The most undesirable and dangerous changes are modifications and mutations induced by radioactive contamination in pathogenic micro organisms, either enhancing or changing their virulence, or suppressing the activities of microorganisms vital for the fertility of soils.
New extensive research on the chronic effects on the organisms of small doses of ionizing radiations (close to the background radiation) has not yet provided sufficient data required for generalizations, so that these will have to be temporarily postponed. Moreover, such generalizations would be beyond the scope of this article.
Together with the misgivings already expressed, it should be mentioned that some scientists / 56-61 / have persistently attempted to use radio isotopes in order to accelerate ripening and increase the yield of agricul tural crops. In view of the stimulated germination observed in seeds soaked in radioisotope solutions, or following introduction of radioisotopes into the soil, certain authors are inclined to implement these techniques.
One suggestion /59/ calls for a mixture of uranium-fission fragments (whose optimum effective doses are fairly high) with the long-lived, for man—most dangerous radioisotopes, and others from wastes of nuclear reactors. Objections to this suggestion were raised by other authors /60, 61/.
It seems to us that agriculture has at its disposal many other means of improving crop yields without the addition of radioisotopes, which might lead to the systematic radioactive contamination of large arable areas, and masses of foodstuff. Such proposals do not seem very logical.
Quite differently, it has been suggested that the seeds be irradiated with X-rays and gamma rays in the laboratory, so that they would be devoid of any traces of radioactivity at the time of seeding /61/. However, even in such cases the possible danger of changes in the genetic structure of the variety cannot be ignored. This also applies to attempts at stimulating growth and ripening of agricultural crops, increasing the yields, and improving certain components by irradiation of plants in the so-called gamma fields /62/.
We have shown that ecological and, correspondingly, radioecological investigations are an absolute requirement in various cases of contamina tion of natural habitats and farmlands with radioactive isotopes. Theo
retical radioecology delineates the solution of many practical problems and gives rise to applied radioecology (in the true sense of this word), which makes possible generalization and forecasting of phenomena occurring with the contamination of biocenosis and resulting in damage to the quality of human food and livestock fodder; furthermore it makes possible the control of these phenomena by decontamination of lands, fields, forests, and water bodies.
With a better understanding of the importance of radioecology and its potentialities in highly developed countries, such as the USSR, USA, and Great Britain, we would be free to devote ourselves to the elaboration of specific radioecological techniques aimed at weakening the undesirable biological cycles of radioactive isotopes, and to the intensification of de activation techniques.
Biological consequences of radioactive contamination fall largely within the scope of radioecology, and we must take issue with the statement made by our most prominent representative of radiation medicine, Prof.
A. V. Lebedinskii /63, p. 7/, that the science engaged in studies of the con sequences of nuclear tests still lacks a name. As long as new trends in science arise in answer to practical requirements, suitable organizational systems must be derived within which radioecology may develop rapidly and efficiently satisfy mankind's current needs. Highly developed countries should organize international and national institutes and radio ecological services; special courses and practical work in radioecology should be introduced in biological, agricultural, and medical courses, and the necessary textbooks and manuals should be published.
The need for trained personnel in radioecology is already acute, and specialists in this field will be needed in the next decades of the atomic century, as in addition to the existing contaminations, the peaceful uses of atomic energy will continue to saturate habitats with ecologically high levels of ionizing radiations.
When developed, radioecology will prove to be an essential tool in the coming age of interplanetary travel and in the investigation of living condi tions on other planets.