Regional dependence of urinary uranium baseline levels in non-exposed subjects with particular reference to volunteers from Northern Italy

Luminescence studies of uranyl-aliphatic dicarboxylic acid complexes in acetonitrile medium

The uranyl (UO2 2+)-aliphatic dicarboxylic acid complexes are studied by luminescence and UV-Vis spectroscopy in acetonitrile (MeCN) medium. The ligands used are malonic acid (MA), succinic acid (SA), glutaric acid (GA), adipic acid (AA) and pimelic acid (PA). The complexes of UO2 2+ with the above ligands showed well resolved luminescence spectra at pH 4.0 with M/L = 5. Both luminescence and UV-Vis spectra indicated the formation of 1:2 and 1:3 complexes of UO2 2+ with MA and GA, AA, PA, respectively. DFT computations indicated the formation of 1:2 chelate complex of UO2 2+ with MA and two types of 1:3 complexes of UO2 2+ with SA, GA, AA and PA. Furthermore, the effect of solvent (water and acetonitrile) on the UO2 2+-ligand complexes has been performed using COSMO model. The present study demonstrates, for the first time, the formation of tris complexes of uranyl with these ligands in acetonitrile medium.

A survey of uranium levels in urine and hair of people living in a coal mining area in Yili, Xinjiang, China

Recent reports have drawn attention to the uranium contamination arising from coal mining activities in the Yili region of Xinjiang, China due to the mixed distribution of uranium and coal mines, and some of the coal mines being associated with a high uranium content. In this study, we have collected water samples, solid samples such as soil, mud, coal, and coal ash, and hair and urine samples from local populations in order to evaluate the uranium level in this environment and its implications for humans in this high uranium coal mining area. Our results showed that uranium concentrations were 8.71-10.91 μg L^-1 in underground water, whereas lower levels of uranium occurred in river water. Among the solid samples, coal ash contained fairly high concentrations of uranium (33.1 μg g^-1) due to enrichment from coal burning. In addition, uranium levels in the other solid samples were around 2.8 μg g^-1 (the Earth's average background value). Uranium concentrations in hair and urine samples were 22.2-634.5 ng g^-1 (mean: 156.2 ng g^-1) and 8.44-761.6 ng L^-1 (mean: 202.6 ng L^-1), respectively, which are significantly higher than reference values reported for unexposed subjects in other areas. Therefore, these results indicate that people living in this coal mining area have been subjected to uranium exposure for long periods of time.

Urinary excretion of uranium in adult inhabitants of the Czech Republic

The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA.

Resonance light scattering determination of uranyl based on labeled DNAzyme-gold nanoparticle system

A resonance light scattering (RLS) method has been developed using a uranyl (UO2(2+)) specific DNAzyme and gold nanoparticles (AuNPs). In this strategy, the cleavage of the substrate strand (SDNA) of DNAzyme results in releasing a shorter duplex in the presence of UO2(2+), leading to the aggregation of AuNPs and the increase of RLS intensity. The response signals linearly correlated with the concentration of UO2(2+) over the range of 1.36×10(-8)-1.50×10(-7) mol L(-1). The limit of detection (LOD) is 4.09×10(-9) mol L(-1). The method has excellent selectivity and higher sensitivity. It could provide a promising potential for the detection of metal ions, and be benefit to extend the application of RLS method.

Polonium (²¹⁰Po), uranium (²³⁴U, ²³⁸U) isotopes and trace metals in mosses from Sobieszewo Island, northern Poland

The activity of polonium (210)Po and uranium (234)U, (238)U radionuclides, as well as trace metals in mosses, collected from Sobieszewo Island area (northern Poland), were determined using the alpha spectrometry, AAS (atomic absorption spectrometry) and OES-ICP (atomic emission spectrometry with inductively coupled plasma). The concentrations of mercury (directly from the solid sample) were determined by the cold vapor technique of CV AAS. The obtained results revealed that the concentrations of (210)Po, (234)U, and (238)U in the two analyzed kinds of mosses: schrebers big red stem moss (Pleurozium schreberi) and broom moss (Dicranum scoparium) were similar. The higher polonium concentrations were found in broom moss (Dicranum scoparium), but uranium concentrations were relatively low for both species of analyzed mosses. Among the analyzed trace metals the highest concentration in mosses was recorded for iron, while the lowest for nickel, cadmium and mercury. The obtained studies showed that the sources of polonium and uranium isotopes, as well as trace metals in analyzed mosses are air city contaminations transported from Gdańsk and from existing in the vicinity the phosphogypsum waste heap in Wiślinka (near Gdańsk).

The radiochemical contamination (²¹⁰Po and ²³⁸U) of zone around phosphogypsum waste heap in Wiślinka (northern Poland)

The aim of this work was the determination of the impact of phosphogypsum waste heap in Wiślinka (northern Poland) for radiological protection of zone around waste heap. These studies are very important for the estimation of natural alpha radionuclides contents in the vicinity of phosphogypsum waste heap and for environmental pollution assessment of this area. The process of bioaccumulation of radionuclides in interior plants parts prove to examine their origin sources, too. The activity of (210)Po, (234)U, and (238)U were measured using an alpha spectrometer. The values of uranium and polonium concentration in water with immediate area of waste heap are considerably higher than in the waters of the Martwa Wisła river. The values of activity ratio (234)U/(238)U are approximately about one in the phosphogypsum (0.97 ± 0.05) and in the water of retention reservoir and pumping station (0.92 ± 0.01 and 0.99 ± 0.08), while in the water from the Martwa Wisła river they are slightly higher than one (1.03 ± 0.07 and 1.17 ± 0.06). In the analyzed plants species the highest amounts of polonium and uranium were found in ruderal plants samples (between 51 ± 1 and 89 ± 1 for (210)Po; between 36 ± 3 and 68 ± 3 for (238)U) as well as hygrophilous plant samples (18 ± 1 and 84 ± 3; 42 ± 2 and 130 ± 4, respectively for (210)Po and (238)U). The more amounts of (210)Po and (238)U radionuclides were accumulated mainly in the roots of plant species in comparison to green parts. The general conclusion of realized study is higher influence of phosphogypsum on radioactive contamination of environmental zone around heap waste in Wiślinka (northern Poland).

Daily urinary excretion of uranium in members of the public of Southwest Nigeria

The main aim of this study was to determine and evaluate urinary excretion values of uranium in members of the public of Southwest Nigeria living in areas of low environmental uranium. As several uranium mines are running in Nigeria and the operations could be a risk of contamination for the workers as well as for the members of the public, biomonitoring of urine could provide information about the exposure to uranium for the subjects. Therefore, baseline values of uranium in urine are needed from subjects living in areas without mining activities. Volunteers of both genders (age range 3 to 78 years) were asked to collect 24h-urine samples. The concentration measurements of uranium in urine were performed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In addition, urinary creatinine values were determined for normalization of the renal uranium relative to the creatinine concentrations. The urinary uranium concentrations and their creatinine normalized values ranged from <10.4 to 150 ng L(-1) (median 13.8 ng L(-1)) and from 2.52 to 252.7 ng g(-1) creatinine (median 33.4 ng g(-1) creatinine), respectively, for adult subjects above 15 years of both genders. An increased uranium excretion value of 61.6 ng L(-1) (median), and of 76.0 ng g(-1) creatinine, respectively, were found in young subjects below 15 years. The median of daily excreted uranium was estimated to be 14.2 ng d(-1) for adults and of 45.1 ng d(-1) for children, respectively. The uranium excretion from males and females living in Nigeria in a non-mining area was comparable to reference values reported from other countries with low level of environmental uranium. The data can be considered as baseline values of urinary uranium in unexposed subjects in Nigeria.

Bioaccumulation of polonium (210Po) and uranium (234U, 238U) in plants around phosphogypsum waste heap in Wiślinka (northern Poland)

In the study the activities of polonium 210Po and uranium 234U, 238U in plants, collected near phosphogypsum waste heap in Wiślinka (northern Poland), were determined by using the alpha spectrometry. The obtained results revealed that the concentrations of 210Po, 234U, and 238U in the analyzed plants were differentiated. In the analyzed flora organisms the highest amounts of polonium and uranium were found in ruderal plant samples as well as willow samples (Salix viminalis) from protection zone of phosphogypsum waste heap. The concentrations of 210Po, 234U and 238U in the analyzed plants were higher in roots than in green parts of plants. The higher concentrations of 210Po and 238U radionuclides were estimated for hydrophyte (common sedge Carex nigra Reichard), the favourite habitat of which is particularly wet meadow and for plants co llected in the vicinity of phosphogypsum waste heap. The major source of polonium and uranium in analyzed plants is root system. The values of 234U/ 238U activity ratio in all analyzed plants are closed to one, what indicated that source of uranium in analyzed plants is phoosphogypsum. The highest uranium and polonium concentrations were characterized for plants, which are covered with tomentose.

The comparability polonium and uranium contents were confirmed in edible plants, but higher accumulation was determined in ripe species than immature species of vegetables. The higher polonium and uranium concentrations were noticed in green parts of plant, the lower in roots. Polonium concentration in cultivated plants samples was not species diverse. Therefore, the significant source of polonium and uranium in analyzed plants is wet and dry atmospheric falls gathering the soil and air dust from phosphogypsum waste dump.

The maximum 210Po and 238U radionuclides concentrations were found in green parts of red beet (Beta vulgaris esculenta), the minimum in garden radish (Raphanus radicula). That's interesting too, that both species have hypocotyls tubers, but tuber of red beet is large than garden radish. In our opinion these differences may be connected with turgidity because leaves and root of radish garden were withered.

Hair analysis as an indicator of exposure to uranium

Medical examinations performed on four monks of a monastery in the northern Greece revealed heavy metal contamination. Hair analysis, performed by a toxicological laboratory abroad, indicated, among other, the presence of uranium. The uranium concentrations determined in a laboratory of "Elemental Hair Analysis' indicated a uranium level that was about five times the maximum value of the reference range, which has been adopted by the measuring laboratory. After these diagnostic findings, on request of 10 monks, uranium determination in hair and urine samples was performed by means of alpha spectrometry in GAEC's laboratory. The measured uranium concentrations in hair varied from 0.15 to 2.10 mBq g(-1), which correspond to 12.1 and 170 ng g(-1), respectively. The uranium concentrations in urine were between 41 and 174 ng d(-1). For comparison purposes, urine and non-dyed hair samples from the staff of the laboratory were analysed. Because one of the major sources of uranium intake is through drinking water, water samples were also analysed. The mean value of the uranium concentration in the two drinking water samples collected from the residence area was found to be 2.35 μg l(-1).

The inflow of uranium 234U and 238U from the Vistula River catchment area to the Baltic Sea

In the study, the activities of uranium 234U and 238U in the Vistula River water samples which were collected from November 2002 to October 2003, were measured using alpha spectrometry. In winter, the highest concentration of uranium isotopes and total uranium was in the Vistula River water from Malbork (13.13±0.22 Bq m−3 for 234U, 12.45±0.21 Bq m−3 for 238U and 1.02±0.30 mg m−3 for total uranium), and the lowest was in water from Dęblin (1.73±0.07 Bq m−3 for 234U, 1.55±0.07 Bq m−3 for 238U and 0.13±0.09 mg m−3 for total uranium). In analyzed river samples uranium isotopes 234U and 238U are not in the radioactive equilibrium state. The values of 234U/238U activity ratio lie between 1.05–1.70. During spring, the highest concentration of uranium isotopes and total uranium was found in the Vistula River water from Malbork (12.36±0.19 Bq m−3 for 234U, 10.77±0.17 Bq m−3 for 238U and 0.88±0.25 mg m−3 for total uranium), and the lowest was in water taken from Sandomierz (5.77±0.14 Bq m−3 for 234U) and Kraków (4.08±0.11 Bq m`−3 for 238U and 0.33±0.18 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.15–1.64. In summer, the highest concentration of uranium isotopes and total uranium was found in the Vistula River water samples taken from Malbork (8.22±0.21 Bq m−3 for 234U, 7.60±0.21 Bq m−3 for 238U and 0.62±0.29 mg m−3 for total uranium), and the lowest was in water from Sandomierz (6.37±0.12 Bq m−3 for 234U) and Kraków (3.56±0.19 Bq m−3 for 238U and 0.29±0.33 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.08–1.95. In autumn the highest concentration of uranium isotopes and total uranium was in the Vistula River water from Malbork (17.80±0.25 Bq m−3 for 234U, 15.12±0.23 Bq m−3 for 238U and 1.23±0.34 mg m−3 for total uranium) and the lowest was in water from Toruń (8.15±0.49 Bq m−3 for 234U) and Kraków (6.34±0.47 Bq m−3 for 238U and 0.52±0.78 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.10–1.74. Annually, the southern Baltic Sea is enriched by about 507 GBq uranium isotopes 234U and 238U, with 490 GBq going to the Gdańsk Bay and 16.5 GBq to Vistula Lagoon. The highest surface 238U runoff was observed in spring (to 1200 kBq km−2 quarter−1 for catchment´s area), the lowest in summer for Bug with Narew catchment´s area to 20 kBq km−2 quarter−1). These studies are very important for the inflow estimation of natural and anthropogenic alpha radionuclides to the Baltic Sea.

Uranium and thorium in soils, mineral sands, water and food samples in a tin mining area in Nigeria with elevated activity

The activity concentrations of uranium and thorium have been determined in soils and mineral sands from the Nigerian tin mining area of Bisichi, located in the Jos Plateau, and from two control areas in Nigeria (Jos City and Akure) using high-purity germanium detectors (HPGe). High resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICP-MS) was used to determine uranium and thorium in liquids and foodstuffs consumed locally in the mining area. The activities of uranium and thorium measured in the soils and mineral sands from Bisichi ranged from 8.7 kBq kg(-1) to 51 kBq kg(-1) for (238)U and from 16.8 kBq kg(-1) to 98 kBq kg(-1) for (232)Th, respectively. These values were significantly higher than those in the control areas of Jos City and Akure and than the reference values reported in the literature. They even exceeded the concentrations reported for areas of high natural radioactive background. Radionuclide concentrations in samples of the local foodstuffs and in water samples collected in Bisichi were found to be higher than UNSCEAR reference values. The results reveal the pollution potential of the mining activities on the surrounding areas.

Measurements of daily urinary uranium excretion in German peacekeeping personnel and residents of the Kosovo region to assess potential intakes of depleted uranium (DU)

Following the end of the Kosovo conflict, in June 1999, a study was instigated to evaluate whether there was a cause for concern of health risk from depleted uranium (DU) to German peacekeeping personnel serving in the Balkans. In addition, the investigations were extended to residents of Kosovo and southern Serbia, who lived in areas where DU ammunitions were deployed. In order to assess a possible DU intake, both the urinary uranium excretion of volunteer residents and water samples were collected and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). More than 1300 urine samples from peacekeeping personnel and unexposed controls of different genders and age were analysed to determine uranium excretion parameters. The urine measurements for 113 unexposed subjects revealed a daily uranium excretion rate with a geometric mean of 13.9 ng/d (geometric standard deviation (GSD)=2.17). The analysis of 1228 urine samples from the peacekeeping personnel resulted in a geometric mean of 12.8 ng/d (GSD=2.60). It follows that both unexposed controls and peacekeeping personnel excreted similar amounts of uranium. Inter-subject variation in uranium excretion was high and no significant age-specific differences were found. The second part of the study monitored 24 h urine samples provided by selected residents of Kosovo and adjacent regions of Serbia compared to controls from Munich, Germany. Total uranium and isotope ratios were measured in order to determine DU content. (235)U/(238)U ratios were within +/-0.3% of the natural value, and (236)U/(238)U was less than 2 x 10(-7), indicating no significant DU in any of the urine samples provided, despite total uranium excretion being relatively high in some cases. Measurements of ground and tap water samples from regions where DU munitions were deployed did not show any contamination with DU, except in one sample. It is concluded that both peacekeeping personnel and residents serving or living in the Balkans, respectively, were not exposed to significant amounts of DU.

Concentration and daily excretion of uranium in urine of Japanese

A study was undertaken to investigate uranium concentrations in urine samples for unexposed Japanese individuals and to evaluate uranium daily excretion. Uranium concentrations were measured with inductively coupled plasma mass spectrometry after microwave-assisted digestion and online separation using the UTEVA extraction chromatographic resin. The concentrations ranged from 0.8 to 35.6 ng of uranium per liter of urine (median 4.5 ng L(-1)). Urinary uranium was normalized relative to the creatinine concentration in order to compensate for the degree of urine dilution. Creatinine-normalized values ranged from 1.2 to 17.8 ng of uranium per gram of creatinine (median 7.4 ng g(-1) creatinine). These results corresponded to the lower end of urinary uranium reported for unexposed populations. The level of daily excreted uranium was calculated as 6.45 ng d(-1) (median value) using ICRP recommended values for 24-h creatinine excretion. These data along with literature data on uranium dietary intake for Japanese populations were used to estimate the uranium gastrointestinal absorption fraction (f(1)). The median f(1) value was calculated to be 0.007. Statistical analysis was done to investigate statistical differences and relationships between the studied variables.

Internal dose assessment of natural uranium from drinking water based on biokinetic modeling and individual bioassay monitoring: a study of a Finnish family

Since the later 1960's, a nationwide survey on natural radionuclides in drinking water showed high concentrations of natural uranium (U) in Finland, especially in uraniferous granite areas. In order to assess the radiation dose from the natural uranium to individuals, the concentrations of natural uranium in drinking water of the drilled wells were determined by radiochemical and alpha spectrometric methods. Uranium contents were measured in the urinary samples of five members of a Finnish family by means of inductively coupled plasma-mass spectrometry. Correspondingly, theoretical biokinetic modeling of natural uranium incorporated for the same persons were performed with the aid of follow-up interviews. The ICRP biokinetic compartmental model and the age-dependent transfer rates for uranium were used to model the intake, transfer, distribution, retention, and excretion of (234)U and (238)U, respectively, from the drinking water for each person of the family. The organ absorbed dose, equivalent dose, and effective dose were evaluated for each family member at time intervals using specific effective energy values calculated by the SEECAL program and compared with recommended values. The modeled urinary excretion rates were found to be mostly higher than the measured values by a factor of three. The mean annual effective dose for this family is 8 muSv y(-1). By comparing the measured and calculated data, estimation of retrospective radiation exposure based on biokinetic modeling and bioassay method is enhanced and, vice versa, the biokinetic and dosimetric models are tested and verified.