Browsing by Author "Carpenter, JG"

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    Developing international radiological risk assessment tools for Australian arid environments
    (South Pacific Environmental Radioactivity Association, 2018-11-06) Popelka-Filcoff, RS; Pring, A; Pandelus, SB; Johns, SM; Tucker, W; Rossouw, D; Lenehan, CE; Hondros, J; Hirth, GA; Carpenter, JG; Johansen, MP; Payne, TE; Roberts, M; Levingstone, K; Tuft, K; Duff, T
    Recent international and Australian regulatory guidance llCRP 108 and ARRANSA Env. Prot. Guide, 2015) has increased the need for effective tools to assess radiological impacts in the environment. The existing internationally accepted methods and models are generally based on data collected in the northern hemisphere and there is a recognised lack of southern hemisphere data, particularly from Australia. When applying the models and methods in Australia, acknowledgement of this lack of data is required which tends to undermine public and regulatory confidence in the assessment. Development of an Australian-specific data set is essential to a better understanding and more credible environmental impact assessment process. In addition, decision-making by operators and regulatory authorities will be based on more relevant local information This presentation describes a collaborative project between university, government and industry researchers and a national industry funding body, aimed at developing a more complete understanding of radiological uptake of native flora and fauna in arid Australian environments. The presentation will cover the framework and sampling and analysis approaches from arid environments, and how these fit into international practice. lnitial data and concentration ratios from analysis of Dodonaea viscosa and Acacia ligulata, rabbits and feral cats and corresponding soil will be presented. Analytical methods include high-resolution gamma spectroscopy with low limits of detection, alpha spectroscopy, elemental analysis by inductively coupled plasma mass spectrometry, scanning electron microscopy. ant"; 3."; 5 Novel approaches to data collection and analysis protocols are used, which form the basis of the databases use: :. i"e internationally accepted models and comparison to extant studies. The project lays the infrastructure towards an effective Australian intenface with existing tools (e.g. ERICA) and assessment for extended long-term studies for industry and regulators. The results of this project build a foundation for environmental radionuclide assessment for Australia's specific climate and species, and build a framework for a comprehensive Australian context and understanding of radionuciides and their concentration ratios as well as towards screening levels which may vary depending on location and species. This project has an industry-wide impact in the generation of robust data sets towards modelling in arid environments.
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    Global seafood dose 2023: assessment by an international team
    (ICRP, 2023-11-06) Johansen, MP; Carpenter, JG; Charmasson, S; Gwynn, JP; McGinnity, P; Mori, A; Orr, B; Simon-Cornu, M; Osvath, I
    It has been known for many years that ingestion dose from seafood is an important component of the background dose rates for billions of consumers worldwide and that eating seafood can contribute proportionally higher dose as compared with terrestrial-sourced foods. However, a well-supported and current estimate of the contribution of seafood to the dose of global consumers is not available. This is mainly because of the difficulty in assembling the underlying data on a global scale, but also due to the varied and dynamic nature of exposures. Global seafood consumption is increasing, diet patterns are shifting (e.g., toward more farmed products), and new inputs of radionuclides into marine systems have occurred (e.g., the Fukushima accident). A new assessment is being conducted on seafood dose in the context of the ongoing stresses on ocean resources and protection of the marine environment. Its global scale makes use of a much-expanded database on radionuclides in seafood (Marine Radioactivity Information System -MARIS) as well as global diet data and updated parameters for dose calculation. The new assessment: • Evaluates global data on 16 natural and anthropogenic radionuclides. • Draws from more than 84,856 activity concentrations data for biota. • Uses seafood consumption data representing approximately 35% of the world population drawn from national and sub-national diet studies. • Develops new correction factors for the loss of 210Po during cooking, radiological decay during storage, as well as the decreases in 210Po in maricultured seafood. • Implements a bespoke Monte Carlo application for calculating seafood dose distributions. • Compiles and evaluates 150+ seafood ingestion dose estimates published in the past 30 years. The new results indicate somewhat higher seafood dose rates for typical global consumers than previous comprehensive assessments (UNSCEAR, MARDOS). Compared with the 150+ previous individual published studies, our distribution of global dose matches closely and helps explain and interpret the previous estimates. Most background seafood dose is from naturally-sourced 210Po (~80%) followed by 210Pb (+10%) and the Ra radionuclides (~7%). A comparatively small background dose (<0.01%) comes from the ambient anthropogenic radionuclides in seafood that derive from worldwide fallout, accidents, releases from waste sites and similar sources. Study outcomes are useful in providing benchmark references for dose assessments performed on the local, regional and national scale for planned facilities or for evaluating accidental releases. They also provide a baseline for quantifying the changes in seafood dose over time. Results show that typical seafood doses are changing as they reflect trends toward more maricultured products (which can have markedly lower levels of 210Po), various stresses and impacts on world fisheries as well as the evolution of seafood production and distribution systems. Numerous researchers and organisations worldwide have provided input into the project. The assessment is being conducted within the IAEA Coordinated Research Project “Behaviour and Effects of Natural and Anthropogenic Radionuclides in the Marine Environment and their Use as Tracers for Oceanography Studies.”
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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.
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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