Uranium Dust Research Articles

Heavy Metal-Laden Particulate Dust Alters Transcriptional Regulation in Human Colonoids

Chronic heavy metals exposure in the southwestern United States co-occurs with greater incidences of metabolic and digestive diseases, particularly in the Indigenous and Hispanic populations. There is a need to understand how particulate heavy metals drive this dysbiotic state and propose a molecular explanation as a result of these exposures. Previously, our group demonstrated human colonoids to be a relevant model for investigating the physiological impact of environmental toxicants on the intestinal tract. The objective of this study is to elucidate the mechanism behind the transcriptional and cellular changes present in the intestinal epithelia upon acute exposure to non fissile uranium particulate dust. We hypothesize that non-fissile uranium exposure biases the differentiation of progenitor cells in the crypt to secretory roles through miRNA regulation. Colonoids were exposed (18 hours) to non-fissile uranium dust obtained from the Jackpile uranium mine, one of the largest open pit uranium mines, located on the Laguna Pueblo in New Mexico. Control and dust-exposed colonoids (n=3 unique donors) were digested into single cells and processed for droplet-based single cell sequencing (scRNAseq). Upon exposure, enteroendocrine cells (EEC) expanded >4 fold, along with increases in serotonin and PYY, as well as goblet cells (>3 fold) which indicates changes to the secretory lineage. Downstream pathway analysis found microRNAs miR-625-3p, miR-320a, miR-29b-3p to be differentially expressed. These results suggest that acute uranium dust exposure induces changes in differentiation pathways which are modulated by regulatory miRNAs. We would like to expand these findings by performing miRNA sequencing and comparing miRNA expression profiles between UBD exposed and control samples. Our results also provide an improved understanding of uranium dust’s impact on the gastrointestinal system, which may inform other physiological studies on the health of individuals exposed to heavy metals. This study was funded by K01DK106323, R56ES034400, P42ES025589, P20GM121176, P20GM130422, and AGA SURF. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Heavy metal-laden particulate dust disrupts intestinal epithelial stem cells and lineage differentiation

Chronic heavy metals exposure has been associated with intestinal inflammation and higher incidences of colorectal cancer, however there is no molecular evidence that metal laden-particulates can cause injury to the gut epithelia. Communities that live adjacent to abandoned uranium mines have higher incidence of metabolic and digestive diseases; however, the cause is unknown. The goal of this study is to characterize particulate dust containing non-fissile uranium as an environmental toxicant that damages intestinal epithelia and characterize the subsequent transcriptomic changes. We hypothesized that non-fissile uranium will alter the differentiation pattern of progenitor cells in the crypt biasing them towards the secretory lineage. Human colonoids derived from healthy adult colonic biopsies (UNM IRB approved study 18-626 and 18-171) were established and shown to physiologically model the intestinal epithelia. Colonoids were acutely exposed (24h) to non-fissile uranium dust obtained near the Jackpile uranium mine in New Mexico, one of the largest open pit uranium mines in the US, located on the Laguna Pueblo. Control and dust-exposed colonoids (n=3 unique donors) were dissociated into single cells and processed for droplet-based single cell sequencing (scRNAseq). scRNAseq identified significant changes in the secretory lineage in uranium dust-exposed colonoids. Specifically, there was a four-fold expansion of enteroendocrine cells (EEC) with increases in EEC hormones serotonin and PYY in all colonoid lines. Proliferative pathways, such as Wnt signaling and negative regulation of apoptosis were upregulated in these EECs. These transcriptomic changes in EECs and proliferative cells and increased basolateral secretion of secretory granules and serotonin was validated in colonoids (˃5 biologically unique human donors) via RNA FISH, immunofluorescence and ELISAs. Our results demonstrate that acute uranium dust exposure directly induces transcriptomic and cellular changes in intestinal epithelia independently of microbiota, stroma, and immune cells. These results indicate that adult human colonoids are a relevant model for investigating environmental toxicants on intestinal epithelia and provide an improved understanding of uranium dust as a model of intestinal injury. This study was funded by NIDDK (K01DK106323), NIEHS (R56ES034400, P42ES025589), and NIGMS (P20GM121176, P20GM130422). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Reconstructed lung doses for the million person study cohort of 26,650 Tennessee Eastman corporation workers employed between 1942 and 1947

Tennessee Eastman Corporation workers were exposed to uranium dust resulting in high-linear energy transfer (LET) irradiation to lung tissue. In this work, radiation lung doses were reconstructed for 26 650 men and women working at the plant between 1942 and 1947. Site air monitoring data of uranium concentrations and payroll records were used to determine the daily inhaled activities and annualized lung doses. Variations in the activity median aerodynamic diameter of the uranium dust, the solubility of particulate matter in the lungs and the sex-specific breathing rate were investigated as part of a sensitivity analysis. Male and female mean lung doses of 18.9 and 32.7 mGy, respectively, from high-LET alpha irradiation, and there was general agreement with evaluations from previously published epidemiological studies. Annual lung dose estimates and sensitivity analysis for the 26 650 workers in the TEC cohort have been archived on the United States Department of Energy Comprehensive Epidemiologic Data Resource.

Shelf-life of uranium oxide microparticle reference materials and possible implications for the identification of optimal storage conditions

During their inspections of nuclear facilities, inspectors of the International Atomic Energy Agency (IAEA) collect environmental swipe samples containing uranium dust particles. As reference materials, well-characterized uranium microparticles are required that are suitable for quality control, analytical refinement and method development tasks. At Forschungszentrum Jülich (FZJ), uranium oxide reference microparticles are produced using an aerosol-based process. A core requirement for distribution of a potential reference material is to guarantee a practical shelf-life. Previous studies of structure and shape of uranium oxide microparticles demonstrated possible alteration leading to the formation of uranium hydroxides such as schoepite. A systematic shelf-life study exploring storage under different environmental conditions was launched in late 2021. Uranium microparticles were stored in three environments simulating potential long-term storage conditions, whereas a fourth experiment used an unrealistically harsh environment to assess the effects of accelerated alteration. At the time of writing, only the uranium microparticles intentionally stored under these extreme conditions have shown significant signs of alteration. This implies that synthetic uranium oxide microparticles under common storage conditions have minimal shelf-lives of at least 1 year, and likely much longer.Graphical abstract

Dust against the Anthropocene: Yhonnie Scarce’s nuclear geo-fictions

Against the universalizing of the Anthropocene, radioactive dust affects specific communities more than others. At the same time, it carries particles from local sites to cosmic horizons. Uranium dust encodes deep timescales of planetary formation and extinction as they intersect with histories of violence and extraction, myth and current politics. This article analyses artwork by Yhonnie Scarce, descendant of the Kokatha and Nukunu peoples of South Australia, arguing for a particulate geo-fiction as method of engagement with colonial politics of deep time. By sampling and literally unearthing nuclear histories, Scarce’s work traces more-than-human toxic ecologies. Through a condensation of uranium-scale temporalities, the present moment of its exhibition is prised open. This becomes a speculative ethical encounter with responsibilities to deep histories and futures beyond itself, the lingering after effects of British colonial violence inscribed into the materiality of the work.

Mortality among Tennessee Eastman Corporation (TEC) uranium processing workers, 1943–2019

Background There are few occupational studies of women exposed to ionizing radiation. During World War II, the Tennessee Eastman Corporation (TEC) operated an electromagnetic field separation facility of 1152 calutrons to obtain enriched uranium (235U) used for the Hiroshima atomic bomb. Thousands of women were involved in these operations. Materials and methods A new study was conducted of 13,951 women and 12,699 men employed at TEC between 1943 and 1947 for at least 90 days. Comprehensive dose reconstruction techniques were used to estimate lung doses from the inhalation of uranium dust based on airborne measurements. Vital status through 2018/2019 was obtained from the National Death Index, Social Security Death Index, Tennessee death records and online public record databases. Analyses included standardized mortality ratios (SMRs) and Cox proportional hazards models. Results Most workers were hourly (77.7%), white (95.6%), born before 1920 (58.3%), worked in dusty environments (57.0%), and had died (94.9%). Vital status was confirmed for 97.4% of the workers. Women were younger than men when first employed: mean ages 25.0 years and 33.0 years, respectively. The estimated mean absorbed dose to the lung was 32.7 mGy (max 1048 mGy) for women and 18.9 mGy (max 501 mGy) for men. The mean dose to thoracic lymph nodes (TLNs) was 127 mGy. Statistically significant SMRs were observed for lung cancer (SMR 1.25; 95% CI 1.19, 1.31; n = 1654), nonmalignant respiratory diseases (NMRDs) (1.23; 95% CI 1.19, 1.28; n = 2585), and cerebrovascular disease (CeVD) (1.13; 95% CI 1.08, 1.18; n = 1945). For lung cancer, the excess relative rate (ERR) at 100 mGy (95% CI) was 0.01 (–0.10, 0.12; n = 652) among women, and −0.15 (–0.38, 0.07; n = 1002) among men based on a preferred model for men with lung doses <300 mGy. NMRD and non-Hodgkin lymphoma were not associated with estimated absorbed dose to the lung or TLN. Conclusions There was little evidence that radiation increased the risk of lung cancer, suggesting that inhalation of uranium dust and the associated high-LET alpha particle exposure to lung tissue experienced over a few years is less effective in causing lung cancer than other types of exposures. There was no statistically significant difference in the lung cancer risk estimates between men and women. The elevation of certain causes of death such as CeVD is unexplained and will require additional scrutiny of workplace or lifestyle factors given that radiation is an unlikely contributor since only the lung and lymph nodes received appreciable dose.

Effects of a Modified Chitosan Compound Combined with Lung Lavage after Inhalation of Depleted Uranium Dust.

When exposed to depleted uranium (DU), the respiratory tract is the main route for DU to enter the body. At present, lung lavage is considered to be a method for removing DU from the lung. However, there is still room for improvement in the efficiency of lung lavage. In this work, a model of DU dust inhalation injury was established in beagle dogs so that chitosan-diethylenetriaminepentaacetic nanoparticles (CS-DTPA NP) could be synthesized. The purpose of this work was to evaluate the removal efficiency of CS-DTPA NP combined with lung lavage in dogs. Results showed that 7 d after DU exposure, the diethylenetriaminepentaacetic (DTPA) and CS-DTPA NP groups showed lower U content in kidney tissue compared with the normal saline (NS) group. In the left lung tissue (lavage fluid and recovery rate of lavage fluid), the U content in the CS-DTPA NP group was higher than in the NS and DTPA groups. In terms of blood levels, the CS-DPTA NP group increased over time at 1, 3 and 7 d of DU exposure without lavage; however, the U levels in the 3 and 7 d lavage groups were significantly lower than in the non-lavage groups. IL-1 in the lavage fluid of the CS-DPTA NP and CS NPs group were lower than in the NS group. In summary, after respiratory exposure to DU, early inhalation of CS-DPTA NP may block insoluble DU particles in the lung, and if combined with lung lavage, the clearance efficiency of DU from lung tissue improves.

Simulation of Kinetic Processes, Optical and Neutron Properties of the Nuclear-Excited Dusty Plasma of Noble Gases

A model of kinetic processes in the argon-xenon gas plasma with the admixture of uranium nanoclusters is developed. This dusty plasma seems to be perspective as an active laser medium in the technologies of direct conversion of the nuclear energy into coherent light. The process of formation of quasistationary states in plasma and the influence of uranium nanoclusters are considered in the developed mathematical model of the kinetic processes in the argon-xenon gas excited by nuclear fission fragments. The suggested system of equations allows one to describe the kinetic processes in the plasma with presence of the uranium dust in a self-consistent way. The model include the evolutionary equations for the distribution function of electron velocities and for concentrations of a different components of plasma, including charged uranium nanoclusters. The model takes 44 components of plasma and 507 plasma-chemical processes into account. The method of solution of such equations is suggested, and the program complex realizing this method is developed. The influence of the dust concentration on the optical and neutronic properties of the plasma media is studied in calculations. The calculation of the neutron multiplication factor for the laser active infinite medium containing uranium dust particles is performed with the use of MCNP-5 code. The neutron cross-sections needed for calculations were taken from the ENDF/b-VI library. The attenuation of electromagnetic waves by uranium dust particles was calculated in the frame of the Mie theory for various spherical particle sizes and different wavelengths. Real and imaginary parts of the refraction coefficient for uranium needed for this calculation were taken from the experimental and theoretical works.

A TRIGA-like subcritical concept for biological waste management (pills, old vaccines etc.)

This subcritical concept is framed in a way that allows use in a single room for some electricity production purposes. It involves a tungsten casing and also helps using depleted uranium dust. The single series of anneals for closure and direct laying of the top opening window onto the left side of the tungsten casing make pressure work impossible ; it also allows for a relatively cheap production.

Research on synthetic formula of a quick-drying type of radioactive contamination detergent

To synthesize a quick-drying type of radioactive contamination detergent, a solvent type of detergent based on polyurethane was designed. And the synthetic formula of the detergent was studied by theoretical calculation and experiment. Through theoretical calculation, the basic molar ratio of toluene diisocyanate, chain extender, and polyether polyol were 1.73:0.73:1. The effects of the type of chain extenders and the content of catalysts on the performance of decontamination material were studied by formula experiment. The optimized formulation of detergent was obtained and a quick-drying type of radioactive contamination detergent was synthesized by prepolymer process. The decontamination effect of the detergent on uranium dust was verified on different surfaces, and both decontamination rates exceeded 90%.

For All they that Take the Sword Shall Perish with the Sword-on the Radiation Hazard of The Use of Shells Containing Depleted Uranium

Uranium is characterized by low activity. It is generally accepted that the biological (mainly carcinogenic) danger of using shells containing depleted uranium is associated with the toxicity of uranium dust. However, when a projectile collides with an object at high speed (1.6km/s or more), the half-life of uranium nuclei decreases significantly. In this case, the main biohazard factor is associated with radiation exposure.

Research on nuclear emergency decontamination technology based on strippable coating

Radioactive contamination caused by nuclear leakage accidents and radioactive source diffusion accidents will pose a threat to the environment and public safety. In order to remove the contamination, an emergency decontamination technique based on strippable coating was studied. The strippable coating takes acrylate emulsion as the main film forming agent and lauryl sodium sulphate as surfactant. The decontamination performance and application dosage of the coating were tested. At the application dosage of 2.5 kg m−2, the single decontamination rate reached 92.26% for uranium dust on concrete surface, which indicates this technology is a promising method for engineering decontamination.

Evaluation of the Nose-to-Brain Transport of Different Physicochemical Forms of Uranium after Exposure via Inhalation of a Aerosol in the Rat.

Background:Health-risk issues are raised concerning inhalation of particulate pollutants that are thought to have potential hazardous effects on the central nervous system. The brain is presented as a direct target of particulate matter (PM) exposure because of the nose-to-brain pathway involvement. The main cause of contamination in nuclear occupational activities is related to exposure to aerosols containing radionuclides, particularly uranium dust. It has been previously demonstrated that instilled solubilized uranium in the rat nasal cavity is conveyed to the brain via the olfactory nerve.Objective:The aim of this study was to analyze the anatomical localization of uranium compounds in the olfactory system after in vivo exposure to a polydisperse aerosol of uranium tetraoxide () particles.Methods:The olfactory neuroepithelium (OE) and selected brain structures—olfactory bulbs (OB), frontal cortex (FC), hippocampus (HIP), cerebellum (Cer), and brainstem (BS)—were microdissected 4 h after aerosol inhalation via a nose-only system in adult rats. Tissues were subjected to complementary analytical techniques.Results:Uranium concentrations measured by inductively coupled plasma mass spectrometry (ICP-MS) were significantly higher in all brain structures from exposed animals compared with their respective controls. We observed that cerebral uranium concentrations followed an anteroposterior gradient with typical accumulation in the OB, characteristic of a direct olfactory transfer of inhaled compounds. Secondary ion mass spectrometry (SIMS) microscopy and transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM-EDX) were used in order to track elemental uranium in situ in the olfactory epithelium. Elemental uranium was detected in precise anatomical regions: olfactory neuron dendrites, paracellular junctions of neuroepithelial cells, and olfactory nerve tracts (around axons and endoneural spaces).Conclusion:These neuroanatomical observations in a rat model are consistent with the transport of elemental uranium in different physicochemical forms (solubilized, nanoparticles) along olfactory nerve bundles after inhalation of microparticles. This work contributes to knowledge of the mechanistic actions of particulate pollutants on the brain. https://doi.org/10.1289/EHP4927

Effect of a novel polyethylene glycol compound on lung lavage in dogs after the inhalation of depleted uranium dust

Purpose: The purpose of this study was to assess the effect of a lavage solution containing methoxypolyethylene glycol 4-(3,4-dihydroxyphenethylamino)-4-oxobutanoate (MDO) for whole lung lavage (WLL) in dogs after the inhalation of depleted uranium (DU) dust at a dose of 30 mgUkg−1.Materials and methods: WLL was performed using lavage solutions made of normal saline (saline group) or normal saline plus MDO (MDO group) at 2 days post-DU exposure. Meanwhile, a control group was set up without any treatment.Results: At 10 days post-DU exposure, the saline and MDO groups had a lower DU content in urine and lung compared with the DU group (without lavage), while the MDO group content was significantly lower than that in the saline group. In terms of blood urea nitrogen and creatinine levels, the DU group maintained relatively high levels from day 3 to day 10; the saline group levels were reduced compared with the DU group at day 8 and day 10, while the MDO group levels remained markedly lower than both the DU and saline group levels. Pathological changes in the lungs and kidneys showed that the saline group was improved compared with the DU group, but not as significantly as the MDO group.Conclusions: In brief, WLL has a remarkable effect in promoting the decorporation of inhaled DU dust in the lungs of dogs. By comparison, a MDO-containing lavage solution has a better lavage effect than normal saline.

Numerical simulation of migration behavior of uranium ore dust particles in the human respiratory tract

There is a certain concentration of radioactive dust particles in the air of workplace of underground uranium mines. Some small diameter particles will pass through the masks and enter the respiratory tract which will cause radiation damage to the human body. In order to study deposition regularity of uranium dust in the human respiratory tract, in this paper, we firstly use the RNG turbulence model to simulate the gas flow field in the human respiratory tract Z0 ∼ Z3 level under different respiratory intensity. Then we use DPM discrete phase model to simulate the concentration, particle size distribution, deposition rate and deposition share of uranium dust particles after being filtered through the masks in the human respiratory tract Z0 to Z3 bronchus. According to the simulation results, we have got the following conclusions: the particles’ number concentration of uranium dust after being filtered through the mask in the human respiratory tract basically decreases with the increasing of particle size under different respiratory intensities on the environment of uranium mine. In addition, the intensity of respiration and the mass concentration of particles have an important influence on the deposition rate and the deposition of particles in the respiratory tract.

Аffect of uranium ore dust on separate indexes of nitrous exchange of rat liver using Lacryc radices root extract

Purpose of the research ‐ to reveal peculiarities of metabolic break of nitrous exchange of rat liver tissue at long‐term inhalation affect of uranium dust in different terms and to evaluate effectiveness of corrective effect of radices root extract. It is determined, that at inhalation of uranium dust in doses, equivalent to 5 maximum‐allowed concentration, during 120 days process of albumen synthesis is activated in liver, that is confirmed by regular increase of albumen concentration in blood serum for 2 times to the end of observation in term of its fixed content in liver tissue. Pointed changes coincide with depression of processes of urea‐formation almost in 2 times, consequent depression of aspartataminotraspherase (AsAT) and gammaglutamiltranspeptidase (GGTP) activity in liver in 2 times. level of adaptive activation of albumen synthesis reduces for 38 and 13,6%, depression affect on process of urea‐formation increases for 16,1%, activity of AsAT and AlAT in liver reduces for 18,2% and 16%, and top of hyperalbumenemia reduces for 30 days. At increasing of doze load for 10 times, duration of exchange processes acutely reduced, effects of albumen content increase for 55% is kept only for the first 7 days, and it coincides with depression of AsAT activity for 36,6% and strengthening of hyperfermentemia of AsAT for 4,9 times and AlAT for 2,5–4 times. It is determined, that water extract of lacryc radices root possesses corrective effects, improving indexes of albumen‐synthetic, fermentative and urea‐formative function of liver. It is showed, that lacryc radices root extract stably increases content of general albumen for 15‐11%, synthesis of urea for 13‐28%, activity of AsAT for 46% and for 2,4 times, and AlAT – for 3‐4 times in liver.

In vitro dissolution of uranium-contaminated soil in simulated lung fluid containing a pulmonary surfactant.

During the latter part of the twentieth century, the United States developed a highly technical nuclear weapons complex that involved workers at many facilities performing complex missions at a number of different industrial sites across the country. Now, many of these sites are being remediated to remove legacy materials including chemical and radioactive wastes. Along with remediation comes the responsibility to adequately assess risk to cleanup workers who could be exposed to any hazardous materials, including resuspended uranium dust, encountered during environmental restoration. Inhalation of resuspended uranium represents one of the exposure hazards at an abandoned former metal rolling mill where approximately 11 thousand tons of uranium metal was rolled between 1947 and 1958. Residual uranium contamination in the dirt floor of this abandoned site has been exposed to rain, ice, snow, and other environmental factors for more than 50 y. This report describes the solubility of the uranium contamination in this dirt measured in vitro using a modified recipe for simulated lung fluid that contains a pulmonary surfactant. Small (0.1 g) aliquots of dirt collected at this site were sequentially dissolved in simulated lung fluid for increasing periods of time up to 30 d. Solubility was classified according to the ICRP categories as fast, medium, and slow. Results demonstrate that the solubility designation for the uranium contamination in the dirt is approximately 50% fast, 15% medium, and 35-40% slow. There was no observed difference in solubility when a pulmonary surfactant was added to the simulated lung fluid.

QUESTIONABLE INCREASE OF CHILDHOOD LEUKEMIA IN BASRAH, IRAQ

The explosion of depleted uranium ammunition generates ultrafine uranium dust particles that may pose health hazards, especially an increased risk for cancer, for people living in combat zones. Hagopian et al.1 claims a more than doubling of childhood leukemia incidence in Basrah governorate over a period of 15 years (1993–2007), based on data of a hospital-based tumor registry, speculating about possible effects of chemical warfare agents, benzene, and exposure to depleted uranium dust. In our opinion this claim is as yet unsubstantiated, because no reliable population figures are available for the whole period. Besides, a hospital-based tumor registry usually cannot provide complete population coverage and lacks at least one indispensable data source of population-based cancer registries: death certificates. One of us (E. G.) was part of a group of World Health Organization (WHO) temporary advisors visiting Baghdad in September 1995 on request from the Iraqi Ministry of Health to advise on problems of cancer control. At that instance proportionate incidence data were presented by scientists from the Iraqi National Cancer Registry indicating higher rates of childhood leukemia for the governorate of Basrah than for the rest of Iraq. Exposure to depleted uranium ammunition in and around Basrah was discussed as a possible cause. In a subsequent WHO mission in December of 1995 we analyzed the National Cancer Registry and abstracted from ledgers data on childhood leukemia for the whole of Iraq. No population figures were available, but we were provided with projections of population data for all Iraqi governorates. Based on these data no increase of childhood leukemia could be detected for the governorate of Basrah. In our report to the WHO we raised the suspicion of gross underreporting for all Iraqi governorates except for Baghdad (report available from the authors). A diverse group of children at Kingsmead Primary School pay close attention during a school assembly. Most of the children live on the Kingsmead Estate in Homerton, Hackney, UK, close to the site of the 2012 Summer Olympic Games. Photograph by Gideon Mendell. Printed with permission of Corbis. Supported by the German Academic Exchange Service (Deutscher Akademischer Austauschdienst (DAAD) 2005, 2006) and the Norwegian Foreign Office (2009) we conducted postgraduate courses on epidemiologic methods for scientists from Basrah and Baghdad in Amman, Jordan (February 2005); Greifswald, Germany (February 2006); and Istanbul, Turkey (July 2009) to enable our colleagues from Iraq to establish a population-based cancer registry in Basrah and to prepare a design for a case-control study on childhood leukemia. This endeavor is still under way.

Modeling the Imprecision in Prospective Dosimetry of Internal Exposure to Uranium

The dosimetry of internal exposure to radionuclides is performed on the basis of biokinetic and dosimetric models. For prospective purpose, the organ or effective dose resulting from potential conditions of exposure can be calculated by applying these models with dedicated software. However, it is acknowledged that a significant uncertainty is associated with such calculation due to the variability of individual cases and to the possible lack of knowledge about some factors influencing the dosimetry. This uncertainty has been studied in a range of situations by modeling the uncertainty on the model parameters by probability distributions and propagating this uncertainty onto the dose result by Monte Carlo calculation. However, while probability distributions are well adapted to model the known variability of a parameter, they may lead to an unrealistically low estimate of the uncertainty due to a lack of knowledge about some input parameters. Here we present a mathematical method, based on the Dempster-Shafer theory, to deal with such imprecise knowledge. We apply this method to the prospective dosimetry of inhaled uranium dust in the nuclear fuel cycle when its physico-chemical properties are not precisely known. The results show an increased estimation of the range of uncertainty as compared to the application of a probabilistic method. This Dempster-Shafer method may valuably be applied in future prospective dosimetry of internal exposure in order to more realistically estimate the uncertainty resulting from an imprecise knowledge of the parameters of the dose calculation.

Depleted uranium: a new battlefield hazard

Depleted uranium: a new battlefield hazard