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Chen S, Ko R, Lai EPC, Wyatt H, Abergel RJ, Li C. ENCAPSULATED 3,4,3-LI(1,2-HOPO) IN CHITOSAN NANOPARTICLES FOR DECORPORATION VIA INHALATION. Radiat Prot Dosimetry 2018; 182:107-111. [PMID: 30165556 DOI: 10.1093/rpd/ncy139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
3,4,3-LI(1,2-HOPO) has been identified as an excellent alternative for DTPA for decorporating actinides, such as Pu and Am, after internal contamination. Efforts have been focused on its application through oral administration. When 3,4,3-LI(1,2-HOPO) was encapsulated with biocompatible, biodegradable nanoparticles made of chitosan, its release from the nanoparticles to lung fluid, observed in in vitro experiments, exhibited an extended release profile. These observations were very encouraging, as this nanomedicine could lead to a reduction in the dosing frequency required to achieve the decorporation efficacy of unformulated 3,4,3-LI(1,2-HOPO) itself. In vivo release tests as well as actinide decorporation experiments, using an inhalation exposure animal model, will follow.
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Affiliation(s)
- Sijing Chen
- Department of Chemistry, Carleton University, Ottawa, Canada
| | - Raymond Ko
- Radiation Protection Bureau, Health Canada, Ottawa, Canada
| | - Edward P C Lai
- Department of Chemistry, Carleton University, Ottawa, Canada
| | | | - Rebecca J Abergel
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, USA
| | - Chunsheng Li
- Department of Chemistry, Carleton University, Ottawa, Canada
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Tazrart A, Bolzinger MA, Lamart S, Coudert S, Angulo JF, Jandard V, Briançon S, Griffiths NM. Actinide-contaminated Skin: Comparing Decontamination Efficacy of Water, Cleansing Gels, and DTPA Gels. Health Phys 2018; 115:12-20. [PMID: 29787426 DOI: 10.1097/hp.0000000000000814] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Skin contamination by alpha-emitting actinides is a risk to workers during nuclear fuel production and reactor decommissioning. Also, the list of items for potential use in radiological dispersal devices includes plutonium and americium. The actinide chemical form is important and solvents such as tributyl phosphate, used to extract plutonium, can influence plutonium behavior. This study investigated skin fixation and efficacy of decontamination products for these actinide forms using viable pig skin in the Franz cell diffusion system. Commonly used or recommended decontamination products such as water, cleansing gel, diethylenetriamine pentaacetic acid, or octadentate hydroxypyridinone compound 3,4,3-LI(1,2-HOPO), as well as diethylenetriamine pentaacetic acid hydrogel formulations, were tested after a 2-h contact time with the contaminant. Analysis of skin samples demonstrated that more plutonium nitrate is bound to skin as compared to plutonium-tributyl phosphate, and fixation of americium to skin was also significant. The data show that for plutonium-tributyl phosphate all the products are effective ranging from 80 to 90% removal of this contaminant. This may be associated with damage to the skin by this complex and suggests a mechanical/wash-out action rather than chelation. For removal of americium and plutonium, both Trait Rouge cleansing gel and diethylenetriamine pentaacetic acid are better than water, and diethylenetriamine pentaacetic acid hydrogel is better than Osmogel. The different treatments, however, did not significantly affect the activity in deeper skin layers, which suggests a need for further improvement of decontamination procedures. The new diethylenetriamine pentaacetic acid hydrogel preparation was effective in removing americium, plutonium, and plutonium-tributyl phosphate from skin; such a formulation offers advantages and thus merits further assessment.
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Affiliation(s)
- A Tazrart
- Laboratoire de Radio Toxicologie, CEA, Université Paris-Saclay, 91297 Arpajon, France
- Université de Lyon, F-69008, Lyon, France and Laboratoire de Dermopharmacie et Cosmétologie, Laboratoire d'Automatique et de Génie des Procédés (LAGEP), UMR CNRS 5007, 8, Avenue Rockefeller, 69373 Lyon Cedex 08, France
| | - M A Bolzinger
- Université de Lyon, F-69008, Lyon, France and Laboratoire de Dermopharmacie et Cosmétologie, Laboratoire d'Automatique et de Génie des Procédés (LAGEP), UMR CNRS 5007, 8, Avenue Rockefeller, 69373 Lyon Cedex 08, France
- Pharmacie Centrale des Armées, 45404 Fleury les Aubrais Cedex, France
| | - S Lamart
- Laboratoire de Radio Toxicologie, CEA, Université Paris-Saclay, 91297 Arpajon, France
| | - S Coudert
- Laboratoire de Radio Toxicologie, CEA, Université Paris-Saclay, 91297 Arpajon, France
| | - J F Angulo
- Laboratoire de Radio Toxicologie, CEA, Université Paris-Saclay, 91297 Arpajon, France
| | - V Jandard
- Pharmacie Centrale des Armées, 45404 Fleury les Aubrais Cedex, France
| | - S Briançon
- Université de Lyon, F-69008, Lyon, France and Laboratoire de Dermopharmacie et Cosmétologie, Laboratoire d'Automatique et de Génie des Procédés (LAGEP), UMR CNRS 5007, 8, Avenue Rockefeller, 69373 Lyon Cedex 08, France
| | - N M Griffiths
- Laboratoire de Radio Toxicologie, CEA, Université Paris-Saclay, 91297 Arpajon, France
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Nicolaou G. Radiation dose aspects in the handling of emerging nuclear fuels. Radiat Prot Dosimetry 2014; 162:459-462. [PMID: 24553050 DOI: 10.1093/rpd/ncu016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The occupational annual dose levels, encountered at fabrication of emerging nuclear fuels, have been studied. Emerging fuels for the single and multiple recycling of Pu and MA have resulted in considerably higher gamma and neutron doses in comparison with commercial fuels. The occupational dose limit is exceeded at fabrication by a single fuel rod in all fuel cases with (241)Am and Cm isotopes present in their composition. In the absence of these isotopes, 2-4 adjacent fuel rods are sufficient to exceed the limit. Self-shielding within the fuel reduces significantly only the gamma dose that would have been delivered otherwise. Hence, only the first row of fuel rods in an assembly contributes to the dose, whereas in the case of neutrons, all fuel rods contribute.
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Affiliation(s)
- G Nicolaou
- Laboratory of Nuclear Technology, Department of Electrical and Computer Engineering, School of Engineering, Demokritus University of Thrace, Xanthi 67100, Greece
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Nadar MY, Akar DK, Patni HK, Singh IS, Mishra L, Rao DD, Pradeepkumar KS. Monte Carlo simulation of skull and knee voxel phantoms for the assessment of skeletal burden of low-energy photon emitters. Radiat Prot Dosimetry 2014; 162:469-477. [PMID: 24435911 DOI: 10.1093/rpd/nct367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In case of internal contamination due to long-lived actinides by inhalation or injection pathway, a major portion of activity will be deposited in the skeleton and liver over a period of time. In this study, calibration factors (CFs) of Phoswich and an array of HPGe detectors are estimated using skull and knee voxel phantoms. These phantoms are generated from International Commission of Radiation Protection reference male voxel phantom. The phantoms as well as 20 cm diameter phoswich, having 1.2 cm thick NaI (Tl) primary and 5cm thick CsI (Tl) secondary detector and an array of three HPGe detectors (each of diameter of 7 cm and thickness of 2.5 cm) are incorporated in Monte Carlo code 'FLUKA'. Biokinetic models of Pu, Am, U and Th are solved using default parameters to identify different parts of the skeleton where activity will accumulate after an inhalation intake of 1 Bq. Accordingly, CFs are evaluated for the uniform source distribution in trabecular bone and bone marrow (TBBM), cortical bone (CB) as well as in both TBBM and CB regions for photon energies of 18, 60, 63, 74, 93, 185 and 238 keV describing sources of (239)Pu, (241)Am, (238)U, (235)U and (232)Th. The CFs are also evaluated for non-uniform distribution of activity in TBBM and CB regions. The variation in the CFs for source distributed in different regions of the bones is studied. The assessment of skeletal activity of actinides from skull and knee activity measurements is discussed along with the errors.
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Affiliation(s)
- M Y Nadar
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - D K Akar
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - H K Patni
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - I S Singh
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - L Mishra
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - D D Rao
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - K S Pradeepkumar
- Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
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Abstract
All of the actinides are radioactive. Taken into the body, they damage and induce cancer in bone and liver, and in the lungs if inhaled, and U(VI) is a chemical kidney poison. Containment of radionuclides is fundamental to radiation protection, but if it is breached accidentally or deliberately, decontamination of exposed persons is needed to reduce the consequences of radionuclide intake. The only known way to reduce the health risks of internally deposited actinides is to accelerate their excretion with chelating agents. Ethylendiaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) were introduced in the 1950's. DTPA is now clinically accepted, but its oral activity is low, it must be injected as a Ca(II) or Zn(II) chelate to avoid toxicity, and it is structurally unsuitable for chelating U(VI) or Np(V). Actinide penetration into the mammalian iron transport and storage systems suggested that actinide ions would form stable complexes with the Fe(III)-binding units found in potent selective natural iron chelators (siderophores). Testing of that biomimetic approach began in the late 1970's with the design, production, and assessment for in vivo Pu(IV) chelation of synthetic multidentate ligands based on the backbone structures and Fe(III)-binding groups of siderophores. New efficacious actinide chelators have emerged from that program, in particular, octadentate 3,4,3-LI(1,2-HOPO) and tetradentate 5-LIO(Me-3,2-HOPO) have potential for clinical acceptance. Both are much more effective than CaNa3-DTPA for decorporation of Pu(IV), Am(III), U(VI), and Np(IV,V), they are orally active, and toxicity is acceptably low at effective dosage.
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Affiliation(s)
- Patricia W Durbin
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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Abstract
Radiation-induced cataracts are predominantly of the posterior sub-capsular (PSC) type, whereas about 90% of age-related cataracts are of other types. Retired workers, likely to have transuranic body burdens, from three DOE-supported installations were questioned regarding their eye-care history and asked for permission to contact their eye-care providers regarding any cataracts. In 97 cases with lifetime exposure records 20 cases (20.6%) were reported to have PSC cataracts. However, of 24 individuals with recorded lifetime doses of 200-600 mSv, nine (37.5%) had PSC cataracts, compared with 15.1% of 73 cases with doses of less than 200 mSv. This difference is statistically significant at the 5% level.
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Affiliation(s)
- Baruch S Jacobson
- US Transuranium and Uranium Registries, Washington State University--TriCities Richland, WA 99354, USA.
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Abstract
First, some of the early work is reviewed on exposure pathways in connection with proposed and early liquid radioactive waste discharges from Sellafield. The main historical features of these discharges, affected by relevant plant operations, are then briefly described. The important radiological exposure pathways resulting from the discharges and people's consumption and occupancy habits are considered. To place the changing scenario onto a consistent basis using present-day methodology, a reconstruction of exposures has been carried out using environmental monitoring data and models. The three major pathways are examined of Porphyra/laverbread consumption in South Wales, fish and shellfish consumption near Sellafield, and external exposure over local and more distant sediments. The results show that over the period 1952 to about 1970 the laverbread pathway was probably critical, taking a cautious approach. Effective dose rates fluctuated at around 1 mSv y(-1) from about 1956 to 1971. From about 1970 to 1985, the fish and shellfish pathway was likely to have been critical, with effective dose rates peaking at about 2 mSv y(-1) in 1975-1976. External exposure was likely to have been of lesser importance than the other two pathways until about 1985, when with the retention of previously-released radiocesium on sediments it has become dominant. This phenomenon applies particularly further afield where radiocesium concentrations have been slower to decline; in the Ribble estuary, houseboat dwellers have been the critical group from about 1985. Effective doses have been at about 0.3 mSv y(-1) and declining; they are due to the effects of radiocesium discharges in earlier years. Dose rates have remained within contemporary ICRP dose limits.
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Affiliation(s)
- G J Hunt
- Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, Suffolk, England
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Radiobiology of radium and the actinides in man. Proceedings of an international conference. Lake Geneva, Wisconsin, 11-16 October 1981. Health Phys 1983; 44 Suppl 1:1-589. [PMID: 6305875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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