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Yusuf I, Hansson E, Eriksson M, Roos P, Lindahl P, Pettersson HBL. Particle Size Dependent Dissolution of Uranium Aerosols in Simulated Gastrointestinal Fluids. HEALTH PHYSICS 2023; 124:285-300. [PMID: 36727932 PMCID: PMC9940842 DOI: 10.1097/hp.0000000000001668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/08/2022] [Indexed: 06/18/2023]
Abstract
ABSTRACT Uranium aerosol exposure can be a health risk factor for workers in the nuclear fuel industry. Good knowledge about aerosol dissolution and absorption characteristics in the gastrointestinal tract is imperative for solid dose assessments and risk management. In this study, an in vitro dissolution model of the GI tract was used to experimentally study solubility of size-fractionated aerosols. The aerosols were collected from four major workshops in a nuclear fuel fabrication plant where uranium compounds such as uranium hexafluoride (UF 6 ), uranium dioxide (UO 2 ), ammonium uranyl carbonate, AUC [UO 2 CO 3 ·2(NH 4 ) 2 CO 3 ] and triuranium octoxide (U 3 O 8 ) are present. The alimentary tract transfer factor, f A , was estimated for the aerosols sampled in the study. The transfer factor was derived from the dissolution in the small intestine in combination with data on absorption of soluble uranium. Results from the conversion workshop indicated a f A in line with what is recommended (0.004) by the ICRP for inhalation exposure to Type M materials. Obtained transfer factors, f A , for the powder preparation and pelletizing workshops where UO 2 and U 3 O 8 are handled are lower for inhalation and much lower for ingestion than those recommended by the ICRP for Type M/S materials f A = 0.00029 and 0.00016 vs. 0.0006 and 0.002, respectively. The results for ingestion and inhalation f A indicate that ICRP's conservative recommendation of f A for inhalation exposure is applicable to both ingestion and inhalation of insoluble material in this study. The dissolution- and subsequent absorption-dependence on particle size showed correlation only for one of the workshops (pelletizing). The absence of correlation at the other workshops may be an effect of multiple chemical compounds with different size distribution and/or the reported presence of agglomerated particles at higher cut points having more impact on the dissolution than particle size. The impact on dose coefficients [committed effective dose (CED) per Bq] of using experimental f A vs. using default f A recommended by the ICRP for the uranium compounds of interest for inhalation exposure was not significant for any of the workshops. However, a significant impact on CED for ingestion exposure was observed for all workshops when comparing with CED estimated for insoluble material using ICRP default f A . This indicates that the use of experimentally derived site-specific f A can improve dose assessments. It is essential to acquire site-specific estimates of the dissolution and absorption of uranium aerosols as this provides more realistic and accurate dose- and risk-estimates of worker exposure. In this study, the results indicate that ICRP's recommendations for ingestion of insoluble material might overestimate absorption and that the lower f A found for inhalation could be more realistic for both inhalation and ingestion of insoluble material.
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Affiliation(s)
- Ibtisam Yusuf
- Department of Medical Radiation Physics, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Edvin Hansson
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
- Westinghouse Electric Sweden AB, Bränslegatan 1, 72136 Västerås, Sweden
| | - Mats Eriksson
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Per Roos
- European Spallation Source ERIC, P.O Box 176, SE-221 00 Lund, Sweden
| | - Patric Lindahl
- Swedish Radiation Safety Authority, 17116 Stockholm, Sweden
| | - Håkan B. L. Pettersson
- Department of Medical Radiation Physics, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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Rashid NSA, Um W, Ijang I, Siong KK, Singh BK, Mahzan NS, Fadzil SM, Rodzi NSD, Nasir ASM. Acute oral toxicity and bioavailability of uranium and thorium in contaminated soil. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Cleveland D, Hinck JE, Lankton JS. Elemental and radionuclide exposures and uptakes by small rodents, invertebrates, and vegetation at active and post-production uranium mines in the Grand Canyon watershed. CHEMOSPHERE 2021; 263:127908. [PMID: 32835973 DOI: 10.1016/j.chemosphere.2020.127908] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 07/31/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized the exposure of biota to uranium and co-occurring ore body elements during active ore production and at a site where ore production had recently concluded. Our results indicate that biota have taken up uranium and other elements (e.g., arsenic, cadmium, copper, molybdenum, uranium) from exposure to ore and surficial contamination, like blowing dust. Results indicate the potential for prolonged exposure to elements and radionuclides upon conclusion of active ore production. Mean radium-226 in deer mice was up to 4 times greater than uranium-234 and uranium-238 in those same samples; this may indicate a potential for, but does not necessarily imply, radium-226 toxicity. Soil screening benchmarks for uranium and molybdenum and other toxicity thresholds for arsenic, copper, selenium, uranium (e.g., growth effects) were exceeded in vegetation, invertebrates, and rodents (Peromyscus spp., Thomomys bottae, Tamias dorsalis, Dipodomys deserti). However, the prevalence and severity of microscopic lesions in rodent tissues (as direct evidence of biological effects of uptake and exposure) could not be definitively linked to mining. Our data indicate that land managers might consider factors like species, seasonal changes in environmental concentrations, and bioavailability, when determining mine permitting and remediation in the Grand Canyon watershed. Ultimately, our results will be useful for site-specific ecological risk analysis and can support future decisions regarding the mineral extraction withdrawal in the Grand Canyon watershed and elsewhere.
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Affiliation(s)
- Danielle Cleveland
- U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO, 65201, USA.
| | - Jo Ellen Hinck
- U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO, 65201, USA
| | - Julia S Lankton
- U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, WI, 53711, USA
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Hayek EE, Brearley AJ, Howard T, Hudson P, Torres C, Spilde MN, Cabaniss S, Ali AMS, Cerrato JM. Calcium in Carbonate Water Facilitates the Transport of U(VI) in Brassica juncea Roots and Enables Root-to-Shoot Translocation. ACS EARTH & SPACE CHEMISTRY 2019; 3:2190-2196. [PMID: 31742240 PMCID: PMC6859903 DOI: 10.1021/acsearthspacechem.9b00171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The role of calcium (Ca) on the cellular distribution of U(VI) in Brassica juncea roots and root-to-shoot translocation was investigated using hydroponic experiments, microscopy, and spectroscopy. Uranium accumulated mainly in the roots (727-9376 mg kg-1) after 30 days of exposure to 80 μM dissolved U in water containing 1 mM HCO3 - at different Ca concentrations (0-6 mM) at pH 7.5. However, the concentration of U in the shoots increased 22 times in experiments with 6 mM Ca compared to 0 mM Ca. In the Ca control experiment, transmission electron microscopy-energy-dispersive spectroscopy analyses detected U-P-bearing precipitates in the cortical apoplast of parenchyma cells. In experiments with 0.3 mM Ca, U-P-bearing precipitates were detected in the cortical apoplast and the bordered pits of xylem cells. In experiments with 6 mM Ca, U-P-bearing precipitates aggregated in the xylem with no apoplastic precipitation. These results indicate that Ca in carbonate water inhibits the transport and precipitation of U in the root cortical apoplast and facilitates the symplastic transport and translocation toward shoots. These findings reveal the considerable role of Ca in the presence of carbonate in facilitating the transport of U in plants and present new insights for future assessment and phytoremediation strategies.
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Affiliation(s)
- Eliane El Hayek
- Department of Chemistry and Chemical Biology, University of New Mexico, MSC03 2060, Albuquerque, New Mexico 87131, United States
| | - Adrian J. Brearley
- Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, Albuquerque, New Mexico 87131, United States
| | - Tamara Howard
- Department of Cell Biology and Physiology, University of New Mexico, MSC08 4750, Albuquerque, New Mexico 87131, United States
| | - Patrick Hudson
- Department of Biology, University of New Mexico, MSC03 2020, Albuquerque, New Mexico 87131, United States
| | - Chris Torres
- Department of Chemical and Biological Engineering, University of New Mexico, MSC01 1120, Albuquerque, New Mexico 87131, United States
| | - Michael N. Spilde
- Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, Albuquerque, New Mexico 87131, United States
| | - Stephen Cabaniss
- Department of Chemistry and Chemical Biology, University of New Mexico, MSC03 2060, Albuquerque, New Mexico 87131, United States
| | - Abdul-Mehdi S. Ali
- Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, Albuquerque, New Mexico 87131, United States
| | - José M. Cerrato
- Department of Civil Engineering, University of New Mexico, MSC01 1070, Albuquerque, New Mexico 87131, United States
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Determination of natural uranium by various analytical techniques in soils of Zacatecas State (Mexico). J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06428-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Foulkes M, Millward G, Henderson S, Blake W. Bioaccessibility of U, Th and Pb in solid wastes and soils from an abandoned uranium mine. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 173:85-96. [PMID: 27979647 DOI: 10.1016/j.jenvrad.2016.11.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 11/27/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
Bioaccessible U, Th, Pb and the 238U decay products 214Pb and 210Pb have been determined, using a modified Unified BARGE Method (UBM), in waste solids and soils from an abandoned uranium mine in South West England, UK. Maximum aqua regia extractable concentrations for U, Th and Pb were 16,200, 3.8 and 4750 μg g-1, respectively. 238U had highest activity concentrations near the mine shaft, where the decay products214Pb and 210Pb had values of 235 and 180 Bq g-1, respectively. UBM extractions gave mean gastro-intestinal bioaccessibility factors (BAFs) for U and Pb in the waste solids of 0.05 and 0.03, respectively, whereas those for the soils were significantly higher at 0.24 and 0.17. The mean BAFs for the transient radionuclides, 214Pb and 210Pb, were similar to those for stable Pb implying that the stable and radioactive Pb isotopes were attached to similar sites on the particles. The doses arising from the ingestion of particulate 210Pb due to soil pica behaviour were in the range 0.2-65 and < 0.1-6.2 μSv day-1 for a 1-year old child or an adult (>17 years), respectively. The results suggest that the health risk posed by abandoned uranium mines, with waste rock and tailings, throughout the world should take account of the dose due to both bioaccessible radionuclides, as well as their stable counterparts.
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Affiliation(s)
- Michael Foulkes
- Plymouth University, School of Geography, Earth and Environmental Sciences, Portland Square, Drake Circus, Plymouth PL4 8AA, United Kingdom.
| | - Geoffrey Millward
- Plymouth University, Consolidated Radio-isotope Facility, Drake Circus, Plymouth PL4 8AA, United Kingdom.
| | - Samuel Henderson
- Plymouth University, School of Geography, Earth and Environmental Sciences, Portland Square, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - William Blake
- Plymouth University, School of Geography, Earth and Environmental Sciences, Portland Square, Drake Circus, Plymouth PL4 8AA, United Kingdom.
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Träber SC, Li WB, Höllriegl V, Nebelung K, Michalke B, Rühm W, Oeh U. Calculation of internal dose from ingested soil-derived uranium in humans: Application of a new method. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2015; 54:265-272. [PMID: 25980738 DOI: 10.1007/s00411-015-0602-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 04/28/2015] [Indexed: 06/04/2023]
Abstract
The aim of the present study was to determine the internal dose in humans after the ingestion of soil highly contaminated with uranium. Therefore, an in vitro solubility assay was performed to estimate the bioaccessibility of uranium for two types of soil. Based on the results, the corresponding bioavailabilities were assessed by using a recently published method. Finally, these bioavailability data were used together with the biokinetic model of uranium to assess the internal doses for a hypothetical but realistic scenario characterized by a daily ingestion of 10 mg of soil over 1 year. The investigated soil samples were from two former uranium mining sites of Germany with (238)U concentrations of about 460 and 550 mg/kg. For these soils, the bioavailabilities of (238)U were quantified as 0.18 and 0.28 % (geometric mean) with 2.5th percentiles of 0.02 and 0.03 % and 97.5th percentiles of 1.48 and 2.34 %, respectively. The corresponding calculated annual committed effective doses for the assumed scenario were 0.4 and 0.6 µSv (GM) with 2.5th percentiles of 0.2 and 0.3 µSv and 97.5th percentiles of 1.6 and 3.0 µSv, respectively. These annual committed effective doses are similar to those from natural uranium intake by food and drinking water, which is estimated to be 0.5 µSv. Based on the present experimental data and the selected ingestion scenario, the investigated soils-although highly contaminated with uranium-are not expected to pose any major health risk to humans related to radiation.
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Affiliation(s)
- S C Träber
- Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany,
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Träber SC, Höllriegl V, Li WB, Czeslik U, Rühm W, Oeh U, Michalke B. Estimating the absorption of soil-derived uranium in humans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14721-14727. [PMID: 25417915 DOI: 10.1021/es504171r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aim of the present study was to improve the estimation of soil-derived uranium absorption in humans. For this purpose, an in vitro solubility assay was combined with a human study by using a specific edible soil low in uranium. The mean bioaccessibility of the soil-derived uranium, determined by the solubility assay in artificial gastrointestinal fluid, was found to be 7.7% with a standard deviation of 0.2%. The corresponding bioavailability of the soil-derived uranium in humans was assumed to be log-normal distributed with a geometric mean of 0.04% and a 95% confidence interval ranging from 0.0049% to 0.34%. Both results were used to calculate a factor, denoted as fA(sol), which describes the relation between the bioaccessibility and the bioavailability of soil-derived uranium. The geometric mean of fA(sol) was determined to be 0.53% with a 95% confidence interval ranging from 0.06% to 4.43%. Based on fA(sol), it is possible to estimate more realistic values on the bioavailability of uranium for highly uranium-contaminated soils in humans by just performing the applied solubility assay. The results of this study can be further used to obtain more reliable results on the internal dose assessment of ingested highly uranium-contaminated soils.
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Affiliation(s)
- Stephan C Träber
- Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
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Guney M, Zagury GJ. Bioaccessibility of As, Cd, Cu, Ni, Pb, and Sb in toys and low-cost jewelry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:1238-1246. [PMID: 24345102 DOI: 10.1021/es4036122] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Children can be exposed to toxic elements in toys and jewelry following ingestion. As, Cd, Cu, Ni, Pb, and Sb bioavailability was assessed (n = 24) via the in vitro gastrointestinal protocol (IVG), the physiologically based extraction test (PBET), and the European Toy Safety Standard protocol (EN 71-3), and health risks were characterized. Cd, Cu, Ni, and Pb were mobilized from 19 metallic toys and jewelry (MJ) and one crayon set. Bioaccessible Cd, Ni, or Pb exceeded EU migratable concentration limits in four to six MJ, depending on the protocol. Using two-phase (gastric + intestinal) IVG or PBET might be preferable over EN 71-3 since they better represent gastrointestinal physiology. Bioaccessible and total metal concentrations were different and not always correlated, indicating that bioaccessibility measurement may provide more accurate risk characterization. More information on impacts of multiple factors affecting metals mobilization from toys and jewelry is needed before recommending specific tests. Hazard index (HI) for Cd, Ni, or Pb were >1 for all six MJ exceeding the EU limits. For infants (6-12 mo old), 10 MJ had HI > 1 for Cd, Cu, Ni, or Pb (up to 75 for Cd and 43 for Pb). Research on prolonged exposure to MJ and comprehensive risk characterization for toys and jewelry exposure is recommended.
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Affiliation(s)
- Mert Guney
- Department of Civil, Geological and Mining Engineering, École Polytechnique de Montréal , Montréal, Québec, H3C 3A7 Canada
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