Radiatsionnaia biologiia, radioecologiia最新文献

Tritium is the least toxic radionuclide. The main contribution into the total tritium content in ecosystems is made by technogenic tritium, which is due to the operation of nuclear fuel cycle enterprises. The tritium content in the ecosystem of the River Yenisei is connected with its background values as well as with tritium entering the water ecosystem as a result of the operation of the Mining and Chemical Combine, MCC Rosatom. Presented here are the investigations of the possible transformation of tritium interacting with certain species of aqueous plants - submerged rnacrophyte Elodea canadensis and an aqueous plant floating on the surface of water reservoirs Lemna minor. Elodea sampling was made in a real water reservoir - the River Yenisei, while lemna was grown in the laboratory conditions. The experiments show that with the chronic exposure of young elodea shoots to tritium, the latter transforms from HTO to OBT. Optimal conditions were also obtained for the maximum transformation of tritium ≈35% from the total content: at 25°C and the light period 6/18 (day/night). In the experiments with duckweed, observed a significant increase in area of fronds in introducing tritium into the system.

The essay contains the author's memories of the events related to the accident at the Chernobyl nuclear power plant and the thoughts about the short and long-term consequences of this disaster for society, human and biota. Awareness of the Chernobyl disaster as a multifaceted great incident which is significant for the whole world came slowly through a series of mistakes and errors. Currently it is essential to give a deeper insight into the lessons of Chernobyl for the sake of the future.

In some cases radioresistant species of plants in radionuclide-contaminated areas have more strong radiation damages than radiosensitive ones. This effect was called "the radioecological paradox". It could be explained by different abilities to accumulate main dose forming radionuclides. It leads to formation of higher doses due to internal irradiation. In the case of the Chernobyl N PP accident it can be conditioned by species specific particularities in consumption of potassium and calcium, and cesium and strontium, correspondingly.

The results of the long term work of the Russian Scientific Centre of Roentgenology and Radiology on me- dical investigation of the participants in the liquidation of the consequences of Chernobyl power plant acci- dent have been summarized. It has been stated that circulatory system and tumor diseases occupy the leading position in the disease rate among the affected liquidators. The important role of cytogenetic investigation was pointed out. It allows us not only to determine the efficient impact on the human body but also to evaluate the effective dose of radiation, the information about which allows us to predict the development of distant post-irradiation pathology. The results of cytogenetic investigations testify to the interrelation between the level of chromosomal abnormalities and cardiovascular diseases and confirm the clinical data on the non- neoplastic.pathology among the liquidators of the accident.

Noted Russian publicist, science historian and specialist in radioecology Zhores Aleksandrovich Medvedev shares its recollections on the residence in the zone of the Chernobyl accident, tells about the projects of co- vers over the destroyed reactor and discusses the prospects of atomic energy in Russia.

The review of our own and literature data on ecosystems decontamination problems after the Chernobyl ac- cident is presented. It has been shown that protective measures are effective in places with the highest radio- capacity of ecosystems, especially those which may enhance the value of factors of ecosystefi radiocapacity. The analysis of a number of possible effects of impact of pollutants on the biosphere and the consequences of the implementation of protective measures (countermeasures) is given. The system of rehabilitation of con- taminated territories and, above all, soils, is proposed. The history of accidents at nuclear plants knows many planned and implemented countermeasures (CM), which can be used with different efficiency to eliminate the consequences of accidents. A variety of CM was implemented during the Chernobyl accident and elimination of its consequences. The main objectives that underlie the choice of CM is desactivation of ecosystems, reduction of individual doses for workers and residents, reducing the collective doses to the population defined by their special reduction factor. The effect of the CM on the condition of ecosystems has virtually never been evaluated. A number of the implemented countermeasures, the mechanical removal of the top lay- er of soil contaminated with radionuclides (bulldozers, scrapers, graders) led to the complete destruction of ecosystems, which are then required to be consolidated, in particular, by creating forests. It seems important and necessary to carry out the analysis and classification of the main CM based on the theory and radioca- pacity.models in order to assess how the parameters affect the countermeasures of ecosystem radiocapacity and to identify optimal solutions for their application.

In the first part of the article the results of studies performed in the 1970-1980s on the progeny of irradiated animals (drosophila, mouse, rat) are presented. It was found that except severe disorders in this progeny named non target genetic radiation effects were observed (genome instability, increased cancer risk, impaired fitness) which were similar to the late somatic radiation effects. The hypothesis on the likeness of pathogenic nature of somatic and genetic effects of ionizing radiation was proposed. Comparison of effects of parental irradiation in humans and animals gave reason to propose that the frequency of severe disorders observed in the progeny (stillbirth, birth defects etc.) depends on the reproductive potential of a species. In the second part of the article the reminiscences on the author's work in Chernobyl in 1987 are presented. The last part is devoted to description of the main results, obtained in the post Chernobyl period in the frames of various national and international projects.

Dynamics of radiation situation in settlements, agriculture and forestry on the Russian Federation areas af- fected by the Chernobyl accident is presented. A set of challenging problems on public radiation protection and rehabilitation of territories was determined. The main objective at a long-term period after the accident is a stage-wise return of the affected areas to normal activity without any radiological criteria restrictions. For practical realization of this process it is necessary to change the national statutes and regulations consid- ering the contemporary international approaches, to pass to the current exposure situation and to establish reference levels, to define criteria of transition of the areas affected after the Chernobyl accident to normal activity. The change of conceptual approaches will allow one to revise the boundaries of settlement zoning and to develop the regulatory framework on procedures of changing their status from radioactively contami- nated zone to normal activity zone; to develop the regulatory framework on the procedures of transition of agricultural and forest lands classified as radioactively contaminated zones to territories where the traditional husbandry is possible. The Russian Federation has positive experience of transition of areas contaminated as a result of the Chernobyl accident to normal activity.

The basic radiobiology problems are considered on the example of the Chernobyl accident. It is noteworthy that a paradoxical disparity is presently observed between the actuality of radiobiology problems in a post- Chernobyl period and low "doses" of efforts from the side,of radiobiologists for their decision. We justify the position that at the present stage of development of a post-emergency situation the existent experimental facts and theoretical notions of radiobiology are.fully sufficient for explanation of the radiobiology and radioecol- ogy phenomena. Special attention is paid to the problem of "low doses" of ionizing radiation. The existence of "hot" particles of a biological origin is experimentally proved. Special attention is also paid to the integral reactions of the biological systems to irradiation on the example of gigantisms of pine-needle of trees in the zone. affected by the Chernobyl disaster. The degrees of actuality of radio ecological problems are given on the basis of rating estimation. The role of radio phobia in the psychosomatic diseases,of population in the area of strict radiation control is considered.

April 26, 1986 a tragedy occurred: a reactor exploded at Chernobyl. A lot is written about this tragedy. Pre- sented here are different estimates of this event, including opportunistic and absolutely non-qualified. The article describes the situation during the first 35 days after the accident, in other words, what the author saw with his own eyes. The author himself was involved in the treatment of irradiated patients at hospital No 6 and took part in the liquidation of the accident at the site of the Chernobyl reactor disaster zone, within a 30-km. zone.