that the National Health Service has been assigned the task of ensuring readiness for the reception and specialized treatment of people who have been exposed to emergency or unplanned radiation. The purpose of the work is to establish criteria for radiation exposure for use in a Belarusian specialized medical institution in case of medical response to radiological accidents. As a result of the analysis of publications of international organizations, the criteria of radiation exposure that can be applied in the conditions of Belarusian specialized medical institutions were selected. Assessment of the criteria was made taking into account existing national technical regulations and the available capabilities of emergency response participants. To account for the quality of radiation in relation to deterministic effects “Gy-equivalent” is used. The criteria include both dosimetric values for cases of external and internal accidental and unplanned exposure, and levels of radioactive substances with unknown physical and chemical properties entering the body that require urgent medical intervention. Criteria for cases of surface contamination of skin and wounds require separate consideration.

The collection of representative soil samples in the territory of settlements and subsequent measurements of the content of radionuclides in these samples under laboratory conditions (the so-called “ex situ method”) is a generally accepted technology for determining the density of soil contamination with ¹³⁷Cs in the populated areas contaminated due to the Chernobyl accident. Recently, as a supplement or alternative to the ex situ method, researchers are developing field (in situ) gamma-spectrometry methods. These methods allow determining the density of soil contamination with 137Cs directly on site, without soil sampling and laboratory analysis. At the same time, the in situ methodology has several limitations, the most important of which is a lack of generally recognized metrological basis for measurements and interpretation of results. Hence, before using a particular technique and measuring device for carrying out large-scale in situ measurements, it is necessary to validate (to assess the suitability) of the selected in situ method using an established ex situ method. The aim of this study was to validate the method for determining the density of ¹³⁷Cs soil contamination in kitchen gardens using the MKS AT6101D spectrometer-dosimeter in situ. The method was recently presented by a Russian-Swedish-Belarusian group of researchers in an article published in the Journal of Environmental Radioactivity (https://doi.org/10.1016/j.jenvrad.2021.106562). To validate this method, we selected 10 representative kitchen garden plots. The plots were located in six settlements of the Bryansk region in Russia. The territory of the settlements had been heavily contaminated with ¹³⁷Cs as a result of the Chernobyl accident: the officially established levels of the density of soil contamination by ¹³⁷Cs ranged from 111 to 511 kBq/m² in 2017. Field gamma-ray spectra were recorded at a height of 1 m above the ground in the center of kitchen garden plots using the MKS AT6101D device. The measurement duration was in the range of 1207–1801 s (the mean value = 1383 s). Samples of soil in the kitchen gardens were taken layer by layer (with a step of 5 cm) to a depth of 20 cm using a demountable cylindrical sampler. The 137Cs content in each soil layer was determined in the laboratory using a stationary semiconductor gamma spectrometer. The values of the 137Cs contamination density of the sampled soils ranged from 77 to 548 kBq/m². It was found that the results of the ex situ analyzes of soil samples were in a good agreement with the contamination density values obtained with the in situ method. On average, the difference between two methodologies was 7% (a maximum of 20%). The results of the study confirm that the method proposed by the international group is suitable for determining the density of soil contamination by 137Cs in kitchen gardens in remote period after the Chernobyl accident.

The content of cesium-137 in the soil cover of the central and southern parts of Tajikistan was studied. The study area of the regions of the republic is about 45,000 km². 92 soil samples from the Central and Southern parts of the republic were collected from cultivated and uncultivated fields to a depth of 25 cm from the ground surface. Each sample at the sampling point was cleared of stones, roots and other inclusions. The sample was dried to an air-dry state, crushed and sieved through a sieve with a hole diameter of 2 mm. When measuring the samples, we used a standard 1 L Marinelli beaker. Measurements of the specific activity of cesium-137 in soil samples were carried out on a gamma spectrometer based on highly pure germanium. The maximum content of cesium-137 was observed in soil sample No. 1 of the Kamarob area of the Rasht district, which specific activity in the sample is 148 Bq / kg. The minimum specific activity of cesium-137 is observed in soil samples from the Tajikabad district. The dependence of the concentration of cesium-137 on the topography in the region under study has been established. In some of the investigated samples, the cesium-137 isotope was not detected (sample no. 2 from the Ayvaj area of the Shahritus district and sample no. 4 from the Farkhor district). The dynamics of the distribution of cesium-137 on the soils of uncultivated fields and soils of cultivated fields of the Khatlon region of Tajikistan has been studied. It was found that the content of the isotope of cesium-137 in the treated fields differs from the untreated ones. It has been determined that in the soils of cultivated lands, the content of cesium-137 is concentrated at a depth of 20-25 cm. At the foot of the mountains and clay soils, a relatively high content of the isotope of cesium-137 is observed in comparison with plains and sandy soils.

The aim of the study was a comparative assessment of radiation doses to the population of the Voronezh and Irkutsk regions according to the unified state system for monitoring individual doses and radiation-hygienic certification. The objects of research were the territories of the Voronezh and Irkutsk regions, significantly differing in climatic conditions and resources, industrial potential, but comparable in terms of population. The subject of the study was the average territorial values of radiation doses to personnel due to the normal operation of anthropogenic sources, radiation doses to the population due to natural sources and anthropogenic background, radiation doses to patients due to the use of ionizing radiation in medical diagnostics. The method of comparative analysis of effective collective and individual average annual radiation doses was used. In the Voronezh and Irkutsk regions, the priority dose-generating factor is natural radiation, which contribution to the annual effective collective dose is 83.33 and 89.18%, respectively. At the same time, the average individual annual effective doses to the population due to natural sources of ionizing radiation in the Irkutsk region in relation to the Voronezh region are significantly higher for radon – 2,81 times, due to the content of radionuclides in drinking water – 1,93 times and external terrigenous radiation – 1,46 times, which leads to a two-fold difference in the total individual effective doses associated with natural sources of ionizing radiation. These differences are explained by the features of the physical and geographical location of territories. There are significant differences in the values of the average effective annual doses of the population due to global fallouts and past radiation accidents, because a part of the territory of the Voronezh region was exposed to radioactive contamination as a result of the accident at the Chernobyl nuclear power plant (in the Voronezh region – 0.062 mSv / year, in the Irkutsk -0.005 mSv / year). Radiography (63.15 and 67.27%) makes the leading contribution to the value of medical radiation doses, which occupy the second place in the structures of the effective collective annual doses to the population (in the Voronezh region make up 16.46%, in the Irkutsk region – 10.74%) and fluorography (31.29 and 27.41% in the regions, respectively). It was established that the radiation situation in the Voronezh and Irkutsk regions remains stable and safe.

The technical passport for the X-ray room in accordance with the current sanitary legislation is a mandatory document certifying the technical condition of X-ray diagnostic equipment, devices for developing, fixing and drying X-ray films, additional equipment and accessories for performing special types of X-ray diagnostics, means of protection against ionizing radiation of workplaces of the office staff and adjacent to the office of the premises and confirming the compliance of their characteristics with the normative and technical documentation and domestic standards. The purpose of this work was to assess the relevance and necessity of issuing a technical passport for the X-ray room and to coordinate the project of the X-ray room with the X-ray department in the light of the current sanitary legislation. Registration of a technical passport by organizations that have special permits for these types of work, and not only by the X-ray and radiological department, would increase the legal value of the technical passport. The information contained in the technical passport is duplicated in the rest of the documentation for the X-ray room, the requirements for which are enshrined in the sanitary legislation, which generally casts doubt on the need for a technical passport as a mandatory document. 

The aim of the study was to estimate the patient effective doses from hepatic arterial chemoembolization. The study was based on the parameters of the protocols of liver chemoembolization collected for 67 patients in Angiography department of the «A.M. Granov Russian Scientific Center of Radiology and Surgical Technologies» of the Ministry of Health of the Russian Federation. The parameters were collected using a dedicated questionnaire and exported from digital image files in DICOM format with preliminary anonymization. The simulation of patient exposure was performed using PCXMC 2.0 software. The median values of the patient dose-related quantities (minimum and maximum values) were as follows: total dose–area product – 6.1 Gy×cm² (3.4-693Gy×cm²), fluoroscopy time – 7.5 min (2.0-28.3 min), effective dose – 11.7 mSv (0.6-132 mSv). For three patients effective doses exceeded 100 mSv. In two cases, total dose-area product exceeded the control values for deterministic effects in the skin. No tissue reactions were identified for the whole patient sample.

If the neutron fields at personnel workplaces differ from the neutron fields in which individual dosimeters are verified, there is a possibility of additional errors in the assessment of such dosimetric quantities as ambient dose equivalent, individual dose equivalent or effective dose. To take into account the energy distribution of the neutron radiation flux density and the geometry of the irradiation of workers, it is necessary to study the characteristics of the fields of neutron radiation at the workplaces of the personnel. In order to obtain conditionally true levels of personnel exposure to neutron radiation at nuclear facilities, studies of the energy and angular distribution of the neutron radiation flux density were carried out at the workplaces of the Institute of Reactor Materials JSC, Zarechny. The energy distribution of the neutron radiation flux density was obtained using an MKS-AT1117M multi-sphere dosimeter-radiometer with a BDKN-06 detection unit and a set of polyethylene spheres-moderators. The angular distribution of the neutron radiation flux density was estimated from the results of measurements of the accumulated dose of neutron radiation by individual thermoluminescent dosimeters placed on four vertical planes of a heterogeneous human phantom. The results of measurements of the energy and angular distribution of the neutron radiation flux density made it possible to estimate the conditionally true values of the ambient and individual dose equivalents. The calculated conventionally true values differ from the measured values from 0.7 to 8.9 times for the ambient dose equivalent and from 6 to 50 times for the individual dose equivalent. In order to reduce the error in assessing the effective dose of personnel using personal dosimeters, correction factors were determined. For different workplaces and types of personal dosimeters, correction factors are in the range of values from 0.02 to 0.16.