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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Vasconcellos, P. Bode, G. Paletti, M. Catharino, A. Ammerlaan, M. Saiki, D. Fávaro, A. Byrne, R. Baruzzi, and D. Rodrigues

Abstract  

Biomonitoring of mercury contamination of Brazilian Indian population groups living in the Xingu Park, a reservation situated in the Amazonic region, has revealed very high levels of mercury in hair samples as compared to controls. Total mercury was determined by INAA in most of the tribes living in the Park and methylmercury was determined by CVAAS in samples with total mercury above 10 mg/kg. Due to the fact that selenium seems to protect animals against the toxic effects of methylmercury, it was considered also of interest to determine its concentrations in the hair samples with very high mercury levels. Selenium was determined by INAA via the short-lived radionuclide 77mSe (T 1/2 = 17.45 s). The correlations between selenium and mercury concentrations in Brazilian controls and in the Indian population groups are discussed.

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In this study a protocol for blood serum analysis was defined and the concentrations for Br, Ca, Cl, Fe, Na, Rb, Se and Zn were obtained by instrumental neutron activation analysis. Blood samples were collected from healthy elderly volunteers who were selected based on the SENIEUR protocol. Contamination of blood by the collection procedure was also evaluated and found negligible. The serum was separated by centrifugation, then freeze-dried and analyzed. Most of results obtained were within the acceptable value ranges used by physicians for normal population. The certified reference material, NIST SRM 1566b Oyster Tissue was analyzed for quality control.

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Abstract  

The femur samples obtained from the general populations were dissected into five different parts: the distal end (DE), distal shaft (DS), middle shaft (MS), proximal shaft (PS) and proximal end (PE). The dissections were performed in the same manner as for the persons exposed to plutonium occupationally. The concentrations of plutonium in these sections were determined by a radiochemical procedure utilizing solvent extraction and alpha-spectrometry. The preliminary results indicate that the distribution of plutonium in the femur was nonuniform and was highest in the proximal end followed by distal end.

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Abstract  

Applying instrumental neutron activation analysis, multielement analysis of human hair was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo metropolitan area. 202 hair samples were collected from the inhabitants classified by sex and five age groups. Using several combinations of irradiation time, cooling time and counting time, forty elements were quantitatively analyzed. The method of analysis for data including samples under detection limit is discussed, assuming that the frequanecy distribution of trace element contents in hair is log-normal.

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Abstract  

Selenium daily intake was determined for two small groups of the Portuguese population, based on the analysis of duplicate diet portions. The total amount of food ingested during a day was collected for 18 workers of the Technological and Nuclear Institute (ITN-Sacavém) and for 6 females of Reguengos de Monsaraz, a small town in the south-eastern hinterland. The average selenium daily intake was 43 ± 20 and 32 ± 13 μg per person, respectively, both lower than the Recommended Dietary Allowance (RDA) of 55 μg day−1. Selenium in diet samples was determined by replicate sample neutron activation analysis (RSINAA). The method was considered accurate for the selenium determination.

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Abstract  

Hair analysis is extensively used in forensic sciences, assessment of occupational or environmental exposure and in some cases also for clinical and nutritional studies. Hair has a series of advantages in relation to other biomonitors, like blood and urine, since it is very easy to collect, very stable at room temperature and it represents not only instantaneous concentrations, but it can reveal the exposure along a given period of time. The assessment of environmental or occupational exposure to uranium is generally done by means of urine analysis, although a few papers have described attempts to use hair as a biomonitor. In the present work, epithermal neutron activation analysis has been used to establish base-line concentrations for a Brazilian populational group, living in Sao Paulo and not exposed to uranium, either environmentally or occupationally. For quality control, the reference materials Pine Needles NIST 1575 and Basalt USGS BCR-1 were used. The concentrations obtained for the control population studied up to now varied from about 2 to 50 ng·g−1.

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Summary  

The 238U and 232 Th concentrations were measured in various potable water samples collected from various cities in Morocco using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The measured 238U and 232 Th concentrations ranged from 0.37±0.02 to 13.60±0.97 mBq . l-1 and 0.33±0.02 to 7.10±0.49 mBq . l-1, respectively. Alpha-activities due to annual 238U and 232 Th intakes were assessed in various compartments of the human body of adult members of the Moroccan population using ICRP biokinetic models. The equivalent doses due to annual intakes of 238U and 232 Th were evaluated. The influence of the target tissue mass and the activities of 238U and 232 Th on the annual committed equivalent doses in the compartments of the human body was investigated.

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Abstract  

Radioactive fallout constitutes the major source of contamination of the environment with fission products. Our primary interest was in selected fission products, such as 131I, 89Sr, 90Sr, and 137Cs, and neutron activation products, such as 3H and 14C. Plutonium-239,240, 241Am and 90Tc are generated from nuclear tests, and they are important by-products of nuclear industries. Polonium-210, 210Pb and 232Th, 230Th and 228Th occur widely in nature. These radionuclides enter the human body through inhalation and the ingestion through food and water. These nuclides may cause radiation doses to certain organs of the body. Assessment of the resulting health hazards is an essential public health activity, which demands reliable techniques for the assay of the various radionuclides in man and his environment. In this paper, we present the accumulation of radionuclides from man-made sources and primordial radionuclides in various tissues of the Japanese population. The studies were performed at the Department of Public Health, Akita University School of Medicine, during the periods from 1973 to 1995.

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Abstract  

Equilibrium constants of H2O/g/ and D2O/g/ associations to clusters /H2O/n/g/ and /D2O/n/g/ have been calculated on the basis of the ab initio SCF CI MCY-B water-water pair potential. Populations of the components of equilibrium cluster mixtures have been evaluated at various temperatures and pressures for both isotopomeric series. Differences between the H and D steam are pointed out and possible consequences are discussed.

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This article is the first report describing a new validated method to determine the content of HupA in Huperzia selago (Huperziaceae) from wild population and obtained in in vitro culture using the chaotropic mobile phase. An aqueous-organic (acetonitrile) mobile phase with an added chaotropic salt (NaPF6) was used. The system of mobile phases ensured very high selectivity and efficiency at up to N = 6683 ± 963 theoretical plates calculated for isocratic mode. A Hypercosil GOLD column, C18 250 × 4.6 mm, and a Hypercosil GOLD precolumn, 5UM 10 × 4 mm, were employed for detection at four wavelengths, 230 nm being analytical. The regression coefficient (R 2) of the calibration was 0.9993 over the range 25–1252 μg mL−1. The recovery rates were 98.36–105.1% with RSD <2.9%. The intra- and inter-day precisions, expressed as RSD, ranged from 1.2% to 2.7%. LOD for HupA was 14 ng mL−1 for a signal-to-noise ratio of 3:1. The limit of quantification was 140 ng mL−1. The huperzine A (HupA) content of the plant material ranged from 0.65 mg g−1 dry weight (d.w.) to 1.59 mg g−1 d.w. (material from wild plants) and from 0.44 to 1.10 mg g−1 d.w. (material from in vitro cultures). Interestingly, in our study, plants of H. selago derived from wild population had one of the highest HupA concentrations recorded for a club moss (1.59 mg g−1 d.w.). The findings demonstrate that H. selago, found in Europe and North America, is an alternative source of HupA, richer than H. serrata. In order to confirm that HupA was present in the alkaloid extracts, HPLC-ESI-MS/MS analyses of the patterns were performed in the positive ion mode. The fragmentation quasi-molecular ion of the standard HupA (m/z = 243, [M+H]+) and the ion with m/z = 243 found in the samples were identical, confirming the compound as HupA.

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