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PubMed1988

Renal thorium deposition associated with transitional cell carcinoma: radiologic demonstration in two patients.

Abdominal radiography, excretory urography, retrograde pyelography, and computed tomography were performed in two patients who had undergone retrograde pyelography with thorium dioxide (Thorotrast) approximately 40 years ago. Both patients developed a transitional cell carcinoma due to suburothelial thorium deposition. Typical thorium densities were demonstrated at CT in the peripelvicalyceal area as well as in retroperitoneal lymph nodes. Elderly patients in whom radiographic examination reveals retained Thorotrast in the kidney should be followed up because of the high risk of renal carcinoma.

Aged↗
PubMed2002

Selective recovery of uranium and thorium ions from dilute aqueous solutions by animal biopolymers.

Selective actinide ion recovery from dilute, aqueous, multication waste streams is an important problem. The recovery of uranium (U) and thorium (Th) by various animal biopolymers was examined. Of four species of biopolymers tested, a high uptake of uranium and thorium was found in hen eggshell membrane (ESM) and silk proteins, with the maximum uranium and thorium recovery exceeding 98% and 79%, respectively. The uptake of U and Th was significantly affected by the pH of the solution. The optimum pH values were 6 and 3 for the uptake of U and Th, respectively. The effect of temperature differed with the metal. The uptake of U decreased with increasing temperature (30-50 degrees C), whereas the Th uptake increased with increasing temperature. Selective recovery of U and Th from dilute aqueous binary and multimetal solutions was also examined. ESM and silk proteins tested were effective and selective for removing each metal by controlling the pH and temperature of the solution. In multimetal systems, the order of sorption of ESM proteins was preferential: U > Cu > Cd > Mn > Pb > Th > Ni > Co > Zn at pH 6 and Th > U > Cu > Pb > Cd > Mn > Co > Ni = Zn at pH 3. These biopolymers appear to have potential for use in a commercial process for actinide recovery from actinide-containing wastewater.

Absorption↗
PubMed1975

Brain stem abscess treated surgically. Wtih special note upon the employment of thorium dioxide.

A 10-year-old girl, with congenital heart disease, harboring a brain stem abscess, was recently treated at the UCLA Hospital. Needle aspirations of the abscess was performed through a posterior occipital craniectomy, and thorium dioxide (Thorotrast) was placed within the abscess cavity as a marker. Postoperatively, the patient improved temporarily but died 18 days later. Autopsy examination included radioactive analysis of brain and liver tissue. Radioautographs were superimposed on H&E preparations of the abscess wall to localize the extent of activity of the thorium dioxide. The unusual occurrence of this abscess in a young patient, clinically diagnosed and treated by operation, provided a rare opportunity to assess the problem of the surgical accessibility of brain stem abscess as well as to reevaluate a role for thorium dioxide as a marker for intracranial purulent collections.

Autoradiography↗
PubMed1975

Thorium induced testicular changes in rats.

Daily intraperitoneal administration of thorium nitrate produced progressive morphological and biochemical alterations with the increase in thorium concentration in rat testis. The degenerative changes in the seminiferous tubules increased with the duration of treatment and after 90 days calcification occurred in about 25% of the tubules and in the connective tissue of the tunica albuginea. The activity of adenosine triphosphatase and alkaline phosphatase increased markedly as a result of thorium administration. An attempt has been made to interrelate histopathological and enzymatic changes and the metal concentration in the testicular tissue.

Adenosine Triphosphatases↗
PubMed2005

[Analysis of health state in individuals exposed to thorium and chemical hazards in occupational environment].

Clinical and epidemiologic study of chronic somatic discases in workers engaged into thorium production (main group) in short-term period revealed significantly higher prevalence of vegetative neurosis, asthenic state, chronic gastritis, arterial hypotension, chronic nasopharyngitis and higher risk of those conditions, if compared to reference group over the period since 1947 to 1959. These findings are caused by combined exposure to occupational hazards: outer and inner radiation due to long-lived thorium, thoron and their radioactive products, associated exposure to toxic chemicals. Chronic radiation sickness was diagnosed only in individuals who worked over the period since 1947 to 1959 and demonstrated hemopoietic disorders associated with functional neural system impairment. Better sanitary and hygienic work conditions and more efficient individual protective means ("Lepestok" respirator) resulted in reliably decreased risk of chronic somatic diseases among thorium production workers employed since 1960 to 1972.

Adult↗
PubMed1966

Hepatoma induced by thorium dioxide (thorotrast).

A case of hepatoma induced by thorium dioxide (Thorotrast) is reported. The literature concerning neoplasia associated with this agent is reviewed, with emphasis on the long latent period before the development of these tumours and the equally long latent period which preceded the recognition of their iatrogenic nature.In particular, this report is intended to illustrate the diagnosis of such tumours on radiological and histological findings, provided that one is aware of their existence and familiar with the distribution and appearance of thorium dioxide deposits in the tissues. Such a diagnosis can be made without a history of thorium dioxide administration, which often may not be available.

Biopsy↗
PubMed1984

[Hemangioendothelioma of the liver 38 years after administration of thorium dioxide].

The case of a 56 years old patient is reported who died of a malignant hepatic angiosarcoma 38 years after administration of thorium dioxide. Although the incidence of thorium dioxide-induced late effects is declining still today in the differential-diagnosis of liver cancers thorium dioxide associated tumors have to be considered. The progress of the disease is described and the radiological findings are discussed.

Aged↗
PubMed1980

Energy dispersive x-ray detection of thorium dioxide.

Since the recognition of the development of certain malignant neoplasms in association with thorium dioxide (Thorotrast), its presence has been documented by light microscopic appearance and time-consuming autoradiography. Energy dispersive x-ray microanalysis can be used in the rapid documentation of thorium in paraffin-embedded tissues and it is confirmed that thorium is the principal component of the granular deposits described by light microscopy.

Bone Marrow↗
PubMed2002

Use of three new SSNTD methods for evaluating thorium contents in different building materials and measuring thoron and its progeny concentrations inside dwellings.

Three new methods based on using CR-39 and LR- 115 type II solid state nuclear track detectors (SSNTD) were used for measuring thorium concentrations (in 10(-6)g/g (ppm)) inside different building materials and evaluating the resulting concentrations of thoron and its progenies in dwellings built by the studied materials. The first technique consists of determining the probabilities for alpha-particles emitted by the uranium and thorium series inside the building materials or by the radon and thoron groups inside the dwelling atmosphere to reach and be registered as tracks on the SSNTD utilized and exploiting the resulting track density rates. The second method consists of evaluating the mean critical angles of etching of the CR-39 and LR-115 II SSNTD and measuring the resulting track densities registered on the detectors utilized. The third technique is based on calculating the detection efficiencies of the CR-39 and LR-115 II SSNTD for a-particles emitted by the uranium and thorium series in the building materials or by the radon and thoron groups in air and measuring track density rates registered on these detectors. The influence of the building material's nature and ventilation rate on the thoron and its decay products inside the dwelling rooms studied has been investigated.

Journal Article↗
PubMed2000

Volatile metal beta-diketonates--new precursors for the sonochemical synthesis of nanosized materials--sonolysis of thorium(IV) beta-diketonates.

Ultrasonic irradiation (22 kHz, Ar atmosphere) of Th(IV) beta-diketonates Th(HFAA)4 and Th(DBM)4, where HFAA and DBM are hexafluoroacetylacetone and dibenzoylmethane respectively, causes them to decompose in hexadecane solutions, forming solid thorium compounds. The first-order rate constants for Th(IV) beta-diketonate degradation were found to be (9.3 +/- 0.8) x 10(-3) for Th(HFAA)4 and (3.8 +/- 0.4) x 10(-3) min-1 for Th(DBM)4, (T = 92 degrees C, I = 3 W cm-2). The rate of the sonochemical reaction increased with the rising beta-diketonate volatility and decreased with the rising hydrocarbon solvent vapor pressure. Solid sonication products consisted of a mixture of thorium carbide ThC2 and Th(IV) beta-diketonate partial degradation products. The average ThC2 particle size was estimated to be about 2 nm. ThC2 formation was attributed to the high-temperature reaction occurring within the cavitating bubble. The thorium beta-diketonate partial degradation products formed in the liquid reaction zones surrounding the cavitating bubbles.

Journal Article↗
PubMed2004

Adsorption of uranium from acidic solution by microbes and effect of thorium on uranium adsorption by Streptomyces levoris.

The adsorption of uranium from an acidic solution by microbes was examined. High uranium adsorption ability was exhibited by actinomycetes. Streptomyces levoris cells could adsorb about 380 micromol of uranium per gram dry cells from the solution. The cells could adsorb uranium over a wide acidic pH range and very rapidly. The amount of uranium adsorbed from a solution containing uranium and thorium was affected by the thorium concentration. The amount adsorbed was reduced and an uranyl-thorium ion exchange reaction occurred in the case of adsorption from a solution containing both metals.

Journal Article↗
PubMed1993

Systemic deposits of thorium in thorotrast patients with particular reference to sites of minor storage.

It is well established that injected Thorotrast is deposited in the liver, spleen, bone marrow, and lymph nodes, but accumulations in organs with lower macrophage activity have previously been given little attention. In this work, neutron activation analysis has been used to investigate concentrations of thorium in autopsy samples taken at sites of major and minor deposition in 24 Thorotrast patients. In the latter category, the highest values were found in the testis [40 x 10(-6) g/g(wet)], followed by those in the adrenal gland, gallbladder, lung, and pancreas. The resulting alpha-particle dose rates (mGy/year) are tentatively estimated to be 8.5 to the testis, 5.5 to the gallbladder, and 5.3 to the lung. These results may be relevant to the residual excess mortality among Thorotrast patients after diseases of the principal organs of deposition have been excluded; they also support previous indications that thorium deposited in pulmonary tissues is responsible for an important component of the total dose to the lung. In another context, our data may bear on the connection, postulated elsewhere, between exposure to alpha-particle emitters and elevated incidence of leukemia in the children of workers engaged in the reprocessing of nuclear fuel.

Adult↗
PubMed1984

Vocal cord paralysis. A latent effect of perivascular thorium dioxide.

The late effects of thorium dioxide (Thorotrast) in the perivascular space of the neck are reviewed. The roentgenographic analysis of the problem consists of both plain films (to detect the residual density of extravasated thorium dioxide) and computed tomography (to help define any involvement of the carotid artery).

Calcinosis↗
PubMed2004

Determination of thorium concentrations and activity ratios in silicate rocks by alpha spectrometry.

A detailed radiochemical procedure for alpha spectrometry measurements of thorium concentrations and of 230Th/232Th activity ratios in silicates is presented. The Th behaviour, during each step of the chemical process, was investigated by using a 234Th tracer, which is a gamma-ray emitter. The described chemical processing provides relatively high thorium yields, which varied between 56% and 88%, in the analysis of GB-1 (granite) and BB-1 (basalt) Brazilian geological standards. Also, the application of the established radiochemical method allowed a determination of both Th concentrations and activity ratios with high reproducibility, on the order of 2%. The estimation of the concentration result accuracy is also about 2%, which was calculated by using published data obtained from neutron activation analysis as reference values.

Alpha Particles↗
PubMed2004

Radioactive waste forms stabilized by ChemChar gasification: characterization and leaching behavior of cerium, thorium, protactinium, uranium, and neptunium.

The uses of a thermally reductive gasification process in conjunction with vitrification and cementation for the long-term disposal of low level radioactive materials have been investigated. gamma-ray spectroscopy was used for analysis of carrier-free protactinium-233 and neptunium-239 and a stoichiometric amount of cerium (observed cerium-141) subsequent to gasification and leaching, up to 48 days. High resolution ICP-MS was used to analyze the cerium, thorium, and uranium from 46 to 438 days of leaching. Leaching procedures followed the guidance of ASTM Procedure C 1220-92, Standard Test Method for Static Leaching of Monolithic Waste Forms for Disposal of Radioactive Waste. The combination of the thermally reductive pretreatment, vitrification and cementation produced a highly non-leachable form suitable for long-term disposal of cerium, thorium, protactinium, uranium, and neptunium.

Cerium↗
PubMed2005

Investigation in thorium phosphate by NMR II-phosphorus dipolar networks.

With through space and through bond experiments in two-dimensional NMR we analyze the transformation from the thorium phosphate-hydrogen phosphate hydrate (TPHPH) to the beta form of the thorium phosphate diphosphate (beta-TPD) in relation with the phosphorus networks. These techniques are complementary: the through space coupling gives an insight on the dipolar phosphorus networks while the through bond coupling is particularly efficient in the detection of the P2O7 groups. With these experiments we show that in a first step, by heating the precursor TPHPH above 250 degrees C, it transforms into an alpha form of TPD. This transformation is due to the complete condensation of hydrogen phosphate groups HPO4 into P2O7 entities. By heating alpha-TPD above 950 degrees C it transforms into its well-known beta form. The alpha form is characterized by a hygroscopic behavior: some water molecules are present near the P2O7 groups that makes non-equivalent their phosphorus nuclei. PO4 dipolar networks are always present in the alpha form. The main effect of these PO4 and P2O7 units is to give the system a channel structure and the water enters in them.

Computer Simulation↗
PubMed2002

About the assumption of linearity in soil-to-plant transfer factors for uranium and thorium isotopes and 226Ra.

The linearity assumption for soil and plant concentrations of radionuclides is usually a good approximation for use in food-chain models. To verify this assumption, different samples of plant and substrate were collected from a granitic zone located near a disused uranium mine in order to cover a large range of concentrations. In all of the samples, the activity concentration of 226Ra and of different isotopes of uranium (238U and 234U) and thorium (232Th, 230Th and 228Th) were determined. The results indicate that the linearity assumption can be considered valid when the range of concentrations taken into account is large (approx. two orders of magnitude). Otherwise, there is a clear deviation from linearity. Also, the influence of different stable elements on the soil-plant transfer factors was studied by using multivariate regression methods. The uptake of uranium, thorium and radium was found to be mainly associated with the concentration of iron in the plant and the phosphorus and alkaline earths in the substrate.

Food Chain↗