In recent years, under the notable incentive of an IUR Task Group initiated as early as 1997, the issue of the protection of the environment from ionizing radiation has evolved and is now a major topic for radioecologists. Several International Organizations (IAEA, UNSCEAR, EC, ICRP) and national Institutions (US DoE, CNSC Canada, NIRS Japan, IRSN France, SCK-CEN Belgium, RIARAE Russia, TYPHOON Russia, etc.) are now engaged in developing systems for the radiological protection of the environment from radiation.
Ongoing developments are aimed at designing conceptual approaches and methodologies for ecological risk assessment of radiation delivered by radionuclides in the environment meant to aid decision making, especially with respect to situations of existing or future possible environmental contamination. Most of these methods expand from the radiotoxicological methods in use for the radioprotection of man on one hand (concept of reference person, radiotoxicological data used to identify dose-response relationships, focus on individuals, etc.), and from the classical ecotoxicological methods based on individual organisms of test species for chemical toxicants, on the other hand. Consequently, they are all based on several types of "reference organisms" designed to exploit dose-response relationships at the level of individual organisms. Most of the ongoing research work is oriented in this direction. The shortcomings of such methods, however, are evident both in the field of radioprotection and also in the field of assessment of risks from other stressors, such as chemical toxicants and physical stressors.
One major limitation stems from the impossibility of the above methods to actually meet the real environment protection objectives that have been set, in the vast majority of situations, at the population and ecosystem levels. This is actually one major difference between the protection of humans, where the target of protection is set at the level of the individual, and the protection of the environment, where the most frequent goal is to protect populations and the structure and function of ecosystems. The protection of individuals is essentially supported by toxicology. The protection of ecosystems can similarly start by making use of toxicology for animals and plants (the current development at this stage), but need to be complemented and expanded by ecological methods and modelling, i.e. true eco-toxicology (still to be implemented).
It is primarily for this reason that several areas of environmental management have already been engaged in working out "ecosystem approaches" of risk assessment, like in halieutics for the protection of fish stocks in the oceans (FAO), or for the sustainable maintenance of biodiversity (International Convention on Biodiversity). Indeed, perturbations induced by stressors within ecosystems cannot be fully grasped from the exclusive toxicological understanding of the stressor's interaction with individual organisms. Such effects only act as triggers of perturbation which propagate within ecosystems, these later being dominated by complex inter-population relationships mostly characterized by non-linear responses which can be quite different from the initial response observed within individual organisms. Inter-population relationships at ecosystem level, such as predator-prey, are also capable of mediating indirect effects by means of which the population actually exposed to the stressor may not be the uppermost suffering, and eventually led to extinction. This is particularly relevant when considering the long-term ecological effect of chronic exposure to toxicants, like radiation, where damage may not be most due to the direct radio-toxicological effect of radiation per se (upon individual organisms), but rather to the build up of imbalances between interacting populations within ecosystems as a result of differences in sensitivity to radiation.
The first objective of this Task Group is therefore to work on reviewing the current approach based upon reference individual organisms, as developed by ICRP, in the general context of environment protection which evolves in various areas, biodiversity, fisheries, forests, specific ecosystems, etc. The second objective is to assemble pertinent elements of justification supporting the development of an "ecosystem approach" to ecological risk assessment of environmental radionuclides. For example, one of the merits of an "ecosystem approach" will be to fill the gaps identified above with the "reference organism approach", and therefore to provide a more complete set of methodologies which will strengthen the overall efficiency of the protection system and its credibility. The third objective is finally to explore its feasibility with emphasis on environment radiological protection, taking advantage of on-going developments in other areas of environment protection.
The Task Group shall assess in particular the following more detailed and provisional objectives:
1) Generic and specific goals of environment protection
2) Legislation about environment protection (halieutics, biodiversity, forests, water courses, endangered ecosystems...)
3) Assessment of the RAPs concept in the general context of environment protection
a. Extent of compatibility with Ecological Risk Assessment for chemicals
b. Extent of compatibility with approach designed for protecting biodiversity
c. Extent of compatibility with approach designed for protecting fish stocks
4) Generic limitations of the RAPs approach
5) Justification and merits of the ecosystem approach
6) Assessing the feasibility of an ecosystem approach
7) R&D needed to support the development of an ecosystem approach
8) Recommendations with respect to radiation protection
The Task group has now produced an assessment report along the lines mentioned above as detailed objectives. The draft report is currrently undergoing final editing. It is expecetd to be ready for publication within the IUR report series, with a collective authorship duly mentioned.
A subset of the Task Group members met in Aix-en-Provence (France) on 27-28-29 April 2011 during a Workshop where the draft Report has been reviewed. A consensus has been further elaborated with respect to identification of reserach priorities, and recommendations towards the radioprotection and the radioecoological scientific communities.
Provisional TG membership
A preliminary list of participants interested to actively participate in this work is given below.
Larry Barnthouse (Chairman of the SETAC population-level ERA Work group, LWB Environmental Services Inc., Oak Ridge, TN, USA)
Clare Bradshaw (University of Stockholm, Sweden)
François Bréchignac (IRSN, France)
Simon Caroll (Center of Biological Diversity, Sweden)
Shoishi Fuma (National Institute of Radiological Sciences, Japan)
Lars Hakanson (Uppsala University, Sweden)
Alicja Jaworska (NRPA, Norway)
Larry Kapustka (Associated chair of the SETAC Nanotechnology Advisory Group, Chair Committee on Biological Effects and Environmental Fate, Coordinating editor for SETAC Books, LK Consultancy, Canada)
Isao Kawagushi (National Institute of Radiological Sciences, Japan)
Alexander Kryshev (Typhoon, Obninsk, Russia)
Deborah Oughton (UMB, University of Life Sciences, As, Norway)
Luigi Monte (ENEA, Italy)
Tatiana Sazykina (Typhoon, Obninsk, Russia)
Per Strand (NRPA, Norway)
 "Reference Animals and Plants", concept developed by ICRP (ICRP n°91, Vol 33(3) 2003 A framework for assessing the impact of ionising radiation on non-human species; ICRP n°108, Vol 38(4-6) 2008 Environment protection: the concept and use of reference animals and plants), or "reference organisms" within the European FASSET-ERICA projects (Larsson C.M. 2004 The FASSET framework for assessment of environmental impact of ionizing radiation in European ecosystems, an overview. J. Radiol. Prot. 24 A-1-A12).
 May be extended further.