The article contains substantiation of criteria of return of territories with radioactive pollution caused by Chernobyl NPP accident to conditions of normal population activity. It is established that in 12 entities of the Russian Federation (except Bryansk and Kaluga regions) all agricultural food produce, including that from the personal part-time farms, corresponds to hygienic specifications. Non- corresponding to the standard SanPiN 2.3.2.1078-01 on 137Cs are part of the milk samples produced at personal part-time farms of the Bryansk region and most of natural foodstuff samples (berries, mushrooms, fish and wild animals meat) in Bryansk and Kaluga regions. The content of 137Cs both in agricultural and in wild-growing foodstuff produced at radioactively contaminated territories depends not only on the density of radioactive pollution, but also on the types of soil. The average settlement annual effective dose of population irradiation (AAED90) in the 3700 among 4413 settlements as of 2014 was below 0.3 mSv/year. Only in 713 settlements of Bryansk, Kaluga, Oryol and Tula regions the AAED90 exceeds 0.3 mSv/year. In the Bryansk region, once subject to the greatest radioactive contamination, in 276 settlements AAED90 exceeds 1 mSv/year, and in 8 of them - 5 mSv/year.

The legislation of the Russian Federation defines only criteria and requirements for consideration of the suffered territories as zones of radioactive contamination. Requirements on transfer of territories polluted by radiation accidents and their population to normal life activity conditions (regarding the radiological factor) are not developed.

Radiological criteria are suggested for transfer of the settlements considered to be the zone of radioactive pollution to conditions of normal life activity: average irradiation dose of critical population group: 1.0 mSv per year and lower (AAED crit); decrease of radionuclide soil contamination density to the level enabling to use the territory for traditional agricultural production meeting sanitary requirements without special measures for decrease of the 137Cs or other radionuclides content.

The article presents major results of the work performed by St. Petersburg Research Institute of Radiation Hygiene after Professor P. V. Ramzaev on public contracts signed within the implementation of the Federal targeted program “ Mitigation of the radiation accidents’ consequences for the period until 2015” ( Direction IV “ Streamlining of monitoring systems and their elements and situation forecasting on radioactively contaminated territories paragraph 14 “The analyses and comprehensive evaluation of radiation situation changes on radioactively contaminated territories “ aimed at compilation of radioactively contaminated zones’ settlements list and Direction VI “Awareness raising and social -psychological rehabilitation of radiation- affected residents”, paragraph 20 “Creation of unified informational system on ensuring population’s radiation safety and overcoming radiation accidents’ consequences via development of the federal and regional informational resources’ systems” and “ Joint activities program on mitigation of the Chernobyl disaster within the Union State for the period until 2016” ( Direction II “ Streamlining of unified radiation protection system in radioactively contaminated territories” paragraph 2.1 “ The harmonization of requirements, methods and technologies aimed at mitigation of Russian and Belorussian population’s internal and external exposure, the development of radiation control and monitoring unified system”, sub-paragraph 2.1.1 “The development of unified assessment and forecast system for population exposure doses and rationing of radionuclide – containing foodstuffs, agricultural products and forest preserves based on the international approaches” ) over the period from 2011 to 2015.

The article is dedicated to the inter-regional seminars on ensuring population radiation safety held in 2015. Each one of the eight inter-regional centers of Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being conducts such seminars once in every two years in order to render organizational, methodological and practical assistance on the issues of population radiation protection ( Inter-Regional Centers on Radiation Safety – IRC RS ) In 2015 the inter-regional seminars were conducted by the following inter-regional centers: the Central IRC RS in Moscow on March 18–19, the Southern IRC RS in Simferopol on April 21-23, the Far Eastern IRC RS in Habarovsk on May 26-28, the Siberian IRC RS in Gorno-Altaisk on September 22-24 and the Head Scientific-Methodological Center of Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being (HSMC) in St. Petersburg on October 7-8.

The seminar elucidated upon current issues of ensuring population radiation protection. The presentations were made by the top-notch specialists of St. Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev. They expanded upon limitation of population exposure from natural, medical and technogenic ionizing radiation sources, implementation of new regulatory-methodological documents devised by the Federal Service for Surveillance on Consumer Rights Protection and Human Well-Being. They also dwelled upon state-of the-art instruments and methods of conducting radiation monitoring. Practical matters were discussed in relation to establishment of sanitary-epidemiological supervision over population radiation protection.

The article highlights the issues discussed at those seminars, major challenges underscored by the participants as the result of the discussions. It provides the general evaluation and conclusions based on the seminars’ outcomes. The smooth organization of those seminars was highly appreciated. It was indicated that such seminars should carry through into the future to be held in different subject of the Russian Federation. The necessity of targeted financing of the inter-regional centers was identified with the aim of conducting sophisticated radiation monitoring in the corresponding Russian Federation Subjects. A mention was given to the importance of enhancing inter-regional centers preparedness for population radiation protection during radiation accidents.

The study aimed at radiation contamination impact assessment due to the 1986 Chernobyl accident in Voronezh Region territory more than 600 kilometers away from the ground zero. The major Chernobyl accident impact assessment indicators were the characteristics of 137Cs and 90Sr radionuclides’ soil surface contamination (Ci/km2) as well as the average annual effective dose of critical population group ( mSv/year) over 1986–2014. The Population oncological morbidity indicators were analyzed (all malignant neoplasms, including those in thyroid gland, lymphatic and hematopoietic tissue) in the territories contrastingly differing on the levels of radiation factor impact. The study covered the period of 2010–2014.

It was established that for Voronezh Region territories referred to as the post- Chernobyl radioactively contaminated zone over 29 years period the maximum soil surface contamination by 137Cs and 90Sr radionuclides reduced by 1.90 and 1.91 times (from 3,15 Ci/km2 to 1,66 Ci/km2 and from 0,063 Ci/km2 to 0,0033 Ci/km2, respectively).

Currently the relationship was not found between the radioactive contamination density in Voronezh Region and the levels of malignant neoplasms for the local residents.

The present situation related to radiation factor impact on Voronezh Region territories remains stable and safe. Mindful of the indicators results the assessment of ionizing sources impact did not identify any exceeding the normative values.

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.

The article presents the data and analyses of personnel’s average annual external exposure doses monitoring via the thermoluminescent dosimetry method used for X-ray radiological personnel in dental polyclinics of Dushanbe, Tadjikistan Republic over a 5-year period ( 2010–2014 ). Out of 42 registered medical institutions dental polyclinics amounted up to only just 14%. For this work thermoluminescent dosimeters were used ( with LiF: Mg, Ti ) with the thermoluminescent dosimetric installation “ Harshaw – 4500” as the reader device. Monitoring results comparison of individual dose equivalent Hp ( 10 ) values was conducted for two groups of medical workers: medical doctors and X-ray lab technicians. It is demonstrated that radiological technicians’ professional exposure doses are on the average by 23% higher than those for medical doctors.

The average individual exposure doses over the above indicated period amount to 0,93 mSv and 1,3 mSv for doctors and X-ray lab technicians, respectively, and are in the range from 0,45 mSv to 2,39 mSv. The doses include contribution from the natural background. The values of doses recorded for the personnel in dental polyclinic correspond to those recorded for the workers in the routine X-ray rooms.