Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PLUTONIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources

Myeloid leukemia 239Pu-treated mice.

Incidence of myeloid leukemia was studied in 79 mice injected i.v. with 180 kBq 239Pu/kg. Plutonium-treated mice were compared with 70 controls of the same origin and sex (random-bred ICR-SPF female mice). The animals were killed moribund and the disease was diagnosed on the basis of histological and cytologic examination of bone marrow, spleen, liver, peripheral blood, and other tissues. It has been found that 22 plutonium-treated mice (27.8%) and 17 controls (24.3%) were leukemic. The mean survival of diseased animals was 459 +/- 19 days in the tested group and 559 +/- 24 days in controls. It means that the occurrence of myeloid leukemia was not very different in irradiated and control mice, but under plutonium contamination the disease appeared significantly earlier and its incidence was shifted to the younger age.

Age Factors↗

Lung cancer mortality among nuclear workers of the Mayak facilities in the former Soviet Union. An updated analysis considering smoking as the main confounding factor.

A new analysis of lung cancer mortality in a cohort of male Mayak workers who started their employment in the plutonium and reprocessing plants between 1948 and 1958 has been carried out in terms of a relative risk model. The follow-up has been extended until 1999, moreover a new dosimetry system (DOSES2000) has been established. Particular emphasis has been given to a discrimination of the effects of external gamma-exposure and internal alpha-exposure due to incorporated plutonium. This study has also utilized and incorporated the information from a cohort of Mayak reactor workers, who were exposed only externally to gamma-rays. The influence of smoking as the main confounding factor for lung cancer has been studied. The baseline lung cancer mortality rate was not taken from national statistics but was derived from the cohort itself. The estimated excess relative risk for the plutonium alpha-rays was 0.23/Sv (95%CI: 0.16-0.31). The resulting risk coefficient for external gamma-ray exposure was very low with a statistically insignificant estimate of 0.058/Sv (95%CI: -0.072-0.20). The inferred relative risk for smokers was 16.5 (95%CI: 12.6-20.5).

Cohort Studies↗

Investigations of the binding of 239Pu to liver cell membranes.

The binding of Pu to liver cell membranes was studied and compared with that of iron with which plutonium shares some physiological properties. The binding of both metals is sensitive to pH changes and they can be dissociated from their binding sites by chelating agents and transferrin. The metal-binding proteins can be extracted with detergents. Both metals have at least two binding sites, the molecular weights of which lie between 150 and 400 kDa; the isoelectric points for iron are 5.5 and 6.5, and for plutonium 6.0 and 6.5. The significance of these results for plutonium uptake into liver cells is discussed.

Animals↗

Study of an alpha track analysis and a fission track analysis for determining the hot particles contaminated with Pu and U isotopes.

A fission track analysis and alpha track analysis were developed to detect fissile particles such as uranium and plutonium isotopes as well as to identify particle-bound plutonium in contaminated soil or sediment. To record a reference point, a locator SEM grid electroplated with boron was used to obtain a recorded grid image on the Lexan or CR-39 detector. With the fission track technique, the track images of the grid coated with boron and the fissile nuclides on the CR-39 detector were clearly recorded so that the location of the fissile particles could be easily identified in the radio-contaminated soil matrix. With the alpha track technique, many of the hot particles in the BOMARC soil turned out to be contaminated with plutonium isotopes rather than uranium isotopes.

Alpha Particles↗

238Pu and 239+240Pu inventory and distribution through the lower Rhone valley terrestrial environment (Southern France).

Because of atmospheric global fallout due to thermonuclear tests performed between 1945 and 1980 and to the American SNAP 9A satellite explosion in 1964, plutonium's long-lived alpha emitter isotopes ((238)Pu, (239)Pu and (240)Pu) can be found everywhere in the environment. In the soils of the lower Rhone valley, over a surface area of approximately 11,000 km(2), existing results allow estimation of the total inventory resulting from this origin of 551 GBq as regards these radionuclides. The Marcoule Nuclear Reprocessing Plant (NRP) has been releasing (238)Pu and (239+240)Pu into the environment for over 40 years in the region and is as such a second likely source for Pu input. This article gives a global review of plutonium distribution in this particular region. It is shown that releases from Marcoule, although accounting for less than 2% of the total Pu inputs into the terrestrial environment, are responsible for localised and measurable Pu enrichments close to the facility (+2.8 GBq), and in the Rhone delta where sediments from the river settled during the past floods (+0.1 GBq). Irrigating with water from the Rhone River also allowed the transfer of approximately 3.8 GBq of (238)Pu and (239+240)Pu to the soils for the whole 1960-1998 period. These inputs, distributed over wide irrigated surface areas, do not induce significant increases of soil Pu-activity levels. In a second section, this study confirms that most of the plutonium existing in the terrestrial environment is accumulated in the soil. Less than 0.1% of the activities exist currently in the plant compartments, and the flows exported by agricultural productions are very low, although we are interested here in a French region where agriculture prevails.

Air Pollutants, Radioactive↗

Radionuclides in seals and porpoises in the coastal waters around the UK.

It has been suggested that marine predators be assessed for biologically relevant contamination levels because of their trophic position. Accordingly, in studying radioactive contamination in the marine environment around the UK, tissues from seals and porpoises have been chosen. Liver and muscle tissue from dead seals and porpoises found stranded around the UK coast have been analysed for the following radionuclides: 134Cs, 137Cs, 238Pu, 239Pu + 240Pu. Multifactor analysis of variance indicated that, for radiocaesium, there was no significant difference for harbour seals, grey seals or porpoises in terms of species or gender; however, the tissue activity concentration increased with body weight and decreased with distance from Sellafield, the major nuclear reprocessing plant in the UK. The levels of radiocaesium in muscle were higher than those in liver, while there appeared to be a concentration factor of approximately 3-4 for muscle radiocaesium when compared to radiocaesium levels reported for fish, the main food source of the marine mammals under study. Approximate radiation dose calculations indicated that the average dose from radiocaesium was less than 10% of the dose from the naturally occurring radioisotope of potassium, 40K. The highest tissue activity concentration for plutonium of 0.037 Bq/kg (239Pu + 240Pu) was detected in a grey seal stranded at Rathlin Island in Northern Ireland. Calculation of approximate radiation doses from plutonium contamination showed that, as with radiocaesium, the average dose was small compared with that from 40K. In summary, the radiocaesium contamination in seals and porpoises decreased with distance from Sellafield indicating that the BNF plc processing plant was the major source of the contamination. The marine mammals concentrated radiocaesium from their environment by a factor of 300 relative to the concentration in seawater indicating the value of using marine mammal tissue to measure radiocaesium contamination in the marine environment. The maximum radiation dose to the marine mammals from radiocaesium was higher than doses previously assessed for critical groups of humans living near Sellafield, while the maximum dose from plutonium was comparable to the doses for humans.

Animals↗

Removal of radionuclides at a waterworks.

A waterworks with an average production rate of 1.3 m3 s(-1), providing several large cities in the province of Scania with drinking water has been studied regarding its capacity to remove several natural and anthropogenic radionuclides. The raw water is surface water from lake Bolmen which is transported through an 80 km long tunnel in the bedrock before it enters the waterworks. The method used for purification is a combination of coagulation-flocculation and filtration in sand filters. Two different purification lines are currently in use, one using Al2(SO4)3 as a coagulant and one using FeCl3. After coagulation and flocculation the precipitate is removed and the water is passed through two different sand filters (rapid filtration and slow filtration). Water samples were collected at the lake, the inlet to the waterworks, after each of the flocculation basins (Al2(SO4)3 and FeCl3), after rapid filtration and from the municipal distribution network. The samples were analysed with respect to their content of uranium, thorium, polonium, radium, plutonium and caesium. The results show a high removal capacity for uranium (about 85%), thorium (>90%), plutonium (>95%) and polonium (>90% in the coagulation-flocculation process) while caesium, strontium and radium pass through the purification process with almost unchanged activity concentrations. During transportation of the water in the tunnel it was also observed that infiltration of groundwater leads to a change in isotopic ratios and/or activity concentrations for the naturally occurring radionuclides and plutonium.

Cesium↗

Pu(V)O2+ adsorption and reduction by synthetic hematite and goethite.

Changes in aqueous- and solid-phase plutonium oxidation state were monitored over time in hematite (alpha-Fe2O3) and goethite (alpha-FeOOH) suspensions containing 239Pu(V)-amended 0.01 M NaCl. Solid-phase oxidation state distribution was quantified by leaching plutonium into the aqueous phase and applying an ultrafiltration/solvent extraction technique. The technique was verified using oxidation state analogues of plutonium and sediment-free controls of known Pu oxidation state. Batch kinetic experiments were conducted at hematite and goethite concentrations between 10 and 500 m2 L(-1) in the pH range of 3-8. Surface-mediated reduction of Pu(V) was observed for both minerals at pH values of 4.5 and greater. At pH 3 no adsorption of Pu(V) was observed on either goethite or hematite; consequently, no reduction was observed. For hematite, adsorption of Pu(V) was the rate-limiting step in the adsorption/reduction process. In the pH range of 5-8, the overall removal of Pu(V) from the system (solid and aqueous phases) was found to be approximately second order with respect to hematite concentration and of order -0.39 with respect to the hydrogen ion concentration. The overall reaction rate constant (k(rxn)), including both adsorption and reduction of Pu(V), was 1.75+/-2.05 x 10(-10) (m(-2) L)(-2.08) (mol(-1) L)(-0.39) (s(-1)). In contrast to hematite, Pu(V) adsorption to goethite occurred rapidly relative to reduction. At a given pH,the reduction rate was approximately independent of the goethite concentration, although the hydrogen ion concentration (pH) had only a slight effect on the overall reaction rate. For goethite, the overall reaction rates at pH 5 and pH 8 were 6.0 x 10(-5) and 1.5 x 10(-4) s(-1), respectively. For hematite, the reaction rate increased by 3 orders of magnitude across the same pH range.

Adsorption↗

Synthetic enterobactin analogues. Carboxamido-2,3-dihydroxyterephthalate conjugates of spermine and spermidine.

Two examples of a new class of synthetic polycatecholate ligands, the carboxamido-2,3-dihydroxyterephthalate conjugates of spermine (8) and of spermidine (10), have been synthesized via the generally useful synthon methyl-2,3-dimethoxyterephthaloyl chloride (6). Initial biological evaluation reveals tetrameric terephthalate (8) to be an extremely effective agent for sequestering and removing plutonium from mice; a single 25-mumol/kg (ip) dose of 8 removed 73% of the plutonium citrate previously injected (iv, 1 h earlier). Under the same conditions, trimeric terephthalate (10) excreted only 49% of injected plutonium. In vitro kinetic experiments have shown that 10 rapidly and quantitatively removed Fe from human transferrin. These results are discussed in relation to the design of metal-ion specific sequestering agents.

Animals↗

Past exposure to densely ionizing radiation leaves a unique permanent signature in the genome.

Speculation has long surrounded the question of whether past exposure to ionizing radiation leaves a unique permanent signature in the genome. Intrachromosomal rearrangements or deletions are produced much more efficiently by densely ionizing radiation than by chemical mutagens, x-rays, or endogenous aging processes. Until recently, such stable intrachromosomal aberrations have been very hard to detect, but a new chromosome band painting technique has made their detection practical. We report the detection and quantification of stable intrachromosomal aberrations in lymphocytes of healthy former nuclear-weapons workers who were exposed to plutonium many years ago. Even many years after occupational exposure, more than half the blood cells of the healthy plutonium workers contain large (>6 Mb) intrachromosomal rearrangements. The yield of these aberrations was highly correlated with plutonium dose to the bone marrow. The control groups contained very few such intrachromosomal aberrations. Quantification of this large-scale chromosomal damage in human populations exposed many years earlier will lead to new insights into the mechanisms and risks of cytogenetic damage.

Alpha Particles↗

Atmospheric deposition, resuspension, and root uptake of Pu in corn and other grain-producing agroecosystems near a nuclear fuel facility.

Plutonium released to the environment may contribute to dose to humans through inhalation or ingestion of contaminated foodstuffs. Plutonium contamination of agricultural plants may result from interception and retention of atmospheric deposition, resuspension of Pu-bearing soil particles to plant surfaces, and root uptake. Plutonium on vegetation surfaces may be transferred to grain surfaces during mechanical harvesting. Data obtained from corn grown near the U.S. Department of Energy's H-Area nuclear fuel chemical separations facility on the Savannah River Site were used to estimate parameters of a simple model of Pu transport in agroecosystems. The parameter estimates for corn were compared to those previously obtained for wheat and soybeans. Despite some differences in parameter estimates among crops, the relative importances of atmospheric deposition, resuspension, and root uptake were similar among crops. For even small deposition rates, the relative importances of processes for Pu contamination of corn grain should be: transfer of atmospheric deposition from vegetation surfaces to grain surfaces during combining greater than resuspension of soil to grain surfaces greater than root uptake. Approximately 3.9 X 10(-5) of a year's atmospheric deposition is transferred to grain. Approximately 6.2 X 10(-9) of the Pu inventory in the soil is resuspended to corn grain, and a further 7.3 X 10(-10) of the soil Pu inventory is absorbed and translocated to grains.

Air Pollution, Radioactive↗

Multifactorial analysis of lung cancer dose-response relationships for workers at the Mayak nuclear enterprise.

Dose-response relationships for alpha-radiation-induced lung cancers (adenocarcinoma, squamous carcinoma and small cell carcinoma) were developed by multifactorial analysis using data for Mayak nuclear enterprise workers chronically exposed by inhalation to 239Pu. The three most important lung cancer risk factors (smoking, plutonium incorporation, and external gamma irradiation), out of six factors previously identified, were used. Relative risks (odds ratios) were determined for 500 nuclear enterprise workers (162 cancer cases, 338 control) for different dose levels using a case-control study design and logistic regression. A threshold at about 3.7 kBq or 0.80 Gy was discovered for incorporated plutonium, which is satisfactorily described by linear-quadratic and quadratic models. Excess relative risk was 0.020 kBq(-2) and 0.97 Gy(-2). This quadratic function was mainly due to adenocarcinoma. A trend for decreasing risk was noted for the lowest levels of plutonium incorporation, near permissible level. No clear-cut dose-response relationship for lung cancer induction by chronic external gamma irradiation was obtained. Lung cancer induction by cigarette smoking had a linear dependence: smoking of one pack of papiroses (a type of Russian cigarette) per day for 5 y increases the lung cancer risk twofold. The effect was most clearly manifested for squamous-cell carcinoma.

Adenocarcinoma↗

USTUR case 0259 whole body donation: a comprehensive test of the current ICRP models for the behavior of inhaled 238PuO2 ceramic particles. U.S. Transuranium and Uranium Registries.

An analysis of 238Pu in the whole body donation to the U.S. Transuranium and Uranium Registries (USTUR) is presented. This donor accidentally inhaled an unusual physical form of plutonium, predominantly the 238Pu isotope in the form of a highly insoluble ceramic. Along with six other workers accidentally exposed at the same time, this donor excreted little or no 238Pu in his urine for several months. Subsequently, however, and, with no further intakes, the urinary excretion of 238Pu by all of these workers increased progressively. Such a pattern of increasing urinary excretion of plutonium resulting from a single acute inhalation was unknown at the time. The subject of this study provided a unique opportunity to analyze not only the pattern of urinary excretion for 17 y following this unusual intake but also the complete distribution of 238Pu in his donated body tissues and skeleton at death. Radiochemical analyses of tissues from this whole body donation were used to perform critical tests of the applicability and accuracy of the respiratory tract model and the systemic biokinetic models for plutonium currently recommended by the International Commission on Radiological Protection. The respiratory tract model was applied to analyze the donor's long-term urinary excretion pattern. The facility provided by this model to represent progressive transformation of insoluble particles in the lungs into a more soluble form, applied in conjunction with the systemic biokinetic model, predicted the total amount of 238Pu measured in the donor's body to within 17% accuracy. The measured division of 238Pu between the donor's lungs and systemic organs was predicted to within 10%. Small adjustments to several rate constants in these models provided precise predictions of the absolute amounts of 238Pu in the lungs, thoracic lymph nodes, liver, red bone marrow, skeleton (including the distribution of 238Pu between trabecular and cortical bone matrices derived from the radiochemical analyses), kidneys, testes, and muscle. The resulting individual-specific parameters were applied to evaluate the equivalent dose rates and cumulative doses received by the donor's organs and the overall effective dose. Whereas these individual modifications to the ICRP models provided a more accurate representation of the distribution of dose between the donor's organs, it was determined that the ICRP models provided an adequate estimate of the overall effective dose.

Air Pollution, Radioactive↗

Room airflow studies using sonic anemometry.

To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s-1 to 9.7 cm s-1. There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s-1 to 35.5 cm s-1 with turbulence intensities from 33% to 108%.

Aerosols↗

Comparative study on Tp53 gene mutations in lung tumors from rats exposed to 239Pu, 237Np and 222Rn.

The tumor suppressor gene Tp53 was analyzed by polymerase chain reaction-amplification of genomic DNA extracted from paraffin-embedded tissue sections of rat lung tumors to compare mutations that occurred after inhalation exposures to plutonium dioxide, neptunium dioxide, or radon and radon progenies. Exons 5 to 8 of the gene were amplified in 16 plutonium-, 23 neptunium- and 15 radon-induced lung tumors, and their polymerase chain reaction products were examined for mutations by single strand conformational polymorphism analysis and direct sequencing method. Two point mutations were detected in the plutonium-induced tumors, i.e., a guanine to adenine transition at codon 219 of exon 6 and a cytosine to thymine transition at codon 266 of exon 8. Although only one point mutation was found at codon 175 of exon 5 (cytosine to thymine transition) from neptunium-induced tumors, no mutations were detectable from radon-induced tumors. These results indicate that the abnormalities of the Tp53 gene might not be so critical for the pulmonary carcinogenesis after the inhalation of different alpha emitters, even though the presence and frequencies of the Tp53 gene mutations were different.

Administration, Inhalation↗

Lung cancer mortality among male nuclear workers of the Mayak facilities in the former Soviet Union.

An analysis of lung cancer mortality in a cohort of 1,669 Mayak workers who started their employment in the plutonium and reprocessing plants between 1948 and 1958 has been carried out in terms of a relative risk model. Particular emphasis has been given to a discrimination of the effects of external gamma-ray exposure and internal alpha-particle exposure due to incorporated plutonium. This study has also used the information from a cohort of 2,172 Mayak reactor workers who were exposed only to external gamma rays. The baseline lung cancer mortality rate has not been taken from national statistics but has been derived from the cohort itself. For both alpha particles and gamma rays, the results of the analysis are consistent with linear dose dependences. The estimated excess relative risk per unit organ dose equivalent in the lung due to the plutonium alpha particles at age 60 equals, according to the present study, 0.6/Sv, with a radiation weighting factor of 20 for alpha particles. The 95% confidence range is 0.39/Sv to 1.0/Sv. For the gamma-ray component, the present analysis suggests an excess relative risk for lung cancer mortality at age 60 of 0.20/Sv, with, however, a large 95% confidence range of-0.04/Sv to 0.69/Sv.

Alpha Particles↗

Stable intrachromosomal biomarkers of past exposure to densely ionizing radiation in several chromosomes of exposed individuals.

A multicolor banding (mBAND) fluorescence in situ hybridization technique was used to investigate the presence inhuman populations of a stable biomarker-intrachromosomal chromosome aberrations-of past exposure to high-LET radiation. Peripheral blood lymphocytes were taken from healthy Russian nuclear workers occupationally exposed from 1949 onward to either plutonium, gamma rays or both. Metaphase spreads were produced and chromosomes 1 and 2 were hybridized with mBAND FISH probes and scored for intra-chromosomal aberrations. A large yield of intrachromosomal aberrations was observed in both chromosomes of the individuals exposed to high doses of plutonium, whereas there was no significant increase over the (low) background control rate in the population who were exposed to high doses of gamma rays. Interchromosome aberration yields were similar in both the high plutonium and the high gamma-ray groups. These results for chromosome 1 and 2 confirm and extend data published previously for chromosome 5. Intrachromosomal aberrations thus represent a potential biomarker for past exposure to high-LET radiations such as alpha particles and neutrons and could possibly be used as a biodosimeter to estimate both the dose and type of radiation exposure in previously exposed populations.

Aged↗

Comparative deterministic effects of inhaled, insoluble alpha- and beta-particle-emitting radionuclides in dogs.

This report compares the deterministic effects from an alpha-particle-emitting radionuclide, (239)PuO(2), and a beta-particle emitter, (144)Ce in fused aluminosilicate particles (FAP). The studies were conducted in beagle dogs of both genders exposed by inhalation to aerosols of the radionuclides. The initial lung burdens of (239)Pu and (144)Ce were determined by whole-body counting of the (169)Yb added to the plutonium aerosol during its preparation or the (144)Ce and its progeny (144)Pr. In addition, organ retention data were obtained from parallel serial sacrifice studies with the same aerosols. After exposure, the dogs were observed for health effects over their lifetime. The deterministic effects observed for both of these relatively insoluble aerosols were lymphopenia, fibrosis, atrophy of the lung-associated lymph nodes, and radiation pneumonitis. Due to the longer half-life of plutonium, the lymphopenia was more prolonged and the clinical course of the radiation pneumonitis more chronic than that resulting from cerium. The greater tissue penetration of the beta-particle emissions from the cerium resulted in more uniform dose distribution over the lung and the atria of the heart than from the alpha-particle emissions from plutonium.

Administration, Inhalation↗