The article presents a comparative analysis of the key performance indicators of the Chelyabinsk Regional Interdepartmental Expert Council on ascertainment of the causal relationship of diseases with radiation exposure over the periods 1990-2009 and 2010-2015. The sources of information were annual reports of the Chelyabinsk Interdepartmental Expert Council as well as its standard protocols of meetings and decisions. During the period under review, all groups of the population served underwent natural aging process; the proportion of reconsidered cases increased mainly due to the cases considered for disability and death of the exposed individuals. The causal relationship was determined more often during the period 2010–2015 than in earlier periods: 43,3% and 67,1% respectively. Positive decisions were taken most often regarding the persons with malignant neoplasms (62.9% of the total number of the positively considered decisions). The relationship of disability and death with radiation exposure during 2010–2015 was established more often, whereas the proportion of postponed cases decreased significantly.

The aim of the work is to assess the compliance of the possible doses to the population of the Russian Federation, calculated on the basis of current data on the levels of food consumption with the activity concentration corresponding to the intervention «A», according to NRB-99/2009, the dose criteria for making decisions on limiting food consumption. Estimates are made for the situation of contamination of the main food products (milk, potatoes, vegetables, meat, fruits and fish) with the cesium-137 and strontium-90 activity concentration of 1000 Bq / kg and 100 Bq / kg, respectively. It is shown that, taking into account the current data on the levels of consumption of various food products, the calculated doses for all age groups of the population do not exceed the NRB-99/2009 dose criterion of 5 mSv with the consumption of any of the listed foods within the first year after the accident, as for cesium-137, and for strontium-90. The results obtained can be used to justify the temporary permissible levels of the cesium-137 and strontium-90 contamination of one or more food products.

The  caesium-134  and  caesium-137  radionuclides released into the atmosphere as a  result of the Fukushima accident were dispersed over the entire Northern Hemisphere. To assess the risks associated with the exposure due to Fukushima fallout, a comprehensive radiological survey was performed in the Russian Far East. One of the objectives of the project was to determine the densities of ground contamination by ¹³⁷Cs and ¹³⁴Cs on Sakhalin and Kuril Islands that constitute the Sakhalin oblast, an administrative region of Russia. In 2011, soil samples were collected at grasslands on Sakhalin, Kunashir and Shikotan Islands and results of the 2011 survey were published earlier. In the present study, activities of ¹³⁷Cs and ¹³⁴Cs were measured in soil samples obtained on Kunashir, Iturup, Urup and Paramushir Islands in 2012. From the studies carried out in 2011–2012,  it was estimated that the Fukushima-derived ¹³⁴Cs inventory at 37 undisturbed grassland sites in the Sakhalin oblast varied from 8 Bq m⁻² to 345 Bq m⁻² (as of 15 March 2011). For this date, the inventory of the ¹³⁷Cs radionuclide originated from the Fukushima NPP was assumed to be the same as that of the ¹³⁴Cs radionuclide. The southern Kuril Islands were the most contaminated due to Fukushima fallout. In 2011 and 2012, Fukushima-derived radiocaesium was detected only in the top 5 cm layer of soil at all sites, excluding one, where ~20% of the ¹³⁴Cs inventory was found at a depth of 5–10  cm. In the period September 2011– September 2012, the inventory of ¹³⁴Cs declined by ~26% at four plots selected for long-term observations. The decline in the ¹³⁴Cs inventory closely corresponded to the reduction (29%) of ¹³⁴Cs activity due to radioactive decay. Pre-accidental inventory of ¹³⁷Cs in the top 20 cm layer of soil ranged from 53 Bq m−2 to 3630 Bq m⁻². The mean reference inventory of pre-accidental ¹³⁷Cs for 13 representative sites was amounted as 2600 Bq m⁻². Hence, the Fukushima accident added relatively small quantities of radioactivity to the reference preaccidental inventory of ¹³⁷Cs in grassland soils in the Sakhalin region: about 3% (~80 Bq m⁻²) on the average and 15% (~350 Bq m⁻²) at the maximum. Such small additional radioactive contamination is absolutely safe from a radiological point of view.

Presumably in the first days of April 2013, the smelting of scrap metal occurred on the territory of the Electrostal Heavy Engineering Works without the use of radiation input control. An unspecified source of ionizing radiation, containing 137Cs in an unknown quantity, was melted. As a result of smelting, contamination of the territory of the plant and the adjacent territory of Elektrostal city occurred. The relevance of the study is due to the high social significance of this accident, which is confirmed by a large number of materials published in both federal and regional mass media. In total, for the period from 12.04.2013 to 12.05.2013, 129 materials were identified. In addition, the total number of video views on this accident on the YOUTUBE website exceeds the population of Electrostal city. The purpose of the study was to analyze the practice of crisis risk communication, used by various officials and specialists in connection with the radiation accident in the territory of the Electrostal Heavy Engineering Works in 2013. The study analyzed publications in the mass media, messages on official websites of departments, organizations and authorities involved in the emergency response, video materials on the YOUTUBE website, messages on Internet forums. In order to record, analyze and store publications, an automated information system for the analysis of publications, developed by specialists of the Rospotrebnadzor Information and Analytical Center for Radiation Safety of the Population was used. The analysis of crisis risk communication with the population conducted by government bodies and representatives of various departments in the liquidation of the consequences of a radiation accident on the territory of the Electrostal Heavy Engineering Works revealed a discrepancy between the real risk communication practices in the case of the radiation accident in Elektrostal with modern scientific recommendations for radiation risk communication. Individual cases of unreliable and mutually exclusive information provided by the authorities to citizens were identified, resulting in a rather negative response on the part of Internet users. As a result of the research, there was revealed a lack of response to information materials distributed on the Internet, devoted to a radiation accident on the part of official authorities. Information from the authorities aimed at appeasing the public, due to the critical perception of the information received from the authorities, was not taken seriously by a significant part of the population. It was shown that in order to reduce the negative consequences of ineffective information work with the public, it is necessary to develop methodological support for crisis risk communication and to introduce it into the everyday practice of Rospotrebnadzor through training and improving the skills of individuals involved in communication with the media, non-governmental organizations and the population.

Radon control in buildings is being performed for decades in different countries of the world, including Russia. However, there is a lack of unified standard for the assessment of the uncertainty of the results of the control, considering the protocol and duration of the measurements. It is obvious that the uncertainty of the control increases with the reduction of the duration of the measurements. The lack of data on confidence interval for the average annual radon concentration in housings does not allow correct and precise comparison with the regulatory level, both for the commissioned and operated buildings. Additionally, it complicates a development of the effective method, mass control strategy and identification of buildings with high radon concertations. A reliable method of control, considering time variations of radon and duration of exposure, was developed in Russia several years ago, but it is not well-known and not applied on practice. This paper is focused on a novel principle of radon control, based on simple criteria, widely used in metrology and complying to the modern standards. This principle introduces a new parameter – the radon time variation coefficient KV(t), which reflects main constituent of the uncertainty of the average annual radon concentration depending on the protocol and duration of the measurements. A novel algorithm for the estimation of KV(t) is proposed, developed on the base of the results of continuous annual radon monitoring in representative experimental housings. Additionally, the structure of the correcting coefficient is presented, considering an impact of the temperature on the radon behavior. The use of the corrective coefficient allows lowering the KV(t)value, but its application is limited.

The first part of the paper was devoted to a detailed investigation of the problems of radon control in buildings as well as to the description of the accurate principle of radon control on housings, which is based on the new parameter – temporal variation coefficient K_V(t). This coefficient equalizes the main component of the uncertainty of the average annual level of radon depending on the protocol and duration of measurements. Additionally, a novel algorithm for the estimation of K_V(t) is proposed, developed on the base of the results of continuous annual radon monitoring in representative experimental housings. This part of the paper is focused on the results of the annual continuous monitoring of volume activities of radon and its daughter products in ten experimental housings in 2006–2013. These housings were located in seven buildings mainly in the Moscow region. All the experimental buildings have the detailed description. The use of original algorithm of the processing of the results of annual monitoring allowed estimating particular and table values of K_V(t) co-efficient, depending on the protocol and duration of the measurements. The values of the coefficient are lower up to a factor of two if the temperature is considered. However, the possibility of such consideration is significantly limited by the number of factors. Additionally, an importance of considering a geological factor is discussed. Evaluation of the representativeness of the data obtained and the method for verification and elaboration of the table values of K_V(t) are provided as well. Based on the results obtained, there is a possibility for the development of the approaches in the field of sanitary-epidemiologic surveillance in the field of practical realization of the strategy of mass radon control and effective identification of buildings with increased radon levels.

According to results of the survey in Ekaterinburg, Russia, indoor radon concentrations above the city average level have been found in each of the studied buildings with high energy efficiency class. Measures to increase energy efficiency were confirmed to decrease the air exchange rate and accumulation of high radon concentrations indoors. Despite of recommendations to use mechanical ventilation with heat recovery as the main scenario for reducing elevated radon concentrations in energy-efficient buildings, the use of such systems did not show an obvious advantage. In real situation, mechanical ventilation system is not used properly both in the automatic and manual mode, which does not give an obvious advantage over the natural ventilation in the climate of the Middle Urals in Ekaterinburg.

Mineral natural table, medical-table and medical water is usually characterized by enhanced mineralization, so annual consumption of such water for drinking and cooking is much lower than standard water consumption of adult population. The limitation of population exposure due to mineral natural table and medical-table water could be achieved by the implementation of limitation of their consumption. The aim of the investigation is to estimate potentially possible population exposure doses from mineral natural medical water consumption on an example of the water which is used for drinking therapy in the complex of sanatorium health resort treatment of patients in one of the sanatoriums of Saint-Petersburg. The data on mineral medical water radionuclides specific activity values used for patients exposure doses estimation was obtained during implemented radiochemical analysis carried out using the techniques developed in the Institute of Radiation Hygiene. Obtained results of the investigations and their analysis demonstrated that potentially possible patients’ maximal annual effective exposure doses due to implementation of mineral natural medical water for drinking therapy in the complex of sanatorium health resort treatment will not exceed definitely the reference dose level, recommended by WHO, equal to 0.1 mSv/year because of a low amount of water consumption prescribed by a physician. It is clear unreasonable to set limitations on natural radionuclides content in mineral medical water because patients take it as a medicine according to physician prescribing and the consumption of such water is connected with their therapy properties. Principle of justification of the procedures appointment has to be applied when the course of mineral medical water treatment is prescribed. The essence of the principle is to compare therapy (medical) benefits as a result of treatment with the damage to health as a result of radiation exposure. It is necessary to estimate the effective internal exposure doses due to mineral natural medical water consumption for different age groups of population for the process of justification of therapy procedures.

Fluoroscopic examinations of the upper gastro-intestinal tract and, especially, barium meal examinations, are commonly performed in a majority of hospitals. These examinations are associated both with substantial individual patient doses and contribution to the collective dose from medical exposure. Effective dose estimation for this type of examinations is complicated due to: 1) the necessity to simulate the moving X-ray irradiation field; 2) differences in study structure for the individual patients; 3) subjectivity of the operators; and 4) differences in the X-ray equipment. The aim of the current study was to estimate conversion coefficients from dose-area product to effective dose for barium meal examinations for the over couch and under couch exposure conditions. The study was based on data collected in the X-ray unit of the surgical department of the St-Petersburg Mariinsky hospital. A model of patient exposure during barium meal examination was developed based on the collected data on fluoroscopy protocols and adult patient irradiation geometry. Conversion coefficients were calculated using PCXMC 2.0 software. Complete examinations were converted into a set of typical fluoroscopy phases and X-ray images, specified by the examined anatomical region and the projection of patient exposure. Conversion coefficients from dose-area product to effective dose were calculated for each phase of the examination and for the complete examination. The resulting values of the conversion coefficients are comparable with published data. Variations in the absolute values of the conversion coefficients can be explained by differences in clinical protocols, models for the estimation of the effective dose and parameters of barium meal examinations. The proposed approach for estimation of effective dose considers such important features of fluoroscopic examinations as: 1) non-uniform structure of examination, 2) significant movement of the X-ray tube within a single fluoroscopic phase, and 3) the variety of exposure geometries within complete examination.

Events connected with the development and improvement of the nuclear industry are usually ambiguously perceived by the public. Mass-media and Internet play a leading role in the development of the public opinion on the most relevant public life issues, ecology and radiation safety in particular. Non-governmental organizations can impact the adequate perception of the issues of the radiation safety in the region by the public. Materials and methods: this study is focused on the primary evaluation of the data on the results of the sociological survey of three regions of the North-West of the Russian Federation: St-Petersburg, Leningrad and Murmansk regions; and the assessment of the websites of the non-governmental organizations, activities of the non-governmental organizations in the Internet and social networks. Results: the study indicated that non-governmental organizations actively use Internet and social networks in their practice. All the relevant non-governmental organizations have websites and social network accounts. Based on the number of the subscribers in social networks, it was possible to mark two non-governmental organizations: Greenpeace and World Wildlife Fund (WWF) with more than 400000 subscribers each. VKontakte social network was assessed as the most effective mean of communicating with the public; a total number of subscribers on the groups of major non-governmental organizations exceeds 500000 persons. These two organizations are the most popular and trusted by the public. Greenpeace is known to 26% of respondents; WWF – to 11%. The population of the Murmansk region is more informed about the actions of the non-governmental organizations. 48% of the respondents in the Murmansk region named at least one non-governmental organization answering the question “What non-governmental organizations active in the field of radiation protection do you know?” with the corresponding 18% and 29% in St-Petersburg and Leningrad region respectively. Nongovernmental organizations have a sufficient potential of influence on the adequate perception of the issues of the radiation protection by the public in the region; however, that potential is not fully implemented. Despite that, activities of the non-governmental organizations should be considered while developing the adequate perception of the radiation factors by the public.

Underground water is one of the sources of water supply and the most important mineral resources. The enrichment of natural groundwater with radium isotopes is a geochemical regularity, and their use a recognized source of additional exposure to the population and the environment. Forecast resources of groundwater in the territory of the Russian Federation are 869055 thousand m³/day. As of 01.01.2015, 15054 deposits (sections) of groundwater have been explored, of which 10556 are in operation. In the federal districts, the volume of extraction and extraction of groundwater varies widely. The percentage of groundwater in domestic and drinking water supply in 35 regions of the Russian Federation ranges from 70 to 100%; in more than 30 regions it exceeds 90%. A whole series of large cities provide water supply through the underground water. Underground waters, depending on the field of application, are divided into drinking, technical, heat power, industrial and medical. The formation of numerous areas with an increased content of natural radionuclides for all types of groundwater is largely determined by the volume of their use. Organized use of groundwater is preceded by special water treatment, where it is possible to form doses of exposure to those above permissible levels established in NRB-99/2009 and the formation of a mass of waste with an increased content of natural radionuclides. In many regions of the country, there is a prospect of a constant increase in the use of all types of groundwater and the creation of new enterprises, which will require monitoring and radiation and hygienic assessment. Particular attention should be paid to the use of associated waters of oil and gas fields that have the highest content of natural radionuclides among groundwaters as a promising source of mineral raw materials.