Abstract  Clays are among the most important industrially used minerals. Three potential clay mineral mining sites in Saudi Arabia were chosen, and 21 clay deposit samples were collected. The activity concentrations (average±standard deviation) of the naturally occurring radioactive materials (NORMs), (238)U, (226)Ra, (232)Th, (228)Ra and (40)K, were 49±20, 47±23, 34±11, 40±20 and 751 Bq kg(-1), respectively. The radiation dose assessments (e.g., absorbed dose rate, nGy h(-1); effective dose equivalent, µSv y(-1); and effective dose rate due to dust inhalation, µSv y(-1)) and hazardous indices (e.g., radium equivalent [Ra-eq] value, external hazardous index [Hex], internal hazardous index [Hin] and representative gamma level [Iγ]) were calculated. The wide variations in the activity concentrations of the NORMs according to sampling region could be due to the origin of the geological formation and the geochemical behaviour of the NORMs. Based on calculated hazardous (external and internal) indices, there were no expected radiological hazardous impacts of using clay deposits as building materials.

Abstract  This report consists of a descriptive analysis of the mortality in 1998. Tables, figures and maps show standardized mortality rates and absolute number of deaths for general mortality and 44 main causes of death. The analysis is by gender, age and geographical areas of residence (regions and four main geographical areas: North-West, North-East, Centre, South and Islands). Besides the data regarding the year 1998, figures show temporal trend for the whole Country and the main geographical areas starting from 1984.

Abstract  In this work, uranyl ion-imprinted resin based on 2-(((4-hydroxyphenyl)amino)methyl)phenol was synthesized by condensation polymerization of its uranyl complex in presence of resorcinol and formaldehyde cross-linkers. Numerous instrumental techniques including elemental analysis, Fourier transform infrared spectroscopy, ultraviolet, (1) H along with (13) C nuclear magnetic resonance spectroscopy have been employed for complete characterization of the synthesized ligand and its uranyl complex. Additionally, the obtained ion-imprinted and non-imprinted resins were investigated using scanning electron microscope and Fourier transform infrared spectroscopy. The effects of various essential parameters such as pH, temperature and contact time on removal of uranyl ions have been examined, and the results indicated that the obtained resin exhibited the optimum activity at pH 5. Furthermore, the adsorption process was spontaneous at all studied temperatures and followed the second-order kinetics model. Also, Langmuir adsorption isotherm exhibited the best fit with the experimental results with maximum adsorption capacity 139.3 mg/g. Moreover, the selectivity studies revealed that the ion-imprinted resin exhibited an obvious affinity toward the uranyl ions in presence of other metal ions compared with the non-imprinted resin.

Abstract  Imino diacetamide styrene divinyl benzene (IDAA SDVB) resin was synthesized and evaluated for separation of molybdenum (Mo) from simulated dissolver solution of irradiated uranium-aluminium alloy. Detailed studies were carried out to understand the influence of various parameters on sorption of Mo. The kinetics of Mo sorption is found to be fast and the kinetics data fit well to the pseudo-second order kinetic equation. Sorption of Mo is found to decrease with the increase of feed acidity. The loading capacity of resin is determined to be 30 mg g(-1), the sorption isotherm data fit well to the Langmuir model. Batch sorption experiments with simulated dissolver solution showed quantitative uptake of Mo along with some co-extraction of iodine (I). Column runs have demonstrated that co-extracted 'I' could be scrubbed easily with solutions of feed acidity. Finally, sorbed Mo could be eluted with 3.0 M HNO3. XAFS and FT-IR studies of Mo sorbed on to IDAA SDVB resin have shown that Mo is sorbed in the + 6 oxidation state (in the form of MoO42-), wherein the complex attains octahedral geometry with contribution from four oxygen atoms of the molybdate anion and two oxygen atoms of the amidic moiety of the imino-diacetamide ligand.

Abstract  The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

Abstract  Activity concentrations of the naturally occurring, short-lived and highly particle-reactive radionuclide tracer Th-234 in the dissolved and particulate phase were determined at 3 shallow-water stations (maximum depths: 65 (S.3), 97 (S.5) and 220 m (S.7)) of the Saronikos Gulf (central Aegean Sea, Greece Eastern Mediterranean) during winter 2010 to assess the time scales of the dynamics and the depositional fate of particulate matter (POC, particulate Th-234). For that reason, the method of in situ pumping was performed previously used by many researchers. The fluxes of POC were estimated using radionuclides' disequilibrium. Specifically, the natural radionuclide Th-234 has been used as an indicator for export flux of particulate species from the euphotic zone. Its particle reactive and short half-life (t(1/2)=24.1 d) nature, in contrast to the conservative and long (t(1/2)=4.5 x 10(9) y) ones of its parent U-238 can be used to trace processes occurring over short timescales. Despite the wide application of Th-234, studies using (TH)-T-234/U-238 disequilibrium on export fluxes are still very limited, largely because of the demanding sampling and analyses.

From the data obtained, the average activity concentrations of particulate and dissolved Th-234 were 5.4 +/- 0.8 and 18.4 +/- 7.4 Bq m(-3), respectively. Regarding the vertical profiles of Th-234 in comparison to the mother radionuclide U-238, a strong deficit of Th-234 was observed and as a result, rapid export of POC was estimated. The cumulative export fluxes of particulate Th-234 (after integration over the total depth of the stations) were estimated to be 52 +/- 7 in S.3, 180 +/- 19 in S.5 and 400 +/- 46 Bq m(-2) d(-1) in S.7. The respective cumulative scavenging rates of dissolved Th-234 onto particles were estimated to be 23 +/- 3 in S.3, 86 +/- 8 in S.5 and 172 +/- 19 Bq m(-2) d(-1) in S.7. Finally, the cumulative export fluxes of POC in the 3 stations examined were found 375 +/- 38, 311 +/- 34 and 300 +/- 33 Bq m(-2) d(-1), respectively.

Large export fluxes of POC were observed here, over one order of magnitude compared to other areas of the Mediterranean Sea, attributed to the enhanced biological activity due to phytoplankton bloom in conjunction with the large amounts of organics that the gulf accepts for a long time period. At the stations S.5 and S.7 fine particles were found to sink rapidly in all depths examined except the bottom nepheloid layer. This is a result of aggregation processes due to the shallow depths of the sampling area or due to the instability of large aggregates during sampling that might induce uncertainty in particle sampling. Larger particles (> 25 mu m) of Th-234 were found increased at the surface, whereas smaller ones (0.6-25 mu m) increased or remained the same near the seabed. Increase of large Th-234 particles at the surface certifies the origin of surface Th-234 linked with the land-based atmospheric deposition and/or surface advective movements. The distribution of particulate Th-234 in both fractions is controlled by SPM, (SPM versus particulate Th-234: R-2 > 0.6), whereas POC follows a different trend attributed to the fact that POC is carried in the volume of a particle, whereas Th-234 sorbs to the surface. It is essential to mention that the Saronikos Gulf is still affected by the wide carbon discharges (domestic, industrial etc.) prior and after the construction of Psitalia WWTP as it is characterized by late renewal times of its waters.

Abstract  This report presents the experimental animal data base from which human health consequences may be predicted from exposures mimicing accidental discharges of uranium hexafluoride (UF sub 6 ) in the uranium industry. Rats or guinea pigs were exposed for two, five, or ten minutes duration to air having 0.44 g U/m exp 3 + 0.16 g HF/m exp 3 to 276.67 g U/m exp 3 + 94.07 g HF/m exp 3 . Survivors of each exposure were observed for 14 days for signs of U or HF intoxication. Selected animals were necropsied and samples of major organs were studied histopathologically. When enriched UF sub 6 (94 percent exp 235 U) was used, the urine and feces from each animal were measured daily for U content. Selected samples of urine were bioassayed in order to trace the course of renal injury during the two week postexposure period. 28 references, 51 figures, 23 tables. (ERA citation 09:031808)

Abstract  The purpose of this survey was to determine the distribution of terrestrial radionuclides ((238)U, (232)Th and (40)K) in surface soil samples collected from different locations in and around Osmaniye and assess the radiological implications of outdoor external exposure. The activity concentrations of (238)U, (232)Th and (40)K in soil samples ranged from 2.6 to 38.1 Bq kg(-1) with a mean of 10.4±0.7 Bq kg(-1), 3.7-40.5 Bq kg(-1) with a mean of 12.2±0.7 Bq kg(-1) and 30.0-639.7 Bq kg(-1) with a mean of 243.4±12.8 Bq kg(-1), respectively. The concentrations of these radionuclides, presented in this article, were compared with those obtained from similar studies related to Turkey reported in the literature as well as earth's crust average values. The results of the activity concentrations were used to assess the external absorbed gamma dose rate (GDR) in outdoor air and the annual effective dose (AED). The outdoor absorbed GDRs fluctuate from 5.2 to 53.6 nGy h(-1) with a mean of 22.4±9.5. The corresponding mean AED is found to be 0.03 mSv.

Abstract  The U.S. Army is currently formulating a strategy for future kinetic energy penetrating materials. This report addresses the environmental and health issues associated with depleted uranium (DU) and tungsten penetrators. The objective of this study was to perform a preliminary assessment to investigate the environmental and health issues associated with DU and tungsten penetrator manufacturing, testing and recycle facilities. This work also included an assessment of requirements for decontamination of ammunition peculiar equipment (APE) and industrial plant equipment (IPE) at U.S. Army manufacturing sites. Combat issues were also addressed.

Abstract  The authors use the Los Alamos LAHET Code System (LCS)/CINDER'90 suite of codes in a variety of spallation neutron source applications to predict neutronic performance and as a basis for making engineering decisions. They have broadened their usage of the suite from designing LANSCE and the next generation of spallation neutron sources for materials science and nuclear physics research to designing a target system for Accelerator Production of Tritium and Accelerator Transmutation of Waste. While designing, they continue to validate the LCS/CINDER'90 code suite against experimental data whenever possible. In the following, they discuss comparisons between calculations and measurements for: integral neutron yields from a bare-target of lead; fertile-to-fissile conversion yields for thorium and depleted uranium targets; dose rates from the LANSCE tungsten target; energy deposition in a variety of light and heavy materials; and neutron spectra from LANSCE water and liquid hydrogen moderators. The accuracy with which the calculations reproduce experimental results is an indication of their confidence in the validity of their design calculations.

Abstract  The paper presents results of the study on depleted uranium (DU) health effects on cows bred in areas exposed to DU ammunition, during NATO bombing of Serbia and Montenegro in 1999. The samples of animal blood, soils and feed were collected randomly in the region of Bujanovac, in 2003. Complete blood cells count was performed according to standard laboratory procedures. Concentration of red blood cells malondialdehyde (RBC MDA) and erythrocyte superoxid dismutase (SOD) activity were determined spectrophotometrically, The functional activity of leukocytes was investigated by NBT reduction and adhesion test. Activity of the radionuclides was determined by standard gamma spectrometry. The obtained results of complete red blood cells count indicate normocytic normochromic anaemia. Considerably increased RBC MDA concentration suggests a violent oxidative stress in cows bred in the exposed area, although the activity of their RBC antioxidant enzyme SOD was in the range of values obtained in the control group. The total number of leukocytes and the differential leukocyte counts were within the physiological range. NBT reduction test revealed the absence of leukocyte oxidative burst, which pointed to the absence of inflammation. A significant decrease of granulocyte adhesiveness pointed at partial impairment of granulocyte functional activity. The activity of U-238/U-235 in soils and feed was below the minimal detectable concentration (10(-3) Bqlkg), while the content of natural (Ra-226 and Th-232) and anthropogenic (Cs-137) radionuclides in soils were within the average values for the region, except for low levels of K-40 - indicating soils impoverishment in potassium.

Abstract  We analyzed archaeological human bone from Teotihuacan and Oaxaca, dating from about 300 BC to 750 AD to distinguish ethnic groups within Teotihuacan using oxygen isotopes. Sixty-eight analyses of bone phosphate delta(18)O were made of 64 individuals. In addition to oxygen isotopic analysis, the bones were examined using FTIR spectra, with some additional DNAA and ICP-MS analyses. Little change occurs in the bone apatite until the amount of collagen (as combustible organics) has been reduced considerably, when the bone becomes softer and FTIR crystallinity increases. The delta(18)O of the phosphate (delta(p)) appears to be unaltered even after extensive diagenesis and, probably, solution. On FTIR plots the relative area of the carbonate peak to the main phosphate peak decreases with diagenetic level. The bones absorb some metals rapidly after burial, for example uranium, which then leach out as diagenesis of the bone apatite progresses. Other metallic elements increase irregularly in concentration as alteration proceeds.

Abstract  A bone fragment (CGDQ-3) of Falcarius utahensis, a therizinosaur from the Early Cretaceous Cedar Mountain Formation, Utah, contained within a carbonate nodule, was analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in order to investigate REE variability within a thin-walled phalanx. Previous studies have found depth-related REE pattern variations; however, in CGDQ-3 variation occurs along the circumference of the bone. NASC-normalized REE patterns and concentrations vary between two apparent end members. A light-REE enriched (LREE) pattern, similar to solution ICP-MS analysis of this bone, characterizes approximately two-thirds of the bone fragment. Total REE concentrations are high and do not vary significantly from the periosteal surface to the medullar surface. Conversely, the remaining one-third of the bone has REE patterns that are MREE-depleted and low in total REE concentrations. REE concentrations in this part of the bone do not vary significantly from the periosteal to the medullar surface. A positive Ce anomaly is found throughout the entire bone, and is greatest within the LREE-enriched portion of the bone. This, in combination with the LREE-enrichment, suggests that the bone fossilized under reducing conditions. The distance between the LREE-enriched and MREE-depleted regions is less than 1 mm. Isotopic and petrographic analyses of the bone and surrounding carbonate matrix suggest the REE patterns in the bone were the result of partial fossilization/incomplete filling of micro-pore spaces around bone crystallites in an environment with changing redox conditions. The lower, MREE-depleted part of the bone fossilized contemporaneously with a pendant cement that formed on the underside of the bone in the vadose zone. Formation of the pendant cement restricted water flow through the bone, isolating the lower portion, which incorporated a MREE-depleted pattern. The upper part of the bone (LREE-enriched side) fossilized under more reducing conditions than the lower part. This resulted in reductive dissolution of minerals (such as hydrous ferric oxides and manganese-oxides) which were LREE-enriched with positive Ce anomalies. These REE were then incorporated into the upper part of the bone. This likely occurred after the bone entered the saturated zone (below the water table). The thinness of the bone and presence of a pendant cement helped facilitate partial fossilization of the bone, preserving the REE signature of an earlier fluid. As demonstrated by this case study, differences in REE patterns within a fossil may record changes in geochemical conditions during fossilization, particularly, when bones are encased in a material that reduces fluid permeability, such as micritic vadose calcite. Analysis of such bones may offer the opportunity to decipher complex fluid histories that occur during fossilization. LA-ICP-MS should be utilized to confirm solution ICP-MS analysis if it yields high REE variability, prior to an interpretation of reworking or time-averaging. (c) 2010 Elsevier Ltd. All rights reserved.

Abstract  Conventional heavy metal poststaining methods on thin sections lend contrast but often cause contamination. To avoid this problem, we tested several en bloc staining techniques to contrast tissue in serial sections mounted on solid substrates for examination by field emission scanning electron microscopy (FESEM). Because FESEM section imaging requires that specimens have higher contrast and greater electrical conductivity than transmission electron microscopy (TEM) samples, our technique uses osmium impregnation (OTO) to make the samples conductive while heavily staining membranes for segmentation studies. Combining this step with other classic heavy metal en bloc stains, including uranyl acetate (UA), lead aspartate, copper sulfate and lead citrate, produced clean, highly contrasted TEM and scanning electron microscopy (SEM) samples of insect, fish and mammalian nervous systems. This protocol takes 7-15 d to prepare resin-embedded tissue, cut sections and produce serial section images.

Abstract  A method based on flow injection extraction chromatography coupled to on-line ICP-MS (FI-EXC-ICPMS) has been developed and validated for simultaneous thorium and uranium determination in human body fluids. By using extraction chromatography, the limits of detection achieved for Th-232, U-235 and U-238 were 0.06 ng.1(-1), 0.0014 ng.1(-1) and 0.05 ng.1(-1), respectively. The accuracy of the FI-EXC-ICPMS method was 102.4% and 101.5% with overall precision (RSDmax at 95% CI) of 5.3% and 4.9% for Th-232 and U-238, respectively. The U-235/U-238 atom ratio is measured with 1.8% precision. The technique was employed for simultaneous thorium and uranium analyses in human urine and blood samples after microwave digestion.

Abstract  Sr-90 appears as a radionuclide in the decay series of nuclear fission and can therefore be found in nuclear waste or released by nuclear accidents. Current methods for the detection of this radionuclide are time consuming and may be prone to a large variety of interferents. In this work, inductively coupled plasma mass spectrometry is explored for the determination of Sr-90 in the presence of stable zirconium in urine. Specific techniques are investigated to remove this as well as other contributions to the background at m/z = 90. A quadrupole ICP-MS equipped with a hexapole collision cell is first explored (final LOD = 2 ng L-1 for water samples), however, the desired limit of detection for Sr-90 in urine is quite low (0.02 pg L-1). The performance of a double-focusing sector field ICP mass spectrometer (ICP-SFMS) is further investigated, which allows measurement of Sr-90 at the ultratrace level. Other potential interferences were investigated and instrumental detection limits are calculated as 3 pg L-1 for water samples. Final parameters include the use of a cool plasma and medium mass resolution in ICP-SFMS. The method is applied to the analysis of Sr-90 extracted from urine using a crown ether extraction resin and concentrated (enrichment factor: 200); high levels of natural strontium in the separated fraction (of about 1 mug mL(-1)) equate to higher detection limits (80 pg L-1) due to Sr-88(+) at m/z = 90 and the relatively low abundance sensitivity of ICP-SFMS at medium mass resolution of 6 x 10(-7). This detection limit in the separated fraction corresponds to the detection limit of 0.4 pg L-1 in the original urine sample. The recovery of Sr-90, determined with the developed analytical method in spiked urine samples, was in the range of 82- 86%.

Abstract  A periodic acid-Schiff (PAS)-type reaction in which osmium-ammmine was used as the reagent was carried out on ultrathin sections of mouse liver in order to study the extent to which glycogen is preserved. Comparisons were made between tissues that were, on the one hand, conventionally fixed and dehydrated and, on the other, those that were high-pressure frozen and cryosubstituted in acetone. A control was carried out for both groups using a routine uranyl acetate-lead citrate staining procedure. In the latter case, glycogen could be identified as electron-clear patches in the cytoplasm whereas after a PAS-type reaction, glycogen became darkly contrasted. In the case of conventionally fixed samples, glycogen appeared to display a certain amount of clumping separated by gaps whereas in cryosubstituted specimens it was denser and often showed elongated interconnecting structures. These results suggest that cryofixation and cryosubstitution provide better preservation of glycogen in mouse liver tissue compared with chemically fixed specimens. In addition, the fine structure of glycogen appears more homogeneous, showing less aggregation in cryo-treated liver samples.

Abstract  The factors which influence the survival or otherwise of archaeological materials in the burial environment must be understood to allow systematic interpretation of the archaeological record. Studies of postdepositional change, or diagenesis, are therefore essential. The dynamic nature of terrestrial burial environments and the complexity of aqueous fluid-mediated transformation mechanisms have hindered detailed diagenetic research to date. The novel use of integrated experimental and geochemical modeling strategies has the potential to make progress toward a quantified understanding of the diagenesis of inorganic and bioinorganic archaeological materials. We describe current work that is attempting to develop this approach.

Abstract  A magnetic field has been applied to accelerate bone healing for a long time. In this study, in order to combine the bone repair capability of calcium phosphate (CaP) ceramics with the magnetic field, a novel CaP ceramic-magnetic nanoparticle (CaP-MNP) composite was fabricated through integrating the superparamagnetic nanoparticles into the CaP ceramics. Two kinds of CaP ceramics were chosen: hydroxyapatite (HA) and HA/tricalcium phosphate (65/35, HT). The samples were cultured with Ros17/2.8 and MG63 cells respectively in vitro to evaluate the cell proliferation and differentiation via MTT and alkaline phosphatase activity tests. In order to find the influence of the magnetic materials on the expression of the bone morphological protein (BMP), the samples composited with BMP-2 were implanted subcutaneously in the fasciae of rat back muscles for 30 days. Compared with ordinary CaP ceramics, the results indicated that the CaP-MNP composite had good biocompatibility and was able to promote cell proliferation and differentiation significantly. The in vivo test showed that the expression of BMP-2 would be accelerated by HT composited with MNPs, and new bone-like tissue formation could be observed. Accordingly, it might be expected that this CaP-MNP composite could become a potential bone substitute or bone tissue engineering scaffold.