[The multiabberant cells in groups of people exposed to radiation due to different situations and their possible biological part].

The results of the analysis of multiaberrant cells (MAC) obtained in the course of long-term investigation of cytogenetic effects in human peripheral blood lymphocytes are presented. MAC were discovered in different groups of the population exposed to the radiation factor. No such cells were found in the control groups. The greatest number of MAC "carriers" was registered among employees of radiochemical plants who had contacts with plutonium salts. The highest frequency of MAC (2.49 +/- 0.59 per 1000 cells) was also revealed in the same group. It exceeded by an order of magnitude the analogous values in other examined groups. In the groups of radiochemical workers, cosmonauts, and miners from Tselinograd the frequency of dicentrics and centric rings was also the highest as compared to that in other groups. The character of chromosome aberrations observed in MAC suggests that they are formed under the action of the radiation factor, and their frequency among different groups of people exposed to radiation makes it possible to assume that the formation of MAC is a result of the action on lymphocytes of alpha-particles emitted by radionuclides incorporated in the organism. Classical MAC was observed in routine studies (FPG staining) are only an extreme manifestation of cell damage. To elucidate the true picture of chromosome rearrangements induced by radiation and the role of MAC in the tumor process, it is necessary to use methodical potentialities of modern molecular cytogenetics, including the FISH method.

[Cytogenetic examination of nuclear specialists exposed to chronic beta-radiation of tritium].

For the first time the cytogenetic examination of the group of nuclear specialists (79 persons) chronically exposed to tritium beta-radiation for a long period was carried out. The frequencies of unstable (conventional method) and stable (FISH-method) chromosome aberrations have been analyzed. 50 years after the beginning of working under the conditions of the increased radiation level the differences (in comparison with control values) were revealed for all cytogenetic parameters. The frequency of the radiation-specific markers (dicentrics and centric rings) exceeds more than 2-fold the control level. A significant but poor correlation between the frequency of unstable aberrations and the total absorbed dose (during the whole working period) was revealed. A retrospective estimation of irradiation doses for 14 nuclear workers was made by the frequency of stable chromosome aberrations. The obtained dose values ranged from 110 to 1250 mSv.

[The results of cytogenetic survey in liquidators of the Chernobyl nuclear accident]. / Rezul'taty tsitogeneticheskogo obsledovaniia uchastnikov likvidatsii avarii na Chernobyl'skoi AES.

The article represents results of long cytogenetic survey among liquidators of Chernobyl accident. The parameters studied are frequency of unstable chromosomal aberrations and frequency of symmetrical translocations. The authors show that, in spite of long term after irradiation, average frequency of cells with dicentrics and centric fusions (unstable chromosomal aberrations) remains relatively high. Discussion includes possible use of cytogenetic methods in reconstruction of absorbed radiation doses in many years after exposure.

[The dynamics of the content of incorporated cesium radionuclides in the population of regions with an elevated background radiation]. / Dinamika soderzhaniia inkorporirovannykh radionuklidov tseziia u naseleniia raionov s povyshennym radiatsionnym fonom.

The authors represent summarized data on the time course of incorporated Cs in the population of the Krasnogorsk District of Bryansk Province over the period of June 1986-July 1989. A RIKh-5M device used as a counter of human radiations, its technical data and calibration methods were described. A retrospective analysis has shown that the main accumulation of radionuclides occurred before May 15 1986. The highest rates of Cs clearance from the body were noted in the period of August 1986 till February 1987, the average resultant periods of semiclearance for different populated areas and groups of population were 55-85 days. The ratio of accumulated Cs in children and adults was 0.3, in men and women--1.4. The effectiveness of measures aimed at reducing collective doses of internal irradiation was analyzed.