Present status and trends of radioecological research

Radioecology can be defined as the science concerned with the interactions between radionuclides and the environment and with the the effects of radionuclides on man and biotic communities. Ecology advanced from radioecological studies because tracer radionuclides were instrumental in understanding many ecological processes. During the period of fallout from nuclear weapons testing the behaviour of the most important radionuclides (typically: Sr-90, I-131, Cs-137, Pu-239,Pu- 240) in the most critical pathways was studied. After the Chernobyl accident studies were extended to natural and semi-natural ecosystems and to other less common radionuclides. In principle the implementation of radiation protection criteria for man, which are based on the protection of a single individual, assures the protection of organisms other than man. In case of serious contamination scenarios there is a need for realistic evaluations of the effectiveness of the countermeasures that could be undertaken. In particular, studies on biogeochemical transfer mechanisms which control the cycling of radionuclides should be developed. With reference to future developments of the nuclear industry, some attention should be paid to the operation and the releases from, e.g., intrinsically safe reactors and fusion plants. Besides such potential new-type sources, the decontamination and possible site restoration of military installations has to be considered.