ABSTRACT
Fish in lakes situated within the Chornobyl exclusion zone have been highly contaminated since the accident and have not been utilized as food for humans. In the present study, field experiments with less-contaminated silver Prussian carp (Carassius gibelio (Bloch, 1782)) caged in contaminated lake within the Chornobyl exclusion zone was performed from June to October 2021 to investigate the effectiveness of clean feed containing potassium ferric hexacyanoferrate (KFCF) KFe[Fe(CN)6], a kind of Prussian Blue as a countermeasure to reduce 137Cs accumulation in fish. The addition of clean feed containing 0.1% or 1% KFCF resulted respectively in 2.4 ± 0.4 or 4.2 ± 0.7 times lower activity concentration of 137Cs in muscle tissue of the carp compared to control fish with clean feed without KFCF and in 7-16 or 12-27 times lower activities compared to fish without additional clean feeding. After 18 weeks exposure, 137Cs levels in all the caged fish except for the control group were below the European permissible level (600 Bq kg-1) for consumption. In contrast, KFCF did not affect the intake of 90Sr in fish, although additional feed increased the growth rate and thereby accumulation in bone tissues. Hence, the use of clean feed containing KFCF is judged to be an effective and inexpensive countermeasure to reduce the 137Cs contamination of edible fish muscles.
Subject(s)
Chernobyl Nuclear Accident , Radiation Monitoring , Animals , Humans , Lakes , FishesABSTRACT
PURPOSE: The FIGARO low dose 60Co gamma irradiation facility at the Norwegian University of Life Sciences, Ås, Norway, is dedicated to the study of effects on living organisms from acute or chronic ionizing radiation exposures, either alone or in combination with other stressors such as UV radiation, metals or radionuclides. Here, we present a framework of working guidelines and computer software for characterization of absorbed dose rates and accumulated doses to organisms exposed within the continuous gamma field at FIGARO. The aims of the framework are to ensure gamma exposures are well characterized, that results from exposures are correctly interpreted in terms of absorbed dose rates and accumulated doses, and that sufficient information is available so that exposures can be reproduced later or at other facilities. METHODS: The software of the framework includes a Geant4 application for Monte Carlo radiation transport simulations and tools for dose planning, recording and reporting. The working guidelines are prepared for expert users who provide simulated, calculated or estimated absorbed dose rates and for regular users who conduct exposure experiments and are responsible for record keeping. To demonstrate the developed framework, we use a case study where 14 freshwater microcosms are exposed to four levels of gamma dose rates at FIGARO. CONCLUSION: The framework guides users towards good dosimetry practices. Lessons learned could be transferable to other gamma irradiation facilities.
Subject(s)
Gamma Rays , Radiation Exposure/analysis , Radiobiology/instrumentation , Universities , Air , Cobalt Radioisotopes , Dose-Response Relationship, Radiation , Guidelines as Topic , Monte Carlo Method , Radiometry , Software , WaterABSTRACT
Available experience from Chernobyl and Fukushima clearly demonstrate that nuclear emergencies may result in low and very low exposure levels, at which psychological and social effects among the affected population will dominate over the actual biological effects of ionising radiation. International protection standards and guidelines request, that both radiological and non-radiological health consequences have to be considered in preparedness and response to an actual emergency and there is a need to broaden the radiation protection system's philosophy beyond the metrics of radioactivity and radiation dose. During the past decade a number of multidisciplinary projects were set up with the aim of evaluating management options according to social, economic and ethical criteria, in addition to technical feasibility to achieve this goal. WHO and partners from the Inter-Agency Standing Committee Task Force on Mental Health and Psychosocial Support in Emergency Settings have developed a comprehensive framework and guidelines, which can be applied to any type of an emergency or disaster regardless of its origin. There is a need to include the available scientific expertise and the technical, managerial and personal resources to be considered within a similar 'decision framework' that will apply to radiation emergencies. Key areas of the required expertise needed to develop such a framework are radiation protection, medical support (especially primary care and emergency medicine, mental health support), social sciences (anthropology, psychology, ethics) and communications experts. The implementation of such a multidisciplinary concept in the operational world requires education and training well beyond the level currently available.
Subject(s)
Disaster Planning/standards , Emergency Medicine/standards , Radiation Injuries/prevention & control , Radiation Protection/methods , Safety Management , Emergency Treatment , Humans , Risk AssessmentABSTRACT
The ALLIANCE working group on effects of ionising radiation on wildlife brings together European researchers to work on the topics of radiosensitivity and transgenerational effects in non-human biota. Differences in radiation sensitivity across species and phyla are poorly understood, but have important implications for understanding the overall effects of radiation and for radiation protection; for example, sensitive species may require special attention in monitoring and radiation protection, and differences in sensitivity between species also lead to overall effects at higher levels (community, ecosystem), since interactions between species can be altered. Hence, understanding the mechanisms of interspecies radiation sensitivity differences may help to clarify mechanisms underpinning intraspecies variation. Differences in sensitivity may only be revealed when organisms are exposed to ionising radiation over several generations. This issue of potential long-term or hereditary effects for both humans and wildlife exposed to low doses of ionising radiation is a major concern. Animal and plant studies suggest that gamma irradiation can lead to observable effects in the F1 generation that are not attributable to inheritance of a rare stable DNA mutation. Several studies have provided evidence of an increase in genomic instability detected in germ or somatic cells of F1 organisms from exposed F0 organisms. This can lead to induced radiosensitivity, and can result in phenotypic effects or lead to reproductive effects and teratogenesis. In particular, studies have been conducted to understand the possible role of epigenetic modifications, such as DNA methylation, histone modifications, or expression of non-coding RNAs in radiosensitivity, as well as in adaptation effects. As such, research using biological models in which the relative contribution of genetic and epigenetic processes can be elucidated is highly valuable.
Subject(s)
Epigenesis, Genetic/radiation effects , Plants/radiation effects , Radiation Protection/standards , Radiation Tolerance , Radiation, Ionizing , Animals , Epigenesis, Genetic/genetics , Europe , International Agencies , Plants/geneticsABSTRACT
NERIS is the European platform on preparedness for nuclear and radiological emergency response and recovery. Created in 2010 with 57 organisations from 28 different countries, the objectives of the platform are to: improve the effectiveness and coherency of current approaches to preparedness; identify further development needs; improve 'know how' and technical expertise; and establish a forum for dialogue and methodological development. The NERIS Strategic Research Agenda is now structured with three main challenges: (i) radiological impact assessments during all phases of nuclear and radiological events; (ii) countermeasures and countermeasure strategies in emergency and recovery, decision support, and disaster informatics; and (iii) setting up a multi-faceted framework for preparedness for emergency response and recovery. The Fukushima accident has highlighted some key issues for further consideration in NERIS research activities, including: the importance of transparency of decision-making processes at local, regional, and national levels; the key role of access to environmental monitoring; the importance of dealing with uncertainties in assessment and management of the different phases of the accident; the use of modern social media in the exchange of information; the role of stakeholder involvement processes in both emergency and recovery situations; considerations of societal, ethical, and economic aspects; and the reinforcement of education and training for various actors. This paper emphasises the main issues at stake for NERIS for post-accident management.
Subject(s)
Radiation Protection/standards , Radioactive Hazard Release , Europe , Humans , International AgenciesABSTRACT
Abstract : Despite a longstanding recognition that radiological protection is not only a matter of science, but also ethics, ICRP publications have rarely addressed the ethical foundations of the system of radiological protection explicitly. The purpose of this publication is to describe how the Commission has relied on ethical values, either intentionally or indirectly, in developing the system of radiological protection with the objective of presenting a coherent view of how ethics is part of this system. In so doing, it helps to clarify the inherent value judgements made in achieving the aim of the radiological protection system as underlined by the Commission in Publication 103. Although primarily addressed to the radiological protection community, this publication is also intended to address authorities, operators, workers, medical professionals, patients, the public, and its representatives (e.g. NGOs) acting in the interest of the protection of people and the environment. This publication provides the key steps concerning the scientific, ethical, and practical evolutions of the system of radiological protection since the first ICRP publication in 1928. It then describes the four core ethical values underpinning the present system: beneficence/ non-maleficence, prudence, justice, and dignity. It also discusses how these core ethical values relate to the principles of radiological protection, namely justification, optimisation, and limitation. The publication finally addresses key procedural values that are required for the practical implementation of the system, focusing on accountability, transparency, and inclusiveness. The Commission sees this publication as a founding document to be elaborated further in different situations and circumstances.
Subject(s)
Radiation Monitoring/ethics , Radiation Protection/standards , HumansABSTRACT
Based on AMS analysis, it is shown that no Pu signals from the Fukushima accident could be discerned in marine sediments collected 1.5-57km away from the Fukushima Da-ichi power plant (FDNPP), which were clearly influenced by accident-derived radiocesium. The 240Pu/239Pu atom ratios (0.21-0.28) were significantly higher than terrestrial global fallout (0.182 ± 0.005), but still in agreement with pre-FDNPP accident baseline data for Pu in near coastal seawaters influenced by global fallout and long-range transport of Pu from the Pacific Proving Grounds.
ABSTRACT
Assessing the potential ecological impact of ionising radiation raises a number of ethical questions. These include fundamental questions such as what exactly constitutes harming the environment, and how the environment should be valued, as well as links to political protection principles such as sustainability and biodiversity. Starting from developments within ecological risk assessment, this paper summarises some of the ethical issues concerning the protection of the environment from radiation. Chapter 2 gives a brief overview of different philosophical and cultural world views on valuing the environment in a context of radiation risk. Chapter 3 addresses some recent challenges to proposed environmental protection frameworks, including practical applications following the Chernobyl and Fukushima accidents, and some scientific developments such as the ecosystem approach. Finally, Chapter 4 offers some recommendations on how ethical evaluation can help produce a more robust and transparent approach to the protection of the environment. In conclusion, there is a need for a holistic evaluation of the environmental impacts of ionising radiation that not only considers the direct consequences on the health of humans and non-human species, but also the more complex social, ethical, and economic consequences of both human and non-human exposures.
Subject(s)
Conservation of Natural Resources , Radiation Exposure , Radiation Protection/methods , Risk Assessment/ethicsABSTRACT
Using an analysis of the way European newspapers covered the Fukushima nuclear accident, this article explores how the mass media transmit information about radiation risks from experts to the general public. The study applied a media content analysis method on a total of 1340 articles from 12 leading newspapers in 6 countries: Belgium (N = 260), Italy (N = 270), Norway (N = 133), Russia (N = 172), Slovenia (N = 190) and Spain (N = 315). All articles analysed were selected as being directly or indirectly related to the Fukushima accident by containing the word 'nuclear' and/or 'Fukushima' and were published between the 11th March and the 11th May 2011. The data presented here focus specifically on a cross-cultural comparison of the way the media use quantitative units. Results suggest that although experts are accustomed to communicating about radiological risks in technical language, often using quantitative units to describe the risks, mass media do not tend to use these units in their reporting. Although the study found a large variation in the measurement units used in different countries, it appeared that journalists in all the analysed countries preferred to describe radioactivity by comparing different radiation exposures, rather than reporting the actual measured units. The paper concludes with some practical guidelines for sound public communication about radiation risks.
Subject(s)
Fukushima Nuclear Accident , Information Dissemination/methods , Mass Media/statistics & numerical data , Radiation Exposure/statistics & numerical data , Radiation Monitoring/statistics & numerical data , Radioactive Fallout/statistics & numerical data , Europe , Risk Assessment/statistics & numerical data , RussiaABSTRACT
In this report, the Commission describes its framework for protection of the environment and how it should be applied within the Commission's system of protection. The report expands upon its objectives in relation to protection of the environment, in so far as it relates to the protection of animals and plants (biota) in their natural environment, and how these can be met by the use of Reference Animals and Plants (RAPs); their Derived Consideration Reference Levels (DCRLs), which relate radiation effects to doses over and above their normal local background natural radiation levels; and different potential pathways of exposure. The report explains the different types of exposure situations to which its recommendations apply; the key principles that are relevant to protection of the environment; and hence how reference values based on the use of DCRLs can be used to inform on the appropriate level of effort relevant to different exposure situations. Further recommendations are made with regard to how the Commission's recommendations can be implemented to satisfy different forms of environmental protection objectives, which may require the use of representative organisms specific to a site, and how these may be compared with the reference values. Additional information is also given with regard to, in particular, communication with other interested parties and stakeholders. Issues that may arise in relation to compliance are also discussed, and the final chapter discusses the overall implications of the Commission's work in this area to date. Appendices A and B provide some numerical information relating to the RAPs. Annex C considers various existing types of environmental protection legislation currently in place in relation to large industrial sites and practices, and the various ways in which wildlife are protected from various threats arising from such sites.
Subject(s)
Conservation of Natural Resources/methods , Environmental Exposure/prevention & control , Plants/radiation effects , Radiation Monitoring/standards , Radiation Protection/standards , Animals , Humans , Reference ValuesABSTRACT
In the present work, state of the art isotopic fingerprinting techniques are applied to an Arctic ice core in order to quantify deposition of U and Pu, and to identify possible tropospheric transport of debris from former Soviet Union test sites Semipalatinsk (Central Asia) and Novaya Zemlya (Arctic Ocean). An ice core chronology of (236)U, (239)Pu, and (240)Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6m deep ice core from the Austfonna glacier at Nordaustlandet, Svalbard is presented. The ice core chronology corresponds to the period 1949 to 1999. The main sources of Pu and (236)U contamination in the Arctic were the atmospheric nuclear detonations in the period 1945 to 1980, as global fallout, and tropospheric fallout from the former Soviet Union test sites Novaya Zemlya and Semipalatinsk. Activity concentrations of (239+240)Pu ranged from 0.008 to 0.254 mBq cm(-2) and (236)U from 0.0039 to 0.053 µBq cm(-2). Concentrations varied in concordance with (137)Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and (236)U were found to be higher at depths corresponding to the pre-moratorium period (1949 to 1959) than to the post-moratorium period (1961 and 1962). The (240)Pu/(239)Pu ratio ranged from 0.15 to 0.19, and (236)U/(239)Pu ranged from 0.18 to 1.4. The Pu atom ratios ranged within the limits of global fallout in the most intensive period of nuclear atmospheric testing (1952 to 1962). To the best knowledge of the authors the present work is the first publication on biogeochemical cycles with respect to (236)U concentrations and (236)U/(239)Pu atom ratios in the Arctic and in ice cores.
Subject(s)
Atmosphere/chemistry , Ice Cover/chemistry , Plutonium/analysis , Radiation Monitoring/methods , Radioactive Fallout/analysis , Uranium/analysis , Arctic Regions , Autoradiography , History, 20th Century , Mass Spectrometry , Radiation Monitoring/history , USSRABSTRACT
Recent field expeditions to Central Asian mining sites have provided a wealth of data on radionuclide and metal concentrations in environmental media. In this paper the ERICA assessment tool was used to provide an assessment of the potential doses to non-human biota at the various sites. The aim was to identify the most exposed organism types and the radionuclides giving rise to the greatest doses. The measured media and biota activity concentrations were also used to compare site-specific Kds and CRs with default tool parameters. At all terrestrial sites, the maximum doses (up to ca. 600 µGy/h) were seen in lichens and bryophytes, with concentrations of radium in soils dominating the assessments. Internal alpha dose from (226)Ra was the biggest dose contributor, representing between 72 and 97% of the total dose, with U isotopes as the next most significant contributor. For aquatic organisms the highest calculated doses were obtained for aquatic plants (ca. 100 µGy/h), followed by molluscs, crustacean, zooplankton and insect larva, based on at site environmental media data. For aquatic plants, the internal alpha doses from uranium isotopes dominated the dose at most of the sites, hence the highest doses were seen at sites with the highest U concentrations. While the measured and modelled concentrations were usually in reasonable agreement, particularly for U and Ra in terrestrial plants, there were some differences, most notably for U and Po in the aquatic environment. Modelled concentrations of U in aquatic plants tended to be higher than those measured in site samples; while Po in fish was greater than modelled concentrations. Furthermore, not all the organisms listed in the ERICA tool had been sampled at the sites. Nevertheless, the assessment results should be of great benefit in identifying priority areas for future field studies.
Subject(s)
Mining , Radiation Monitoring/methods , Risk Assessment/methods , Asia, Central , UraniumABSTRACT
With intentions of integrating a portion of their respective research efforts into a trans-national programme that will enhance radioecology, eight European organisations recently formed the European Radioecology ALLIANCE (www.er-alliance.org). The ALLIANCE is an Association open to other organisations throughout the world with similar interests in promoting radioecology. The ALLIANCE members recognised that their shared radioecological research could be enhanced by efficiently pooling resources among its partner organizations and prioritising group efforts along common themes of mutual interest. A major step in this prioritisation process was to develop a Strategic Research Agenda (SRA). An EC-funded Network of Excellence in Radioecology, called STAR (Strategy for Allied Radioecology), was formed, in part, to develop the SRA. This document is the first published draft of the SRA. The SRA outlines a suggested prioritisation of research topics in radioecology, with the goal of improving research efficiency and more rapidly advancing the science. It responds to the question: "What topics, if critically addressed over the next 20 years, would significantly advance radioecology?" The three Scientific Challenges presented within the SRA, with their 15 associated research lines, are a strategic vision of what radioecology can achieve in the future. Meeting these challenges will require a directed effort and collaboration with many organisations the world over. Addressing these challenges is important to the advancement of radioecology and in providing scientific knowledge to decision makers. Although the development of the draft SRA has largely been a European effort, the hope is that it will initiate an open dialogue within the international radioecology community and its stakeholders. This is an abbreviated document with the intention of introducing the SRA and inviting contributions from interested stakeholders. Critique and input for improving the SRA are welcomed via a link on the STAR website (www.star-radioecology.org).
Subject(s)
Ecology , Radioactivity , Research , Environment , Radioactive Pollutants , Societies, ScientificABSTRACT
The contamination of environments with radionuclides can give rise to consequences that encompass far more than health risks from exposure to radiation. As experience from Chernobyl demonstrated, both the accident and remediation measures can have serious social and economic consequences. This paper presents a review of some of these issues, including their ethical relevance, and presents a check-list of socio-ethical aspects of remediation measures. The paper concludes with an overview of social remediation measures, encompassing actions that are directed towards benefits other than dose reduction (e.g., local food monitoring stations or medical check-up), or measures that require social rather than technical implementation (e.g. information centres, stakeholder dialogue).
Subject(s)
Chernobyl Nuclear Accident , Environmental Restoration and Remediation/ethics , Radioactive Pollutants , Compensation and Redress , Environmental Restoration and Remediation/economics , Radiation Monitoring , Social ResponsibilityABSTRACT
Silver nanoparticles (Ag-NP) are components in numerous commercial products and are discharged into the environment in quantities that are largely unknown. In the present study, juvenile Atlantic salmon were exposed to 1, 20, and 100 µg/L (48 h, static renewal) of a commercially available Ag-NP colloidal suspension in natural (soft) lake water. A solution of AgNO(3) containing 20 µg/L Ag(I) ions was also included to discriminate the effect of NPs from that of ionic silver. Furthermore, the commercial Ag-NP suspension was compared to an in-house synthesised colloidal NP suspension prepared from AgNO(3) and NaBH(4) in citrate buffer. The size distribution of Ag in all exposure solutions was characterised by 0.22 µm filtration and 10 kDa hollow fibre cross-flow ultrafiltration in combination with ICP-MS. All exposures were characterised by a relatively high proportion of Ag-NP in the colloidal size fraction 3-220 nm. For assessment of biological effects, acute toxicity, gill histopathology, blood plasma parameters (Na, Cl, glucose, haemoglobin), and gene expression of a selection of gill biomarkers were measured. Results showed that the gills accumulated Ag in all exposure groups apart from the fish exposed to 1 µg/L Ag-NP. Accumulated Ag caused concentration-dependent response increases in general stress markers such as plasma glucose and gill gene expression of heat shock protein 70. Furthermore, induction of the metallothionein A gene indicated that Ag had been internalized in the gills, whereas a concentration-dependant inhibition of Na/K ATPase expression indicated impaired osmoregulation at as low as 20 µg/L concentrations of Ag-NP. The commercial Ag-NP suspension caused acute gill lamellae necrosis at high concentrations (100 µg/L), potentially giving rise to the substantial (73%) fish mortality at this concentration. The two different Ag-NP preparations gave comparable results for several endpoints measured, but differed in MT-A induction and mortality, thus emphasising the variation in effects that may arise from different Ag-NP preparations.
Subject(s)
Gene Expression Regulation/drug effects , Nanoparticles/toxicity , Salmo salar/physiology , Silver/toxicity , Water Pollutants, Chemical/toxicity , Animals , Fresh Water/chemistry , Gills/drug effects , Particle Size , Silver/metabolism , Stress, Physiological/drug effectsABSTRACT
The outcome of the PROTECT project (Protection of the Environment from Ionising Radiation in a Regulatory Context) is summarised, focusing on the protection goal and derivation of dose rates which may detrimentally affect wildlife populations. To carry out an impact assessment for radioactive substances, the estimated dose rates produced by assessment tools need to be compared with some form of criteria to judge the level of risk. To do this, appropriate protection goals need to be defined and associated predefined dose rate values, or benchmarks, derived and agreed upon. Previous approaches used to estimate dose rates at which there may be observable changes in populations or individuals are described and discussed, as are more recent derivations of screening benchmarks for use in regulatory frameworks. We have adopted guidance and procedures used for assessment and regulation of other chemical stressors to derive benchmarks. On the basis of consultation with many relevant experts, PROTECT has derived a benchmark screening dose rate, using data on largely reproductive effects to derive species sensitivity distributions, of 10 microGy h(-1) which can be used to identify situations which are below regulatory concern with a high degree of confidence.
Subject(s)
Conservation of Natural Resources/methods , Environmental Exposure/prevention & control , Environmental Pollution/prevention & control , Government Regulation , Guidelines as Topic , Radiation Injuries/prevention & control , Radiation Injuries/veterinary , Radiation Monitoring/standards , Animals , Ecosystem , Radiation, Ionizing , United KingdomABSTRACT
The ERICA Integrated Approach requires that a risk assessment screening dose rate is defined for the risk characterisation within Tiers 1 and 2. At Tier 3, no numerical screening dose rate is used, and the risk characterisation is driven by methods that can evaluate the possible effects of ionising radiation on reproduction, mortality and morbidity. Species sensitivity distribution has been used to derive the ERICA risk assessment predicted no-effect dose rate (PNEDR). The method used was based on the mathematical processing of data from FRED (FASSET radiation effects database merged with the EPIC database to form FREDERICA) and resulted in a PNEDR of 10 microGy/h. This rate was assumed to ascribe sufficient protection of all ecosystems from detrimental effects on structure and function under chronic exposure. The value was weighed against a number of points of comparison: (i) PNEDR values obtained by application of the safety factor method, (ii) background levels, (iii) dose rates triggering effects on radioactively contaminated sites and (iv) former guidelines from literature reviews. In Tier 3, the effects analysis must be driven by the problem formulation and is thus highly case specific. Instead of specific recommendations on numeric values, guidance on the sorts of methods that may be applied for refined effect analysis is provided and illustrated.
Subject(s)
Ecosystem , Radiation Monitoring/methods , Radiation, Ionizing , Risk Assessment/methods , Animals , Environmental Exposure/adverse effects , Environmental Exposure/analysis , Plant Development , Plants/radiation effects , Review Literature as TopicABSTRACT
These experiments were designed to identify stress effects in 3 key organs in Atlantic Salmon (Salmo salar, L.) after exposure in vivo to very low doses of radiation, and subtoxic levels of aluminum (Al) and cadmium (Cd) alone or in combination. Six fish per group were sacrificed after exposure and the anterior kidney, fin, and gill were dissected and sentfor assay of bystander signal production as a stress response end point. Radiation doses as low as 4 mGy delivered over 5 h, alone or in combination with Cd and/or Al, caused bystander signals to be produced in tissues harvested from in vivo exposed salmon. The effects vary among different organs and are not consistently additive or synergistic for a given treatment although gill cells do show high degrees of synergism between radiation and metal exposure. Data for individual fish did not suggest any systemic sensitivity to the stressors. Interestingly, the data for Cd suggest that lower toxicity is found when the metal is used in combination with radiation exposure. Expression of two proteins associated with survival responses (Bcl-2) or death responses (cmyc) after radiation was measured in the tissue cultures and showed a highly significant correlation with response outcome. The results, although complex, indicate that these stress signal responses may aid in the mechanistic investigation of mixed contaminant effects in fish exposed to metals and radiation.
Subject(s)
Environmental Pollutants/analysis , Metals, Heavy/toxicity , Radioactive Pollutants/analysis , Water Pollutants, Chemical/analysis , Aluminum/analysis , Aluminum/chemistry , Animals , Biomarkers , Cadmium/analysis , Cadmium/chemistry , Gene Expression Regulation/drug effects , Hydrogen-Ion Concentration , Proto-Oncogene Proteins c-myc/metabolism , Radiation , Salmo salar , Time Factors , Water/chemistryABSTRACT
Like any complex environmental problem, ecological risk assessment of the impacts of ionising radiation is confounded by uncertainty. At all stages, from problem formulation through to risk characterisation, the assessment is dependent on models, scenarios, assumptions and extrapolations. These include technical uncertainties related to the data used, conceptual uncertainties associated with models and scenarios, as well as social uncertainties such as economic impacts, the interpretation of legislation, and the acceptability of the assessment results to stakeholders. The ERICA Integrated Approach has been developed to allow an assessment of the risks of ionising radiation, and includes a number of methods that are intended to make the uncertainties and assumptions inherent in the assessment more transparent to users and stakeholders. Throughout its development, ERICA has recommended that assessors deal openly with the deeper dimensions of uncertainty and acknowledge that uncertainty is intrinsic to complex systems. Since the tool is based on a tiered approach, the approaches to dealing with uncertainty vary between the tiers, ranging from a simple, but highly conservative screening to a full probabilistic risk assessment including sensitivity analysis. This paper gives on overview of types of uncertainty that are manifest in ecological risk assessment and the ERICA Integrated Approach to dealing with some of these uncertainties.
Subject(s)
Environmental Monitoring/methods , Radiation, Ionizing , Risk Assessment/methods , Models, TheoreticalABSTRACT
An essential step in the development of any modelling tool is the validation of its predictions. This paper describes a study conducted within the Chernobyl exclusion zone to acquire data to conduct an independent test of the predictions of the ERICA Tool which is designed for use in assessments of radiological risk to the environment. Small mammals were repeatedly trapped at three woodland sites between early July and mid-August 2005. Thermoluminescent dosimeters mounted on collars were fitted to Apodemus flavicollis, Clethrionomys glareolus and Microtus spp. to provide measurements of external dose rate. A total of 85 TLDs were recovered. All animals from which TLDs were recovered were live-monitored to determine (90)Sr and (137)Cs whole-body activity concentrations. A limited number of animals were also analysed to determine (239,240)Pu activity concentrations. Measurements of whole-body activity concentrations and dose rates recorded by the TLDs were compared to predictions of the ERICA-Tool. The predicted (90)Sr and (137)Cs mean activity concentrations were within an order of magnitude of the observed data means. Whilst there was some variation between sites in the agreement between measurements and predictions this was consistent with what would be expected from the differences in soil types at the sites. Given the uncertainties of conducting a study such as this, the agreement observed between the TLD results and the predicted external dose rates gives confidence to the predictions of the ERICA Tool.