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[en] The theory underlying radiation protection was developed from studies of people, laboratory animals, tissues, cells and macromolecules. Data on people were obtained from opportunistic studies of individuals previously exposed to radiation. Rarely has it been possible to conduct prospective studies of people exposed to known quantities of radiation, which sharply restricts the nature of questions that they can address. In contrast, studies using laboratory animals and simpler biological systems can be designed to address specific questions, using controlled exposure conditions. In-vitro research with macromolecules, cells and tissues leads to understanding normal and disease processes in isolated biological components. Studies of the intact animals provide opportunities to study in vivo interactive mechanisms observed in vitro and their role in development of radiation-induced diseases such as cancer. In the future, studies of intact animals should prove increasingly valuable in linking new knowledge at the subanimal level with the more fragmentary information obtained from direct observations on people. This will provide insight into important issues such as (a) effects of low-level radiation exposures, (b) mechanism of cancer induction at high versus low radiation doses, and (c) influence of factors such as nutrition and exposure to chemicals on radiation-induced cancer. This presentation describes strategies for conducting and integrating results of research using macromolecules, cells, tissues, laboratory animals and people to improve our understanding of radiation-induced cancer. It will also emphasize the problems encountered in studies at all levels of biological organization when the disease is observed in low excess incidence long after exposure to the toxicant

[en] A comparison is made between the mutagenic effects of various chemicals (mutagens) and ionizing radiation. The following topics are included in the discussion; differences between the effects of chemicals and irradiation; relationship between mutations and chromosome aberrations; specificity; dose effect relationships; and the mutation spectrum

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[en] Physical efficiency and factors affecting it for persons exposed to irradiation (the radiation dose being in the range up to 0.75 Gy) has been studied. 670 participants of liquidating the consequences of ChNPP accident have been examined. Depending on the radiation doses to which the people have been exposed the liquidators have been subdivided into 4 groups: for the 1st group the radiation doses ranging from 0.25 to 0.75 Gy; for the 2nd group the radiation doses ranging from 0.10 to 0.24 Gy; for the 3rd group the radiation doses ranging from 0.05 to 0.10 Gy; for the 4th group the radiation dose being up to 0.05 Gy. The physical load was ensured with veloergometer. The results have made it possible to estimate one of the basic health criterion for liquidators of consequences of ChNPP accident (i.e. exercise (effort) tolerance). No direct relationship of the exercise magnitude and the radiation dose within the range up to 0.75 Gy and the irradiation time have been observed. The correlation of the exercise magnitude with due account to age has been provided. 15 refs.; 2 tabs

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[en] Short note

[en] A slight rearrangement of the data included in a recent report from the Radiation Effects Research Foundation (RERF) has shown differences between cardiovascular and other non-malignant diseases of A-bomb survivors which probably result from two factors: selection effects of early infection deaths and residual effects of marrow damage. Both effects were dose related but neither was obvious because one reduced the risk of later infection deaths and the other increased the risk. Allowance for these factors is bound to alter present RERF estimates for cancer effects of radiation and the change will probably be in an upward direction, thus bringing these estimates closer to ones based on radiation workers. (author)

[en] Short communication