Browsing by Author "Bollhöfer, A"

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    The IAEA handbook on radionuclide transfer to wildlife
    (Elsevier B.V., 2013-07-01) Howard, BJ; Beresford, NA; Copplestone, D; Telleria, D; Proehl, G; Fesenko, S; Jeffree, RA; Yankovich, TL; Brown, JE; Higley, K; Johansen, MP; Mulye, H; Vandenhove, H; Gashchakk, S; Wood, MD; Takatam, H; Andersson, P; Dale, P; Ryan, J; Bollhöfer, A; Doering, C; Barnett, CL; Wells, C
    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. © 2012, Elsevier Ltd.
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    Recent developments in the modelling of radionuclide uptake, radiation dose and effects in wildlife
    (South Pacific Environmental Radioactivity Association, 2014-09) Johansen, MP; Beresford, NA; Howard, BJ; Hinton, TG; Bollhöfer, A; Doering, C; Hirth, GA; Grzechnik, M; Ruedig, E; Payne, TE; Twining, JR
    Of the ~600 scientific publications on the Fukushima event, more than 80% relate to themes of transport of radionuclides in environmental media, transfer to wildlife and foodstuffs, and dose to environmental receptors. This focus reflects a continued need for development and harmonisation of radiological modelling approaches such as has been underway through recent IAEA and ICRP initiatives (e.g. EMRAS I and II, MODARIA). Key developments in improving the understanding of uptake of radionuclides in wildlife include establishing the Wildlife Transfer Parameter Database and related IAEA handbook on transfer to wildlife. These sources provide access to a comprehensive collection of transfer parameters, including input from Australian sources (www.wildlifetransferdatabase.org). Key improvements were highlighted in a recent Journal of Environmental Radioactivity special issue (Vol. 121). Dose modelling for wildlife continues to be challenged by the high diversity of biotic types (plankton to whales) and the breadth of exposure scenarios in diverse ecosystems. Modelling codes (e.g. ERICA Tool, RESRAD-Biota) are undergoing updates of their transfer parameters, improvement of capabilities such as probabilistic analysis (e.g. Monte Carlo), and harmonization of approaches through IAEA model testing exercises (e.g., Little Forest Burial Ground biota dose modelling assessment). A recent development has been the use of voxel dosimetry approaches which build on the standard simplified ellipsoid approach by modelling the absorbed doses in individual organs. Recent improvements in defining dose effects to environmental receptors have focused on updating the FREDERICA Radiation Effects Database. The more comprehensive data have allowed for the updating/development of new Species Sensitivity Distributions that better support the benchmark values for potential dose effects, and for improving estimation of population effects (rather than individuals) upon which the environmental protection strategies are based.
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    Whole-organism concentration ratios in wildlife inhabiting Australian uranium mining environments
    (International Union of Radioecology, 2014-09-07) Hirth, GA; Carpenter, JG; Bollhöfer, A; Johansen, MP; Beresford, NA
    Environmental impact assessments conducted for Australian mine sites involving naturally occurring radioactive material require an assessment of radiation doses to wildlife. Whole-organism concentration ratios (CRwo) are pivotal in these assessments and previous reviews have identified a need for a more complete and consolidated database of Australian-specific CRwo that could be used. Concern had also been expressed by some stakeholders in Australia about the suitability of the default CRwo values provided in standard biota dose models (e.g., ERICA Tool, RESRAD-BIOTA, ICRP framework) for Australian wildlife and environmental conditions. In order to address these concerns and support the implementation of best-practice standards in environmental radiological assessment, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), with support from the Department of Resources, Energy and Tourism (RET), undertook an evaluation of existing data relating to wildlife inhabiting Australian uranium mining environments. CRwo values were calculated using data from a range of original sources. These included scientific journal publications, technical reports from Australian government organisations, site-specific data from mining operators and data from baseline environmental surveys undertaken during the 1970's and 1980's. The Australian data previously included in the international Wildlife Transfer Database (WTD, www.wildlifetransferdatabase.org) were also reviewed and updated. This paper discusses the data analysis process and associated uncertainties. CRwo values are reported for uranium, thorium, radium-226, lead-210 and polonium-210 for a range of endemic and introduced wildlife, with a focus on plants and animals from both terrestrial and freshwater environments where uranium mining has been proposed or undertaken. This has resulted in the calculation of more than 500 CRwo values for inclusion in the database. Australian-specific CRwo values will be compared to general values reported in the WTD including examples of specific wildlife groups or unique environmental conditions that are outside the range of the CRwo values in the WTD. Recommendations regarding biota types and environmental conditions for which data are most lacking will also be discussed. ©2008 IUR - International Union of Radioecology
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    Whole-organism concentration ratios in wildlife inhabiting Australian uranium mining environments
    (Elsevier B. V., 2017-11) Hirth, GA; Johansen, MP; Carpenter, JG; Bollhöfer, A; Beresford, NA
    Wildlife concentration ratios for 226Ra, 210Pb, 210Po and isotopes of Th and U from soil, water, and sediments were evaluated for a range of Australian uranium mining environments. Whole-organism concentration ratios (CRwo-media) were developed for 271 radionuclide-organism pairs within the terrestrial and freshwater wildlife groups. Australian wildlife often has distinct physiological attributes, such as the lower metabolic rates of macropod marsupials as compared with placental mammals. In addition, the Australian CRswo-media originate from tropical and semi-arid climates, rather than from the temperate-dominated climates of Europe and North America from which most (>90%) of internationally available CRwo-media values originate. When compared, the Australian and non-Australian CRs are significantly different for some wildlife categories (e.g. grasses, mammals) but not others (e.g. shrubs). Where differences exist, the Australian values were higher, suggesting that site-, or region-specific CRswo-media should be used in detailed Australian assessments. However, in screening studies, use of the international mean values in the Wildlife Transfer Database (WTD) appears to be appropriate, as long as the values used encompass the Australian 95th percentile values. Gaps in the Australian datasets include a lack of marine parameters, and no CR data are available for freshwater phytoplankton, zooplankton, insects, insect larvae or amphibians; for terrestrial environments, there are no data for amphibians, annelids, ferns, fungi or lichens & bryophytes. The new Australian specific parameters will aide in evaluating remediation plans and ongoing operations at mining and waste sites within Australia. They have also substantially bolstered the body of U- and Th-series CRwo-media data for use internationally. ©2017 The Authors.