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Journal of Environmental Radioactivity | 2008

The ERICA Tool

J.E. Brown; Boris Alfonso; R. Avila; N.A. Beresford; David Copplestone; G. Pröhl; Alexander Ulanovsky

The ERICA Tool is a computerised, flexible software system that has a structure based upon the ERICA Integrated Approach to assessing the radiological risk to biota. The Tool guides the user through the assessment process, recording information and decisions and allowing the necessary calculations to be performed to estimate risks to selected animals and plants. Tier 1 assessments are media concentration based and use pre-calculated environmental media concentration limits to estimate risk quotients. Tier 2 calculates dose rates but allows the user to examine and edit most of the parameters used in the calculation including concentration ratios, distribution coefficients, percentage dry weight soil or sediment, dose conversion coefficients, radiation weighting factors and occupancy factors. Tier 3 offers the same flexibility as Tier 2 but allows the option to run the assessment probabilistically if the underling parameter probability distribution functions are defined. Results from the Tool can be put into context using incorporated data on dose-effects relationships and background dose rates.


Journal of Environmental Radioactivity | 2008

Derivation of transfer parameters for use within the ERICA Tool and the default concentration ratios for terrestrial biota.

N.A. Beresford; C.L. Barnett; B.J. Howard; W.A. Scott; J.E. Brown; David Copplestone

An ability to predict radionuclide activity concentrations in biota is a requirement of any method assessing the exposure of biota to ionising radiation. Within the ERICA Tool fresh weight whole-body activity concentrations in organisms are estimated using concentration ratios (the ratio of the activity concentration in the organism to the activity concentration in an environmental media). This paper describes the methodology used to derive the default terrestrial ecosystem concentration ratio database available within the ERICA Tool and provides details of the provenance of each value for terrestrial reference organisms. As the ERICA Tool considers 13 terrestrial reference organisms and the radioisotopes of 31 elements, a total of 403 concentration ratios were required for terrestrial reference organisms. Of these, 129 could be derived from literature review. The approaches taken for selecting the remaining values are described. These included, for example, assuming values for similar reference organisms and/or biogeochemically similar elements, and various simple modelling approaches.


Annals of The Icrp | 2009

Environmental protection : transfer parameters for reference animals and plants

P. Strand; N.A. Beresford; David Copplestone; J. Godoy; L. Jianguo; R. Saxén; T. Yankovich; J.E. Brown

In Publication 103 (ICRP, 2007), the Commission included a section on the protection of the environment, and indicated that it would be further developing its approach to this difficult subject by way of a set of Reference Animals and Plants (RAPs) as the basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants. Subsequently, a set of 12 RAPs has been described in some detail (ICRP, 2008), particularly with regard to estimation of the doses received by them, at a whole-body level, in relation to internal and external radionuclide concentrations; and what is known about the effects of radiation on such types of animals and plants. A set of dose conversion factors for all of the RAPs has been derived, and the resultant dose rates can be compared with evaluations of the effects of dose rates using derived consideration reference levels (DCRLs). Each DCRL constitutes a band of dose rates for each RAP within which there is likely to be some chance of the occurrence of deleterious effects. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making. It is intended that the Commissions approach to protection of the environment be applied to all exposure situations. In some situations, the relevant radionuclide concentrations can be measured directly, but this is not always possible or feasible. In such cases, modelling techniques are used to estimate the radionuclide concentrations. This report is an initial step in addressing the needs of such modelling techniques. After briefly reviewing the basic factors relating to the accumulation of radionuclides by different types of biota, in different habitats, and at different stages in the life cycle, this report focuses on the approaches used to model the transfer of radionuclides through the environment. It concludes that equilibrium concentration ratios (CRs) are most commonly used to model such transfers, and that they currently offer the most comprehensive data coverage. The report also reviews the methods used to derive CRs, and describes a means of summarising statistical information from empirical data sets. Emphasis has been placed on using data from field studies, although some data from laboratory experiments have been included for some RAPs. There are, inevitably, many data gaps for each RAP, and other data have been used to help fill these gaps. CRs specific to each RAP were extracted from a larger database, structured in terms of generic wildlife groups. In cases where data were lacking, values from taxonomically-related organisms were used to derive suitable surrogate values. The full set of rules which have been applied for filling gaps in RAP-specific CRs is described. Statistical summaries of the data sets are provided, and CR values for 39 elements and 12 RAP combinations are given. The data coverage, reliance on derived values, and applicability of the CR approach for each of the RAPs is discussed. Finally, some consideration is given to approaches where RAPs and their life stages could be measured for the elements of interest under more rigorously controlled conditions to help fill the current data gaps.


Journal of Environmental Radioactivity | 2013

The IAEA handbook on radionuclide transfer to wildlife

B.J. Howard; N.A. Beresford; David Copplestone; D. Telleria; G. Proehl; Ross Jeffree; T. Yankovich; J.E. Brown; Kathryn A. Higley; Mathew P. Johansen; H. Mulye; Hildegarde Vandenhove; S. Gashchak; Michael D. Wood; Hyoe Takata; P. Andersson; Paul Dale; J. Ryan; A. Bollhöfer; C. Doering; C.L. Barnett; C. Wells

An IAEA handbook presenting transfer parameter values for wildlife has recently been produced. Concentration ratios (CRwo-media) between the whole organism (fresh weight) and either soil (dry weight) or water were collated for a range of wildlife groups (classified taxonomically and by feeding strategy) in terrestrial, freshwater, marine and brackish generic ecosystems. The data have been compiled in an on line database, which will continue to be updated in the future providing the basis for subsequent revision of the Wildlife TRS values. An overview of the compilation and analysis, and discussion of the extent and limitations of the data is presented. Example comparisons of the CRwo-media values are given for polonium across all wildlife groups and ecosystems and for molluscs for all radionuclides. The CRwo-media values have also been compared with those currently used in the ERICA Tool which represented the most complete published database for wildlife transfer values prior to this work. The use of CRwo-media values is a pragmatic approach to predicting radionuclide activity concentrations in wildlife and is similar to that used for screening assessments for the human food chain. The CRwo-media values are most suitable for a screening application where there are several conservative assumptions built into the models which will, to varying extents, compensate for the variable data quality and quantity, and associated uncertainty.


Radiation and Environmental Biophysics | 2008

Inter-comparison of models to estimate radionuclide activity concentrations in non-human biota

N.A. Beresford; C.L. Barnett; J.E. Brown; J.-J. Cheng; David Copplestone; V. Filistovic; A. Hosseini; B.J. Howard; Steve R Jones; S. Kamboj; A. Kryshev; T. Nedveckaite; G. Olyslaegers; R. Saxén; Tatiana G. Sazykina; J. Vives i Batlle; S. Vives-Lynch; T. Yankovich; C. Yu

A number of models have recently been, or are currently being, developed to enable the assessment of radiation doses from ionising radiation to non-human species. A key component of these models is the ability to predict whole-organism activity concentrations in a wide range of wildlife. In this paper, we compare the whole-organism activity concentrations predicted by eight models participating within the IAEA Environmental Modelling for Radiation Safety programme for a range of radionuclides to terrestrial and freshwater organisms. In many instances, there was considerable variation, ranging over orders of magnitude, between the predictions of the different models. Reasons for this variability (including methodology, data source and data availability) are identified and discussed. The active participation of groups responsible for the development of key models within this exercise is a useful step forward in providing the transparency in methodology and data provenance required for models which are either currently being used for regulatory purposes or which may be used in the future. The work reported in this paper, and supported by other findings, demonstrates that the largest contribution to variability between model predictions is the parameterisation of their transfer components. There is a clear need to focus efforts and provide authoritative compilations of those data which are available.


Applied Radiation and Isotopes | 2008

An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota.

N.A. Beresford; M. Balonov; K. Beaugelin-Seiller; J.E. Brown; David Copplestone; J. L. Hingston; J. Horyna; A. Hosseini; B.J. Howard; S. Kamboj; T. Nedveckaite; G. Olyslaegers; Tatiana G. Sazykina; Jordi Vives i Batlle; T. Yankovich; C. Yu

Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionising radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the International Atomic Energy Agencys EMRAS Biota Working Group which compares the predictions of a number of such models in model-model and model-data inter-comparisons.


Journal of Radiological Protection | 2004

Radiation doses to aquatic organisms from natural radionuclides

J.E. Brown; Steve R Jones; R. Saxén; H. Thørring; J. Vives i Batlle

A framework for protection of the environment is likely to require a methodology for assessing dose rates arising from naturally occurring radionuclides. This paper addresses this issue for European aquatic environments through a process of (a) data collation, mainly with respect to levels of radioactivity in water sediments and aquatic flora and fauna, (b) the use of suitable distribution coefficients, concentration factors and global data where data gaps are present and (c) the utilisation of a reference organism approach whereby a finite number of suitable geometries are selected to allow dose per unit concentration factors to be derived and subsequent absorbed dose calculations (weighted or unweighted) to be made. The majority of the calculated absorbed dose, for both marine and freshwater organisms, arises from internally incorporated alpha emitters, with 210Po and 226Ra being the major contributors. Calculated doses are somewhat higher for freshwater compared to marine organisms, and the range of doses is also much greater. This reflects both the much greater variability of radionuclide concentrations in freshwater as compared to seawater, and also variability or uncertainty in concentration factor values. This work has revealed a number of substantial gaps in published empirical data especially for European aquatic environments.


Journal of Radiological Protection | 2010

Protection of the environment from ionising radiation in a regulatory context—an overview of the PROTECT coordinated action project

B.J. Howard; N.A. Beresford; P. Andersson; J.E. Brown; David Copplestone; K. Beaugelin-Seiller; Jacqueline Garnier-Laplace; Paul Howe; Deborah Oughton; Paul Whitehouse

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.


Radiation and Environmental Biophysics | 2010

Whole-body to tissue concentration ratios for use in biota dose assessments for animals

T. Yankovich; N.A. Beresford; Michael D. Wood; Tasuo Aono; P. Andersson; C.L. Barnett; Pamela Bennett; J.E. Brown; J. Fesenko; A. Hosseini; B.J. Howard; Mathew P. Johansen; Marcel M. Phaneuf; Keiko Tagami; Hyoe Takata; John R. Twining; Shigeo Uchida

Environmental monitoring programs often measure contaminant concentrations in animal tissues consumed by humans (e.g., muscle). By comparison, demonstration of the protection of biota from the potential effects of radionuclides involves a comparison of whole-body doses to radiological dose benchmarks. Consequently, methods for deriving whole-body concentration ratios based on tissue-specific data are required to make best use of the available information. This paper provides a series of look-up tables with whole-body:tissue-specific concentration ratios for non-human biota. Focus was placed on relatively broad animal categories (including molluscs, crustaceans, freshwater fishes, marine fishes, amphibians, reptiles, birds and mammals) and commonly measured tissues (specifically, bone, muscle, liver and kidney). Depending upon organism, whole-body to tissue concentration ratios were derived for between 12 and 47 elements. The whole-body to tissue concentration ratios can be used to estimate whole-body concentrations from tissue-specific measurements. However, we recommend that any given whole-body to tissue concentration ratio should not be used if the value falls between 0.75 and 1.5. Instead, a value of one should be assumed.


Journal of Environmental Radioactivity | 2013

An international database of radionuclide concentration ratios for wildlife: development and uses

David Copplestone; N.A. Beresford; J.E. Brown; T. Yankovich

A key element of most systems for assessing the impact of radionuclides on the environment is a means to estimate the transfer of radionuclides to organisms. To facilitate this, an international wildlife transfer database has been developed to provide an online, searchable compilation of transfer parameters in the form of equilibrium-based whole-organism to media concentration ratios. This paper describes the derivation of the wildlife transfer database, the key data sources it contains and highlights the applications for the data.

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A. Hosseini

Norwegian Radiation Protection Authority

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B.J. Howard

Natural Environment Research Council

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P. Strand

Norwegian Radiation Protection Authority

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C.L. Barnett

Natural Environment Research Council

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Deborah Oughton

Norwegian University of Life Sciences

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T. Yankovich

Saskatchewan Research Council

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K. Beaugelin-Seiller

Institut de radioprotection et de sûreté nucléaire

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R. Avila

Swedish University of Agricultural Sciences

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