Search

Health effects as a result of the accident at the Chernobyl nuclear power plant occurred in 1986 are considered in the paper. Wrong prognosis of the health effects with respect to mortality and morbidity among the population exposed to low radiation doses is shown. Proven increase in thyroid cancer cases among people who were children aged from 0 to 18 at the time of the accident is shown. Linear relationship between thyroid cancer cases and dose to thyroid ranged from 0.2 to 4.0 Gy is considered. An additional absolute risk of thyroid cancer in children varies in the range 1.9-2.6 cases per 10(4) person-year Gy. During the fifteen years following the accident no cases of acute and chronic radiation sickness have been revealed because the population living in contaminated areas received low radiation doses. Also, exposures to low radiation doses did not result in excess of malignant tumors among population. In some cases the outcomes of acute radiation sickness were as follows: radiation damages to the skin, cancer cataracts, development of oncopathology.

The formation of aerosols over the radioactive polluted areas results from some natural and industrial factors. In this paper physico-chemical characteristics of secondary aerosols generated by the Chernobyl accident are presented. The results of monitoring of the aerosol from traffic, dust storms and forest fires in 30-km zone of the Chernobyl nuclear power plant and other regions are compared. Some methodical aspects of the sampling and analyses of aerosols are considered. The recommendations for choice of the personal respirators are given.

The paper presents the results of 14-year (1987-2000) random cytogenetic monitoring of the Ukraine's population exposed to radiation due to the Chernobyl Atomic Power Plant accident. Conventional, G-banding, and molecular (FISH-WCP) cytogenetic methods were used to examine groups of victims exposed to radiation of varying intensity (reconvalescents diagnosed as having acute radiation disease, liquidators, Chernobyl power plant staff, and persons who had lived in the radionuclide-polluted areas, etc.). The examinees from all groups were found to have a considerable increase in the incidence of chromosomal aberrations in the peripheral lymphocytes as compared to their spontaneous levels. There was an interindividual variability in the chromosomal aberrations under identical radiation conditions. It was ascertained that even small human doses of long-term ionizing radiation could induce specific chromosomal aberrations. The findings show that conventional cytogenetic monitoring, and particularly by applying FISH and WCP methods, is an good procedure for assessing the human cell genetic apparatuses after radiation.

The paper presents the results of implementation of the first stage of WHO programme concerning consequences of the Chernobyl accident in terms of influence of radiation on mental health of children whose mothers were exposed to radiation. 4210 children born in the period from April 26, 1986 to February 1, 1987 in Byelorussia, Ukraine, Russia in contaminated and non-polluted (control) regions. In radiation-contaminated regions there was higher frequency of mental retardation and other mental disorders as well as deterioration of both mental and physic health of their parents. A preliminary character of the data obtained is emphasized as well as the necessity of more detailed follow-up of these groups.

Many years' experience with complex supervision of the environmental radiation situation, the specific features of the population's physiological and health status after radiation accidents (the Chernobyl, Kyshtym and other accidents). The paper emphasized the necessity of having a knowledge of the specific features of the influence of a radiation factor (and its components) on establishing the radiation dose for the population due to the environmental peculiarities of the radiation background in different regions and abnormal zones of the Earth. The paper provides evidence for the need to apply an environmental and physiological approach to working out the standards of radiation doses for the inhabitants of post-accident polluted areas. To this end, a concept of the regional standard of exposure is proposed for different regions of the Earth with regard to the specific natural radiation background, technogenic and medical "additives" on making diagnostic and therapeutical efforts by using X-rays and radiation therapy. A new concept is offered to develop the life-support systems in the areas exposed to radiation contamination, whose main goal is to minimize radiation exposures with regard of data on each area-specific data on the regional standard of the pre-accident radiation background, technogenic background, medical additives and prediction of future radiation doses. Exposure of the population to radiation is minimized by reasonably operating its components and making special life regimens in the contaminated areas.

The role of external beta-radiation as one of the major radiation factors effected persons involved in recovery operations (liquidators) after the accident at the Chernobyl nuclear power plant is considered. The paper uses the data of discriminate individual dosimetric monitoring of beta- and gamma-radiation for different groups of liquidators and experimentally received dose distribution in tissue equivalent material in the places of carrying out work. The results obtained by calculation were also used. It was established that experimentally determined ratios of beta-radiation doses to gamma-radiation doses have a good correlation with estimates resulted by calculation. It allowed the authors to use these estimates and individual gamma-radiation dose distribution for drawing histograms of individual beta-radiation dose distribution for open parts of skin, for lens, and gonads in cases of liquidators involved in building "sarcophagus". The obtained estimates of individual doses in the near surface tissue and organs exceeds significantly exposure levels for the whole body. This fact should draw the special attention to the rise in the number of radiation-induced cancer and cataracts.

The paper presents the general results from the 10-year (1986-1996) studies on radioecology and radiobiology conducted in the region affected by radiation after the accident at the Chernobyl NPP. The regularities of radionuclide migration along the trophic chains, as well as effect of ionising radiation on biota in its habitat are described. The protective measures are reported aimed at mitigating consequences of the accident for the environment. The paper also presents the main findings of studies on agricultural radioecology with taking into account the importance of radionuclide turnover in agrosphere and implementation of countermeasures in the agro-industrial production.

The paper discusses the approaches and scientific and organizational principles used in the development of some International research projects in the study of consequences of the Chernobyl accident, which are under way by Russia's Ministry of Science and Engineering Policy. Special attention is given to sociomedical aspects and the possibilities of defining an individual medical policy while working with the liquidators and the members of their families.

The paper presents morphological, morphometric and densitometric evidence obtained on cytoplasmic inclusions of alveolar macrophages from bronchoalveolar lavage of chronic obstructive bronchitis (COB) sufferers. All of them previously worked in the zone contaminated after the Chernobyl accident. The control consisted of nonexposed to radiation COB patients. In the exposed subjects alveolar macrophages were more active, 20% of cytoplasm was occupied by numerous phagolysosomes varying in form. Their densitometric evaluation has been performed. Further bronchoalveolar lavages will be conducted to follow up the above changes in alveolar macrophages.

The paper describes processing of peripheral blood screening based on methods of mathematical statistics and partially ordered sets theory. This allows global assay of individual and populational blood, assessment of borderline conditions by introduction of global criterion. The above methodology was tried to analyze data obtained at screening of peripheral blood from children living in radionuclide-contaminated regions. The most considerable contribution to region-specific populational differences belongs to red cells, monocytes, band neutrophils, eosinophils. Hemogram deterioration in children and adolescents seems to result rather from chemical pollution and social factors than radiation effect (in doses not high than 2.2 rem a year).

The paper reports on the preliminary experience of treatment of those patients having been the victims to the reactor accident at the Chernobyl NPP as well as of those with acute and chronic leukoses, having received courses of modern cytostatic therapy. The patients were exposed to therapeutic plasmapheresis and enterosorption as part of a complex conventional treatment programme. The conclusion the authors have come to is as follows: enterosorption strikingly reduces manifestations of "cytostatic disease"; the use of plasmapheresis in those persons having been previously exposed to small dose chronic radiation, makes for improvement of clinical and laboratory values but further studies are warranted to determine indications for therapeutic plasmapheresis.