Radioecology in Europe

Exposure to ionising radiations is ubiquitous, but varies both in time and space. Contributions include sources of natural background, both unperturbed by humans and perturbed by activities such as uranium mining, and artificial sources, such as those that originated from the atmospheric testing of nuclear weapons and because of accidents, such as Chernobyl and Fukushima.

Thus, exposure to ionising radiations places environmental stresses on all types of biota, including humans, but are these stresses significant, and how do they interact with the effects of other stressors, such as chemical pollutants or habitat disturbance? Answering questions such as these is the province of radioecology.

Despite several decades of research in this area from the 1940s onwards, many deep and challenging issues remain to be addressed (see Hinton et al 2013, Bréchignac et al 2016). Addressing these requires expertise in a wide variety of disciplines, such as hydrology, dosimetry, genetics, and systems biology. This expertise is widely distributed in a variety of departments in a diverse array of institutions throughout the world, and progress in the field can best be facilitated by co-ordinating the research undertaken by these various bodies.

The need for international co-ordination provided the context for the EU-sponsored COMET project (Coordination and implementation of a pan-European instrument for radioecology, a combined Collaborative Project and Coordination and Support Action under the EC/Euratom 7th Framework Programme) that was completed in May 2017 (Muikku et al 2017, Vandenhove et al 2017). This project followed on from earlier EU-sponsored work. From 2006–2008, the FUTURAE ('A Future for Radioecology in Europe') coordination action was launched to produce an analysis of the state of radioecology in Europe. This recommended that a European structure capable of ensuring long-term governance of research in radioecology should be created. Following from this, the European Radioecology Alliance (ALLIANCE) was created. This had 8 founding members, but has now expanded to 27 members from 14 different countries. Although focused on Europe, the ALLIANCE is open to all organisations throughout the world with interest in supporting research in radioecology (www.er-ALLIANCE.eu/).

One of the first actions of the ALLIANCE, even before it was officially founded, was to propose to the EC the creation of a Network of Excellence in radioecology. This led to the formation of the Strategic Network for Integrating Radioecology (STAR; www.radioecology-exchange.org/content/star). STAR initiated integration processes and established mechanisms to ensure long-term sustainability, and this work has been carried forward under COMET.

Under both STAR and COMET, an important focus has been on developing a strategic research agenda (SRA) to provide a long-term (20 year) specification of radioecological research needs (Hinton et al 2013).

The current radioecology SRA has identified three challenges to be addressed. These are:

• To predict human and wildlife exposure in a robust way by quantifying key processes that influence radionuclide transfer and exposure.
• To determine ecological consequences under realistic exposure conditions.
• To improve human and environmental protection by integrating radioecology.

The first of these largely relates to model development and the provision of data for parameterising these models, whereas the third mainly concerns the application of radioecology in the integration of protection frameworks for humans and the environment, and for ionising radiations and chemicals. The second challenge is perhaps the most difficult, as it involves establishing processes that link radiation-induced effects from molecular to population, community or ecosystem levels, for a wide diversity of taxa and in the presence of co-stressors. A variety of drivers have determined the definition of these challenges and the 15 lines of research that are associated with them (Garnier-Laplace et al 2017).

Within the context of the SRA, COMET together with ALLIANCE set up several working groups to develop roadmaps for research on specific topics. These comprised transfer processes of atmospheric radionuclides, marine radioecology, human foodchain modelling, environmental issues associated with naturally occurring radioactive material, and inter- and intra-species differences in radiation sensitivity and trans-generational effects. These topical working groups provide the basis of a short-term (five year) scientific roadmap for radioecology.

Other European radiation protection platforms, i.e. MELODI, NERIS, EURADOS and EURAMED¹ , as well as the developing SHINE (Social Sciences and Humanities in Ionizing Radiation Research) platform, have developed similar SRAs and are in the process of developing roadmaps. The aim is to have a joint roadmap across all these areas as input to the European Joint Programme for the Integration of Radiation Protection Research (EJP-CONCERT). As COMET has now been completed, further development of the SRA and roadmap for radioecology and interactions with EJP-CONCERT will be undertaken by the ALLIANCE.

Although a major role of COMET has been in planning for the future of research in radioecology, it has also been important in forwarding actual research studies, in supporting education and training (30 PhD studies have been associated with COMET) (Bradshaw et al 2017) and in developing infrastructure. Some of the research has focused on marine, forest and human foodchain modelling, and a number of significant papers have been published (Belharet et al 2016, van de Walle et al 2016, Vives i Batlle 2016, Buesseler et al 2017, Diener et al 2017, Vives i Batlle et al 2018). A particularly interesting strand of research relates to laboratory and field studies of epigenetic effects in several types of organism (epigenetic changes are stable heritable traits (or 'phenotypes') that cannot be explained by changes in DNA sequence).

An interesting type of infrastructure development is related to the establishment of long-term radioecological observatory sites in the Chernobyl exclusion zone, the Fukushima Prefecture, the aquatic environment of a previous coal mining and processing site in Poland, and a Belgian waste landfill related to the phosphate industry (Muikku et al 2017). Radioecological observatories are intended to provide a focus for long-term joint field investigations. The intention is to perform multidisciplinary joint research addressing the research priorities identified by the SRA.

Though European radioecological research has been forwarded through COMET, with continuation via other EC-funded projects like TERRITORIES and CONFIDENCE, and with ongoing coordination occurring through the ALLIANCE, it largely relies on national research programmes and funding to address the challenges that have been identified. In the UK, radioecological research is being progressed by the NERC TREE (transfer–exposure–effects) Project (http://tree.ceh.ac.uk/), a collaboration between the Centre for Ecology & Hydrology, the universities of Lancaster, Nottingham, Plymouth, Portsmouth, Salford, Stirling and the West of England and the Scottish Universities Environmental Research Centre. Studies include investigations of biogeochemical processes in soil–plant systems (mainly in the context of radionuclides relevant to long-term waste repositories and using the Chernobyl exclusion zone as an open-air laboratory to provide samples for model validation), the use of phylogenetically derived relationships to predict radionuclide uptake by various types of biota and crops, estimating uncertainties in exposure under field conditions, taking into account how animals utilise their environment, and multi-generational studies on radiation effects in several different organisms exposed under both laboratory and field conditions. The TREE project has already resulted in the publication of a substantial number of journal papers (e.g. Deryabina et al 2015, Fuller et al 2015, 2017, Siasou and Willey 2015, Howard et al 2016, Beresford et al 2016a, 2016b, Guillen et al 2017, Siasou et al 2017). In 2016, the TREE Project was named as the Research Project of the Year by the Times Higher Education Supplement. Specifically, the judges said the research had captured the imagination and attention of people worldwide and that the collaboration with Ukrainian colleagues was impressive in the way that it used 'groundbreaking radiological methods to explore the impact of nuclear radiation on wildlife in the Chernobyl area' (see also Wood and Beresford 2017).

The TREE Project forms one component of the UK RATE (Radioactivity and the Environment) Programme (www.bgs.ac.uk/rate/) that is jointly funded by the Natural Environment Research Council (NERC), the Environment Agency and Radioactive Waste Management Limited. This Programme runs from 2013–2018 and covers geological and biogeochemical studies, as well as the radioecological work included in TREE.

Beyond 2018, prospects for radioecology in Europe and the UK remain unclear. An ambitious 20-year strategic research agenda has been developed and an appropriate, shorter-term 5-year roadmap has been constructed. However, the degree to which national and international organisations are motivated to implement these plans remains, to some extent, in doubt. However, ALLIANCE and the other European radiation protection platforms are striving towards achieving sustainability of European funding for radiation protection research (including radioecology) via European Joint programming initiatives like EJP-CONCERT or similar structures. Meanwhile, some aspects of radioecology are being developed further through other fora, such as the IAEA-sponsored MODARIA (Modelling and Data for Radiological Assessments) Programme (www-ns.iaea.org/projects/modaria/default.asp) and the somewhat more informal BIOPROTA Programme (www.bioprota.org/) that was set up to address the key uncertainties in long-term assessments of contaminant release into the environment arising from radioactive waste disposal, and involves a wide variety of waste management organisations, regulators, consultants and academic researchers (though neither of these fund large-scale research programmes). It is to be hoped that suitable long-term funding will be put in place to address the issues that need to be addressed in a variety of radioecological contexts, including assessment of the impact of accidents, remediation of contaminated land and evaluating the safety of proposals for the disposal of solid radioactive wastes. There is also a need for radioecology to establish its proper place within the wider field of ecology, with ionising radiation given due weight as one of a wide variety of environmental stressors whose impact on human health and the environment needs to be monitored, assessed and controlled. Furthermore, there is a need to strengthen links with the broader field of environmental sciences (e.g. hydrology and systems biology) and with the biomedical disciplines (e.g. molecular and cell biology, including genetics and epigenetics). The concerns for the future of radioecology that existed at the time that FUTURAE was undertaken have not gone away. Rather, the subsequent programmes, such as COMET and TREE, have helped to avert a significant decrease in available expertise over the last ten years. Continued diligence and investment is required to ensure that this expertise is maintained in the future. Let us not wait for another major accident to serve as a reminder that radioecological expertise needs to be maintained.