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Smith R, Ellender M, Guo C, Hammond D, Laycock A, Leonard MO, Wright M, Davidson M, Malard V, Payet M, Grisolia C, Blanchardon E. Biokinetics and Internal Dosimetry of Tritiated Steel Particles. TOXICS 2022; 10:toxics10100602. [PMID: 36287882 PMCID: PMC9607624 DOI: 10.3390/toxics10100602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 05/14/2023]
Abstract
Decommissioning fission and fusion facilities can result in the production of airborne particles containing tritium that could inadvertently be inhaled by workers directly involved in the operations, and potentially others, resulting in internal exposures to tritium. Of particular interest in this context, given the potentially large masses of material involved, is tritiated steel. The International Commission on Radiological Protection (ICRP) has recommended committed effective dose coefficients for inhalation of some tritiated materials, but not specifically for tritiated steel. The lack of a dose coefficient for tritiated steel is a concern given the potential importance of the material. To address this knowledge gap, a "dissolution" study, in vivo biokinetic study in a rodent model (1 MBq intratracheal instillation, 3-month follow-up) and associated state-of-the-art modelling were undertaken to derive dose coefficients for model tritiated steel particles. A committed effective dose coefficient for the inhalation of 3.3 × 10-12 Sv Bq-1 was evaluated for the particles, reflecting an activity median aerodynamic diameter (AMAD) of 13.3 µm, with the value for a reference AMAD for workers (5 µm) of 5.6 × 10-12 Sv Bq-1 that may be applied to occupational inhalation exposure to tritiated steel particles.
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Affiliation(s)
- Rachel Smith
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
- Correspondence: (R.S.); (E.B.)
| | - Michele Ellender
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Chang Guo
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Derek Hammond
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Adam Laycock
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Martin O. Leonard
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Matthew Wright
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Michael Davidson
- Radiation Chemicals and Environmental Hazards, UK Health Security Agency, Harwell Campus, Didcot OX11 0RQ, UK
| | - Véronique Malard
- Biosciences and Biotechnology Institute of Aix-Marseille (BIAM) (Aix-Marseille University, French Alternative Energies and Atomic Energy Commission (CEA), French National Centre for Scientific Research (CNRS)), 13108 Saint Paul-Lez-Durance, France
| | - Mickaël Payet
- Institute for Magnetic Fusion Research (IRFM), French Alternative Energies and Atomic Energy Commission (CEA), 13108 Saint-Paul-lez-Durance, France
| | - Christian Grisolia
- Institute for Magnetic Fusion Research (IRFM), French Alternative Energies and Atomic Energy Commission (CEA), 13108 Saint-Paul-lez-Durance, France
| | - Eric Blanchardon
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), 92260 Fontenay-aux-Roses, France
- Correspondence: (R.S.); (E.B.)
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Cyto-Genotoxicity of Tritiated Stainless Steel and Cement Particles in Human Lung Cell Models. Int J Mol Sci 2022; 23:ijms231810398. [PMID: 36142309 PMCID: PMC9499181 DOI: 10.3390/ijms231810398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022] Open
Abstract
During the decommissioning of nuclear facilities, the tritiated materials must be removed. These operations generate tritiated steel and cement particles that could be accidentally inhaled by workers. Thus, the consequences of human exposure by inhalation to these particles in terms of radiotoxicology were investigated. Their cyto-genotoxicity was studied using two human lung models: the BEAS-2B cell line and the 3D MucilAirTM model. Exposures of the BEAS-2B cell line to particles (2 and 24 h) did not induce significant cytotoxicity. Nevertheless, DNA damage occurred upon exposure to tritiated and non-tritiated particles, as observed by alkaline comet assay. Tritiated particles only induced cytostasis; however, both induced a significant increase in centromere negative micronuclei. Particles were also assessed for their effects on epithelial integrity and metabolic activity using the MucilAirTM model in a 14-day kinetic mode. No effect was noted. Tritium transfer through the epithelium was observed without intracellular accumulation. Overall, tritiated and non-tritiated stainless steel and cement particles were associated with moderate toxicity. However, these particles induce DNA lesions and chromosome breakage to which tritium seems to contribute. These data should help in a better management of the risk related to the inhalation of these types of particles.
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Innes E, Yiu HHP, McLean P, Brown W, Boyles M. Simulated biological fluids - a systematic review of their biological relevance and use in relation to inhalation toxicology of particles and fibres. Crit Rev Toxicol 2021; 51:217-248. [PMID: 33905298 DOI: 10.1080/10408444.2021.1903386] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The use of simulated biological fluids (SBFs) is a promising in vitro technique to better understand the release mechanisms and possible in vivo behaviour of materials, including fibres, metal-containing particles and nanomaterials. Applications of SBFs in dissolution tests allow a measure of material biopersistence or, conversely, bioaccessibility that in turn can provide a useful inference of a materials biodistribution, its acute and long-term toxicity, as well as its pathogenicity. Given the wide range of SBFs reported in the literature, a review was conducted, with a focus on fluids used to replicate environments that may be encountered upon material inhalation, including extracellular and intracellular compartments. The review aims to identify when a fluid design can replicate realistic biological conditions, demonstrate operation validation, and/or provide robustness and reproducibility. The studies examined highlight simulated lung fluids (SLFs) that have been shown to suitably replicate physiological conditions, and identify specific components that play a pivotal role in dissolution mechanisms and biological activity; including organic molecules, redox-active species and chelating agents. Material dissolution was not always driven by pH, and likewise not only driven by SLF composition; specific materials and formulations correspond to specific dissolution mechanisms. It is recommended that SLF developments focus on biological predictivity and if not practical, on better biological mimicry, as such an approach ensures results are more likely to reflect in vivo behaviour regardless of the material under investigation.
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Affiliation(s)
- Emma Innes
- Institute of Occupational Medicine (IOM), Edinburgh, UK
| | - Humphrey H P Yiu
- Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Polly McLean
- Institute of Occupational Medicine (IOM), Edinburgh, UK
| | - William Brown
- Institute of Occupational Medicine (IOM), Edinburgh, UK
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