The report presents results of multiannual epidemiological, clinical, biochemical, cytogenetic, immunological research devoted to distinctive features identification of somatic pathology forming during the long-term period after radiation accidents.

The results of own scientific research and literature data on immunology violation in the immunity of the population, suffered or being influenced with low ionization irradiation doses in the territories contaminated with radionuclides after radiation accidents and nuclear weapon tests, or with the of natural irradiation sources are presented. The role of the immunity changing in the health violation is marked.
The presence of immunity changing under radiation influence points to unfavorable influence on the organism of the low doses of ionizing irradiation as a single factor or in combination with factors of non-radiation nature. Their absence is one of the indices of the absence in health violation among the population of the arrears with high radiation level.

An article contains analysis of cohort numerical strength, exposure doses and frequency of deterministic and stochastic effects incidence among personnel and population from various ionizing sources and exposure situations. The value of educational system for adequate radiation risk assessment for various population groups is being emphasized.

The present radiological situation in the agricultural production of Ukraine is considered and analyzed. On the basis of optimization of the countermeasures application the approaches are proposed which would guarantee the compliance of the agricultural production with the corresponding State hygienic regulations, as well as reduction of the effective exposure dose to population below the approved limits. Taking into account the lately growing interest to radiation protection of not only human, but the environment as well, the results of the studies of frequency of the radiobiological effects of chronic irradiation to plantations of Scots pine in the Chernobyl exclusion zone depending on the levels of the dose to the trees' apical meristem are presented.

The specification and current status of the dosimetry problems in Ukraine at the late stage of the Chernobyl accident is given. There are: the permanent monitoring of the Chernobyl exposure doses for the inhabitances of the contaminated areas; the improvement of the retrospective dosimetry of whole body exposure at the early stage of the Chernobyl accident; the improvement of the retrospective thyroid dosimetry; dosimetric support of the radioepidemiological studies; the dosimetric maintenance and radiological control of the works for the stabilization and reconstruction of the Object Shelter.

The system for the operative analysis of dosimetric situation after radiation emergencies at nuclear power plants in Ukraine (KADO) is developed for decision making support. Emergency release in KADO is modelled as sequence of the discrete elements which are emitted after small time intervals that allows to take into account in calculations heterogeneity of distribution of pollution in a released cloud. Calculated predicted and avertable doses are the base information for justification of emergency and urgent countermeasures.

Given paper, states the ensuring of the interpretation of the basic radiation protection principles, relative to the works at the Object Shelter (OS). Analysis of the factors of radiation situation at the OS is figured out. Functioning at the present time individual dose monitoring (IDM) system at the OS is describe. The system is based on the methods of biophysical monitoring. A series of the results, obtained during internal exposure individual dose monitoring of the personnel is presented. It is mentioned, that implementation of the internal exposure dose biophysical monitoring system (during the works on transformation of the OS into ecologically safe system) allows:  provide adequate level of the IDM of the internal exposure dose (the level is corresponds to the present day requirements of the radiation protection); develop the recommendations on selection of individual means of protection of respiratory tract; ensure determination of the parameters of radioactive air contamination in the work areas; and, provide the optimal planning of dose load to the personnel.

Experimental investigations of hemoprotection effect of algiclam were carried out on not thoroughbred white rats of different sex (50 females and 50 males of the same age), exposured by sublethal dose. It was obtained that algiclam exert strongly radioprotection effect on the form elements of red blood and thrombocytes.
The results obtained in the experiment allows to estimate in the better extent the influence of the modificators and indicates the real possibility of reducing or even averting of a number of hematological symptoms of emission effect with the help of biologically active food additive named algiclam.

The article contains the results of investigation of human reaction to low doses of ionizing radiation at combination with factors of non-radiation origin: presence of diseases - chronic tonsillitis or effect of toxic chemical substances. Such combinations change body response to radiation, this was revealed during examination of immunologic indicators.
Distinctive features of reaction due to joint effect of radiation and non-radiation origin factors should be considered during radiation hygiene examinations.

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.

Summarized information of the literature about dozes radiation of staff while carrying out angiography researching. Technical and dosimetric characteristics of  angiograph apparatus are represented. Analyzed radiation dozes of staff while carrying out researching of the brain vessels and carotid zones, angiogcardiograhpy, hepatic abdomen, renal and pelvic zones. Make conclusion that main directions of minimizing of dozes are protection  working places, using individual thyroid shields and protective  glasses, limiting number of carrying out researches by increasing number angiograph groups, technical improving apparatus and etc.

Contemporary system of student training in radiation hygiene, created in Russia, is considered in the article. An analysis of its peculiarities and current problems is given, ways of its further development.