What do we clearly know on environmental impact and its causes ?
Workshop “Radiological protection of the Environment: the path forward to a new policy?” Nuclear Energy Agency forum in collaboration with the ICRP, Taormina, Sicily – Italy 12-14 Feb 2002. Proceedings in Radiation Protection 2003, OECD publications, pp 109-119.
Impact or fluctuations?
We know a lot on acute and large impact but nearly nothing about chronic and small impact. We are not yet able to resolve whether a change is a fluctuation that will have no serious consequences, or the start of a catastrophic evolution.
It is clear that radioactivity is only one among a number of other stressors, and certainly not the primary one, except for large accidents. Since living organisms, and even the biosphere as a whole, react to the entirety of their surroundings, it is necessary to take all this into account in a holistic way. This means caring about the effects of usual toxicants in addition to radiotoxicants of course, but also about effects of other cofactors such as nutrients availability and ecological interactions between biota.
It is hence necessary to conduct research in a real pluridisciplinary way. It is time to level out past boundaries that have existed between radioecology and ecotoxicology, which are both integral parts of ecology. The radioprotection of the environment cannot be separated from the overall protection of the environment, and as such should not be addressed as a stand-alone objective.
A first question is to identify an environmental impact and a second one is to identify its causes. Responses to such questions are not straightforward since changes in the environment are quite usual. The desert borders are going forward and backward, as do forests, coral reefs or other important
ecological systems. Climate may be the initial cause but there are also examples of cyclic evolution of animal populations that may be due to complex interactions between predators, prey and plant biomass resources. The difficulty inherent when identifying an impact is to be able to distinguish between fluctuations around a dynamic equilibrium and changes that have a persistent trend and that may eventually arise from human activity. Identifying an impact poses the same problem as identifying its causes. In any case, this requires sufficient ecological knowledge.