One of the main aims of the study was an experimental determination of the conversion coefficient from ambient dose equivalent rate, Н*(10), to absorbed dose rate in air, D, in the case of radioactive contamination of the environment following the Chernobyl accident. More than 800 measurements of gamma-dose rates in air were performed at the typical locations (one-storey residential house, street, yard, kitchen-garden, ploughed field, undisturbed grassland, forest) of rural settlements and their surroundings in the heavily contaminated areas of the Bryansk region, Russia in the period of 1996–2010. Five commercially available models of portable gamma-ray dosimeters were employed in the investigation. All tested dosimeters were included into the State register of approved measuring instruments of Russia. In all dosimeters, scintillation detectors are used as detection elements. A photon spectrometry technique is applied in the dosimeters to determine gamma dose rate in air. The dosimeters are calibrated in terms of exposure rate, X, absorbed dose rate in air, D, and ambient dose equivalent rate, Н*(10). A very good agreement was found between different dosimeters calibrated in the same units; the reading ratios were close to 1 and the correlation coefficients (Pearson’s or Spearman’s) were higher than 0.99. The Н*(10)/D ratio values were location-specific ranging from 1.23 Sv/Gy for undisturbed grasslands and forests to 1.47 Sv/Gy for wooden houses and asphalted streets. A statistically significant negative correlation (Spearman’s coefficient = -0.833; P<0.01; n=9) was found between the Н*(10)/D ratio and the average energy of gamma-rays determined with a NaI(Tl)-based gamma-ray monitor. For the whole area of a settlement and its surroundings, the average ratio of Н*(10) to D was calculated as 1.33 Sv/Gy. The overall conversion coefficient from ambient dose equivalent rate, Н*(10), to external effective dose rate, Ė, for adults was estimated by a value of 0.52 Sv/Sv. This value is valid for the remote period after the severe radiation accident that had resulted in large-scale contamination of the environment by radioactive cesium. The findings of this study are discussed in comparison with results obtained by other researches shortly after the Chernobyl and Fukushima accidents.

By this time in the Russian Federation there is collected a huge file of data describing the influence of all natural sources of ionizing radiation on population in municipal conditions. These data are collected and generalized in radiation hygiene passports of the Russian Federation for the last 16 years and in the reporting forms of federal statistical supervision No 4-DOZ “Data on doses of population irradiation due to the natural and manchanged radiation background” for a period of 14 years. These data are received by direct measurements of gamma radiation dose rate in the premises and in the open air on the territory of settlements. Measurements were made with the most different dosimeters; their technical and metrological parameters differ considerably. In this regard of certain interest is evaluation of this data reliability degree; that will help to find out the reasons of higher levels of the Russian Federation population external irradiation in comparison with average global dose values.

In this article an attempt was made to evaluate reliability degree of data on the population external irradiation doses using the radiation hygiene passports of territories and reporting forms No 4-DOZ for the whole period of supervision. For this there was used the known dependence between the gamma radiation dose rate and natural radionuclides effective specific activity (AEFF) in inhabitancy objects. For this purpose there were used the data on average AEFF values of building raw materials and of local manufacture materials, which are presented in radiation hygiene passports of territories. Definition of design value of gamma radiation dose rate in the buildings and in the open air according to AEFF measurement data in building raw materials and in local manufacture materials actually enables to get an independent evaluation of the population external irradiation doses. Comparison of two evaluations of the population external irradiation levels enabled to reveal certain territories on which the population external irradiation doses are obviously overestimated or underestimated. It is proved that the specified population external irradiation dose values for certain entities and for the whole country are much closer to corresponding evaluations by foreign experts and to the average global levels.

The article presents results of the study made in 2014 on evaluation of the content of Cs-137 in different homemade dried and pickled mushrooms picked by residents of most contaminated areas of the Bryansk region. The aim of the study was to evaluate actual content levels of Cs-137 in homemade preserves of dried and pickled mushrooms picked in the Bryansk region areas with high level of radioactive contamination after Chernobyl accident. Sampling was conducted in residential settlements in proximity to most visited forest areas located at different distances to residential settlements in the range from 0.3 to 5 kilometers, with different forest types, with different soil surface contamination density by Cs-137 in the range from 33 to 944 kBq/m2 (Tentative levels of surface contamination of forest soil are evaluated based on the results of gammaspectrometry measurements in soil samples). The sampling was done at voluntary consent of local residents. In the frameworks of the research in ten settlements with 6112 residents altogether 25 samples were selected (8 samples of dried and 17 of pickled mushrooms).

The analyses of study results resulted in the following conclusions: specific activity in samples of different kinds of dry and pickled mushrooms picked by residents of south-west areas of the Bryansk region vary in broad range from 32 to 34000 Bq/kg. The most part of homemade preserves of dried and pickled mushrooms of the local residents exceeds normative levels of permissible mushroom contamination. Cs-137 content in pickled mushrooms is not explicitly dependent on the level of soil surface contamination whereas specific activity of dry mushrooms increases along with the level of surface contamination increase. In the process of mushroom pickling, the additional reduction of Cs-137 content is observed: from 17% to 67% which averages to 37%. Due to the gradual reduction of transfer coefficients for Cs-137 into forest mushrooms and significant contribution of mushroom consumption into internal radiation dose as well as due to a wide scatter of transfer coefficients of the radionuclide into different kinds of mushrooms, the robust forecasting of the expected levels of population exposure requires further study of dynamics of time-dependent changes of the transfer coefficient.

The article reviews the results of long-term sanitary-epidemiological examination of projects of placing of ionizing radiation (generating) sources in health care institutions of Saint-Petersburg. The majority among the placed sources presented for examination was X-ray diagnostic units and sets – 35.7%, dentist X-rays – 39.4% and fluorography units – 10.8%. Mammography units and computer tomographs made 6.7% each, accelerants – 0.7%.

The most frequent reasons of primary refusals to accept design documentation were: absence of calculations of protection against all placed diagnostic X-ray devices (23.6% – at placing of diagnostic X-ray sets, 16.2% – at placing of dentist devices), absence of the upper floors layouts (26.5% – at placing of dentist X-rays) and absence of permitting documentation for X-ray devices (at placing of dentist X-ray devices – 22.2%).

At carrying out of design activity of special importance is creation of medical and technical projects which were absent in 22.9% of presented projects and in 34.6% were replaced with technical projects. Significant drawbacks of the projects were ignoring the necessity to consider the distance from the personnel workplaces and the width of technical passes (34.0%). That was caused by the absence of corresponding documentation from suppliers of equipment for X-ray rooms.

At calculation of protection against X-ray radiation in 11.3% of projects of placing X-ray diagnostic devices (sets) and in 7.7% of projects of placing dentist X-ray devices, radiation directivity factors (N) were determined incorrectly.

Of importance is the issue of adequate choice of building and finishing materials. In 50.0% of projects of placing of diagnostic X-ray devices (sets) and 37.6% of projects of placing dentist X-ray devices there were no sanitary-epidemiological conclusions regarding the building and finishing materials to confirming their feasibility for healthcare institutions.

Analysis of the main stages of preparation of design documentation and the sanitary-epidemiological examination carried out upon the application to the Center of hygiene and epidemiology in Saint-Petersburg between the years 2011-2014 presented the main drawbacks of design activity, systematized design errors and suggested tools of expert work optimization.

This article presents the assessment of some natural sources of ionizing radiation in theNovgorodregion. Among natural environment factors affecting human health in the region from radiological standpoint radon and it’s progeny are most hazardous. This is due to a very high contamination by uranium (radium) of some geological formations located at the depth from several meters to several dozen meters from the earth level. Massive exploration of uranium in the region conducted on more than 30-40 blocs identified the two potentially radon-hazardous areas totaling about 25500 square kilometers: Starorusskaya and BorovitchskoLiubytinskaya. These territories contain most of the identified radioactive anomalies in the rocks, underground and ground waters. Such anomalies are typically observed at depths not exceeding 100 m.

On the basis of the anomalies’, the study zoning of theNovgorodregion was conducted in accordance with the severity of potential radon hazard. Local radon-hazardous spots were pinpointed as well as their impact upon the population health. The enrichment of the rocks creates the premises for radon emission into soil air, then into the atmosphere and into dwellings. People continuously living in a house with high radon content in the air are subject to the risk of lung or upper respiratory airway cancer.

The objective is to substantiate the urgency of prolongation of Radon Program.

Radon, the main radiological hazard for theNovgorodregion. The study of its’ effect upon local potentially hazardous spots. Territorial radon hazard-specific zoning, determination of causality in relation to the lungand upper respiratory airway cancer.

We considered conditions of patients’ medical radiation exposure in Russian diagnostic radiology and nuclear medicine basing on the data of our own research, of the Unified system of individual dose control and of some relevant literature. We analyzed the data on the number of diagnostic examinations, patients’ individual and collective doses and their distribution by examination types. Time trends of the studied parameters are presented for the period between 1999 and 2013. Current level of Russian patients’ medical exposure is the lowest over the whole observation period and one of the lowest among the developed countries. The annual number of X-ray diagnostic examinations is 1.8 per capita. In 2013 median effective dose of medical exposure per capita in Russia was 0.45 mSv and median dose per procedure was 0.25 mSv. The major contribution to collective dose of medical exposure was from computed tomography and radiography; the largest individual doses were caused by interventional radiology, computed X-Ray and nuclear medicine tomographic examinations. The range of median doses comprises about four orders of magnitude, i.e. from several microSv in dental X-ray examinations up to several tens of milliSv in interventional and multistage tomographic examinations. The median effective dose of adult patients increases by about an order of magnitude with each transition from dental X-ray examinations to conventional radiology and further to computed tomography and interventional radiology examinations. During interventional X-Ray examinations, absorbed skin doses at radiation beam entrance site may reach several Gray, which may lead to deterministic radiation effects in skin and subcutaneous tissues. Due to replacement of low-dose ‘functional’ nuclear medicine examinations with more informative modern scintigraphy and tomography examination, patient doses substantially increased over the last decade. With current trend for re-equipment of Russian diagnostic facilities with modern sophisticated equipment one may expect a substantial increase of diagnostic X-ray services, especially of computed tomography, and the associated increase of medical exposure in the coming years. In order to prevent increased medical radiation exposure of patients, which took place in some leading countries, it is necessary to pay attention to patient radiation protection, including justification of examinations and protection optimization. The priority issue is the patient protection at examinations with the increased radiation doses: interventional, computed tomography and radionuclide tomography, especially when combined with X-ray.

Modification of attitude to labor in the society, in professional communities and among people is necessary for further development of society and national economy. This goal may be achieved if the system of professional training is modified: switched to competence approach which should include training of experts, including those in radiation hygiene, with a set of general cultural and professional competences. The system of future experts training should be based on traditions of domestic and international education; it should use modern forms of active and interactive education (computer simulations, business games and role-playing, analysis of concrete situations, portfolio, psychological and other trainings, remote education, etc.) It should consider actuality of knowledge and skills and develop independence and responsibility that will enable the young expert to be competitive at the modern labor market and to meet employers’ expectations. Under the new federal educational standard on radiation hygiene accepted in 2014 at present primary specialization in radiation hygiene takes place in internship. At training of experts the new standard provides great use of on-the-job training, independent work, scientific and practical work. Employers should play an important role in training of experts.

The article presents the outcomes of the generalized analysis of personnel, patients and population radiation doses information obtained from the Unified System of Individual Dose Control (USIDC) for 2014. The analysis is conducted on the basis of the annual information from the forms of Federal State Statistical Observation No.1-DOZ, No.2-DOZ, No.3-DOZ and No.4-DOZ. The information is submitted by the organizations and territories accountable to Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being – ROSPOTREBNADZOR.

According to No. 1-DOZ data the total number of organizations which submitted the information about personnel dose exposure in 2014 amounted to 16424, with the total headcount of 130688 employees. The average radiation dose of group A personnel was 1,13 mSv/annum. The collective personnel radiation doze totalled 132,5 man-Sv/annum.

According to No.3-DOZ data 261 mln X-ray diagnostics were conducted in Russian Federation in 2014. The average medical radiation dose per capita was 0,46 mSv/annum and collective population dose was 66883.4 man-Sv/annum. Computer tomography makes the highest contribution into collective population radiation dose (40,3% ).

According to the forms of statistical reporting No. 4-DOZ for 2014 in Russian Federation the population’s average effective dose from natural ionizing radiation sources amounted to 3.48 mSv/annum. The population’s annual effective radiation dose from natural sources of ionizing radiation includes about 59% of radon isotopes and progeny. In 2014 the data was submitted about job-specific doses of 5651 employees from 50 enterprises located in 18 regions of Russia. The values of job-specific radiation of these enterprises’ employees ranged between 0.01 and 3,42 mSv/annum.

The article includes the Annexes with final generalized forms of Unified System of Individual Dose Control based on the forms of statistical observations No. 1-, 2- and 4-DOZ.