Uranium concentration in blood samples of Southern Iraqi leukemia patients using CR-39 track detector

The simple and effective technique of fission track etch has been applied to determine trace concentration of uranium in human blood samples taken from two groups of male and female participants: leukemia patients and healthy subjects group. The blood samples of leukemia patients and healthy subjects were collected from three key southern governorates namely, Basrah, Muthanna and Dhi-Qar. These governorates were the centers of intensive military activities during the 1991 and 2003 Gulf wars, and the discarded weapons are still lying around in these regions. CR-39 track detector was used for registration of induced fission tracks. The results show that the highest recorded uranium concentration in the blood samples of leukemia patients was 4.71 ppb (female, 45 years old, from Basrah) and the minimum concentration was 1.91 ppb (male, 3 years old, from Muthanna). For healthy group, the maximum uranium concentration was 2.15 ppb (female, 55 years old, from Basrah) and the minimum concentration was 0.86 ppb (male, 5 years old, from Dhi-Qar). It has been found that the uranium concentrations in human blood samples of leukemia patients are higher than those of the healthy group. These uranium concentrations in the leukemia patients group were significantly different (P < 0.001) from those in the healthy group.     

Determination of uranium concentration in urine of workers in an Iraqi phosphate mine and fertilizer plants

Precise determination of uranium concentration in human urine is quite important in assessment of occupational and public exposure to uranium. In the present work, a pulsed dye nitrogen laser-induced kinetic phosphorescence analysis (KPA) was used to determine uranium in urine of Iraqi phosphate mine and fertilizer plant workers and in the population living near the mining region. A total of 92 urine samples were collected from workers of the Akashat phosphate mine, the Al-Qaim fertilizer complex, and the Akashat residential region. Uranium concentration in urine of all samples ranged between 0.49 to 5.26 μg L^?1 with a total average of 1.47 ± 0.01 μg L^?1. For comparison, all samples were also analyzed using a completely different technique; the nuclear fission track analysis using CR-39 SSNTD. Both techniques were capable of such measurements, although not with an equal degree of uncertainty. KPA technique is found to be more suitable for analysis of urine samples having high concentrations of uranium.     

Estimation of uranium in bioassay samples of occupational workers by laser fluorimetry

A newly established uranium processing facility has been commissioned at BARC, Trombay. Monitoring of occupational workers is essential to assess intake of uranium in this facility. A group of 21 workers was selected for bioassay monitoring to assess the existing urinary excretion levels of uranium before the commencement of actual work. Bioassay samples collected from these workers were analyzed by ion-exchange technique followed by laser fluorimetry. Standard addition method was followed for estimation of uranium concentration in the samples. The minimum detectable activity by this technique is about 0.2 ng. The range of uranium observed in these samples varies from 19 to 132 ng/L. Few of these samples were also analyzed by fission track analysis technique and the results were found to be comparable to those obtained by laser fluorimetry. The urinary excretion rate observed for the individual can be regarded as a ‘personal baseline’ and will be treated as the existing level of uranium in urine for these workers at the facility.     

Distribution of uranium at Mumbai Harbour Bay (MHB)

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay. In addition, the Bay is also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. The average value of uranium concentration reported for Indian Bay water at Tarapur and Mumbai is ~3.0 ppb which is comparable with the reported value for Arabian sea. As such the global average is reported to be ~3.3 ppb by Oceanologists. The present study deals with the distribution of uranium in seawater of MHB. The uranium activity in MHB by alpha spectrometry was found to be between 1.0 and 4.4 ppb with an average concentration of 2.5 ppb which is comparable with the earlier reported average activity of 2.6 ppb in the MHB as well as those reported globally. To compare the results obtained by alpha spectrometry, uranium estimation was also carried out using Laser fluorimeter and the levels of uranium concentration have ranged between 0.8 and 4.9 ppb with an average concentration of 2.7 ppb.     

Occurrence of uranium in groundwater of a shallow granitic aquifer and its suitability for domestic use in southern India

Groundwater used for domestic purpose without proper treatment should be free from chemical and biological contaminants. This study was carried out to assess the groundwater quality with respect to uranium in a part of Nalgonda district, Andhra Pradesh, India. Groundwater was regularly monitored for uranium concentration by collection of samples once every two months from March 2008 to November 2009 from 44 wells. The concentration of uranium in groundwater ranged from 0.2 to 118.4 ppb. Groundwater is unsuitable for domestic use in 2 % of this area based on the limit of 60 ppb prescribed by the Atomic Energy Regulatory Board of India. However, due the wide variation in limit suggested by different organizations and countries, the no-observed-adverse-effect level and lowest-observed-adverse-effect level (in mg/kg day) was used to understand the dosage of uranium that reaches the people through drinking water pathway. This level varied from 0 to 0.02 mg/kg day and 0 to 0.08 mg/kg day based on an uncertainty factor of 10 and 50 respectively for the mean uranium concentration in groundwater in each well. With an uncertainty factor of 50, 5 groundwater samples had uranium above 0.06 mg/kg day which is the lowest-observed-adverse-effect level. This study showed that with the presence of present level of uranium concentration in groundwater of this area there is no major threat to humans through the drinking water pathway.     

Determination of uranium in powdered quartz at ppb level by fission track method

Summary The demand for powdered quartz with low alpha —radioactivity has been increasing in the field of manufacturing semiconductor memory device packages. In this work, the determination of uranium in powdered high-purity quartz samples was studied using a simplified fission track procedure in which 0.5 g each of sample and a fission track detector (synthetic quartz glass plate, uranium impurity 0.04 ppb) were loaded in a polyethylene capsule and irradiated with a thermal neutron flux of 10¹⁷ cm^–2. An easy procedure was also employed for chemical etching of fission tracks. All measurements of uranium concentration in the samples were made on a relative basis by comparing the unknown track densities to that measured for NBS glass SRM 617. The reliability was established for the present determination of uranium down to 0.1 ppb. The concentrations of uranium in powdered quartz samples studied in this work were in a range from 7.9 down to 0.12 ppb.

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Uranbestimmung in Quarzpulver im ppb-Bereich mit Hilfe der Kernspurmethode

Zusammenfassung Da im Bereich der Halbleiterindustrie eine steigende Nachfrage nach Quarzpulver mit niedriger Alpha-Aktivität besteht, wurde die Uranbestimmung in hochreinem Quarzpulver mit Hilfe einer vereinfachten Kernspurmethode untersucht, bei der jeweils etwa 0,5 g der Probe und des Kernspurdetektors (synthetisches Quarzglasplättchen mit etwa 0,04 ppb U) in eine Polyethylenkapsel gegeben und mit einem thermischen Neutronenfluß von etwa 10¹⁷ cm^–2 bestrahlt wurden. Ein einfaches Verfahren zum chemischen Ätzen der Spuren wurde angewendet. Alle Messungen der Urankonzentration wurden relativ durchgeführt durch Vergleich der unbekannten Spurdichten mit denen von Standardglas NBS SRM 617. Die Zuverlässigkeit des Verfahrens wurde bis herab zu etwa 0,1 ppb U geprüft. Die in den untersuchten Proben gefundenen Urankonzentrationen lagen im Bereich von 7,9 bis 0,12 ppb.

     

Biomonitoring for uranium exposure among young children living in nineteen states across five regions of Brazil

In this study, concentration of uranium was determined in urine samples collected from 400 Brazilian children (6–14 years old) from different geographic regions. The mean concentration was 33.2 ng/g creatinine. Urinary concentrations of uranium were found to have region and age as predictors. The concentrations of uranium were higher in the South, Southeast and Central-West than in the other regions of Brazil. Moreover, higher concentrations of this element were found in younger children (<?10 years old). To the best of our knowledge, this is the first study to report the exposure of a Brazilian population to uranium.     

Application of fission track technique for estimation of uranium concentration in drinking waters of Punjab

Drinking water samples were collected from four different districts, namely Bhatinda, Mansa, Faridkot and Firozpur, of Punjab for ascertaining the U(nat.) concentrations. All samples were preserved, processed and analyzed by laser fluorimetry (LF). To ensure accuracy of the data obtained by LF, few samples (10 nos) from each district were analyzed by alpha spectrometry as well as by fission track analysis (FTA) technique. For FTA technique few μl of water sample was transferred to polythene tube, lexan detector was immersed in it and the other end of the tube was also heat-sealed. Two samples and one uranium standard were irradiated in DHRUVA reactor. Irradiated detectors were chemically etched and tracks counted using an optical microscope. Uranium concentrations in samples ranged from 3.2 to 60.5 ppb and were comparable with those observed by LF.     

Assessment of natural uranium and 226Ra concentration in ground water around the uranium mine at Narwapahar, Jharkhand, India and its radiological significance

A brief study on dissolved radionuclides in aquatic environment, especially in ground water, constitutes the key aspect for assessment and control of natural exposure. In the present study the distribution of natural uranium and ²²⁶Ra concentration were measured in ground water samples collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007–2008. The natural uranium content in the ground water samples in this region was found to vary from 0.1 to 3.75 μg L^?1 with an average of 0.87 ± 0.73 μg L^?1 and ²²⁶Ra concentration was found to vary from 5.2 to 38.1 mBq L^?1 with an average of 13.73 ± 7.34 mBq L^?1. The mean annual ingestion dose due to intake of natural uranium and ²²⁶Ra through drinking water pathway to male and female adults population was estimated to be 6.55 and 4.78 μSv y^?1, respectively, which constitutes merely a small fraction of the reference dose level of 100 μSv y^?1 as recommended by WHO.     

Ultrahigh sensitivity uranium analyses using fission track counting: Further analyses of semiconductor packaging materials

Neutron activation analysis with fission track counting was applied to a study of a variety of ceramic and plastic semiconductor packaging materials. By using a high purity synthetic fused silic as a detector, the method has a lower limit for uranium of 0.02 ppb. The highly sensitive, accurate technique permitted study of individual, highly contaminated glass fibers in molded plastics and also studies of bulk ceramic and plastic materials.     

Radiochemical neutron activation analysis of Mo and W in geochemical and cosmochemical samples with an emphasis on the correction of fission products

Radiochemical neutron activation analysis (RNAA) was applied to geochemical and cosmochemical samples to determine trace amounts of Mo and W. To determine the Mo concentration by NAA accurately, the contribution of the fission products of U should be corrected. For that reason, we developed a simple and effective method, where a contribution of fissiogenic ⁹⁹Mo was estimated by monitoring the ratio of uranium fission-product ⁹⁹Mo to ¹³³I. Mo concentrations corrected for fission with the W concentrations were consistent with the literature values, showing that ¹³³I was found to be an effective monitor for fission correction. Detection limits are estimated to be 10 ppb for Mo and W and 30 ppb for U under the present experimental conditions.     

Track etching characteristics of polyester track detector and its application to uranium estimation in seawater samples

Garware Polyester Film, an indigenously available material has been evaluated systematically as a nuclear track detector for the detection of fission fragments. The relative fission track detection efficiency of this film was found to be (86.0±4.0)%. The bulk etch rate, determined by the gravimetric method, was found to be 0.75±0.05 μm/h. The track etch rate was determined as 15.0±1.5 μm/h. This detector was employed for the estimation of uranium in seawater samples and the results obtained were compared with the results obtained by using the commonly used Lexan detector. Uranium fractions after chemical separation from seawater samples were also analyzed by alpha-spectrometry and neutron activation analysis techniques and the results were compared with that obtained by the fission track method. Fission track method has the advantage, as it does not require any chemical separation. The indigenously available polyester film (polyethylene terphthalate) appears to be a good substitute of Lexan as nuclear track detector.     

Nuclear analytical techniques for quantification of uranium for its recovery from seawater

Nuclear analytical techniques namely fission track technique using solid state nuclear track detector (SSNTD) and instrumental neutron activation analysis (INAA) have been standardized and applied for quantification of low uranium concentrations in liquid samples such as feed, elute and brine and solid sorbent samples respectively. The quantification of uranium is required for its recovery study from seawater, which is one of the potential sources of uranium. The uranium concentration of a liquid sample obtained by SSNTD method was compared with the other well established conventional techniques like ICP-MS, ICP-AES, adsorptive stripping voltametry and alpha spectrometry. INAA was applied for uranium concentration determination in the radiation grafted polyamidoxime sorbent samples.     

Plutonium and uranium in Japanese human tissues

Plutonium and uranium in human tissues obtained from residents of the Tokyo area were determined by a-spectrometry and the fission track method, respectively. The distribution pattern of each element was estimated on the basis of mean concentration obtained. Plutonium is concentrated in some special organs, while uranium is distributed rather generally throughout the whole body. This difference of distribution tendency is considered to be due to the characteristics of stable chemical states of the elements in body fluid; Pu4+ for plutonium and UO2(2+) for uranium.     

Technetium chemistry in a novel group actinide extraction process

A newly developed method for advanced reprocessing of used nuclear fuel is the Group ActiNide EXtraction (GANEX) process. It is a liquid–liquid extraction process that aims at extracting all the actinides as a group from dissolved used nuclear fuel. This extraction can either be performed after a removal of the bulk uranium or directly on the dissolution liquor. At Chalmers University of Technology in Sweden a solvent that utilizes tributyl-phosphate (TBP) and a molecule from the bis-triazine bipyridine (BTBP) class of ligands dissolved in cyclohexanone has been developed for the use in a GANEX process. Previously the system has not been tested with the presence of technetium that is one of the major fission products. Technetium is often considered a problem within reprocessing since it has a chemical behaviour that differs from most other elements in the spent fuel. Therefore, a special emphasis was put on the investigation of technetium in the selected GANEX system. It was shown that technetium is readily extracted by the GANEX solvent and that cyclohexanone is the main extractant when no other metals were present in the system. It was also found that the presence of uranium decreased the overall technetium extraction despite a slight co-extraction with TBP, while irradiation of the GANEX solvent to large doses (>1 MGy) increased its technetium extraction capability. It was also discovered that an increased nitrate concentration in the aqueous phase and an addition of other fission products both inhibited the technetium extraction even though fission product loading most likely changed the extraction mechanism to co-extraction by BTBP.     

Determination of uranium concentration in domestic water samples by fission track method

The sensitive and simple fission track detection technique using a dry method with Melinex-0 plastic track detector has been applied for the determination of uranium concentration in samples of domestic water supply plants collected from different states of India, namely West Bengal, Uttar Pradesh, Rajasthan, Punjab and Delhi. Our analyses show that uranium concentration of water samples collected from different types of domestic water supply plants vary from 0.6±0.02 to 19.2±0.6 g/l. The present investigations may be useful from the point of view of radiation hygiene.     

Radiochronological age of a uranium metal sample from an abandoned facility

A piece of scrap uranium metal bar buried in the dirt floor of an old, abandoned metal rolling mill was analyzed using multi-collector inductively coupled plasma mass spectroscopy (MC-ICP-MS). The mill rolled uranium rods in the 1940 and 1950s. Samples of the contaminated dirt in which the bar was buried were also analyzed. The isotopic composition of uranium in the bar and dirt samples were both the same as natural uranium, though a few samples of dirt also contained recycled uranium; likely a result of contamination with other material rolled at the mill. The time elapsed since the uranium metal bar was last purified can be determined by the in-growth of the isotope ²³⁰Th from the decay of ²³⁴U, assuming that only uranium isotopes were present in the bar after purification. The age of the metal bar was determined to be 61 years at the time of this analysis and corresponds to a purification date of July 1950 ± 1.5 years.     

Analysis of uranium in dissolver solution of fast reactor carbide fuel reprocessing

Uranium in simulated dissolver solution of FBTR mixed carbide fuel containing fission products is analyzed by modified Davies–Gray method. The uranium is analyzed after the sample is evaporated with 1 M H₂SO₄ and followed all the steps carried out by Davies–Gray method. The proposed method assures analysis of uranium in dissolver solution of FBTR fuel can be titrated directly without prior separation of fission products.     

Fast sensitive analysis of uranium and thorium in natural samples based on delayed neutron counting using an ultrafast conveyor tube system

A fast, sensitive and routine methode for quantitative analysis of uranium and thorium in natural samples is described. The identification is done by counting the delayed neutrons of mainly the short living fission products after sample-irradiation with and without cadmium shielding. The rabbit system used is installed at the Forschungsreaktor Neuherberg, type TRIGA Mark III. The limits of detection (relative to 2 g of sample weight) were specified to be 20 ppb (U) and 3 ppm (Th) using puls irradiations, 150 ppb (U) and 15 ppm (Th) using 1 MW steady state reactor power. A single determination is done within less than 60 s. The methods were proved by about 3000 measurements also including comparison experiments.     

Analysis of trace uranium in Indian tobacco samples

The trace uranium concentrations have been determined in tobacco obtained from different brands of commercially available cigarette, beedi, chewing tobacco and also in pan masala, using fission track registration technique. Consumption of tobacco orally or by smoking may result in the intake of radioactive elements into the human body causing hazardous effects. External detector method was employed for the determination of uranium using Makrofol-KG as the fission track detector. The range of uranium was found to vary between 0.066–0.106 ppm, 0.042–0.079 ppm and 0.043–0.092 ppm, in tobacco from samples of cigarette, beedi and chewing tobacco, respectively, and between 0.073–0.203 ppm in pan masala samples.