The first 5–7 years of the period under review in the history of the Natural Sources Dosimetry Laboratory happened to be in very hard period, which had a time the entire country. A severe funding reduction of the Institute in the 90-s created a threat of loss of the most active and highly professional middle-aged specialists. In these conditions, the only and the most efficient way to maintain Institute as a scientific establishment was to organize the Federal Radiological Center under the guidance of Dr. A.N. Barkovskiy. The Federal Radiological Center consisted of the all physical laboratories, including the Natural Sources Dosimetry Laboratory, without government funding. Nevertheless, as it is shown below, this period was the most fruitful for theoretical and experimental researches, and for development of legal documents and instructional guidance documents. Over these years, more than 10 sanitary regulations and hygienic standards, and more than 20 guidance documents were developed and implemented. Doses of the population due to the natural exposure data-collecting system on the base of federal statistical observation №4-DOZ form were designed. At this period, the first Federal Target Program «Radon» and the System of radiation and hygienic passportization of organizations and territories were developed and authorized. Dr. E.M. Krisiuk was fully engaged in these activities. In these years a great number of non-nuclear companies were examined. Large-scale studies of levels of exposure of the population on specific territories were conducted. The paper examines a summary of the main results, which were obtained in the most important areas of research and practical studies in the period under review.

The article addresses issues of the population radiation protection regulatory framework development for the natural sources of radiation. Calculations for justification of standard for natural radionuclide concentration in the wide range of contemporary building materials - facing products - are formulated. The basic consideration of calculations is that implementation of these products could lead to the additional population exposure from natural sources less than 0,1 mSv/year. On the base of this assumption it is shown that effective specific activity of natural radionuclides in these products must not exceed 740 Bq/kg.

The article contains the analysis of the results of radiation survey at more than 100 non-uranium mining enterprises fulfilled by the Institute over the last 20 years. The article considers radiation situation formation appropriateness, demonstrates the evaluation of effective exposure doses of mining enterprises personnel from natural irradiation sources in working conditions, the dose structure is given.

The article discusses the current state of normative ensuring of radiation safety of package drinking water. The article analyses radiation-hygienic requirements for packaged drinking water in the regulatory documents of the Customs Union and the Eurasian Economic Union. It is shown that the methodology for regulation of radiation safety of drinking water in the RSS-99/2009 and the “Guidelines for Drinking-water Quality” of the World Health Organization are practically identical. However, the direct application of the similar approach to the regulation of radiation safety indicators of packaged water is associated with significant difficulties, which in some degree are related to the lack of established classification of packaged drinking water. We propose to divide natural mineral medical water which is not intended for free sale as a separate category. For this category, regulations on the content of the radionuclides is not established. The article presents a justification of approaches to regulation of radiation safety of natural mineral drinking water and packaged blended drinking water. In the light of the unique flavor and medicinal properties of most of these waters, we considered various options for the radiation safety of the population, including through recommendations on limitation of the consumption of water. It is shown that for other types of packaged water, including drinking water for baby food, there is a perfectly acceptable application of the requirements on radiation safety, which are set for water.

In the Sanitary Rules SR 2.6.1.1292-03 and SR 2.6.6.1169-02 classification of the industrial waste containing naturally occurring radioactive materials is adopted in accordance to the values of their effective specific activity Aeff. In a case of the disturbed equilibrium in 238U and 232Th series it is necessary to take into consideration actual contribution of the separate natural radionuclides of the mentioned series into the value of gamma dose rate of the waste. This will permit to avoid unjustified overestimating or understating of the waste category which prevents as unjustified expenditures on their treating so undertaking of the necessary measures providing radiation safety.

The ceramic industry widely uses zirconium materials with an increased amount of natural radionuclides. The external irradiation gives a major contribution to the dose of exposure of workers in this branch of industry. The contribution of dust radiation factor at various stages of the production technology is mainly given by a dispersiveness of used materials. The contribution of radon isotopes to the exposure of workers is about 0.1 mSv/year. When traditional zirconium raw materials are used, the doze of natural exposure of workers in the modern industry usually does not exceed 1 mSv/year. The necessity of the industrial radiation control is caused by a wide range of natural radionuclides content in zirconium materials, the peculiarities in the production technology etc.

An analysis is presented of the joint activities of the Institute and State Sanitary and Epidemiological Supervision bodies aimed on the city citizens' dose from natural exposure decreasing in the term of the last decade. Estimation of the dynamics of Saint-Petersburg citizens' dose from natural exposure sources for the mentioned period is obtained basing on the generalization of the data from radiation-hygienic passports and forms of Federal statistic supervision № 4-DOS. Positive dynamics of the decreasing of city citizens dose from natural exposure sources is demonstrated, which could be considered as unbiased criteria of the efficiency of Sanitary and Epidemiological Supervision bodies activities aimed on population radiation protection providing.

An analysis is presented of the joint activities of the Institute and State Sanitary and Epidemiological Supervision bodies aimed on the city citizens' dose from natural exposure decreasing in the term of the last decade. Estimation of the dynamics of Saint-Petersburg citizens' dose from natural exposure sources for the mentioned period is obtained basing on the generalization of the data from radiation-hygienic passports and forms of Federal statistic supervision № 4-DOS. Positive dynamics of the decreasing of city citizens dose from natural exposure sources is demonstrated, which could be considered as unbiased criteria of the efficiency of Sanitary and Epidemiological Supervision bodies activities aimed on population radiation protection providing.

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 2015. The analysis is conducted on the basis of the annual information from the forms of Federal State Statistical. Observation No.1-DOZ (personnel individual doses), No.2-DOZ (emergency doses), No.3-DOZ (patients’ exposure doses) and No.4-DOZ (population exposure doses from natural and technogenically impacted background). The information is submitted by the organizations and territories accountable to the Rospotrebnadzor. The article presents a comparison with data obtained within the framework of Radiation-Hygiene passportization. In 2015, 16769 organizations providing management with artificial radiation sources submitted the form No.1-DOZ.The form No.1-DOZ contains data on 134 812 personnel individual doses, 123 404 of the personnel group A and 11 408 the personnel group B with personnel monitoring.Iin 2015,the average individual dose for the personnel group A was 1,14 mSv, the personnel group B – 0,79 mSv. In 2015, 11 720 healthcare organizations submitted the form No.3-DOZ. According to the No.3-DOZ data, more than 272 mln X-ray diagnostics were conducted in theRussian Federation in 2015. An average medical radiation dose per capita was 0,48 mSv/year and a mean medical radiation dose per an X-ray examination was 0,26 mSv. In 2015, the form No.4-DOZ contains results of 8 681 measurements of gamma dose rate in wooden houses, 12 642 measurements in one-storey stone houses, 160 174 measurements in multi-storey stone houses and 217 746 measurements on the open ground. Results of 4 441 measurements of radon concentration levels in wooden houses, 5 565 measurements in one-storey stone houses, 61 541 measurements in multi-storey stone houses are given. The population’s average effective dose from natural ionizing radiation sources amounted to 3.44 mSv/year, the average values for the subjects of the Russian Federation fall in the range from 1,6 mSv/year (Sakhalin Oblast) to 11,4 mSv/year (Jewish Autonomous Oblast). The article includes the Annexes with the final generalized forms of the Unified System of Individual Dose Control in 2015 based on the forms of statistical observations No. 1-, 3- and 4-DOZ

The article contains the analysis of the results of radiation survey at more than 100 non-uranium mining enterprises fulfilled by the Institute over the last 20 years. The article considers radiation situation formation appropriateness, demonstrates the evaluation of effective exposure doses of mining enterprises personnel from natural irradiation sources in working conditions, the dose structure is given.

The results of the radon screening in the premises of the preschool and school institutions in the Leningrad region are analized. The data were obtained from measurements of radon volume activity by the integral method. As objects of control were selected the old buildings built before 2000 and relatively new buildings. It is shown that the territory of the Leningrad region is highly heterogeneous by the potential radon hazardous. The highest levels of radon were identified in the surveyed buildings in Boksitogorsk, Volosovo, Vyborg and Slantsy.

The article addresses issues of regulation of radionuclide content in the drinking water according to adult population. It is shown that setting of direct limits on the base of value of directly measured drinking water for radiation safety indicators - radionuclide specific activity will substantially simplify the control and supervision of the drinking water radiation safety without losses of the quality ofpopulation radiation protection.

The article presents issues of average annual radon concentration estimation in the dwelling air after finishing construction works based on the results of short-term measurements. It is shown that, if certain requirements to the measuring conditions are met, results of measurements and estimation of their uncertainty are enough for these issues.

The article presents regulation of radon concentration in the air of dwellings and public buildings in Russia in the historical aspect. It is shown with a specific reference to Saint-Petersburg that implementation of obligatory radiation survey of new buildings has led to the significant reduction of radon concentration in the dwelling air and, consequently, the levels of population exposure due to natural sources.

At the initial development stage of the Leningrad Research Institute of Radiation Hygiene natural sources dosimetry laboratory the experts focused at establishment of equipment and methodology. The following period of the lab activity was rather related to theoretical and experimental research which finally led to creation of a new in radiation hygiene field of work on standard protection of population irradiation caused by natural sources of ionizing radiation. The article describes the main results of the laboratory research of construction materials natural radioactivity and the subsequent substantiation of specifications on natural radionuclides content in them. There was parallel research of natural radionuclides transfer in the system “fertilizers→soil→plants” and further along the nutrition chain into the human body. In these works there were first obtained the quantitative data on coefficients of natural radionuclides transfer from fertilizers into agricultural plants, data on the natural radionuclides content in phosphate fertilizers of the main manufacturers, and the reference data on the natural radioactivity of arable soils. This research provided substantiation of a standard of natural radionuclides content in phosphate fertilizers. Important results were also received in a large-scale research of natural environment radioactivity and of technological processes of production, processing and use of mineral raw materials. During this research for the first time there were obtained the tool data on irradiation levels and structure of doses of non-uranium industries enterprises’ employees and on natural radionuclides balance parameters in different technologies.For the last two years of the considered period the laboratory was practically not engaged in its primary activity – the efforts of all laboratory and the Institute experts were focused at analysis of Chernobyl NPP accident consequences, research of man-caused environmental contamination and development of protective activities.

This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc.) which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

The paper presents conceptually new requirements to the limitation of population exposure from the natural ionizing irradiation sources in industrial conditions, introduced into Basic Sanitary Rules of Radiation Safety (OSPORB-99/2010). It is shown that, first of all, introduction of these requirements is aimed at the resolution of variety of previously existing serious contradictions in organization of radiation safety control and supervision for the impact of natural ionizing irradiation sources in industry.

The article examines issues of rehabilitation of facilities and territories contaminated by the man-made and natural radionuclides as a result of past activities of enterprises of nuclear and non-nuclear industries. Rehabilitated facilities and territories contaminated with radionuclides as a result of past activities of enterprises must meet criteria based on the analysis of requirements of existing normative legislative documents in the field of radiation protection of the population taking into account the recommendations of international organizations that are justified dose quantities and derivative indicators used in criteria setting. It is shown that the criteria for rehabilitation of facilities and territories contaminated by man-made radionuclides as a result of past activities, should be the same regardless of whether the contamination occurred as a result of planned activities of the enterprise or due to unauthorized activities. For these situations, the criteria for rehabilitation should be based on dose quantities and derived indicators of the residual contamination of the environment after rehabilitation. Only indicators of radiation safety of the environment can be used in almost all cases for justification of the criteria for rehabilitation of facilities and territories contaminated by natural radionuclides. The article shows that such approaches are applicable not only to environmental media contaminated as result of past activities of enterprises of traditional non-nuclear industries but the mining of uranium and thorium ores. From the standpoint of modern classification of industrial waste with a high concentration of natural radionuclides, the characteristics of these wastes according to their potential radiation hazard to people and the environment are identical.

In the present overview we analyze the available data concerning residues from non-nuclear industries which contain naturally occurring radioactive material (NORM). We consider their quantity, radiation properties, placement, utilization, regulatory and management.