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Dumit S, Avtandilashvili M, McComish SL, Miller G, Swanson J, Tolmachev SY. Modeling Plutonium Decorporation in a Female Nuclear Worker Treated with Ca-DTPA after Inhalation Intake. HEALTH PHYSICS 2024:00004032-990000000-00170. [PMID: 39037363 DOI: 10.1097/hp.0000000000001859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
ABSTRACT The present work models plutonium (Pu) biokinetics in a female former nuclear worker. Her bioassay measurements are available at the US Transuranium and Uranium Registries. The worker was internally exposed to a plutonium-americium mixture via acute inhalation at a nuclear weapons facility. She was medically treated with injections of 1 g Ca-DTPA on days 0, 5, and 14 after the intake. Between days 0 and 20, fecal and urine samples were collected and analyzed for 239Pu and 241Am. Subsequently, she was followed up for bioassay monitoring over 14 y, with additional post-treatment urine samples collected and analyzed for 239Pu. The uniqueness of this dataset is due to the availability of: (1) both early and long-term bioassay data from a female with plutonium intake; (2) data on chelation therapy for a female; and (3) fecal measurement results. Chelation therapy with Ca- and/or Zn-salts of DTPA is known to aid in reducing the internal radiation dose by enhancing the excretion of plutonium and americium from the body. Such enhancement affects plutonium biokinetics in the human body, posing a challenge to the internal dose assessment. The current radiation dose assessment practice is to exclude the data affected by Ca-DTPA from the analysis. The present analysis is the first to explicitly model the chelation-affected bioassay data in a female by using a newly developed chelation model. Thus, the bioassay data collected during and after the Ca-DTPA administrations were used for biokinetic modeling and dose assessment. The Markov Chain Monte Carlo method was used to investigate model parameter uncertainty, based on the bioassay data and assumed prior probability distributions. A χ2/nData (number of data points) ≈ 1 was observed in this study, which indicates self-consistency of the data with the model. Results of this study show that the worker's 239Pu intake was 12 Bq, with a committed effective dose to the whole-body of 1.2 mSv and a committed equivalent dose to the bone surfaces, liver, and lungs of 37.8, 9.1, and 0.8 mSv, respectively. This study also discusses the worker's dose reduction due to chelation treatment.
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Affiliation(s)
- Sara Dumit
- Los Alamos National Laboratory (LANL), Los Alamos, NM 87545
| | - Maia Avtandilashvili
- United States Transuranium and Uranium Registries (USTUR), College of Pharmacy and Pharmaceutical Sciences, Washington State University (WSU), Richland, WA 99354
| | - Stacey L McComish
- United States Transuranium and Uranium Registries (USTUR), College of Pharmacy and Pharmaceutical Sciences, Washington State University (WSU), Richland, WA 99354
| | | | | | - Sergey Y Tolmachev
- United States Transuranium and Uranium Registries (USTUR), College of Pharmacy and Pharmaceutical Sciences, Washington State University (WSU), Richland, WA 99354
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Mate-Kole EM, Dewji SA. Mathematical complexities in radionuclide metabolic modelling: a review of ordinary differential equation kinetics solvers in biokinetic modelling. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2024; 44:021001. [PMID: 38324906 PMCID: PMC11214694 DOI: 10.1088/1361-6498/ad270d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 01/26/2024] [Accepted: 02/07/2024] [Indexed: 02/09/2024]
Abstract
Biokinetic models have been employed in internal dosimetry (ID) to model the human body's time-dependent retention and excretion of radionuclides. Consequently, biokinetic models have become instrumental in modelling the body burden from biological processes from internalized radionuclides for prospective and retrospective dose assessment. Solutions to biokinetic equations have been modelled as a system of coupled ordinary differential equations (ODEs) representing the time-dependent distribution of materials deposited within the body. In parallel, several mathematical algorithms were developed for solving general kinetic problems, upon which biokinetic solution tools were constructed. This paper provides a comprehensive review of mathematical solving methods adopted by some known internal dose computer codes for modelling the distribution and dosimetry for internal emitters, highlighting the mathematical frameworks, capabilities, and limitations. Further discussion details the mathematical underpinnings of biokinetic solutions in a unique approach paralleling advancements in ID. The capabilities of available mathematical solvers in computational systems were also emphasized. A survey of ODE forms, methods, and solvers was conducted to highlight capabilities for advancing the utilization of modern toolkits in ID. This review is the first of its kind in framing the development of biokinetic solving methods as the juxtaposition of mathematical solving schemes and computational capabilities, highlighting the evolution in biokinetic solving for radiation dose assessment.
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Affiliation(s)
- Emmanuel Matey Mate-Kole
- Nuclear and Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Shaheen Azim Dewji
- Nuclear and Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, Atlanta, GA, United States of America
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Poudel D, Dumit S, Klumpp JA. Effectiveness of Surgical Excision Following Plutonium-contaminated Wounds: Inferences from Historical Cases. HEALTH PHYSICS 2023; 124:462-474. [PMID: 36880975 DOI: 10.1097/hp.0000000000001686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
ABSTRACT As with any medical treatment, the decision to excise a wound contaminated with actinides is a risk-benefit analysis. The potential benefits of surgical excision following such contaminated wounds are reduction in the probability of stochastic effects, avoidance of local effects, and psychological comfort knowing that radioactive material deposited in the wound is prevented from being systemic. These benefits should be balanced against the potential risks such as pain, numbness, infection, and loss of function due to excision. To that end, the responsibility of an internal dosimetrist is to provide advice to both the patient and the treating physician about the likely benefits of excision that include, but not limited to, averted doses. This paper provides a review of the effectiveness of surgical excisions following plutonium-contaminated wounds and finds that excisions are highly effective at removing plutonium from wounds and at averting the doses they would have caused.
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Affiliation(s)
- Deepesh Poudel
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM
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Dumit S, Miller G, Poudel D, Bertelli L, Klumpp J. Chelation Model Validation: Modeling of a Plutonium-238 Inhalation Incident Treated with DTPA at Los Alamos National Laboratory. HEALTH PHYSICS 2023; 124:113-124. [PMID: 36625835 PMCID: PMC9803384 DOI: 10.1097/hp.0000000000001647] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
ABSTRACT Accidental inhalation of plutonium at the workplace is a non-negligible risk, even when rigorous safety standards are in place. The intake and retention of plutonium in the human body may be a source of concern. Thus, if there is a suspicion of a significant intake of plutonium, medical countermeasures such as chelation treatment may be administered to the worker. The present work aimed to interpret the bioassay data of a worker involved in an inhalation incident due to a glovebox breach at Los Alamos National Laboratory's plutonium facility. The worker was treated with intravenous injections of calcium salts of diethylenetriaminepentaacetic acid (DTPA) in an attempt to reduce the amount of plutonium from the body and therefore reduce the internal radiation dose. It is well known in the internal dosimetry field that the administration of chelation treatment poses additional challenges to the dose assessment. Hence, a recently developed chelation model was used for the modeling of the bioassay data. The objectives of this work are to describe the incident, model the chelation-affected and non-affected bioassay data, estimate the plutonium intake, and assess the internal radiation dose.
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Affiliation(s)
- Sara Dumit
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
| | - Guthrie Miller
- Unaffiliated (retired from Los Alamos National Laboratory), Santa Fe, NM
| | - Deepesh Poudel
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
| | - Luiz Bertelli
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
| | - John Klumpp
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
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Poudel D, Dumit S, Bertelli L, Miller G, Macsik Z, Klumpp J. Dose Assessment Following a 238 Pu Inhalation Incident at Los Alamos National Laboratory. HEALTH PHYSICS 2023; 124:88-96. [PMID: 36318044 DOI: 10.1097/hp.0000000000001628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A glovebox breach at the plutonium facility at Los Alamos National Laboratory potentially exposed 15 individuals to 238 Pu aerosols. One of the individuals (P0) received two 1-g intravenous DTPA treatments, one on the day of the intake and another the following day. Several urine samples were collected from the individuals involved in the incident. Particle size analysis on the PPE and solubility analysis of the particles on a filter sample were conducted in vitro. The applicability of the results from the in vitro studies for dose assessment was questionable because of the effect of the cloth mask the workers were wearing for COVID-related protection. Based on several considerations, including the effect of cloth masks on the "effective" particle size inhaled and the analysis of fecal-to-urine ratio, the default Type M 1 μm AMAD model was used to estimate intakes and doses. Using the urinary excretion data collected after 100 d post last chelation treatment, the committed effective dose, E(50), for P0 was calculated to be 5.2 mSv. For all others, the bioassay data were consistent with no intakes or very small intakes [corresponding to E(50) less than 0.1 mSv].
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Affiliation(s)
- Deepesh Poudel
- Radiation Protection Services, Los Alamos National Laboratory, Los Alamos, NM
| | - Sara Dumit
- Radiation Protection Services, Los Alamos National Laboratory, Los Alamos, NM
| | - Luiz Bertelli
- Radiation Protection Services, Los Alamos National Laboratory, Los Alamos, NM
| | | | - Zsuzsanna Macsik
- Nuclear and Radiochemistry, Los Alamos National Laboratory, Los Alamos, NM
| | - John Klumpp
- Radiation Protection Services, Los Alamos National Laboratory, Los Alamos, NM
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Miller G, Dumit S, Poudel D, Klumpp J. Use of Nasal Swab Activity to Estimate Intake in Internal Dosimetry. HEALTH PHYSICS 2023; 124:125-128. [PMID: 36625836 DOI: 10.1097/hp.0000000000001646] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In addition to a review of theoretical analyses, this work presents an empirical study of nasal swab data from the Los Alamos National Laboratory (LANL) database correlated with intake obtained from plutonium internal dosimetry calculations. As a result of this work, several "intake-versus-nasal-swab" models were derived. We advocate quantitative use of nasal swab measurements in dose assessment calculations and discuss ways that this can be done. The best description of the LANL plutonium internal dose database is arguably intake = A + Bx, where A = 2.7 Bq, B = 3.8, and x = summed nasal swab activity. The geometric standard deviation was found to be 8.2. This relationship, obtained using plutonium data, should apply also for other radionuclides.
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Affiliation(s)
- Guthrie Miller
- Unaffiliated (retired from Los Alamos National Laboratory), Santa Fe, NM
| | - Sara Dumit
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
| | - Deepesh Poudel
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
| | - John Klumpp
- Los Alamos National Laboratory, Radiation Protection Division, Los Alamos, NM 87545
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Poudel D, Avtandilashvili M, Klumpp JA, Bertelli L, Tolmachev SY. Modelling of long-term retention of high-fired plutonium oxide in the human respiratory tract: importance of scar-tissue compartments. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:940-961. [PMID: 33186925 DOI: 10.1088/1361-6498/abca49] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/13/2020] [Indexed: 06/11/2023]
Abstract
The U.S. Transuranium and Uranium Registries whole-body tissue donor Case 0407 had an acute intake of 'high-fired' plutonium oxide resulting from a glove-box fire in a fabrication plant at a nuclear defence facility. The respiratory tract of this individual was dissected into five regions (larynx, bronchi, bronchioles, alveolar-interstitial, and thoracic lymph nodes) and analysed for plutonium content. The activities in certain compartments of the respiratory tract were found to be higher than expected from the default models described in publications of the International Commission on Radiological Protection. Because of the extremely slow rate of dissolution of the material inhaled, the presence of bound fraction is incapable of explaining the higher-than-expected retention. A plausible hypothesis-encapsulation of plutonium in scar tissues-is supported by the review of literature. Therefore, scar-tissue compartments corresponding to the larynx, bronchi, bronchioles and alveolar-interstitial regions were added to the existing human respiratory tract model structure. The transfer rates between these compartments were determined using Markov Chain Monte Carlo analysis of data on urinary excretion, lung counts and post-mortem measurements of the liver, skeleton and regional retention in the respiratory tract. Modelling of the data showed that approximately 30% of plutonium activity in the lung was sequestered in scar tissues. The dose consequence of such sequestration is qualitatively compared against that of chemical binding.
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Affiliation(s)
- Deepesh Poudel
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM, United States of America
| | - Maia Avtandilashvili
- U.S. Transuranium and Uranium Registries, Washington State University, Richland, WA, United States of America
| | - John A Klumpp
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM, United States of America
| | - Luiz Bertelli
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM, United States of America
| | - Sergei Y Tolmachev
- U.S. Transuranium and Uranium Registries, Washington State University, Richland, WA, United States of America
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Klumpp J, Poudel D. Maximum Possible Doses for a Cohort of Individuals with Intakes Possibly Containing a Component of a Ceramic-type Material. HEALTH PHYSICS 2021; 121:69-72. [PMID: 33867438 DOI: 10.1097/hp.0000000000001408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
ABSTRACT Recently, a glovebox breach led to the potential exposure of 15 Los Alamos National Laboratory employees to 238Pu. Given what is known about the material involved in the incident, the possibility of an intake with a ceramic-type component must be considered. Incidents in which intakes of ceramic solubility-type material is suspected represent a challenge for internal dose assessment via urine bioassay because even relatively large doses cannot be detected in urine until many months after the intake. Ideally, in these situations fecal samples should be collected to assess the intake, but in this case fecal sampling was delayed. This paper presents a method to calculate the maximum possible doses for all individuals involved in an incident using only early time-decreasing urine bioassay measurements.
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Affiliation(s)
- John Klumpp
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM
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Boice JD, Cohen SS, Mumma MT, Golden AP, Howard SC, Girardi DJ, Ellis ED, Bellamy MB, Dauer LT, Samuels C, Eckerman KF, Leggett RW. Mortality among workers at the Los Alamos National Laboratory, 1943-2017. Int J Radiat Biol 2021; 98:722-749. [PMID: 34047625 DOI: 10.1080/09553002.2021.1917784] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND During World War II (WWII), the Manhattan Engineering District established a secret laboratory in the mountains of northern New Mexico. The mission was to design, construct and test the first atomic weapon, nicknamed 'The Gadget' that was detonated at the TRINITY site in Alamogordo, NM. After WWII, nuclear weapons research continued, and the laboratory became the Los Alamos National Laboratory (LANL). MATERIALS AND METHODS The mortality experience of 26,328 workers first employed between 1943 and 1980 at LANL was determined through 2017. Included were 6157 contract workers employed by the ZIA Company. Organ dose estimates for each worker considered all sources of exposure, notably photons, neutrons, tritium, 238Pu and 239Pu. Vital status determination included searches within the National Death Index, Social Security Administration and New Mexico State Mortality Files. Standardized Mortality Ratios (SMR) and Cox regression models were used in the analyses. RESULTS Most workers (55%) were hired before 1960, 38% had a college degree, 25% were female, 81% white, 13% Hispanic and 60% had died. Vital status was complete, with only 0.1% lost to follow-up. The mean dose to the lung for the 17,053 workers monitored for radiation was 28.6 weighted-mGy (maximum 16.8 weighted-Gy) assuming a Dose Weighting Factor of 20 for alpha particle dose to lung. The Excess Relative Risk (ERR) at 100 weighted-mGy was 0.01 (95%CI -0.02, 0.03; n = 839) for lung cancer. The ERR at 100 mGy was -0.43 (95%CI -1.11, 0.24; n = 160) for leukemia other than chronic lymphocytic leukemia (CLL), -0.06 (95%CI -0.16, 0.04; n = 3043) for ischemic heart disease (IHD), and 0.29 (95%CI 0.02, 0.55; n = 106) for esophageal cancer. Among the 6499 workers with measurable intakes of plutonium, an increase in bone cancer (SMR 2.44; 95%CI 0.98, 5.03; n = 7) was related to dose. The SMR for berylliosis was significantly high, based on 4 deaths. SMRs for Hispanic workers were significantly high for cancers of the stomach and liver, cirrhosis of the liver, nonmalignant kidney disease and diabetes, but the excesses were not related to radiation dose. CONCLUSIONS There was little evidence that radiation increased the risk of lung cancer or leukemia. Esophageal cancer was associated with radiation, and plutonium intakes were linked to an increase of bone cancer. IHD was not associated with radiation dose. More precise evaluations will await the pooled analysis of workers with similar exposures such as at Rocky Flats, Savannah River and Hanford.
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Affiliation(s)
- John D Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA.,Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | | | - Michael T Mumma
- International Epidemiology Institute, Rockville, MD, USA.,International Epidemiology Field Station, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ashley P Golden
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Sara C Howard
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - David J Girardi
- ORISE Health Studies Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | | | - Michael B Bellamy
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lawrence T Dauer
- Department of Medical Physics and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Poudel D, Avtandilashvili M, Bertelli L, Klumpp JA, Tolmachev SY. Long-term Retention of Plutonium in the Respiratory Tracts of Two Acutely-exposed Workers: Estimation of Bound Fraction. HEALTH PHYSICS 2021; 120:258-270. [PMID: 32881734 DOI: 10.1097/hp.0000000000001311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
ABSTRACT Inhalation of plutonium is a significant contributor of occupational doses in plutonium production, nuclear fuel reprocessing, and cleanup operations. Accurate assessment of the residence time of plutonium in the lungs is important to properly characterize dose and, consequently, the risk from inhalation of plutonium aerosols. This paper discusses the long-term retention of plutonium in different parts of the respiratory tract of two workers who donated their bodies to the US Transuranium and Uranium Registries. The post-mortem tissue radiochemical analysis results, along with the urine bioassay data, were interpreted using Markov Chain Monte Carlo and the latest biokinetic models presented in the Occupational Intakes of Radionuclides series of ICRP publications. The materials inhaled by both workers were found to have solubility between that of plutonium nitrates and oxides. The long-term solubility was also confirmed by comparison of the activity concentration in the lungs and the thoracic lymph nodes. The data from the two individuals can be explained by assuming a bound fraction (fraction of plutonium deposited in the respiratory tract that becomes bound to lung tissue after dissolution) of 1% and 4%, respectively, without having to significantly alter the particle clearance parameters. Effects of different assumptions about the bound fraction on radiation doses to different target regions was also investigated. For inhalation of soluble materials, an assumption of fb of 1%, compared to the ICRP default of 0.2%, increases the dose to the most sensitive target region of the respiratory tract by 258% and that to the total lung by 116%. Some possible alternate methods of explaining higher-than-expected long-term retention of plutonium in the upper respiratory tract of these individuals-such as physical sequestration of material into the scar tissues and possible uptake by lungs-are also briefly discussed.
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Affiliation(s)
- Deepesh Poudel
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM
| | - Maia Avtandilashvili
- US Transuranium and Uranium Registries, Washington State University, Richland, WA
| | - Luiz Bertelli
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM
| | - John A Klumpp
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM
| | - Sergei Y Tolmachev
- US Transuranium and Uranium Registries, Washington State University, Richland, WA
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Poudel D, Klumpp JA, Bertelli L, Dumit S, Waters TL. Dose Assessment Following a 238Pu-contaminated Wound Case with Chelation and Excision. HEALTH PHYSICS 2020; 119:690-703. [PMID: 33196522 DOI: 10.1097/hp.0000000000001202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The urinary excretion and wound retention data collected after a Pu-contaminated wound were analyzed using Markov Chain Monte Carlo (MCMC) to obtain the posterior distribution of the intakes and doses. An empirical approach was used to model the effects of medical treatments (chelation and excision) on the reduction of doses. It was calculated that DTPA enhanced the urinary excretion, on average, by a factor of 17. The empirical analysis also allowed calculation of the efficacies of the medical treatments-excision and chelation averted approximately 76% and 5.5%, respectively, of the doses that would have been if there were no medical treatment. All bioassay data are provided in the appendix for independent analysis and to facilitate the compartmental modeling approaches being developed by the health physics community.
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Dumit S, Miller G, Klumpp JA, Poudel D, Bertelli L, Waters TL. Development of a New Chelation Model: Bioassay Data Interpretation and Dose Assessment after Plutonium Intake via Wound and Treatment with DTPA. HEALTH PHYSICS 2020; 119:715-732. [PMID: 33196524 DOI: 10.1097/hp.0000000000001282] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The administration of chelation therapy to treat significant intakes of actinides, such as plutonium, affects the actinide's normal biokinetics. In particular, it enhances the actinide's rate of excretion, such that the standard biokinetic models cannot be applied directly to the chelation-affected bioassay data in order to estimate the intake and assess the radiation dose. The present study proposes a new chelation model that can be applied to the chelation-affected bioassay data after plutonium intake via wound and treatment with DTPA. In the proposed model, chelation is assumed to occur in the blood, liver, and parts of the skeleton. Ten datasets, consisting of measurements of C-DTPA, Pu, and Pu involving humans given radiolabeled DTPA and humans occupationally exposed to plutonium via wound and treated with chelation therapy, were used for model development. The combined dataset consisted of daily and cumulative excretion (urine and feces), wound counts, measurements of excised tissue, blood, and post-mortem tissue analyses of liver and skeleton. The combined data were simultaneously fit using the chelation model linked with a plutonium systemic model, which was linked to an ad hoc wound model. The proposed chelation model was used for dose assessment of the wound cases used in this study.
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Affiliation(s)
- Sara Dumit
- Los Alamos National Laboratory Los Alamos, NM
| | - Guthrie Miller
- Los Alamos National Laboratory, Radiation Protection Division, MS G761, Los Alamos, NM 87545
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Bayesian Analysis of Plutonium Bioassay Data at Los Alamos National Laboratory: Erratum. HEALTH PHYSICS 2019; 116:722. [PMID: 30908320 DOI: 10.1097/hp.0000000000001044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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14
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Poudel D, Bertelli L, Klumpp JA, Dumit S, Waters TL. Biokinetics of 238Pu oxides: inferences from bioassay data. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:208-248. [PMID: 30523984 DOI: 10.1088/1361-6498/aaf653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The bioassay data collected from several workers involved in 238Pu inhalation incidents have been analysed using the most recent biokinetic models described in the Occupational Intakes of Radionuclides (OIR) series of publications. Although all exposures were thought to be to 238Pu oxides, the observed urinary excretion patterns differed in different inhalation incidents. The urinary excretion from individuals involved in one of the incidents increased steadily with time, peaking around two to three years before decreasing. This pattern is described in Part 4 of the OIR series using the '238PuO2, ceramic' model. This non-monotonic behaviour, explained as being due to fragmentation and dissolution, was not specific to the incident, but observed in other incidents. The urinary excretion data collected from individuals involved in another incident showed dissolution behaviour between Type M and Type S. Finally, the bioassay data from yet another incident showed a pattern that appears to represent behaviour more insoluble than Type S, which is possibly a result of self-heating due to the decay heat from 238Pu. The urinary excretion patterns and corresponding dose coefficients have been calculated and compared.
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Affiliation(s)
- Deepesh Poudel
- Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM 87544, United States of America
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Leggett RW, Eckerman KF, Bellamy M. MPS dose reconstruction for internal emitters: some site-specific issues and approaches. Int J Radiat Biol 2019; 98:631-643. [DOI: 10.1080/09553002.2018.1558302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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