Uranium concentration measurements in human blood for some governorates in Iraq using CR-39 track detector

The sensitive and simple technique of fission track etch has been applied to determine trace concentration of uranium in blood samples for occupational and non-occupational workers, male and female, using CR-39 track detector that is employed for registration of induced fission tracks. The results show that the highest recorded uranium concentration in human blood of workers in the ministry of Science and Technology were 1.90 ppb (male, 36 years old, 12 years' work experience, and living in Basrah governorate) and minimum concentration 0.26 ppb (female, 40 years old, 10 years' work experience, and living in Baghdad), while for non-occupational worker, the maximum uranium concentration was 1.76 ppb (female, 63 years old, and living in Al-Muthana) and minimum concentration was 0.28 ppb (female, 20 years old, and living in Baghdad). It has also been found that the uranium concentration in human blood samples of workers in the ministry of Science and Technology are higher than those of non-occupational workers, and the uranium concentrations for female workers and for non-occupational workers were higher than those for male workers and non-occupational workers.     

Study of gamma irradiation effects on the etching and optical properties of CR-39 solid state nuclear track detector and its application to uranium assay in soil samples

The gamma irradiation effects in the dose range of 2.5?C43.0 Mrad on the etching and optical characteristics of CR-39 solid state nuclear track detector (SSNTD) have been studied by using etching and UV?CVisible spectroscopic techniques. From the measured bulk etch rates at different temperatures, the activation energies for bulk etching at different doses have also been determined. It is seen that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. The optical band gaps of the unirradiated and the gamma -irradiated detectors determined from the UV?CVisible spectra were found to decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation. The present studies can be used for the estimation of gamma dose in the range of 2.5?C43.0 Mrad and can also be used for estimating track registration efficiency in the presence of gamma dose. The CR-39 detector has also been applied for the assay of uranium in some soil samples of Jammu city.     

Determination of the calibration factor for CR-39 based indoor radon detector

CR-39 based radon detectors are widely used in measuring indoor radon. In this regard, different groups have developed their own systems. However, before using any system for indoor radon measurements, it has, first, to be calibrated with a known source of radon. In the current study, CR-39 based NRPB type radon detector has been calibrated and presented. In this regard, about 200 holders for CR-39 were obtained from the Radiation Protection Division of the Health Protection Agency (former NRPB), UK and several thousand more similar detector holders, hereafter called NRPB type holders, were fabricated locally in Pakistan. Uranium ore samples of known grade were placed into the plastic containers of volume 5.4 × 10³ cm³ and CR-39 detectors were placed in the NRPB type holders and were then installed into the containers at a distance of 25 cm from the surface of the known grade ore samples. The containers were hermetically sealed and the detectors were allowed to expose to radon for 3 weeks. After 16 h etching in 25 % NaOH at 80 °C, the measured track densities were related to the radon concentration. The calibration factor of 2.563 tracks cm^?2 h^?1/kBq m^?3 was obtained.     

Determination of natural uranium in biological samples using the solid state nuclear track detector method

For the solution of most of the problems which are connected to the biological and physiological role of natural uranium in plants and animal organisms about 10⁻¹⁴ g uranium should be determined. However most of the physico-chemical methods for the determination of natural uranium in biomaterials are time-consuming and possess considerable error. On the basis of addition and inner standard methods a version of Solid State Nuclear Track Detectors (SSNTD) method has been developed in order to determine the natural uranium in biospecimens. According to the experimental data simple relations have been obtained for the calculation of uranium concentration in biomaterial and minium uranium concentration in biosolution which can be measured by the detector used. Under irradiation of SSNTD at a thermal neutron flux of (3–5)·10¹⁵n·cm⁻² the detector sensitivity is 2.30·10⁻⁹ g U/ml for glass detectors; 9.60·10⁻¹⁰g U/ml for the detectors made from artificial mica.     

Field measurement of radon exhalation rate from the soil by CR-39 detector

Determination technique of radon exhalation rate (RER) from soils in field measured by track detector CR-39 was developed. For this purpose, the method “Russian dolls” (matrieshka) was created and used, consisting of three cylindrical plastic chambers and located inside each other. Entrance mouths of chambers are installed in opposite directions to make an artificial barrier up on the path of ²²⁰Rn. Field measurements of the RER from soils were within 16.4–22.1 Bq/m²h, that are 160 and 220 times more than laboratory measurement. The RER values from soils as laboratory and field measurements have been compared with the data of other authors.     

Uranium determination in water samples with elevated salinity from Southern Poland by micro coprecipitation using alpha spectrometry

Due to the importance of water in human life, its quality must be strictly controlled; so simple and reliable analytical methods must be available. For this purpose a rapid procedure for the determination of uranium isotopes in natural water samples with elevated salinity was adopted. It was tested in 16 water samples from Upper and Lower Silesia Regions in Poland. Water samples had salinity in a range of 290–26,925 mg l^{− 1}.In water samples the concentrations of ²³⁴U and ²³⁸U ranged from 2.07 to 52.08 mBq l^{– 1} and from 2.18 to 43.38 mBq l^{– 1} respectively, while ²³⁵U level was below MDA (0.7 mBq l^{− 1}).The isotopic ratio of ²³⁴U/²³⁸U varies in the range from 0.949 to 3.344 in all investigated waters which means that there is usually no radioactive equilibrium between the parent nuclide ²³⁸U and its daughter product ²³⁴U.These results do not show a correlation between total dissolved solids (TDS) values and concentration of dissolved uranium isotopes.Committed effective dose for adults due to uranium intake as a result of drinking water usage was in range of 0.15–3.29 µSv y^{− 1} with an average value of 1.09 µSv y^{− 1} far below the 100 µSv y^{− 1} WHO recommendation.     

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.     

Estimation of track registration efficiency in solution medium and study of gamma irradiation effects on the bulk-etch rate and the activation energy for bulk etching of CR-39 (DOP) solid state nuclear track detector

The fission track registration efficiency of diethylene glycol bis allyl carbonate (dioctyl phthalate doped) [CR-39 (DOP)] solid state nuclear track detector (SSNTD) in solution medium (K _wet) has been experimentally determined and is found to be (9.7 ± 0.5) × 10⁻⁴ cm. This is in good agreement with the values of other SSNTDs. The gamma irradiation effects in the dose range of 50.0–220.0 kGy on the bulk etch rate, V _b and the activation energy for bulk etching, E of this solid state nuclear track detector (SSNTD) have also been studied. It is observed that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation.     

Determination of uranium concentration in water samples by the fission track registration technique

The fission track registration technique using Makrofol KG as detector and the wet method was developed for the determination of microgram amounts of uranium in water samples. This method allows the determination of uranium concentrations within the interval of 8.0 to 0.4 μg. U/l, the overall ranging from 3.3% to 29.0%. Results obtained for water samples from several sources in the State of São Paulo, Brasil, are reported.     

Study of degraded neutron spectra through metal matrix composites using CR-39 films

Considerable interest has grown in the last decade in the use of CR-39 films in routine neutron monitoring and dosimetry. In addition, work in neutron spectrometry has been undertaken by various workers (Decossas et al., 1984; Faermann et al., 1983; Fews et al., 1984; Turner et al., 1984). In the present study metal matrix composites (MMC) samples of Pb-Li, Pb-Cd, Al-Li and Al-B₄C were prepared by using powder metallurgy and alloying elements techniques. The density was obtained for these MMC samples in the range of 80-90% of the metal density. Degraded neutron spectra were obtained by exposing these samples to a ²⁵²Cf source housed in a camera and the detector used was CR-39 films covered with a 1 mm PE radiator. These spectra have also been validated through Monte Carlo Neutron and Photon Transport Code (1983).     

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.     

Microanalysis of uranium in Antarctica soil samples using fission track method

Soil samples collected at the Indian Antarctic station Maitree, situated at the Schirmachar Oasis and belonging to the East Antarctic charnockite provinces have been analysed to determine trace uranium concentrations. The fission track technique using Makrofol-KG as the track detector was used for the analyses. Finely powdered samples and pellets were irradiated with thermal neutrons from a nuclear reactor. Uranium concentrations were obtained from the tracks of the detector. Uranium concentrations were found to vary from 0.036 to 0.364 ppm in the samples investigated. The low levels of uranium indicate the absence of human intervention with the lithosphere in this region.     

An automated system for track measurement for the employment of CR-39 as alpha spectrometer in radon and its daughters monitoring

In this work we studied an automated analysis of alpha particle tracks in CR-39, by employing a MITAKA photo-microdensitometer with a C1522 HAMAMATSU Image Analysis System. This system can be used to measure track diameters (with a nominal precision of 0.8 m), superficial track density, and track darkness. This information can be used to determine the alpha particle energies and also their incidence angles (azimuthal and zenithal). The performance of such an automated system, to analyze CR-39 samples which were exposed to alpha particles of known energies, was studied, comparing its response with measurements performed manually by experienced microscopists. The experimental results indicate that the MITAKA/HAMAMATSU system is very reliable for alpha track analysis in CR-39, making possible its use to perform time-consuming measurements in microscopy, as in the case of radon and its daughters surveys.     

Development of an appropriate method for measuring gross alpha activity concentration in low-mass size-fractionated samples of sediment using solid-state nuclear track detectors

Journal of Radioanalytical and Nuclear Chemistry - A passive technique using solid state nuclear track detectors was developed to detect the low-level gross alpha activity (Aα) in low-mass...     

HRGC assay of antihistaminic drugs in plasma samples using a nitrogen-phosphorus detector

Thirteen antihistaminic drugs are separated on a CP-Sil 5 capillary column and are evaluated by a NP detector after extraction of spiked plasma samples, alkalinized, in a solvent mixture of chloroform, dichloromethane, and methanol. Intra- and inter-assay analyses showed high reliability, therefore this method can be usefully applied in experimental or clinical pharmacokinetic investigations.     

Uranium in ground water samples of Northern Greece

In this study, a gamma–gamma coincidence spectrometry was developed and examined for environmental low-level cosmogenic ²²Na monitoring purposes. The spectrometry consists of two bismuth germanate scintillators (BGO) and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The developed spectrometry was optimized according to the considerations of output count rate and gamma peak energy resolution. This spectrometry provides a more sensitive and effective way to quantify even trace amounts of ²²Na with critical detection limit of 9 mBq. A sophisticated computer simulation was also created with the goal of obtaining a better understanding of the experimental results and gamma–gamma coincidence efficiencies at different sample geometries.     

Investigation of alpha emitters in fresh and powdered blood of fertile women: an in vitro application of CR-39 NTDs

Blood samples were acquired from 60 women aged 20–44 years having decreased fertility, infertile or with uterine tumors in the Iraqi Kurdistan region. The concentrations of α emitters in fresh blood ranged from 0.0029 to 0.0088 ppm, whereas those in powdered blood ranged from 0.0036 ppm in Eiskan to 0.0096 ppm in Halabjay–Kon in Sulaymania. The α emitter concentrations in fresh blood ranged from 0.0029 to 0.0139 ppm, whereas those in powdered blood ranged from 0.0031 ppm in Shorsh to 0.0146 ppm in Sedakan in the Erbil Governorate. However, the concentrations of α emitters in the blood of women with decreased fertility were higher in the North than women from South Iraq. The difference significantly p < 0.001 revealed higher means of track density of fresh and powder blood in Erbil compared to Sulaymania. α are more damaging to the living tissue and exposure of the gonads leads to decreased fertility in women, most of data have been significant therefore, the result shown the radiation effect on women fertility.     

Natural radioactivity levels of limestone rocks in northern Iraq using gamma spectroscopy and nuclear track detector

The activity concentration of radionuclides, such as ²³⁸U, ²²⁶Ra and ⁴⁰K of limestone rocks in northern Iraq was measured using gamma spectroscopy. The radionuclide activities were obtained and discussed. CR-39 nuclear track detector was used to measure the radon exhalation rates as well as the effective radium contents of these samples and are found to correspond with uranium concentration values measured by NaI(Tl) detector in the corresponding limestone rocks samples. The absorbed gamma dose rates in air due to the presence of ²³⁸U, ²²⁶Ra, ⁴⁰K and cosmic ray contribution varied between 105.3 and 223.11 nGy/h. The annual effective dose of each sample has been calculated. The correlation between activities of ²²⁶Ra, ²²²Rn exhalation rates and ²³⁸U is explained. Results show a symmetrical distribution of activity concentrations of primordial of radionuclides in selected samples. The values of all studied radionuclides are considered to be a typical level of natural background and compared with results of similar investigations carried out else where.     

Detection of dideuterium in diprotium gas at infinitesimal concentration using a trace reduction detector

An analyzer able to detect extremely small concentrations of dideuterium in diprotium gas was developed. To examine its performance, four gas samples of pure diprotium with dideuterium concentrations of 0.25, 0.5, 1, and 5 cm(3)/m(3) were measured using the analyzer, and peak areas and retention times from 18 chromatograms were determined. Results indicated that the peaks were distributed within a relative standard deviation of approximately 15% and a linear correlation existed between peak area and concentration. Retention times were stable, showing a relative standard deviation of 1% with repeated tests and having no correlation with concentration of the four gas samples.