[en] An increase in the natural radiation background, development of nuclear power engineering, severe radiation accidents with the release of radionuclides into the environment, the need for the remediation of areas affected by previous human activity, all make the problem of environmental protection against radiation extremely urgent. The problems of radiation protection of biota can be solved in two ways: (1) through the system of basic principles of ICRP according to which if the radiation standards protect man, biota are also protected against ionising radiation; (2) at the same time, in recent years increasing in popularity, is the viewpoint according to which the analysis of radiation protection of man and biota must be independent. A viewpoint is suggested that radiation protection of man and biota need to be based on a unified system of conceptual representations ensuring the simultaneous radiation safety of man and living organisms as connected components of ecosystems. (author)

[en] A method for calculation is described and the results of estimation in 1989-1995 and prediction for 1996 of ¹³⁷Cs contamination of plant products, structure of internal irradiation doses for population, as well as efficiency of countermeasures aimed at improving fodder lands in six contaminated districts of the Bryansk region after the Chernobyl Nuclear Power Plant accident in 1986. (author)

[en] A quantitative assessment is made of the influence of plant and animal life on the migration and redistribution of naturally occurring radionuclides in several localized areas with unusually high soil concentrations of ²²⁶Ra, ²³⁸U, or ²³²Th. In the taiga and tundra zones examined, the effects of radionuclide accumulation in certain plant species and of the feeding and burrowing habits of small mammals were particularly significant. The observed regularities have predictive applications in assessing the redistribution of radionuclides in regions of high radioactivity

[en] In severe radiation accidents with releases of radionuclides into the environment, high enough radiation doses are formed to potentially cause direct radiation injury of natural ecosystems. The dose fields characterizing the irradiation of plants, animals and humans in radioactive contamination of the environment are highly heterogeneous, and irradiation of natural objects per se has features such as non-equidosal effects. In other words, humans and various objects in the natural environment can receive different absorbed doses for an equal density of radioactive fallout. 5 refs

[en] Experimental data are given on the content of genetically related pairs of radionuclides (²²⁶Ra and ²²²Rn; ²²⁴Ra and ²²⁰Rn) in soils and the above-ground phytomass of plants growing on plots with differing genesis of the higher concentrations of natural radionuclides in soils. Methods for determining gaseous radionuclides in the above-ground phytomass are described. Different transport routes of ²²²Rn and ²²⁰Rn into above-ground plant organs are considered. The noted absence of balance between ²²²Rn and ²²⁶Ra in plants as well as higher ²²²Rn/²²⁶Ra ratios in the above-ground phytomass as compared to that of the root-containing soil layer (25- to 185-fold) appears to be accounted for by the root pathway of ²²²Rn uptake and transport of this radionuclide to above-ground plants organs. The existence of the root pathway for ²²²Rn uptake is proved by direct observations of daily radionuclide movement with bleeding sap in experiments on pumpkins. For the short-lived Rn isotopes, ²²⁰Rn and ²¹⁸Rn, the root pathway of uptake and transport to the above-ground phytomass is less probable, and this causes a notable redistribution of gaseous radionuclides during their movement along the soil-plant route

[en] Regularities and biochemical peculiarities of the migrations of heavy natural radionuclides in the environment are examined, with special reference to two regions in a humid climatic zone representing natural patterns of radionuclide distribution and to four plots artificially contaminated with high levels of natural radioactivity more than 20 years previously. It was determined that the migration of thorium, uranium, and radium isotopes through the rock-water-soil-plant system is dependent on many physiochemical properties of these radionuclides, their compounds, and the local environment. Isotopic activity ratios provide a useful tool for studying the direction of radionuclide migration and its influence on observed distribution patterns

[en] Radioactive contamination of the agricultural production sphere in case of a radiation accident with radionuclide release is one of the most important sources of additional irradiation for population. As a result, realisation of the measures for mitigating the consequences of the accident in agro-industrial complex assumes the leading role in total system of measures providing radiation safety. The possibility to obtain agricultural production meeting the radiological standards is one of the main indications of effectiveness of liquidation of the accident consequences. First, obtaining of agricultural production meeting the radiological standards provides decreasing of the total radiation dose. The evidence is obtained in the 8-year experience of liquidation of the Chernobyl NPP accident that the 70% decrease of the internal dose for population became possible through a complex of protection measures in agriculture (during the first year after the accident, the contribution of internal dose into the total one amounted to 45%, and that of external irradiation - 52%; for the 70-year period these values are 39% and 60%, respectively). Second, the possibility to obtain 'pure' agricultural production is one of the most important factors of psychological stability for population. Third, obtaining of consumable (as to radionuclide content) agricultural production in private small holdings is one of the guarantees of stability of demographic sector in the accident-affected zone. From the point of view of organization of agricultural production in liquidation of the consequences of accidents with radioactive releases into environment, some periods can be distinguished: (i) the first (early) period takes 10-12 days after the accident. The main measures in the field of agricultural production are in operative assessment of the radiological situation, organization of radiation survey, express classification of agricultural products ready to consumption. If radionuclide content in food products and feeds exceeds the DILs, their consumption is prohibited. The prophylactic measures to prevent adverse iodine effects are rendered a special place. If necessary, agricultural animals are relocated; (ii) the second period lasts 2-3 months after the accident. At that time radiological maps of contaminated lands are made, the system of radiation control of agricultural lands and agro-industrial production is perfected, the program of technological processing of contaminated agricultural products is implemented which guarantees obtaining of non-contaminated products; (iii) the third period is completed after the first 1.5 post-accident years. Agroamelioration measures are carried out at that time, the main scope of measures for detailed radiological survey of contaminated lands is realised; gradually the concept of production classification is replaced by the zonal production organization guaranteeing the Derived Intervention Levels established for the given period are not exceeded. The scientifically substantiated program of agricultural production management on contaminated lands for maximum possible obtaining of pure production and rational use of agricultural lands is formed; (iv) the fourth period starts in 1.5-2 years after the accident. In case that the deposited mixture of radioactive substances contains the log-lived radionuclides (⁹⁰Sr, ¹³⁷Cs, ²³⁹Pu, etc.), the program of obtaining production meeting the radiological standards is realised as a constant long-term complex, in parallel with realisation of long-term system of agro-industrial measures, reorientation of agro-industrial production system and processing of contaminated products. (author)

[en] The second half of the 20. century was dominated in the field of radiation protection by the anthropocentric concept stated by the International Commission on Radiological Protection (ICRP). According to this concept 'if radiation standards protect man then biota are also adequately protected from ionizing radiation'. At the end of the 20. beginning of the 21. centuries in the area of radiation protection of nature an eco-centric strategy is beginning to develop where emphasis has swung to the protection of biota in their environment. Inadequacy of ICRP's anthropocentric concept is reported. Issues are discussed such as ecological dosimetry, non-equi-dose irradiation of man and biota, criteria for estimating radiation induced changes in biota and man, as well as the need to harmonize permissible exposure doses to man and biota. An urgent need is stressed to develop a single (synthetic) concept of radiation protection which simultaneously ensures protection of human health and biota well-being in their environment. This concept is to be based on the recognition of the integrity of socio-natural ecosystems where man and biota are considered as a unity. (author)

[en] An increase in the natural radiation background, development of nuclear power engineering, heavy radiation accidents with the release of radionuclides into the environment, need for the remediation of areas affected by previous anthropogenic activity (both military and peaceful) all made the problem of the environmental protection against radiation extremely urgent. The problems of radiation protection of biota can be solved in two ways -through the system of basic principles of the International Commission of Radiological Protection (ICRP) according to which if the radiation standards protect man, biota are also protected against ionizing radiation (Publication 60). The basis for justification of the thesis 'protected is man, protected are biota' is the fact that man is the most radiosensitive living organism. Besides, protection of human health is the highest priority. At the same time, in recent years increasing in popularity is the view point according to which the analysis of radiation protection of man, on the one hand, and biota, on the other hand, must be independent. It should be noted that there may be situations where man is not present or there are no food chains leading to man (eg, at sites of radwastes burial). For these situations independent standards on permissible exposure levels need to be developed. An essential aspect of radiation protection of biota is a nonequidosal irradiation of plants and animals, on the one hand, and man on the other hand in the same radiological situations, with biota receiving in most cases significantly higher absorbed doses. An anthropocentric approach to the environmental protection against ionizing radiation (protected is man, protected are biota), developed by ICRP, requires experimental evidence that biota are really protected (it is insufficient to state this only a priori). The main ICRP principles of radiation protection of man were analyzed. Special features of biota protection against ionizing radiation were described. According to the Declaration on Environment adopted at the conference in Rio de Janeiro in 1992, special attention should be paid to maintain biodiversity in nature and sustainable environmental conditions of growing anthropogenic burdens. At present, in a number of countries, standards on the permissible exposure of biota have been legislatively introduced. Arguments in favour of an independent analysis of radiation protection of the environment versus man were analyzed. A viewpoint was put forward that radiation protection of man and biota need to be based on a unified system of conceptual representations ensuring a simultaneous radiation safety of man and living organisms as connected components of ecosystems. This suggests a rational use of theoretically justificated and tested by the longtime practice basic ICRP approaches providing the radiation protection of humans. It is important that principles of the environmental protection from ionizing radiation should be compatible with principles of the environmental protection against other pollutants. (author)

[en] The experience gained in the aftermath after the heavy radiation accidents shows the need for improvement in site characterisation techniques and methodology in order to provide a link between site characterisation and the selection of restoration strategies. This paper gives an overview of the site characterisation techniques used in restoration of contaminated agricultural lands on the territory of the Russian Federation. The approach used for site characterisation and selection of restoration strategies is described. The main site specific factors influencing the choice of restoration options are identified. Data on the efficiency of major restoration measures used for the remediation of agricultural lands after the Chernobyl Nuclear Power Plant and the Kyshtym accidents are given. A description of the decision support system FORCON, designed to simplify the selection of restoration options, is presented. (author)