STATEMENT OF WORK
“Ecological risk assessment of radiation - putting the ecosystem approach into practice”
2nd “Ecosystem approach” IUR/CERAD* Task Group
1. Overall context
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 (IAEA1, UNSCEAR2, EC3, ICRP4) and national Institutions (US DoE5, CNSC6 Canada, NIRS7 Japan, IRSN8 France, SCK-CEN9 Belgium, RIARAE10 Russia, TYPHOON11 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 utilise 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 frequently stated 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 or species. Such effects only act as triggers of perturbation which propagate within ecosystems, the 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 between predators and prey, are also capable of causing indirect effects by means of which the population less affected directly by the stressor may be the most severely affected. 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.
2. Achievements of the 1st “Ecosystem approach” Task group
IUR has extensively reviewed the current approach based upon reference individual organisms, as developed by ICRP and others, with particular emphasis on assessing its relevance in the general context of environment protection which evolves in various areas; biodiversity, fisheries, forests, specific ecosystems, etc. This review assembled and discussed 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. Finally, the Task Group started to explore the feasibility of setting up an ecosystem approach for environment radiological protection, taking advantage of on-going developments in other areas of environment protection.
The final findings of this first Task Group have been assembled in a report published within the IUR Report series which provides extensive review and discussion together with R&D needs and recommendations to the radiation protection community (IUR Report n° 7).
3. Objectives of the 2nd “Ecosystem approach” Task Group
By paying special attention to the conclusions and recommendations from the previous Task Group, the primary objective of this 2nd Task Group is to work out possible practical methods to achieve ecological risk assessment in line with an ecosystem approach. In order to achieve this goal, a new membership has been assembled gathering high-level expertise from different fields: ecological science (radioecology, population ecotoxicology, systems ecology,…), professionals in regulation and operators of environmental protection applied to radiation.
The more detailed objectives of this Task Group work are as follows:
- Review the existing/developing actual methods of ecological risk assessment along an ecosystem approach (irrespective of the stressor)
- Discuss how ecological processes could be considered in order to attain a meaningful application of the ecosystem approach for radiation protection
- Discuss and identify the effect endpoints to be considered for an ecosystem approach of radiation protection
- Propose one/a set of method/s for ecological risk assessment of radiation effects
- Propose a general framework for the overall harmonisation of methods for use in radiation protection, reference organism and ecosystem approaches, human and environmental risk assessment
- Identify R&D further needs to achieve the ecosystem approach for radiation and provide recommendations for radiation protection
The Task group shall first aim at producing a position/discussion paper by June 2014, to be presented at the Barcelona Conference ICRER 2014 as a keynote lecture. Elaboration of this position/discussion paper and the way forward will be the essential purpose of the first workshop in Stockholm.
The Task group shall also produce a final report with special emphasis given to proposing and developing practical and concrete approaches for ways that the ecosystem approach can be applied for evaluation of radiation risks. As a minimum, the report shall elaborate upon the detailed objectives as mentioned above, and propose one or several methods of ecological risk assessment of radiation effects that could usefully complement the current approach based upon “reference organisms”. This report will ultimately be published within the IUR report series, with the collective authorship duly mentioned. A first draft of this report shall be elaborated before the end of 2015.
IUR intends to organize and to provide some funds to hold several 3-4 days Workshops in order to promote discussion and developments. The first one is already scheduled on 18-20 December 2013 in Stockholm, hosted by Stockholm University. Additional ones will be implemented as required for the promotion and development of this work.
6. Provisional TG membership12
A preliminary list of participants having declared their interest for such an action is as follows:
- Lawrence Barnthouse Chairman of the SETAC13 population-level ERA Work group, ecotoxicologist and ecological risk assessment, LWB Environmental Services Inc., Oak Ridge, TN, USA
- Clare Bradshaw Professor, Systems ecology and radioecology, Stockholm University, Sweden
- François Bréchignac President of IUR14, radioecology, IRSN, France
- Justin Brown Senior researcher and expert, radioecology, NRPA15, Oslo, Norway
- Philippe Ciffroy, Senior limnologist, expert in radiological impact assessment of NPP, Electricité de France EDF, Paris, France
- Valery Forbes Professor, Ecological modelling and environmental risk assessment, University of Lincoln, Nebraska, USA
- Lawrence Kapustka Former chairman of the SETAC ERA Advisory Group, ecotoxicology and ecological risk assessment, LK Consultancy, Calgary, Canada
- Ulrik Kautsky Member of the Swedish National Committee on Radiation Protection Research, systems ecology and radioactive waste, SKB16, Stockholm, Sweden
- Per Strand Vice President of the European Radioecology Alliance, radioecology, NRPA, Oslo, Norway
- Stanislav Geras'kin, Head of Laboratory, Russian Institute of Agricultural Radiology and Agroecology, RIARAE, Obninsk, Russia
*CERAD: Center for Enviromental Radioactivity, http://www.umb.no/cerad/article/centre-for-environmental-radioactivity
1 International Atomic Energy Agency
2 United Nations Scientific Committee on the Effects of Atomic Radiation
3 European Commission
4 International Commission on Radiological Protection
5 US Department of Energy
6 Canadian Nuclear Safety Commission
7 National Institute of Radiological Sciences
8 Institute for Nuclear Safety and Radioprotection
9 Studiecentrum voor Kernenergie – Centre d’Etudes Nucléaires
10 Russian Institute of Agricultural Radiology and AgroEcology
11 Scientific & Production Association “Typhoon”
12 May be extended further.
13 Society for Environmental Toxicity And Chemistry
14 International Union of Radioecology
15 Norwegian Radiation Protection Authority
16 Swedish Nuclear Fuel and Waste Management Company