Browsing by Author "Tagami, K"

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    Final report on a field study of soil-to-plant transfer of radioactive caesium, strontium and zinc in tropical Northern Australia to the IAEA/FAO/IUR CRP on classification of soils systems on the basis of transfer factors of radionuclides from soil to reference plants
    (Australian Nuclear Science and Technology Organisation, 2003-09) Twining, JR; Shotton, P; Tagami, K; Payne, TE; Itakura, T; Russell, RA; Wilde, KL; McOrist, GD; Wong, HKY
    Soil-to-plant radionuclide transfer factors for cesium (134Cs), strontium (85Sr) and zinc (65Zn) into sorghum and mung plants grown in tropical Australia have been determined over a four-year study period. The crops were grown on two types of red earth soils. Transfer factors for Cs and Sr are not substantially different from the expected values based on previous studies, reported in the general literature and compiled in the IUR database, mainly performed within temperate climates. In contrast, the values for zinc (Zn) are more than an order of magnitude greater than anticipated. Most of the radioactivity added to the soils has been retained in the top 5 cm of both soils. There has been a general decline in soil-to-plant transfer of Cs and Zn as time has increased.
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    Radiological dose rates to marine fish from the Fukushima Daiichi Accident: the first three years across the North Pacific
    (American Chemical Society, 2014-12-22) Johansen, MP; Ruedig, E; Tagami, K; Uchida, S; Higley, K; Beresford, NA
    A more complete record is emerging of radionuclide measurements in fish tissue, sediment, and seawater samples from near the Fukushima Daiichi Nuclear Power Plant (FDNPP) and across the Pacific Ocean. Our analysis of publicly available data indicates the dose rates to the most impacted fish species near the FDNPP (median 1.1 mGy d–1, 2012–2014 data) have remained above benchmark levels for potential dose effects at least three years longer than was indicated by previous, data-limited evaluations. Dose rates from 134,137Cs were highest in demersal species with sediment-associated food chains and feeding behaviors. In addition to 134,137Cs, the radionuclide 90Sr was estimated to contribute up to approximately one-half of the total 2013 dose rate to fish near the FDNPP. Mesopelagic fish 100–200 km east of the FDNPP, coastal fish in the Aleutian Islands (3300 km), and trans-Pacific migratory species all had increased dose rates as a consequence of the FDNPP accident, but their total dose rates remained dominated by background radionuclides. A hypothetical human consumer of 50 kg of fish, gathered 3 km from the FDNPP in 2013, would have received a total committed effective dose of approximately 0.95 mSv a–1 from combined FDNPP and ambient radionuclides, of which 0.13 mSv a–1 (14%) was solely from the FDNPP radionuclides and below the 1 mSv a–1 benchmark for public exposure. © 2014 American Chemical Society
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    Whole-body to tissue concentration ratios for use in biota dose assessments for animals
    (Springer, 2010-11) Yankovich, TL; Beresford, NA; Wood, MD; Aono, T; Andersson, P; Barnett, CL; Bennett, P; Brown, JE; Fesenko, S; Fesenko, J; Hosseini, A; Howard, BJ; Johansen, MP; Phaneuf, MM; Tagami, K; Takata, H; Twining, JR; Uchida, S
    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. © 2010, Springer.