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Sample records for actinium 210

  1. Extraction of actinium with di-(2-ethylhexyl)phosphoric acid from hydrochloric and nitric acid solutions

    The extraction of actinium with HDEHP from Cl- and NO3- systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO3 solutions. Stability constants of actinium complexes Ac(X-)+2 with Cl- and NO3- ligands were determined. Our results show that the actinium formed less stable complexes with Cl- than with NO3- ligands. 5 refs., 3 figs., 1 tab. (author)

  2. The sorption of polonium, actinium and protactinium onto geological materials

    This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results

  3. Separation of Actinium 227 from the uranium minerals

    The purpose of this work was to separate Actinium 227, whose content is 18%, from the mineral carnotite found in Gomez Chihuahua mountain range in Mexico. The mineral before processing is is pre-concentrated and passed, first through anionic exchange resins, later the eluate obtained is passed through cationic resins. The resins were 20-50 MESH QOWEX and 100-200 MESH 50 X 8-20 in some cased 200-400 MESH AG 50W-X8, 1X8 in other cases. The eluates from the ionic exchange were electrodeposited on stainless steel polished disc cathode and platinum electrode as anode; under a current ODF 10mA for 2.5 to 5 hours and of 100mA for .5 of an hour. it was possible to identify the Actinium 227 by means of its descendents, TH-227 and RA-223, through alpha spectroscopy. Due to the radiochemical purity which the electro deposits were obtained the Actinium 227 was low and was not quantitatively determined. A large majority of the members of the natural radioactive series 3 were identified and even alpha energies reported in the literature with very low percentages of non-identified emissions were observed. We conclude that a more precise study is needed concerning ionic exchange and electrodeposit to obtain an Actinium 227 of radiochemical purity. (Author)

  4. Spectroscopic and computational investigation of actinium coordination chemistry.

    Ferrier, Maryline G; Batista, Enrique R; Berg, John M; Birnbaum, Eva R; Cross, Justin N; Engle, Jonathan W; La Pierre, Henry S; Kozimor, Stosh A; Lezama Pacheco, Juan S; Stein, Benjamin W; Stieber, S Chantal E; Wilson, Justin J

    2016-01-01

    Actinium-225 is a promising isotope for targeted-α therapy. Unfortunately, progress in developing chelators for medicinal applications has been hindered by a limited understanding of actinium chemistry. This knowledge gap is primarily associated with handling actinium, as it is highly radioactive and in short supply. Hence, Ac(III) reactivity is often inferred from the lanthanides and minor actinides (that is, Am, Cm), with limited success. Here we overcome these challenges and characterize actinium in HCl solutions using X-ray absorption spectroscopy and molecular dynamics density functional theory. The Ac-Cl and Ac-OH2O distances are measured to be 2.95(3) and 2.59(3) Å, respectively. The X-ray absorption spectroscopy comparisons between Ac(III) and Am(III) in HCl solutions indicate Ac(III) coordinates more inner-sphere Cl(1-) ligands (3.2±1.1) than Am(III) (0.8±0.3). These results imply diverse reactivity for the +3 actinides and highlight the unexpected and unique Ac(III) chemical behaviour. PMID:27531582

  5. Discovery of the actinium, thorium, protactinium, and uranium isotopes

    Fry, C; Thoennessen, M

    2012-01-01

    Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  6. Production of high-purity radium-223 from legacy actinium-beryllium neutron sources.

    Soderquist, Chuck Z; McNamara, Bruce K; Fisher, Darrell R

    2012-07-01

    Radium-223 is a short-lived alpha-particle-emitting radionuclide with potential applications in cancer treatment. Research to develop new radiopharmaceuticals employing (223)Ra has been hindered by poor availability due to the small quantities of parent actinium-227 available world-wide. The purpose of this study was to develop innovative and cost-effective methods to obtain high-purity (223)Ra from (227)Ac. We obtained (227)Ac from two surplus actinium-beryllium neutron generators. We retrieved the actinium/beryllium buttons from the sources and dissolved them in a sulfuric-nitric acid solution. A crude actinium solid was recovered from the solution by coprecipitation with thorium fluoride, leaving beryllium in solution. The crude actinium was purified to provide about 40 milligrams of actinium nitrate using anion exchange in methanol-water-nitric acid solution. The purified actinium was then used to generate high-purity (223)Ra. We extracted (223)Ra using anion exchange in a methanol-water-nitric acid solution. After the radium was separated, actinium and thorium were then eluted from the column and dried for interim storage. This single-pass separation produces high purity, carrier-free (223)Ra product, and does not disturb the (227)Ac/(227)Th equilibrium. A high purity, carrier-free (227)Th was also obtained from the actinium using a similar anion exchange in nitric acid. These methods enable efficient production of (223)Ra for research and new alpha-emitter radiopharmaceutical development. PMID:22697483

  7. Radium, thorium, and actinium extraction from seawater using an improved manganese-oxide-coated fiber

    Laboratory experiments were conducted to determine the efficiency with which improved manganese-oxide-coated acrylic fibers extract radium, thorium, and actinium from seawater. Tests were made using surface seawater spiked with 227Ac, 227Th and 223Ra. For sample volumes of approximately 30 liters and flow rates up to 0.5 liters per minute, radium and actinium are removed quantitatively. Approximately 80-95% of the thorium is removed under these same conditions. (Auth.)

  8. IT 210 Uop Material - it210dotcom

    honey

    2015-01-01

    IT 210 Entire Course For more course tutorials visit www.uopit210.com   IT 210 Week 1 CheckPoint Input Data and Output Process IT 210 Week 1 DQ 1 and DQ 2 IT 210 Week 2 CheckPoint Software Development Activities Purposes IT 210 Week 2 CheckPoint Chapter 2 Programming Problem IT 210 Week 2 Assignment Application Level Requirements IT 210 Week 3 CheckPoint Sequential and Selection Processing Control Structure IT 210 Week 3 DQ 1 and DQ 2 IT 210 We...

  9. MGT 210 Uop Material - mgt210dotcom

    honey

    2015-01-01

    MGT 210 Entire Course For more course tutorials visit www.mgt210.com   MGT 210 Week 1 CheckPoint 1 Incident 1-1: Promotion Into Supervision MGT 210 Week 1 CheckPoint 2 Article Review on Diversity in the Workplace MGT 210 Week 1 Assignment Article Search MGT 210 Week 2 CheckPoint Incident 2-2: Bad Times at Quality Shoe MGT 210 Week 2 DQ 1 and DQ 2 MGT 210 Week 3 CheckPoint: Incident 6-2: What Should I Do Next? MGT 210 Week 3 Assignment: Exercise 7-2...

  10. HCR 210 uop / uophelp

    uophelp

    2015-01-01

    HCR 210 Week 1 CheckPoint Patient Self-Determination Act HCR 210 Week 1 DQ 1 and DQ 2 HCR 210 Week 2 CheckPoint Records Administrators and Technicians HCR 210 Week 2 Assignment U.S. Health Care Settings HCR 210 Week 3 CheckPoint Record Formats HCR 210 Week 3 DQ 1     And DQ 2 HCR 210 Week 4 CheckPoint Patient Reports (Appendix C) HCR 210 Week 4 Exercise Career Self-Reflection HCR 210 Week 4 Assignment Interview Data (Appendix B) HCR 210 Week 5 Ch...

  11. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces ∼100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons

  12. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  13. Neutron-Induced Fission of Actinium-227, Protactinium-231 and Neptunium-237: Mass Distribution

    Results of radiochemical studies on the mass distribution in the neutron-induced fission of actinium-227, protactinium-231 and neptunium-237 have been presented. This work has been carried out as part of a programme to determine the mass distribution in the fission of heavy elements as a function of Z and A. All irradiations have been carried out in the core of the swimming-pool type reactor APSARA with cadmium shielding wherever necessary. Relative yields of several fission product nuclides have been obtained by a method involving a comparison of the fission product activities from the respective targets with those formed from uranium-235 simultaneously irradiated. Thermal-neutron fission yields of uranium-235 have been assumed. These results indicate a predominantly asymmetric mass distribution in all the three cases, and also a distinct though small symmetric peak in the case of actinium-227. (author)

  14. A new method for the determination of low-level actinium-227 in geological samples

    We developed a new method for the determination of 227Ac in geological samples. The method uses extraction chromatographic techniques and alpha-spectrometry and is applicable for a range of natural matrices. Here we report on the procedure and results of the analysis of water (fresh and seawater) and rock samples. Water samples were acidified and rock samples underwent total dissolution via acid leaching. A DGA (N,N,N',N'-tetra-n-octyldiglycolamide) extraction chromatographic column was used for the separation of actinium. The actinium fraction was prepared for alpha spectrometric measurement via cerium fluoride micro-precipitation. Recoveries of actinium in water samples were 80 ± 8 % (number of analyses n = 14) and in rock samples 70 ± 12 % (n = 30). The minimum detectable activities (MDA) were 0.017-0.5 Bq kg-1 for both matrices. Rock sample 227Ac activities ranged from 0.17 to 8.3 Bq kg-1 and water sample activities ranged from below MDA values to 14 Bq kg-1of 227Ac. From the analysis of several standard rock and water samples with the method we found very good agreement between our results and certified values. (author)

  15. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  16. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore

  17. Levels of lead-210 (210Pb) and polonium 210 (210Po) in Cuban Tobacco products

    The release of 210Po in tobacco smoke and the radiation dose for man have been studied because of the high incidence of lung cancer among smoker. The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the meted used for 210 Po determination in tobacco products. The Polonium daughter is used to determine both the 210Pb and 210Po using the Baseman equations for radioactive growth and decay. A cigarette contains between 10.6 and 14.7 mBq of 210Pb with an average activity of 13.0 mBq and between 8.5 and 12.3 mBq of 210Po with an average activity of 10.4 mBq for different Cuban cigarette brands. For a person smoking a pack of 20 cigarettes a day, the values of intakes estimated range from 32 to 44 mBq for 210Pb and from 34 to 49 mBq for 210 Po with an average daily intake of 39 mBq for 210 Pb and 42 mBq for 210Po. The annual effective dose estimated due to inhalation of these nuclides contained in cigarette smoke shows a value of 66[Sv and was in correspondence with world-wide range dose, 46 - 90 mSv.year 1 - for tobacco product consumption

  18. HCR 210 Courses/sanptutorial

    genio

    2015-01-01

    HCR 210 Week 1 CheckPoint Patient Self-Determination Act HCR 210 Week 1 DQ 1 and DQ 2 HCR 210 Week 2 CheckPoint Records Administrators and Technicians HCR 210 Week 2 Assignment U.S. Health Care Settings HCR 210 Week 3 CheckPoint Record Formats HCR 210 Week 3 DQ 1     And DQ 2 HCR 210 Week 4 CheckPoint Patient Reports (Appendix C) HCR 210 Week 4 Exercise Career Self-Reflection HCR 210 Week 4 Assignment Interview Data (Appendix B) HCR 210 Week 5 Ch...

  19. MGT 210 UOP Tutorial / Uoptutorial

    roster

    2015-01-01

    MGT 210 Week 1 CheckPoint 1 Incident 1-1: Promotion Into Supervision MGT 210 Week 1 CheckPoint 2 Article Review on Diversity in the Workplace MGT 210 Week 1 Assignment Article Search MGT 210 Week 2 CheckPoint Incident 2-2: Bad Times at Quality Shoe MGT 210 week 2 DQ 1 and DQ 2 MGT 210 Week 3 CheckPoint: Incident 6-2: What Should I Do Next? MGT 210 Week 3 Assignment: Exercise 7-2: “In-Basket” MGT 210 Week 4 CheckPoint: Work Team Concepts MGT 210 week...

  20. BUS 210 Course tutorial/ indigohelp

    WVFD

    2015-01-01

    For more classes visit www.indigohelp.com   BUS 210 Week 1 DQ1 and DQ2 BUS 210 Week 1 Checkpoint Business Models and Systems (2 Sets) BUS 210 Week 1 Knowledge Check BUS 210 Week 2 CheckPoint Business Organization  (2 Sets) BUS 210 Week 2 Knowledge Check BUS 210 Week 2 Assignment Evolution of Business Presentation (2 Sets) BUS 210 Week 3 DQ 1 and DQ 2 BUS 210 Week 3 CheckPoint Code of Ethics (2 Sets) BUS 210 Week 3 Knowledge Check BUS 2...

  1. In-source laser spectroscopy developments at TRILIS—towards spectroscopy on actinium and scandium

    Resonance Ionization Laser Ion Sources (RILIS) have become a versatile tool for production and study of exotic nuclides at Isotope Separator On-Line (ISOL) facilities such as ISAC at TRIUMF. The recent development and addition of a grating tuned spectroscopy laser to the TRIUMF RILIS solid state laser system allows for wide range spectral scans to investigate atomic structures on short lived isotopes, e.g., those from the element actinium, produced in uranium targets at ISAC. In addition, development of new and improved laser ionization schemes for rare isotope production at ISAC is ongoing. Here spectroscopic studies on bound states, Rydberg states and autoionizing (AI) resonances on scandium using the existing off-line capabilities are reported. These results allowed to identify a suitable ionization scheme for scandium via excitation into an autoionizing state at 58,104 cm − 1 which has subsequently been used for ionization of on-line produced exotic scandium isotopes.

  2. 210Po/210Pb equilibrium ratios in Kaveri river ecosystem

    The behaviour of 210Po, the terminal radioactive member of the naturally occurring 238U series is reported to display markedly interesting movement and accumulation behaviour in the aquatic environment, from that of its parent 210Pb. A study was therefore carried out to investigate the status of 210Po/210Pb activity ratios in Kaveri river ecosystem extending from Karur to Grand Anicut (95 km). The paper presents the activity distribution of 210Po and 210Pb, and the observed 210Po/210Pb activity ratios in water, sediment and certain aquatic organisms (plankton, prawn, bivalve and fish) of the river. The aquatic organisms preferentially accumulated more 210Po than 210Pb. The results also demonstrate that while dissolved 210Po/210Pb ratios in river water are less than unity (0.52 - 0.71), there is a gradual enhancement of these ratios in river sediments (1.31 - 1.67) and plankton (5.2). Significantly higher ratios were recorded in higher species like crustacea, mollusca and fish, with a typical range observed from ∼10 to ∼102. The study thus illustrates the active uptake of 210Po than 210Pb by the biotic components of the river. (author). 11 refs., 1 fig., 3 tabs

  3. Concentrations of 207Bi and 210Pb-210Bi-210Po disequilibrium in fish

    Radioactive 207Bi, produced during nuclear testing at the Pacific Proving Grounds, concentrates in the muscle tissue and organs of goatfish and certain pelagic lagoon fish from Bikini and Enewetak Atolls. It is reasonable to expect that fish capable of accumulating 207Bi could also be efficient accumulators of other bismuth isotopes - namely 210Bi, the daughter of naturally occurring 210Pb. Therefore, 210Bi and consequently 210Po, the decay product of 210Bi, would be expected in notable excess over the precursor 210Pb in specific tissues. To test this assumption, we compared concentrations of 210Pb, 210Bi, and 210Po in muscle, liver, and bone separated from some reef species from the Marshall Islands. Concentrations of 210Bi in muscle and liver were found to exceed those of its precursor by factors of 2 to 15. The excess 210Bi in some species, however, is not from the environmental sources (either food or water) from which 207Bi is derived. The data suggest that the excess 210Bi may be translocated to muscle and liver tissue following the decay of 210Pb in bone

  4. Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

    Raeder, S.; Bastin, B.; Block, M.; Creemers, P.; Delahaye, P.; Ferrer, R.; Fléchard, X.; Franchoo, S.; Ghys, L.; Gaffney, L. P.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Luton, F.; Moore, I. D.; Martinez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

    2016-06-01

    To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

  5. {sup 210}Pb and {sup 210}Po in Finnish cereals

    Turtiainen, Tuukka, E-mail: tuukka.turtiainen@stuk.f [STUK, Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland); Kostiainen, Eila, E-mail: eila.kostiainen@stuk.f [STUK, Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland); Hallikainen, Anja, E-mail: anja.hallikainen@evira.f [Finnish Food Safety Authority Evira, Mustialankatu 3, 00790 Helsinki (Finland)

    2011-05-15

    A survey was carried out on the activity concentrations of {sup 210}Pb and {sup 210}Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean {sup 210}Pb/{sup 210}Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg{sup -1}, respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from {sup 210}Pb and {sup 210}Po in cereal products for the adult male and female population are 22 and 17 {mu}Sv per year, respectively.

  6. 210Pb and 210Po activities in French foodstuffs

    The data on 210Pb and 210Po activities in French foodstuffs acquired during the last 15 years are numerous enough to derive reference values which will be usable to assess the dose to the French population due to the intake of these two natural radionuclides. The means and ranges are close to those observed in various countries and are most often higher than the reference values proposed by UNSCEAR. Mussels and oysters exhibit the highest 210Po activities of all kinds of foodstuffs, with a mean value of 27 Bq.kg-1 fresh weight, followed by crustaceans and small fish species (anchovies, mullets, sardines, etc.) with 210Po activities in the order of 3 to 10 Bq.k-1 fresh weight; cephalopods and other fish species presenting activities around 1 to 3 Bq.kg-1 fresh, close to the UNSCEAR reference value. Below these highest 210Po activities are those of 210Po and 210Pb in terrestrial kinds of foodstuffs, by decreasing order: meats (around 1 Bq.kg-1 fresh), cereals (0.4 Bq.kg-1), leafy vegetables (0.3 Bq.kg-1), other vegetables and fruits (0.1 Bq.kg-1), and milk (from 0.03 to 0.1 Bq.L-1). (authors)

  7. Determination of 210Pb and 210Po in cigarette tobacco

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210Pb was determined by counting the beta activity of the 210Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr04. The 210Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for 210Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for 210Po. (author)

  8. Determination of lead-210 in bottom sediments via bismuth-210

    Determination of lead-210 in bottom sediments is applied for evaluation of sedimentation rates and sediments ages by concentration profiles of disequilibrated lead-210 from atmospheric sources. Advances in low level liquid scintillation spectrometry (LS) fitted for natural radioactivity measurements, permit to combine the possibility of immediate bismuth-210 separation with its radioactivity registration using LS spectrometer Quantulus (LKS-1220, Wallak, Finland). The method was tested on bottom sediment samples from Baltic Sea shelf, collected during the 76th cruise of RV 'Academician S. Vavilov'. (author) 6 refs.; 1 tab

  9. Determination of 210Pb, 210Bi and 210Po in natural drinking water

    A new method for the radioanalytical determination of the 222Rn progenies 210Pb, 210Bi and 210Po will be presented, which has been improved for analyses of water samples from different regions in Austria. 1-2 liter samples were taken in polyethylene bottles prefilled with conc. HNO3 to obtain 0.2M acidic solutions, thus avoiding adsorption effects. After adding 1.6 mg of inactive lead carrier, the water sample was evaporated to dryness, converted to the chloride form and dissolved in 1M HCl. From this solution (pH ∼ 1.5) sulfide precipitation was carried out using Na2S (1M). The precipitate was dissolved in HNO3, fumed with HCl and transferred into a phosphate system, which is necessary for extraction of 210Bi and 210Po with Polex TM, a liquid scintillation cocktail suitable for α/β-measurements using pulse shape analysis. Lead-210 was determined via ingrown 210Bi by a second extraction after ∼ 2 weeks. The radiochemical yield of the whole procedure was > 90% determined via lead recovery with AAS. Minimum detectable activities of 0.4 and 1.0 mBq x l-1 could be achieved for 210Po and 210Bi (210Pb), respectively. Results ranged from 1.5-20 mBq x l-1 and more in waters with extremely high 222Rn concentrations. Radon decay during the period between sampling and analysis plays an important role and strongly influences the results. (author)

  10. Diagenesis and 210Pb

    One of the basic questions when studying cores for historical reconstructions of environmental changes is whether the profiles of 210Pb heavy metals and temporal distributions represent actual or have been affected by diagenetic processes. The term refers to processes occurring in the sediment during and after its formation. Such processes can be physical (such as water loss by compaction in clay sludge), biogeochemical (as the decomposition of organic matter) or biological (eg the ingestion of sediments by infauna.) In this chapter we will refer specifically to diagenetic processes caused by the establishment of a vertical zonation of redox conditions and their effects on concentrations of Fe, Mn and other redox-sensitive metals associated. The redox conditions (defined redox potential Eh) of sediments are primarily controlled by the bacterial decomposition of sedimentary organic matter, and are limited by the rate of supply of organic matter (primary production or other sources) and the rate at that accumulates (rate of accumulation of organic matter). During the bacterial decomposition occurs a sequence of reactions involving a succession of oxidants (or electron acceptors) between which the primary oxidant is O2. However, when the dissolved O2 is consumed and the redox potential has decreased enough to favor the most efficient oxidizing the organic matter decomposition can continue through secondary sources of oxidants (suboxic diagenesis).

  11. Special hydrogen target (Prop. 210)

    This guide contains a description of the electrical control and automatic vacuum systems for the Special Hydrogen Target (Prop. 210) together with the flow diagram and the mimic control panel layout for the system. (U.K.)

  12. 7 CFR 210.13 - Facilities management.

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Facilities management. 210.13 Section 210.13... Participation § 210.13 Facilities management. Link to an amendment published at 74 FR 66216, Dec. 15, 2009. (a..., the added text is set forth as follows: § 210.13 Facilities management. (c) Food safety program....

  13. Sequential and rapid determination of Po-210, Bi-210 and Pb-210 in natural waters.

    Tokieda, T; Narita, H; Harada, K; Tsunogai, S

    1994-12-01

    A sequential and rapid separation method for the determination of radon daughter nuclides, Pb-210, Bi-210 and Po-210 has been developed for application to natural waters. Rapid separation is attained by the use of the same hydrochloric acid solution. After isolation of the three radionuclides from the sample by co-precipitation with added Fe(3+), polonium isotopes are first spontaneously deposited onto a silver disc from a 0.5N hydrochloric acid solution. Next, bismuth isotopes are electrodeposited onto a platinum net cathode coupled with a platinum coil anode at 1.2 V. Finally, lead isotopes are electrodeposited onto a platinum net cathode at 1.8 V from the remaining solution by adding hydroxylamine hydrochloride as an anodic depolarizer. This method can be applied to meteorological precipitation samples where these three nuclides are separated within 10 hr after the sampling with chemical yields of more than 80% for Po-210 and Bi-210 and more than 70% for Pb-210. This method is applicable to other environmental water samples. PMID:18966174

  14. Polonium-210 as Weapon for Mass Destruction

    Properties of Po-210 make it possible for its use as weapon of mass destruction. Po-210 occurs naturally in minute quantities in the human body, in Uranium ore (< 0.1 mg Po-210 / ton ) and as a product of Radon-222 gas decay chain. Po-210 also occurs as deposition on vegetation (tobacco leaves). Po-210 is produced by bombardment of Bi-209 with neutrons in a nuclear reactor. Russia produces 8 grams per year for export to USA market

  15. Models dated by 210Pb

    The 210Pbex present in sediments, regardless of their origin, decays following the law of radioactive decay. If the rate of sediment accumulation and flow of 210Pb are constant and there are no redistribution processes of 210Pbex in the sediment, a profile of 210Pbex should be perfectly exponential. Although some of these conditions are not met in all cases and observed profiles are rarely found perfect exponentials, models dated by 210Pb described in this chapter allow to obtain valid dated. Anyway, the models described should be seen as tools of interpretation and the dates obtained as estimates to be corroborated by alternative observations. It is recommended to the reader to go deeper into the topics discussed in this chapter reading references and bibliography at the end. Throughout, the closed system hypothesis must be met. For dating of sediments implies that the radionuclide used is integrated into the matrix tested unaffected by redistribution processes. No cases of mixed sediments or showing evidence of mobility by diagenesis are addressed in this chapter, although we believe that in some circumstances estimates of the accumulation rates are provided but not of the age of formation. Starting with the first published use of 210Pb as a tool dating ice cores, different authors develop model conditions adapted to the dating of sediments. In this chapter we describe the most widely used models, which are based on assumptions about the flow of 210Pbex the sediment surface, the rate of accumulation and concentration of initial210Pbex in surface sediments. The models describing nomenclatures have been different and even contradictory. To facilitate reading of the chapter we propose a nomenclature based on the fundamental assumptions of each model (not in implementation) and have homogenised the nomenclature used. While the model most commonly used for dating sediments is the CF (Constant Flux - Constant Flow), commonly known as CRS (Constant Rate of Supply), the

  16. Atmospheric depositions of 210Pb and 210Po in Lisbon, Portugal

    The long lived radon daughters 210Pb and 210Po were determined in samples of total surface deposition obtained with collectors continuously operated during 5 years, near Lisbon. The annual 210Pb flux was 66±12 Bqm-2, and the average annual 210Po flux was 8±3 Bq m-2, with an overall 210Po/210Pb activity ratio of 0.15±0.06. The deposition of 210Pb was positively correlated with seasonal rainfall, while 210Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high 210Po/210Pb activity ratios, higher than unity, were occasionally recorded and the sources and causes are discussed. Long time-series of 210Pb and 210Po deposition fluxes, as presented herein, are rare although essential to test and constrain parameter of the atmospheric Global Circulation Models. (author)

  17. Multi-year Surface Deposition of {sup 210}Pb and {sup 210}Po at Lisbon - Atmospheric Depositions of {sup 210}Pb and {sup 210}Po in Lisbon, Portugal

    Carvalho, Fernando P.; Oliveira, Joao M.; Alberto, G. [Instituto Superior Tecnico/ Campus Tecnologico e Nuclear, Universidade Tecnica de Lisboa, E.N. 10, 2686-953 Sacavem (Portugal)

    2014-07-01

    The long lived radon daughters {sup 210}Pb and {sup 210}Po were determined in samples of total atmospheric depositions obtained with surface collectors continuously operated during 5 years, near Lisbon. The average annual {sup 210}Pb flux was 66±12 Bq m{sup -2}, and the average annual {sup 210}Po flux was 8±3 Bq m{sup -2}, with an overall {sup 210}Po/{sup 210}Pb activity ratio of 0.15±0.06. Direct determination of the {sup 210}Pb atmospheric flux was compared with the {sup 210}Pb excess determined in soil surface layers along with atmospheric depositions of {sup 137}Cs. The deposition of atmospheric {sup 210}Pb was positively correlated with seasonal rainfall, while {sup 210}Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high {sup 210}Po/{sup 210}Pb activity ratios, higher than unity, were occasionally recorded in atmospheric depositions and the sources and causes are discussed. Long time-series of {sup 210}Pb and {sup 210}Po deposition fluxes, as presented herein are useful to test and constrain parameters of the atmospheric Global Circulation Models. (authors)

  18. Multi-year Surface Deposition of 210Pb and 210Po at Lisbon - Atmospheric Depositions of 210Pb and 210Po in Lisbon, Portugal

    The long lived radon daughters 210Pb and 210Po were determined in samples of total atmospheric depositions obtained with surface collectors continuously operated during 5 years, near Lisbon. The average annual 210Pb flux was 66±12 Bq m-2, and the average annual 210Po flux was 8±3 Bq m-2, with an overall 210Po/210Pb activity ratio of 0.15±0.06. Direct determination of the 210Pb atmospheric flux was compared with the 210Pb excess determined in soil surface layers along with atmospheric depositions of 137Cs. The deposition of atmospheric 210Pb was positively correlated with seasonal rainfall, while 210Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high 210Po/210Pb activity ratios, higher than unity, were occasionally recorded in atmospheric depositions and the sources and causes are discussed. Long time-series of 210Pb and 210Po deposition fluxes, as presented herein are useful to test and constrain parameters of the atmospheric Global Circulation Models. (authors)

  19. Analysis of human teeth for Pb-210 and Po-210

    The cumulative radon daughter exposure of miners in units of working level months is estimated by measuring the Pb-210 content of their teeth. The exposure value so estimated agrees reasonably well with measured working levels. The exposure of coal miners is not significant

  20. BUS 210 UOP Course Tutorial/ Tutorialrank

    john

    2015-01-01

                      For more course tutorials visit www.tutorialrank.com Tutorial Purchased: 6 Times, Rating: A+   BUS 210 Week 1 DQ1 and DQ2 (UOP Course) BUS 210 Week 1 Checkpoint Business Models and Systems (UOP Course) BUS 210 Week 2 CheckPoint Business Organization (UOP Course) BUS 210 Week 2 Assignment Evolution of Business Presentation (UOP Course) BUS 210 Week 3 DQ 1 and DQ 2 (UOP Course) BUS 210 W...

  1. Spatial and depth variation of 210Po and 210Pb in monazite sand along HBRA of coastal Kerala

    The samples collected from high background radiation area were analyzed for 210Po and 210Pb activities in order to understand their distribution, enrichment and depth profile in the beach sand. The 210Po and 210Pb activities vary from 1.85 to 31.27 Bq kg-1 and 9.77 to 132.30 Bq kg-1 respectively. The 210Po/210Pb indicate that the radionuclides 210Po and 210Pb are not in equilibrium and the accumulation of 210Pb in sand is greater than for 210Po. The spatial variations of 210Po and 210Pb activities were studied in detail. (author)

  2. Atmospheric residence time of (210)Pb determined from the activity ratios with its daughter radionuclides (210)Bi and (210)Po.

    Semertzidou, P; Piliposian, G T; Appleby, P G

    2016-08-01

    The residence time of (210)Pb created in the atmosphere by the decay of gaseous (222)Rn is a key parameter controlling its distribution and fallout onto the landscape. These in turn are key parameters governing the use of this natural radionuclide for dating and interpreting environmental records stored in natural archives such as lake sediments. One of the principal methods for estimating the atmospheric residence time is through measurements of the activities of the daughter radionuclides (210)Bi and (210)Po, and in particular the (210)Bi/(210)Pb and (210)Po/(210)Pb activity ratios. Calculations used in early empirical studies assumed that these were governed by a simple series of equilibrium equations. This approach does however have two failings; it takes no account of the effect of global circulation on spatial variations in the activity ratios, and no allowance is made for the impact of transport processes across the tropopause. This paper presents a simple model for calculating the distributions of (210)Pb, (210)Bi and (210)Po at northern mid-latitudes (30°-65°N), a region containing almost all the available empirical data. By comparing modelled (210)Bi/(210)Pb activity ratios with empirical data a best estimate for the tropospheric residence time of around 10 days is obtained. This is significantly longer than earlier estimates of between 4 and 7 days. The process whereby (210)Pb is transported into the stratosphere when tropospheric concentrations are high and returned from it when they are low, significantly increases the effective residence time in the atmosphere as a whole. The effect of this is to significantly enhance the long range transport of (210)Pb from its source locations. The impact is illustrated by calculations showing the distribution of (210)Pb fallout versus longitude at northern mid-latitudes. PMID:27132252

  3. 7 CFR 210.3 - Administration.

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration. 210.3 Section 210.3 Agriculture... CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.3 Administration. (a) FNS. FNS will act on behalf of the Department in the administration of the Program. Within FNS, the CND will...

  4. 32 CFR 210.3 - Policy.

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Policy. 210.3 Section 210.3 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS ENFORCEMENT OF STATE TRAFFIC LAWS ON DOD INSTALLATIONS § 210.3 Policy. (a) It is the policy of the Department...

  5. 20 CFR 498.210 - Fees.

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Fees. 498.210 Section 498.210 Employees... § 498.210 Fees. The party requesting a subpoena will pay the cost of the fees and mileage of any witness.... A check for witness fees and mileage will accompany the subpoena when served, except that when...

  6. 46 CFR 179.210 - Collision bulkhead.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Collision bulkhead. 179.210 Section 179.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) SUBDIVISION, DAMAGE STABILITY, AND WATERTIGHT INTEGRITY Subdivision and Damage Stability Requirements § 179.210 Collision bulkhead. (a) A vessel...

  7. 40 CFR 240.210-1 - Requirement.

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Requirement. 240.210-1 Section 240.210... THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.210-1 Requirement... the design requirements. An operations manual describing the various tasks to be performed,...

  8. 5 CFR 179.210 - Special review.

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Special review. 179.210 Section 179.210 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CLAIMS COLLECTION STANDARDS Salary Offset § 179.210 Special review. (a) An OPM employee subject to salary offset or a...

  9. 40 CFR 211.210 - Requirements.

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Requirements. 211.210 Section 211.210 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRODUCT NOISE LABELING Hearing Protective Devices § 211.210 Requirements....

  10. 40 CFR 210.1 - Purpose.

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Purpose. 210.1 Section 210.1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRIOR NOTICE OF CITIZEN SUITS § 210.1 Purpose. Section 12 of the Noise Control Act authorizes any person...

  11. 7 CFR 210.14 - Resource management.

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Resource management. 210.14 Section 210.14 Agriculture... Participation § 210.14 Resource management. (a) Nonprofit school food service. School food authorities shall.... Expenditures of nonprofit school food service revenues shall be in accordance with the financial...

  12. 12 CFR 347.210 - Asset maintenance.

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Asset maintenance. 347.210 Section 347.210 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY INTERNATIONAL BANKING Foreign Banks § 347.210 Asset maintenance. (a) An insured branch of a foreign bank...

  13. 32 CFR 210.4 - Responsibilities.

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Responsibilities. 210.4 Section 210.4 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS ENFORCEMENT OF STATE TRAFFIC LAWS ON DOD INSTALLATIONS § 210.4 Responsibilities. (a) The Assistant...

  14. 47 CFR 90.210 - Emission masks.

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (m)...

  15. 7 CFR 65.210 - Person.

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Person. 65.210 Section 65.210 Agriculture Regulations... MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) COUNTRY OF ORIGIN LABELING OF BEEF..., AND GINSENG General Provisions Definitions § 65.210 Person. Person means any individual,...

  16. 28 CFR 36.210 - Smoking.

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Smoking. 36.210 Section 36.210 Judicial... COMMERCIAL FACILITIES General Requirements § 36.210 Smoking. This part does not preclude the prohibition of, or the imposition of restrictions on, smoking in places of public accommodation....

  17. 6 CFR 27.210 - Submissions schedule.

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Submissions schedule. 27.210 Section 27.210... STANDARDS Chemical Facility Security Program § 27.210 Submissions schedule. (a) Initial Submission. The... Schedule for Covered Facilities. The timeframes in this subsection also apply to covered facilities...

  18. 46 CFR 132.210 - Classification.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Classification. 132.210 Section 132.210 Shipping COAST... Portable and Semiportable Fire Extinguishers § 132.210 Classification. (a) Each portable fire extinguisher... Classification Type Size Halon 1211, 1301, and 1211-1301 mixtures kgs. (lbs.) Foam, liters (gallons)...

  19. 31 CFR 210.3 - Governing law.

    2010-07-01

    ...) and 1 CFR part 51. Copies of the “2007 ACH Rules” are available from NACHA—The Electronic Payments... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Governing law. 210.3 Section 210.3... CLEARING HOUSE § 210.3 Governing law. (a) Federal law. The rights and obligations of the United States...

  20. 19 CFR 210.37 - Evidence.

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Evidence. 210.37 Section 210.37 Customs Duties... ADJUDICATION AND ENFORCEMENT Prehearing Conferences and Hearings § 210.37 Evidence. (a) Burden of proof. The.... (b) Admissibility. Relevant, material, and reliable evidence shall be admitted....

  1. Behaviors of 210Pb and 210Po around hydrothermal vents in the Okinawa Trough

    杨永亮; 日下部正志; 山本惠幸

    2002-01-01

    Vertical profiles for the uranium-series radioisotopes 210Pb and 210Po were obtained at the two hydrothermal vent sites, the Iheya Ridge and the Minami-Ensei Knoll, in the Mid-Okinawa Trough in 1993 and 1994, respectively. In 1995, both radioisotopes were measured at the Minami-Ensei Knoll again. At the Iheya Ridge, where the hydrothermal activity is not active as reflected by the CH4 and 222Rn data, both the total 210Pb and 210Po activities show deficiency relative to their parents, and the mean residence time of 210Pb and 210Po is approximately equal to 20 and 2~ 5 a, respectively. At the Minami-Ensei Knoll, which is characterized by black smokers, the total 210Pb(0.167 × 10-3 ~2.5 × 10-3 Bq/kg) around the plumes is deficient relative to 226Ra but the total 210Po activities ( 1.83 × 10- 3 ~ 2.83× 10-3 Bq/kg) are in excess relative to 210Pb. The 210Po activities are higher than those in the East China Sea and the Okinawa Trough and excess 210Po has been found. The 210Pb/226Ra and 210Po/210Pb activity ratios are 0.1~ 0.4 and 1.1 ~ 7.8, respectively. 210Pb is preferentially scavenged in the hydrothermal plumes. The possible mechanisms governing the concentration of 210Pb in the Minami-Ensei Knoll involve a lateral transport of 210Pb via diffusion. The high 210Po/210Pb activity ratios in the hydrothermal plumes suggest a depletion of 210Pb and addition of 210Po in the hydrothermal vent area.

  2. 210Po and 210Pb activity concentration in the coral bands of Pulau Tuba, Langkawi

    We examined the concentrations of 210Po and 210Pb in each layers of coral banding of coral skeletons. Concentrations of 210Po and 210Pb in massive corals (i.e. Porites, Favites, Platygyra and Goniostrea) from Pulau Tuba, Langkawi were measured using the Alpha-Spectrometry. The concentrations of 210Po were higher than the concentrations of 210Pb. This may due to continuing source of 210Po from 210Pb. Highest concentration on 210Po in coral banding was 48.30 ± 28.53 Bq/ kg, meanwhile for 210Pb was 12.86 ± 5.80 Bq/ kg. The ratios of 210Po/ 210Pb were in the range of 2.21 to 5.49. The variation activity concentrations of 210Po and 210Pb in the coral bands are important to consider in using coral as retrospective study of environmental changes. The coral can represent the total of 210Po and 210Pb in the surrounding water for the past few years. (author)

  3. An evaluation of the exposure to 210Pb-210Po in italian population

    Following an introduction on the behaviour in the environment and in man of 210Pb-210Po, experimental data are reported on 210Pb-210Po exposure of the italian population. The analytical methods used to measure 210Pb-210Po activity in the many biological and environmental samples analyzed are also reported. The data collected refer to the intake, excretion, internal burden and metabolism both in a group of subjects representative of the general population and in other critical groups exposed to high internal contamination of 210Pb-210Po, as the radioactive spa wopkes and the miners. The absorbed dose due to 210Pb-210Po has also been evaluated, on the basis of data referring to the various population groups

  4. Decay/ingrowth uncertainty correction of 210Po/210Pb in seawater

    Due to increasing application of 210Po/210Pb in studying particle dynamics, a consistent procedure and calculation to derive accurate and precise result of 210Po and 210Pb in seawater should be proposed in the framework of intercalibration by GEOTRACES. The associated uncertainty of radioactivity, which is a significant component of data report, plays a vital role in intercomparison and should be well evaluated. Although measurement uncertainty of laboratory result was well defined in ISO standards and IAEA technical documents, the decay/ingrowth uncertainty correction from laboratory result to in-situ result was less studied. It was demonstrated that the relative uncertainty of in-situ 210Pb activity was independent of elapsed time and equal to relative uncertainty of laboratory measuring 210Po activity at second spontaneous deposition date. The relative uncertainty of in-situ 210Po activity decreases with in-situ activity ratio of 210Po to 210Pb and increases with elapsed time between sampling date and separation date, relative uncertainty of laboratory measuring 210Po activity at first spontaneous deposition date and relative uncertainty of in-situ 210Pb activity. It was more important to improve precision of 210Po at first spontaneous deposition date than that of 210Po at second spontaneous deposition date. To obtain a desirable relative uncertainty of in-situ 210Po activity, the maximum allowing elapsed time for 210Po, which was important for sampling strategy making and quality assurance, was calculated by in-situ activity ratio of 210Po to 210Pb and precision of analytical method for 210Po. The methodology of decay/ingrowth uncertainty correction could also be applied for other radionuclide pairs (234Th/238U, 90Y/90Sr, 210Bi/210Pb), sample matrixes (aerosols), and disciplines. - Highlights: • Uncertainty of 210Po/210Pb in seawater was comprehensively represented. • Decay/ingrowth uncertainty correction was well quantified and concisely expressed.

  5. 210Pb and 210Po in tobacco - with a special focus on estimating the doses of 210Po to man

    Inhalation of tobacco smoke is ranked second to food as a source of 210Pb and 210Po exposure to man. assay of 210Pb and 210Po in commercially available tobacco collected from many countries have been carried out to assess the potential risk from 210Po present in tobacco. The range of 210Po contained in the tobacco grands varied from 10.08 to 15.0 mBq/tob or 13.0 to 20.1 mBq/g and the mean was 11.6 mBq/tob or 15.4 mBq/g. During the International Standard Smoking process about 50% of 210Po present in tobaccos was transferred into the smoke and the other 50% remained in the ash and butt. About 10% of the total 210Po of tobacco was inhaled by smoke through mainstream smoke. One pack-a-day smoker inhaled 24 mBq of 210Po per day through smoking and the annual inhalation was 8.8 Bq. The risk of mortality from lung cancer caused by 210Po in tobaccos was 18 per million persons for the above model. (author) 6 refs.; 1 fig.; 4 tabs

  6. Groundwater seepage from the Ranger uranium mine tailings dam: radioisotopes of radium, thorium and actinium. Supervising Scientist report 106

    Monitoring of bores near the Ranger uranium mine tailings dam has revealed deterioration in water quality in several bores since 1983. In a group of bores to the north of the dam, increases have been observed of up to 500 times for sulphate concentrations and of up to 5 times for 226Ra concentrations. Results are presented here of measurements of members of the uranium, thorium and actinium decay series in borewater samples collected between 1985 and 1993. In particular, measurements of all four naturally-occurring radium isotopes have been used in an investigation of the mechanism of radium concentration changes. For the most seepage-affected bores the major findings of the study include: 228Ra/226Ra 223Ra /226Ra and 224Ra/228Ra ratios all increased over the course of the study; barium concentrations show high seasonal variability, being lower in November than May, but strontium concentrations show a steady increase with time. Calculations show that the groundwater is probably saturated with respect to barite but not with respect to celestite or anglesite; sulphide concentrations are low in comparison with sulphate, and are higher in November than in May; and 227Ac concentrations have increased with time, but do not account for the high 223Ra/226Ra ratios. It is concluded on the basis of these observations that increases in Ra isotope concentrations observed in a number of seepage-affected bores arise from increases in salinity leading to desorption of radium from adsorption sites in the vicinity of the bore rather by direct transport of radium from the tailings. Increased salinity is also causing the observed increases in 227Ac and strontium concentrations, while formation of a barite solid phase in the groundwater is causing the removal of some radium from solution. This is the cause of the increasing radium isotope ratios noted above

  7. 17 CFR 210.1-02 - Definitions of terms used in Regulation S-X (17 CFR part 210).

    2010-04-01

    ... Regulation S-X (17 CFR part 210). 210.1-02 Section 210.1-02 Commodity and Securities Exchanges SECURITIES AND... (17 Cfr Part 210) § 210.1-02 Definitions of terms used in Regulation S-X (17 CFR part 210). Unless the... this chapter) such that there is a reasonable possibility that a material misstatement of...

  8. Exposure of cuban population due to dietary intake of lead 210 and polonium 210

    Data are presented on the concentrations of 210Pb and 210Po in potable water and different food items collected from various locations in Cuba. The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the method used for 210Po determination in foods and water. The Polonium daughter is used to determine both the 210Pb and 210Po using the Bateman equations for radioactive growth and decay. The average 210Pb and 210Po concentration in potable water was 3 and 2 mBq.l-1, respectively and concentration in total diet averaged 47.7 mBq.kg-1 for 210Pb and 131.9 mBq.kg-1 for 210Po. The annual effective dose estimated due to ingestion of these nuclides contained in foods and potable water reported a value of 77.7 [Sv corresponding the 95.7 % to the food consuming

  9. Degassing dynamics at Mount Etna inferred from radioactive disequilibria (210Pb-210Bi-210Po) in volcanic gases

    Terray, Luca; Gauthier, Pierre-Jean; Salerno, Giuseppe; La Spina, Alessandro; Giammanco, Salvatore; Sellitto, Pasquale; Briole, Pierre

    2016-04-01

    Volcanic gases are significantly enriched in the last short-half-life radionuclides of the 238U series, namely the so-called Radon daughters 210Pb, 210Bi and 210Po. Because of their contrasted volatilities, these isotopes are strongly fractionated upon degassing, which gives rise to significant radioactive disequilibria between them in the gas phase. These disequilibria carry precious information on shallow degassing processes beneath active volcanoes: they remarkably constrain the magma residence time in the degassing reservoir and the duration of gas extraction from magma to surface. On Mount Etna (Sicily), where the study of these disequilibria was initiated thirty years ago (Lambert et al., EPSL, 1985-86), no measurement of 210Pb, 210Bi and 210Po in the gases has been performed for the last twenty years. Here we present new 210Pb-210Bi-210Po radioactive disequilibria measurements in volcanic plume gases of Mount Etna. Samples were collected in the bulk diluted plume at kilometric distance from the summit area during the May 2015 eruption, then in more concentrated plumes arising from each summit crater of Etna during quiescent degassing in July 2015. We found values of (210Bi/210Pb) = 7.0 ± 0.3 and (210Po/210Pb) = 80 ± 6 during both periods. These results suggest that 210Pb, 210Bi and 210Po are not significantly fractionated during the transport of the plume from the crater rim to close-downslope sites (<1 km). None of the previous degassing models (Lambert et al., EPSL, 1985-86 ; Gauthier et al., JVGR, 2000) satisfactorily explain measured activity ratios. We propose here a new degassing model based on the previous conceptualization designed for basaltic open-conduit volcanoes, like Stromboli. This model considers extreme Radon enrichments in volcanic gases as a source of 210Pb atoms produced by radioactive decay of 222Rn within gas bubbles travelling to surface. We constrain a magma residence time of 470 ± 170 days and an extraction time of the gases of 4

  10. 210Po and 210Pb in soils and vegetables in Kucuk Menderes basin of Turkey

    In this study concentrations of 210Po and 210Pb radionuclides in soils and vegetables collected from both cultivated and uncultivated agricultural lands of the Kucuk Menderes basin were determined. 210Po and 210Pb activity concentrations of vegetables collected from cultivated lands were found to be slightly higher than those collected from undisturbed lands. The activity concentrations in vegetables were detected between 0.15-9.40Bqkg-1 and 0.23-0.62Bqkg-1 for 210Po and 210Pb, respectively. In the bulk soil cores sampled from phosphate fertilizer-applied agricultural lands, the ranges for activity concentrations of 210Po and 210Pb are 30.10-47.15Bqkg-1 and 31.27-61.53Bqkg-1, respectively. 210Po and 210Pb activity concentrations in soil cores collected from uncultivated soils were also determined for comparison. The annual effective dose equivalents to man from 210Po and 210Pb due to consumption of leafy vegetables are calculated to be 30.51 and 22.73μSva-1, respectively. Likewise root vegetables give a dose equivalent of 22.89μSva-1 from 210Po and 44.77μSva-1 from 210Pb

  11. Po-210 and Pb-210 in water and fish from Taboshar uranium mining Pit Lake, Tajikistan

    Polonium-210 in water and 210Pb and 210Po in different fish organs from 3 different fish species in Taboshar Pit Lake (n = 13), located in the uranium mining area in Tajikistan, and in Kairakkum Reservoir (reference lake, n = 3), have been determined as part of a Joint project between Norway, Kazakhstan, Kyrgyzstan and Tajikistan. The average activity concentration of 210Pb and 210Po in liver, muscle and bone of Carassius auratus was higher than the concentration in similar tissues of C. carpio and Sander lucioperca from the reference site. The accumulation of 210Po was higher than for 210Pb, and the accumulation of 210Po was highest in the liver of C. auratus (3673 ± 434 Bq kg−1 ww). Although the average activity concentration of 210Pb in liver and bones of C. auratus from Pit Lake were fairly similar, a huge variation in the liver activity concentrations (25–327 Bq kg−1 ww) was found. The results confirm direct uptake of unsupported 210Po into the liver, and that the distributions of 210Po and 210Pb in fish organs were different. The BCF (L/kg) for 210Po in bone, liver and muscle clearly demonstrates high accumulation of 210Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 105, >2.5 × 104 and >1.4 × 104, respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210Po in liver and δ15N could indicate biomagnification of 210Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210Po, the concentration of 210Po in muscle tissues of C. auratus is alarming, as there is a high probability for the local population at risk to exceed the recommended ALI through consumption of fish from Taboshar Pit Lake

  12. Research to improvement of the definition of 210 Po and 210 Pb in deposition

    Investigation to the improvement of the determination of 210Po and 210Pb in deposition. The results of the determination of 210Po and 210Pb in deposition in 1995 do not meet the criteria specified. The chemical recovery of the 208Po tracer added is by many analyses less than the required 50%. The cause of the poor chemical recovery is investigated. This report describes the execution of the investigation and the results. The investigation has led to the improvement of the determination of 210Po and 210Pb in deposition. 12 refs

  13. Contribution to the study of polonium-210 and lead-210 in marine organisms and their environment

    The following topics were emphasized: the role of 210Po as a major source of natural radiation dose received by marin organisms; the contribution of 210Po to the total α radioactivity in the hepatopancreas of crustaceans or mollusc cephalopods is more than 95%; in the euphausiid Meganyctiphanes norvegica, the main source of 210Po is the food they consume; the possible use of 210Po as a natural biological tracer of the feeding of deep-sea mesopelagic animals; the 210Po/210Pb ratio is a good indicator of the importance of biological processes in the marine environment

  14. Separation of 210Pb, 210Bi and 210Po by ion exchange and their Iiquid scintillation standardization

    We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''TM II, HiSafe''TM III, Ultima-Gold''TM, Ultima-Gold''TM XR, Ultima-Gold''TM AB, Insta-Gel''R and e Insta-Gel''R lI. Also we analyzed the disequilibrium of the radioactive chain 210Pb+210Bi+210Po, achieving an excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs

  15. Separation of 210 Pb, 210 Bi and 210 Po by ion exchange and their liquid scintillation standardization

    We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210 Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''tm II, HiSafe''tmIII, Ultima-Gold''tm, Ultima-Gold''tmXR, Ultima-Gold''tmAB, Insta-Gel and e Insta-Gel II. Also we analyzed the disequilibrium of the radioactive chain ''210Pb+''210Bi+''210Po, achieving and excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs

  16. Metabolism of 210Po in rats: Volatile 210Po in excreta

    Polonium-210 (210Po) is one of the most toxic radionuclides and was used as a poison in the Alexander Litvinenko case. In this study of the metabolism of 210Po in rats, volatile 210Po in excreta was measured, filling a knowledge gap of the previous studies. Five rats were intravenously administrated with 2 kBq and another five with 10 kBq of 210Po (citrate form). They were housed in a glass MetabowlR system for 4 d following the administration. Volatile 210Po from the excreta was collected in a trapping system filled with liquid scintillation cocktail and was measured by liquid scintillation counting. Results showed that the daily excretion of volatile 210Po by the rats is in a very small percentage (0.002-0.009%) of the administered amounts. However, if the administered amount is large, the excretion of volatile 210Po can be significant. (authors)

  17. Analysis of 210Pb and 210Po in Brazilian foods and diets

    Radiochemical procedures for the analysis of 210Pb and 210Po in foods and diets are presented. Because of the low beta energy of 210Pb, its analysis was based on a separation of the daughter radionuclide 210Bi by precipitation of lead sulphate, 210Bi ingrowing and beta counting of this nuclide. 210Po analysis was based on wet dissolution of the sample, deposition onto silver disc and counting by alpha-spectrometry. Levels of these radionuclides in individual items and diets of selected university students were determined in order to evaluate the intakes of 210Pb and 210Po as well as the dose due to ingestion of foods and diets in Sao Paulo city. (author)

  18. Determination of 210Pb e 210Po in marine samples and aerosols

    In this work the methodologies for 210Pb e 210Po analyses in marine samples, such as fish, seaweed, sediment, and aerosol samples are presented. The 210Pb levels in the samples were obtained by both210Bi and 210Po ingrowth. The 210Pb analysis via 210Bi presents the following steps: 210Pb leaching from samples with 8 M nitric acid and hydrogen peroxide; lead sulphate precipitation; conversion to carbonate; dissolution; lead sulphate precipitation; gravimetric analysis of lead; waiting of time to reach radioactive equilibrium and 210Bi beta counting by employing a Geiger-Mueller detector with a low background radiation. The 210Pb analysis via 210Po presents the following steps: 210Pb and 210Po leaching from samples with 8 M nitric acid and hydrogen peroxide; nitric acid elimination by heating and hydrochloric acid addition; spontaneous deposition onto silver disc and alpha counting of polonium in silicon surface-barrier detector. In order to determine 210Pb activity, the solution was percolated in the Dowex AG 1-X 8 anion exchange resin; preconditioned with 8 M nitric acid; the lead was eluted by 8 M hydrochloric acid; the solution was gently evaporated to dryness and diluted with 0.5 N hydrochloric acid. After 3-6 months a second 210Po spontaneous deposition onto silver disc was carried out. The methodology for 210Pb analysis via 210Bi showed lead recoveries from 63 to 100%. In the method via 210Po the polonium recoveries were varied from 39 to 63% under manual agitation, and from 60 to 100% under mechanical agitation. The radiochemical methods for 210Po and 210Pb analyses were applied in reference samples from International Atomic Energy Agency (IAEA) and the results obtained showed the good precision and accuracy of the established methods. The analysis of marine sediment samples of Antarctica presented 210Pb and Po levels from 8 to 60 Bq.kg-1, and fish samples from Sao Paulo Coast presented 210Po levels from 0.5 to 5.3 Bq.kg-1. These results for fish are

  19. Polonium-210 and lead-210 in the terrestrial environment: a historical review.

    Persson, Bertil R R; Holm, Elis

    2011-05-01

    The radionuclides (210)Po and (210)Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of (238)U in the earth's crust. Their presence in the atmosphere is due to the decay of (222)Rn diffusing from the ground. The range of activity concentrations in ground level air for (210)Po is 0.03-0.3 Bq m(-3) and for (210)Pb 0.2-1.5 Bq m(-3). In drinking water from private wells the activity concentration of (210)Po is in the order of 7-48 mBq l(-1) and for (210)Pb around 11-40 mBq l(-1). From water works, however, the activity concentration for both (210)Po and (210)Pb is only in the order of 3 mBq l(-1). Mosses, lichens and peat have a high efficiency in capturing (210)Po and (210)Pb from atmospheric fallout and exhibit an inventory of both (210)Po and (210)Pb in the order of 0.5-5 kBq m(-2) in mosses and in lichens around 0.6 kBq m(-2). The activity concentrations in lichens lies around 250 Bq kg(-1), dry mass. Reindeer and caribou graze lichen which results in an activity concentration of (210)Po and (210)Pb of about 1-15 Bq kg(-1) in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of (210)Po and (210)Pb in humans. The effective annual dose due to (210)Po and (210)Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 μSv a(-1) respectively. In soils, (210)Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of (210)Po in various soils are in the range of 20-240 Bq kg(-1). Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of (210)Po is particularly high as the result of the

  20. Polonium-210 and lead-210 in the terrestrial environment: a historical review

    The radionuclides 210Po and 210Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of 238U in the earth's crust. Their presence in the atmosphere is due to the decay of 222Rn diffusing from the ground. The range of activity concentrations in ground level air for 210Po is 0.03-0.3 Bq m-3 and for 210Pb 0.2-1.5 Bq m-3. In drinking water from private wells the activity concentration of 210Po is in the order of 7-48 mBq l-1 and for 210Pb around 11-40 mBq l-1. From water works, however, the activity concentration for both 210Po and 210Pb is only in the order of 3 mBq l-1. Mosses, lichens and peat have a high efficiency in capturing 210Po and 210Pb from atmospheric fallout and exhibit an inventory of both 210Po and 210Pb in the order of 0.5-5 kBq m-2 in mosses and in lichens around 0.6 kBq m-2. The activity concentrations in lichens lies around 250 Bq kg-1, dry mass. Reindeer and caribou graze lichen which results in an activity concentration of 210Po and 210Pb of about 1-15 Bq kg-1 in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of 210Po and 210Pb in humans. The effective annual dose due to 210Po and 210Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 μSv a-1 respectively. In soils, 210Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of 210Po in various soils are in the range of 20-240 Bq kg-1. Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of 210Po is particularly high as the result of the direct deposition of 222Rn daughters from atmospheric deposition

  1. Example dated with 210Pb

    In this chapter we describe in detail, using an example, the procedure to date a core with the technique of 210Pb using the models described in Chapter 7. Described below, one by one, the spreadsheets containing the information and calculations necessary to complete a profile geochronology of 210Pb core adapted from Gulf of Tehuantepec, Mexico. In this case, the old model obtained from the CA model could not be validated with 137Cs because the peak age of 137Cs is too old (1985 ± 3 years). Moreover, there was an investment of age between sections 2-3 and 3-4 cm because the activity of the lower section is higher than at the top, most likely due to a change in sediment accumulation. The average value of MAR (obtained with the CFCS model: 0.222 ± 0.016 g cm-2 yr-1) is in good agreement with the range obtained with the model MAR CF (0.03 ± 0.02 to 0.30 ± 0.01 g cm-2 yr-1). The chronology obtained with the CF model is well validated with the peak of 137Cs (section 6-7 cm: 1960-1972). SAR profiles and MAR show a progressive increase from the late nineteenth century, due to economic development and population growth in the Gulf of Tehuantepec. This growth, which has altered the coastal marine circulation and sedimentation regimes, had its greatest impact during the past two decades, after the establishment of three major industrial complexes in the region.

  2. 210Polonium and 210lead content of marine birds from Southeastern Brazil

    In this study, we report the 210Po and 210Pb concentrations of bone, muscle and liver samples that were obtained from twelve different marine bird species stranded on beaches in the central–north region of Rio de Janeiro State. Both radionuclides were highly concentrated in the liver samples; however, the lowest mean 210Po/210Pb activity ratio (1.3) was observed in bones compared with liver and muscle (16.8 and 13.8, respectively). Among the species that were studied, Fregata magnificens, with a diet based exclusively on fish, had the lowest 210Pb and 210Po concentrations and the lowest 210Po/210Pb activity ratio. The 210Po concentrations in Puffinus spp. liver samples followed a log-normal distribution, with a geometric mean of 300 Bq kg-1wet weight. Only two references pertaining to 210Po in marine birds were found in a Web of Science search of the literature, and each study reported a different concentration value. The values determined in this experiment are consistent with those in one of the previous studies, which also included one of the species studied in this work. No values for 210Pb in marine birds have been published previously. - Highlights: • 210Po and 210Pb were determined in muscle, liver and bone samples of marine birds. • For both radionuclides, the highest concentrations were observed on liver samples. • Only three previous publications on 210Po in marine birds were found in the literature. • The obtained results represent the first one related to 210Pb in marine birds

  3. 22 CFR 210.650 - Grant.

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Grant. 210.650 Section 210.650 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE... authorized by a law of the United States, rather than to acquire property or services for the...

  4. 7 CFR 1709.210 - Application process.

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Application process. 1709.210 Section 1709.210 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF... Application process. (a) Applications. The Agency will solicit applications on a competitive basis...

  5. 41 CFR 101-29.210 - Product.

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Product. 101-29.210... FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 29-FEDERAL PRODUCT DESCRIPTIONS 29.2-Definitions § 101-29.210 Product. The term product is any end item, either manufactured or produced, and...

  6. 31 CFR 210.8 - Financial institutions.

    2010-07-01

    ... of a financial institution under Regulation E, 12 CFR part 205, or the Electronic Funds Transfer Act... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Financial institutions. 210.8 Section... CLEARING HOUSE General § 210.8 Financial institutions. (a) Status as a Treasury depositary. The...

  7. Polonium-210 in food and tobacco

    The objective of this study is concerned with the radioactivity in food and tobacco, derived mainly from 210Po which contribute to the radiation dose received through diet and smoking. This subject was covered under four chapters. Chapter one deals with historical background of polonium-210 and its behavior in living system. Sources of polonium-210 in food and tobacco are explained in the second chapter. Relevant issues such as separation and measurement of polonium-210 covered in subsequent chapter. Chapter four reviewed recent studies on polonium-210. It was found that the main source of this radionuclide is the phosphatic fertilizers that used in food and tobacco cultivation. These fertilizers contain the decay products of 238U series of which 210Po is known to be very important from environmental point of view. Many studies conducted showed that the committed effective dose derived mainly from 210 Po due to the consumption of food, particularly sea food is significant, furthermore 210Po in tobacco is known to be the main cause of many diseases such as lung cancer.(Author)

  8. 7 CFR 210.21 - Procurement.

    2010-01-01

    ... the requirements of this part and 7 CFR part 3016 or 7 CFR part 3019, as applicable, which implement... contained in this part and 7 CFR part 3015, 7 CFR part 3016 and 7 CFR part 3019, as applicable, do not... 7 Agriculture 4 2010-01-01 2010-01-01 false Procurement. 210.21 Section 210.21...

  9. 46 CFR 178.210 - Stability information.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Stability information. 178.210 Section 178.210 Shipping... information. (a) Stability information (stability details indicated on the Certificate of Inspection, a... section. Enough stability information, including stability calculations and assumptions made to use...

  10. 40 CFR 86.210-94 - [Reserved

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false 86.210-94 Section 86.210-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty...

  11. Dating of glaciers by lead-210

    A method is described of dating neve and ice, based on the radioactive decay of 210Pb or RaD (T1/2 = 22 yr). Two techniques have been developed to measure the very low activities of 210Pb (0.1 to 5 dpm). One uses a semi-conductor detector to take spectral measurements of the α-activity of 210Po labelled with 208Po; the other is based on measurement of the β-radiation of 210Bi by a proportional counter. The method has been applied to several sections of neve taken in the Antarctic, in Greenland and on an alpine glacier, each covering a period of more than 100 yr. The results show that in the Polar regions the neve behaves as a closed system from the moment of precipitation, the 210Pb dating this moment. The accumulation rates deduced from the 210Pb distribution as a function of depth are in excellent agreement with those of other methods. In temperate glaciers, because of the homogenization of the neve caused by percolation of the melting water, the event dated by the 210Pb is the transformation of the neve into compact ice. The 210Pb ages obtained with ice samples from the ablation area of the Kesselwandferner (Austrian Tyrol) are in good agreement with current ideas on glacier dynamics. Comparison of the 210Pb and fission product concentrations has revealed no evidence of the artificial production of 210Pb by the explosion of nuclear devices. With samples of 2 kg, this method can be used to date ice with an age of 100 yr in the Antarctic and more than 120 yr in Greenland and in temperate zones. (author)

  12. Inhalation of 210Po and 210Pb from cigarette smoking in Poland

    The carcinogenic effect of 210Po and 210Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of 210Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of 210Po and 210Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of 210Po and 210Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 μSv from 210Po and 210Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 μSv yr-1) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of 210Po and 210Pb intake of smokers in Poland

  13. Metabolism of 210Po in rats: Volatile 210Po from faeces

    The metabolic formation of volatile 210Po species in a rat that was intravenously administered with 210Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210Po species. The amount of 210Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210Po species in the faeces. The presence of volatile 210Po in the faeces indicates that the metabolic formation of volatile 210Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210Po species was compared with the daily faecal excretion of 210Po. After 2 h of bubbling, the volatile 210Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210Po-citrate administration. (authors)

  14. Dicty_cDB: SSA210 [Dicty_cDB

    Full Text Available SS (Link to library) SSA210 (Link to dictyBase) ssa210 - - Contig-U04334-1 SSA210F ...(Link to Original site) SSA210F 105 - - - - - - Show SSA210 Library SS (Link to library) Clone ID SSA210 (Li...nk to dictyBase) Atlas ID ssa210 NBRP ID - dictyBase ID - Link to Contig Contig-U04334-1 Original site URL h...ttp://dictycdb.biol.tsukuba.ac.jp/CSM/SS/SSA2-A/SSA210Q.Seq.d/ Representative seq. ID SSA...210F (Link to Original site) Representative DNA sequence >SSA210 (SSA210Q) /CSM/SS/SSA2-A/SSA210Q.Se

  15. Determination of {sup 210}Pb and {sup 210}Po in cigarette tobacco; Determinacao de {sup 210}Pb e {sup 210}Po em tabaco de cigarros nacionais

    Peres, Ana Claudia

    1999-07-01

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of {sup 210}Pb and {sup 210}Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The {sup 210}Pb was determined by counting the beta activity of the {sup 210}Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0{sub 4}. The {sup 210}Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for {sup 210}Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for {sup 210}Po. (author)

  16. Intake of 226Ra, 210Pb and 210Po with food in Poland

    Intake with food and water of 226Ra, 210Pb and 210Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210Po/210Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was found to be approximately 10. In central Poland the largest intake of 226Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210Pb was with flour and meat (approx. 50%) and the largest intake of 210Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210Pb and 210Po was approx. 54 μSv year-1, and the dose from 226Ra was approx. 4 μSv year-1

  17. Intake of {sup 226}Ra, {sup 210}Pb and {sup 210}Po with food in Poland

    Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S. [Department of Radiation Hygiene, Central Laboratory for Radiological Protection, Warsaw (Poland)

    1997-09-06

    Intake with food and water of {sup 226}Ra, {sup 210}Pb and {sup 210}Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The {sup 226}Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The {sup 210}Po/{sup 210}Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the {sup 210}Po/{sup 210}Pb ratio was found to be approximately 10. In central Poland the largest intake of {sup 226}Ra was with flour and vegetables (contribution approx. 60%), the largest intake of {sup 210}Pb was with flour and meat (approx. 50%) and the largest intake of {sup 210}Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from {sup 210}Pb and {sup 210}Po was approx. 54 {mu}Sv year{sup -1}, and the dose from {sup 226}Ra was approx. 4 {mu}Sv year{sup -1}.

  18. Alpha-spectroscopic determination of 210Pb and 210Po in snow samples

    The concentrations of 210Pb and 210Po in several snow samples were determined using α-spectrometry. After 5 l of snow-melt water was subjected to coprecipitation of both nuclides with AlPO4, the solvent extraction procedure with TBP (tri-butyl phosphate)-isopropyl ether was applied to purify the polonium fraction, followed by the spontaneous electro-deposition on a Ni-sheet. The α-spectrum was measured with a Si(Au)-semiconductor detector coupled with a multichannel pulse-height analyzer. After the first determination of 210Po, the concentration of 210Pb was estimated from second measurement of 210Po grown newly from the remaining Pb-fraction during the storage period of more than 3 months. In these analytical procedures, 212Pb and 208Po tracers were conveniently utilized for the determination of collection yield for 210Pb and of the final chemical yield of 210Po, respectively. The contents of 210Po and 210Pb in the fresh snow were 3 -- 30 mBq/l (81 -- 810 fCi/l) and 250 -- 720 mBq/l(6.8 -- 19.5 pCi/l), respectively, and the residence time of 210Pb was given to be 6 -- 12 days from the decay-growth relationships of both nuclides. (author)

  19. Biogeochemistry of (210)Pb and (210)Po in fresh waters and sediments. Doctoral thesis

    The geochemical cycling of (210)Pb in a Massachusetts lake was studied. A mass balance for the epilimnion showed that (210)Pb inputs by precipitation were matched by outputs on settling particles, so direct uptake by bottom sediments was inconsequential. Below the epilimnion, vertical mixing was very low because of a steep temperature/density gradient, and this limited vertical transport. Anoxic conditions caused remobilization of iron and (210)Pb, which reprecipitated at the oxycline and returned to the bottom via settling. Below the zone of precipitation, (210)Pb and iron distributions resulted from constant release from anoxic sediments and dilution in the water column. Sediment (210)Pb distributions were caused by sedimentation and Fickian transport. The Fickian component was equal to the pore water diffusive flux. In pore waters, (210)Pb and (210)Po were 100 times greater that in overlying water and had steep concentration gradients, unlike Fe, Mn, S(-II), and alkalinity. (210)Pb partition coefficients decreased from 15000 to 1500 with depth controlled by sorption on iron oxides. Remobilization to the water column comes from a thin layer of iron-rich floc near the sediment/water interface. Deeper in the cores, diffusive transport can cause redistribution of (210)Pb to an extent that can affect (210)Pb dating

  20. The speciation and determination of 210Pb and 210Po in soil samples

    A method for speciation and determination of 210Pb and 210Po in soil samples was developed. The speciation was carried out by fractionating the soil samples into 5 fractions which are water soluble or exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and bound to residue. After mineralisation, 10% solution of each fraction was used to spontaneously deposit polonium on a silver disk at 85-90 degree C and pH 1.5 and 210Po was measured by α-spectrometry; the remain solution was used to separate lead by anion-exchange resin and purified by precipitation as PbS and PbSO4, and 210Pb was determined by a low background β-counter. IAEA-327 reference material (soil) has been studied for 210Pb and 210Po speciation. The results show that: (1) the average yields are 88.7±6.4% for 210Pb and 93.8±8.2% for 210Po; (2) if compared to the total 210Pb activity in the sample, 210Pb fractions are 0.95% in exchangeable form, 10.6% bound to carbonates, 14.3% bound to Fe-Mn oxides, 7.00% bound to organic matter, and 67.2% bound to residue or acid soluble, and the corresponding values for 210Po are 0.17%, 0.97%, 21.0%, 0.47% and 77.4%, respectively; and (3) the obtained 210Pb concentration is in good agreement with the recommended value given by IAEA.

  1. 210Po bioaccumulation by mushrooms from Poland.

    Skwarzec, B; Jakusik, A

    2003-10-01

    The paper presents results on 210Po activity concentration measured in mushroom samples collected in northern Poland (Białogard and Elblag areas). Among 20 species of wild mushrooms, King Bolete (Boletus edulis), accumulated 210Po in the highest degree. Therefore this species of higher mushrooms is an excellent bioindicator for 210Po radioactivity in the land environment. Finally, the effective dose of polonium emission was calculated for a consumer of King Bolete. Wild mushroom consumption contributed up to 37 microSv to the effective dose in an individual consuming about 5 kg (fresh weight) of heavily contaminated Boletus edulis species per year. PMID:14587851

  2. (210)Po and (210)Pb in medicinal plants in the region of Karnataka, Southern India.

    Chandrashekara, K; Somashekarappa, H M

    2016-08-01

    The activity concentrations of naturally occurring radionuclides (210)Po and (210)Pb were estimated in some selected medicinal plants and soil samples of coastal Karnataka in India. The mean activity concentrations of (210)Po and (210)Pb varied in the range of 4.7-42.9 Bq kg(-1) (dry weight) and 36.1-124 Bq kg(-1) (dry weight) in the soil samples, and 3.3-63.7 Bq kg(-1) (dry weight) and 12.0-406 Bq kg(-1) (dry weight), in the medicinal plant samples, respectively. The plants, Ocimum sanctum L. and Plectranthus amboinicus (Lour.) Spreng had significantly higher activity concentrations of (210)Po and (210)Pb than other species sampled. In spite of disequilibrium between them, these two radionuclides were well correlated in both soil and medicinal plants. PMID:27155527

  3. 5 CFR 551.210 - Computer employees.

    2010-01-01

    ....210 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY... solve complex business, scientific or engineering problems of the organization or the organization's..., documentation, analysis, creation, testing or modification of computer systems or programs, including...

  4. 210Pb as tracer of environmental processes

    210Pb is a radionuclide naturally occurring radioactive belonging to the chain of 238U. Its half-life is T1/2 = 22.23 ± 0.12 yr. There is some discrepancy in the order of 0.1% of this value and, therefore, not significantly affect the results of the chronology, affected by sources of much greater uncertainty. Assuming that 210Pb can be detected up to about 5 times its half-life, we can expect that 210Pb can provide useful information for the last 100 years or so, although this depends on the analytical techniques used and the precision of the assay. 210Pb plays an important role in the study of the environment as it is present in the atmosphere, lithosphere and hydrosphere. This tracer has been used successfully in the study of biogeochemical processes in the oceans, atmospheric deposition and anthropogenic pollution, sedimentary processes and sediment geochronology.

  5. Aspects on the analysis of 210Po.

    Henricsson, F; Ranebo, Y; Holm, E; Roos, P

    2011-05-01

    There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960 ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two depositions. Counting was often done using ZnS scintillation counter coupled to a photomultiplier tube. However, the use of the yield determinants (208)Po and (209)Po and the development of alpha spectrometry showed that the yield was lower. Furthermore, the tendency of Po to volatilize at low temperatures constrains the sample preparation techniques; dry-ashing cannot be used. But during the wet-ashing procedure, there are still some losses. The aim of this study was to evaluate the Po losses during wet-ashing by the use of a double-tracer technique. We have found that the losses were about 30% when open glass beakers were used and about 17% when the samples were digested in microwave oven. When long-necked bottles (Kjeldahl flasks) were used, a loss of about 20% was registered. It has also been observed that (210)Pb to some extent is plating out together with its daughter nuclide Po during the electrochemical deposition. This will result in a systematic error since an unknown amount of supported (210)Po will be produced from the (210)Pb decay depending on the fraction of (210)Pb being deposited on the disc and the waiting time between deposition and measurement of the sample. A further consequence of this is that in the assessment of the (210)Pb content in the sample, very often the remaining liquid is stored after deposition for build-up of (210)Po. Since some (210)Pb is lost on the disc, the result for (210)Pb will be too low. Both these systematic errors give rise to a too high (210)Po/(210)Pb ratio. The fraction of (210)Pb which is plating out has been assessed in this

  6. Biogeochemical cycling of 210Po and 210Pb in the upper ocean

    The naturally occurring radionuclide 210Po is typically deficient relative to its parent 210Pb in the surface ocean due to preferential removal by biota, while in near equilibrium or excess below the surface mixed layer due to rapid regeneration from sinking organic matter. In general, larger deficit of 210Po is observed in the oligotrophic oceans interior, which seems to be due to efficient uptake of Po by cyanobacteria. The activities of 210Pb and 210Po were measured for the truly dissolved (< 10 kD), colloidal (10 kD - 0.45 mm), and particulate (> 0.45 mm) phases in the upper ocean (0-200 m) of the East/Japan Sea (EJS) in the summer of 2009. The total 210Pb and 210Po activities in the EJS were in the range of 6.3-23 and 3.3-10 dpm/100L, respectively. The proportions of the truly dissolved, colloidal, and particulate phases were 35±3, 48±7 and 17±8% for 210Pb and 19±2, 36±6, and 45±6% for 210Po, respectively, in the upper ocean. Using a net residence time model, which accounts for biological uptake and remineralization, the residence times of 210Po in the upper 100-m layer were calculated to be 92±41, 63±14, and 166±45 days for the truly dissolved, colloidal, an particulate phases, respectively. The residence time of colloidal 210Po was several-fold longer than typical turnover times (<10 days) of high-molecular-weight dissolved organic carbon and colloidal residence times of short-live 234Th in the surface water. This result suggests that 210Po turns over several times through the colloidal phase perhaps together with other bio-reactive elements, before settling down from the upper ocean. (author)

  7. Metabolic balances of 210Pb and 210Po at natural levels

    Metabolic balances of 210Po and 210Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210Pb was 1.25 pCi/day and of 210Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract; the urinary excretion is much lower. The total excretions of 210Pb and 210Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound, Hydrodiuril, appeared to decrease the fecal 210Pb excretion

  8. Unusually large 210Po deficiencies relative to 210Pb in the Kuroshio Current of the East China and Philippine seas

    Three vertical water profiles of 210Pb and 210Po have been measured in the East China and Philippine seas. All the profiles show a large 210Po deficiency of ∼ 8 dpm/cm2 relative to 210Pb in the top ∼ 1,000 m of the water column. Based on the 210Po deficiency, the steady state flux for 210Po removal from the surface water is estimated to be 14 dpm cm-2/yr. The 210Po/210Pb ratio of sinking particles will be too high unless an additional source of 210Pb into the surface is accounted for. Thus the large 210Po deficit is probably caused by the increased atmospheric input of 210Pb without any significant 210Po, which is focused in the Kuroshio region by isopycnal transport, and the preferential scavenging of 210Po relative to 210Pb by settling particles. The transient model calculations indicate that the model can account for the observed high excess 210Pb inventory and large 210Po deficiency in the water column if focusing of atmospherically derived 210Pb in the Kuroshio water is a factor of 2-3 more than the local input. Such lateral redistribution by the western North Pacific gyre circulation is not inconsistent with the deeper penetration and the high water column inventories of anthropogenic substances observed in this region

  9. Determination of 210Pb and 210Po in Brazilian cigarette tobacco

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCrO4. The 210Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 15,8 to 30,2 mBq per gram of dry tobacco for 210Pb and from 18,8 to 27,4 mBq per gram of dry tobacco for 210Po. Taking in account the experimental error of the measurements, radioactive equilibrium between 210Pb and 210Po is observed for all analyzed samples. This result was expected, since the delayed time from the harvest of tobacco leaves to the introduction of cigarettes in the market is enough to reach that equilibrium. Assuming a 20 cigarettes per day consumption, and a 10% of Pb and 20% of Po being inhaled by the primary smokers, it is obtained a value of yearly intake of 11,3 Bq of 210Pb and 21,2 Bq of 210Po, due to cigarette consumption. These values lead to an increment to the committed effective dose of 0,025 mSv year-1 and an increment to the probability of getting cancer of 1 x 10-6 per year. (author)

  10. {sup 210}Po and {sup 210}Pb in seals from the Baltic Sea and Lake Saimaa, Finland

    Solatie, D.; Rissanen, K. [Radiation and Nuclear Safety Authority - STUK, Rovaniemi (Finland). Regional Laboratory in Northern Finland; Vesterbacka, P. [Radiation and Nuclear Safety Authority - STUK, Helsinki (Finland). Natural Radiation Laboratory

    2005-09-15

    {sup 210}Po and {sup 210}Pb are members of the {sup 238}U decay chain. {sup 210}Po is an {alpha}-emitter with a half-life of 138 days, while its grandmother, {sup 210}Pb is a {beta}-emitter with 22.3 year half-life. In the atmosphere {sup 222}Rn formats its decay products {sup 210}Po and {sup 210}Pb. These nuclides are deposited on to the surface of land and sea and thus enter the food chain. The naturally occurring radionuclides {sup 210}Po and {sup 210}Pb are important because their great contribution to radiation dose to human and other species. As top predators in the aquatic food chain, fish-eating seals are vulnerable to the accumulation of contaminants. In the Regional Laboratory in Northern Finland, measurements of {sup 210}Po and {sup 210}Pb activity concentrations in seals from the Baltic Sea and in ringed seals from Lake Saimaa have been performed. Concentrations of {sup 210}Po and {sup 210}Pb in seals were determined in muscle, liver, kidney and spleen. The results of {sup 210}Po and {sup 210}Pb activity concentrations and the ratio of {sup 210}Po / {sup 210}Pb in these samples are presented. (Summary-only contribution)

  11. The effect of water treatment on the presence of particle-bound 210Po and 210Pb in groundwater

    The distribution of 210Po and 210Pb in various particle-size fractions in Finnish groundwater was studied at five private homes. Each site had water treatment equipment comprising either an ion exchange unit or a granular activated carbon filter. Samples of both raw and treated water were filtered using pore sizes ranging from 450 nm to 100 kDa and the activity concentration of 210Po and 210Pb in the filtrate was determined. In untreated groundwater 86% of 210Pb, on average, was found in the large particle fraction (> 450 nm). However, in Fe- and Mn-rich water with a high Fe/Mn ratio and in organic-rich water, the majority of 210Pb was found in either the intermediate particle (100 kDa-450 nm) or small particle (210Pb, 210Po was bound more to the intermediate and small particle fraction. After water treatment, 210Pb was found most frequently in the large particle fraction. The size distribution of particle-bound 210Po was not as clear as that for 210Pb, and in treated water, 210Po was more evenly distributed among fractions. The ion exchange unit removed 210Pb and 210Po bound to the intermediate or small particle fraction, whereas the efficiency of the activated carbon filters in removing 210Pb and 210Po was independent of the particle size. (orig.)

  12. 226Ra, 210Pb and 210Po in food and in population in Poland

    Content of 226Ra, 210Pb and 210Po was determined in daily diet, foodstuffs and drinking water in various regions in Poland. The annual intake of the radionuclides with foodstuffs for an adult population was estimated on the basis of the average annual consumption. The 226Ra intake was in all the places similar; variations between the samples from a locality were bigger than the differences between various localities. Slightly higher 226Ra intake was observed in Suwalki, evidently being associated with the higher concentration of this radionuclide in the soil. The average 210Po/210Pb ratios was below and close to unity in the daily diet of continental regions, whereas at the Baltic Sea coast it was about 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was close to 10. The calculated body burden for an adult man was 1.6 Bq for 226Ra, 6.8 Bq for210Pb and 6.8 Bq for 210Po. (author)

  13. Kretanje Pb-210 i Po-210 u prehrambenom lancu krava-mlijeko-sir

    Milošević, Zdravko; Horšić, Emilija; Kljaić, Ranko; Bauman, Alice

    1980-01-01

    Kretanje prirodnih radionuklida iz niza urana u prehrambenom lancu nedovoljno je ispitano uopće, a kod nas gotovo nije niti načeto. Ispitivanja su vršena na teritoriji BiH, kako bi se moglo predvidjeti kretanje Pb-210 i Po-210 u prehrambenom lancu na područjima s povišenim prirodnim fonom.

  14. Technologically enhanced 210Pb and 210Po in iron and steel industry

    Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the 210Pb and 210Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of 210Pb and 210Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of 210Pb and 210Po in the range of 210Pb and 210Po radionuclides. → Both radionuclides are enriched through the thermal processes. → For radiation dose assessment inhalation would be the main route of exposure.

  15. Distribution of 210Pb and 210Po in boreal forest soil

    Vertical distribution and activity contents of 210Pb and 210Po were investigated in forest soils of Scots pine-dominated (Pinus sylvestris L.) stands from seven different locations in Finland. The mean total inventory in the soil profile, up to 20 cm, of 210Pb was 4.0 kBq m-2 (range 3.1-5.0 kBq m-2) and 210Po 5.5 kBq m-2 (range 4.0-7.4 kBq m-2), the organic soil layer containing 45% of the total inventory of both nuclides. In both the organic and the mineral layers the 210Po/210Pb ratio was close to unity indicating a radioactive equilibrium between them. In the litter layer there was, however, a clear excess of 210Po suggesting that polonium is recycled via root uptake from the root zone to the ground surface. The activity concentration (Bq kg-1) of 210Pb clearly correlated with organic matter and the Fe, Al and Mn concentrations in soil indicating that radioactive lead is associated both with humic substances and the oxides of iron, aluminium and manganese. Radioactive lead was also seen to follow the behavior of stable lead. No systematic correlation between polonium and soil properties was seen.

  16. Wechselwirkung von Wasserstoff mit einer Pd(210)- und einer Ni(210)-Oberfläche

    Schmidt, Pia Katharina

    2010-01-01

    8 This work presents investigations of the interaction of hydrogen with a Pd(210) and Ni(210) surface using LEED (low energy electron diffraction), thermal desorption spectroscopy (TDS), work-function measurements (DF),vibrational loss measurements (HREELS), and isotope exchange experiments. The interaction of hydrogen with both surfaces is very similar. For temperatures above 100K, hydrogen chemisorbs spontan...

  17. Unusual 210Po/210Pb ratios in the surface water of the Gulf of Lions

    Concentrations of 210Po and 210Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of 210Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the 210Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have 210Po at levels rather higher than expected, and their 210Po/210Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of 210Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors)

  18. Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

    Brown, J.E.; Gjelsvik, R.; Roos, Per;

    2011-01-01

    concentrations of the main dose forming radionuclides 210Po and 210Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell...

  19. Radioactive {sup 210}Po in magnesium supplements

    Struminska-Parulska, Dagmara Ida [Gdansk Univ. (Poland). Environmental Chemistry and Radiochemistry Chair

    2016-08-01

    The aim of this pioneer study was to determine polonium {sup 210}Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring {sup 210}Po activity concentrations in magnesium supplements, find the correlations between {sup 210}Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest {sup 210}Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g{sup -1} (sample Mg17). The highest annual radiation dose from {sup 210}Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year{sup -1} respectively.

  20. Assessment of soil contamination by 210Po and 210Pb around heavy oil and natural gas fired power plants

    Soil contamination by 210Pb and 210Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of 210Pb and 210Po were found to be the main source of surface soil contamination. The results showed that 210Pb and 210Po in fly-ash (economizer, superheater) is highly enriched with 210Pb and 210Po, while bottom-ash (boiler) is depleted. The highest 210Pb and 210Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, 210Pb and 210Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased. - Highlights: • Fly ash containing 210Po and 210Pb is the main enhancement factor in surface soil. • 210Pb and 210Po in soil are higher inside the campus area than the surrounding areas. • 210Pb and 210Po in ash along the combustion path varied with compartment temperature. • Fly-ash contains 210Pb and 210Po much higher than bottom-ash

  1. The Use of Excess 210Pb (210Pbex) as a Soil and Sediment Tracer

    Lead-210 (210Pb) is one of the fallout radionuclides offering the broadest spectrum for environmental applications due to its geogenic origin and relatively long half-life of around 22 years. For more than five decades, 210Pb has been widely used for dating sediments and investigating sedimentation processes. It is only since the 1990s that studies have been using fallout 210Pb for providing information on the magnitude of soil erosion and sedimentation in agricultural landscapes. As it is rapidly and strongly adsorbed at the soil surface, 210Pb has an environmental behaviour similar to 137Cs. The use of fallout 210Pb for documenting soil redistribution rates involves the same advantages and limitations as 137Cs. However, 210Pb can extend the temporal scale, associated with other FRNs measurements, to provide a retrospective assessment of long-term soil redistribution rates over a period of up to 100 years. In addition, since the fallout of 210Pb is continuous, its use does not face the problems associated with short- and medium-lived radioactive soil tracers. This paper summarizes the state-of-the-art related to the main assumptions, the requirements and the limitations which have to be recognised when using this FRN as a soil and sediment tracer. In particular, measurement of fallout 210Pb by gamma spectrometry requires more accurate analytical measurements, as compared to 137Cs, to be performed by skilled staff, and appropriate analytical quality assurance systems. Lessons learned and future research needs in the application of fallout 210Pb are also presented and discussed in this paper. (author)

  2. Polonium-210 and lead-210 in the terrestrial environment: a historical review

    Persson, Bertil R.R., E-mail: bertil_r.persson@med.lu.s [Dept. of Medical Radiation Physics, Lund University, Barngatan 2, SE-221 85 Lund (Sweden); Holm, Elis [Norwegian Radiation Protection Authority, Osteras (Norway)

    2011-05-15

    The radionuclides {sup 210}Po and {sup 210}Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of {sup 238}U in the earth's crust. Their presence in the atmosphere is due to the decay of {sup 222}Rn diffusing from the ground. The range of activity concentrations in ground level air for {sup 210}Po is 0.03-0.3 Bq m{sup -3} and for {sup 210}Pb 0.2-1.5 Bq m{sup -3}. In drinking water from private wells the activity concentration of {sup 210}Po is in the order of 7-48 mBq l{sup -1} and for {sup 210}Pb around 11-40 mBq l{sup -1}. From water works, however, the activity concentration for both {sup 210}Po and {sup 210}Pb is only in the order of 3 mBq l{sup -1}. Mosses, lichens and peat have a high efficiency in capturing {sup 210}Po and {sup 210}Pb from atmospheric fallout and exhibit an inventory of both {sup 210}Po and {sup 210}Pb in the order of 0.5-5 kBq m{sup -2} in mosses and in lichens around 0.6 kBq m{sup -2}. The activity concentrations in lichens lies around 250 Bq kg{sup -1}, dry mass. Reindeer and caribou graze lichen which results in an activity concentration of {sup 210}Po and {sup 210}Pb of about 1-15 Bq kg{sup -1} in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of {sup 210}Po and {sup 210}Pb in humans. The effective annual dose due to {sup 210}Po and {sup 210}Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 {mu}Sv a{sup -1} respectively. In soils, {sup 210}Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of {sup 210}Po in various soils are in the range of 20-240 Bq kg{sup -1}. Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive

  3. Polonium-210 analysis in fish samples

    A method for Po-210 analysis in fish samples is described which is based on acid digestion of the samples with nitric acid and peroxide; spontaneous deposition of polonium onto silver disc and alpha spectrometry. The procedure was applied to fish samples collected along the Mediterranean Coast and the Brazilian Coast. For accurate results Po-208 was used as internal tracer. Po-210 levels in fish from Mediterranean Coast varied from 0.7 to 11.6 Bq.Kg-1 (wet dry) and from Brazilian Coast ranged from 0.5 to 5.3 Bq.kg-1 (wet dry). (author). 7 refs., 2 tabs

  4. Evaluation of 210Pb and 210Po in cigarette tobacco produced in Brazil

    Cigarette smoking is one of the pathways that might contribute significantly to the increase in the radiation dose reaching man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In the present study, the concentrations of these two radionuclides were determined in eight of the most frequently sold cigarette brands produced in Brazil. 210Pb was determined by counting the beta activity of 210Bi with a gas flow proportional detector after radiochemical separation and precipitation of PbCrO4. 210Po was determined by alpha spectrometry using a surface barrier detector after radiochemical separation and spontaneous deposition of Po on a copper disk. The results showed concentrations ranging from 11.9 to 30.2 mBq per gram of dry tobacco for 210Pb and from 10.9 to 27.4 mBq per gram of dry tobacco for 210Po. The collective committed effective dose resulting from the use of cigarettes produced in Brazil per year is estimated to be 1.5x104 man-Sv

  5. Export of particulate matter from Tokyo Bay studied with radiochemical tracers, 210Po and 210Pb

    Sediment traps were deployed at the mouth of Tokyo Bay in the winter of 1991 and the summer of 1993, each for a few days. The fluxes of total mass, 210Pb (parent) and 210Po (daughter) increased with depth, especially in the near-bottom layer. All the fluxes of total mass, 210Po and 210Pb decreased offshore at the same depth, while they increased offshore at the same distance above the bottom. The observed particulate flux of 210Pb in the water column was one to two orders of magnitude larger than the sedimentation rate at the bottom. The activity ratio of 210Po/210Pb in the near-bottom layer was largest at each station and did not vary from station to station. These findings indicate that enormous amounts of particulate matter are transported fairly quickly offshore through the near-bottom layer at the entrance. The variation in total mass flux was well synchronized with the tidal cycle at a mid-depth of 85 m in the water column of 240 m in winter of 1991, where the fluxes were larger during ebb and smaller during flood tides. The particulate flux of 210Po was also larger by a factor of about 2 during ebb, while the concentration of 210Pb was about 40 % larger during flood than ebb. These findings indicate that the tidal current is a major conveyor of particulate matter at the mid-depths. The tidal variation, however, was weak for the results obtained in the near-bottom layer in 1993, where much particulate matter was transported toward the Kuroshio region along the valley of Tokyo Bay. Our results suggest that even bays having narrow mouths, such as Tokyo Bay, are a large source of particulate material to the open oceans. (author)

  6. Atmospheric deposition of 210Po and 210Pb in Malaysian waters during haze events

    Biogenic burning as forest fire phenomena occurring from April to August each year in the Sumatra and Borneo islands are major sources of biogenic uranium–thorium decay series in marine systems. 30 samples were collected during the Ekspedisi Pelayaran Saintifik Perdana 2009 cruise (EPSP 2009 cruise) between 12th June and 1st August 2009 from the Straits of Malacca to the Sulu and Sulawesi Seas to study the effect of haze and the monsoon season on the deposition rate of 210Po and 210Pb in Malaysian waters. All samples were spiked with 1 ml of lead [Pb(NO3)2; 25 mg ml-1] and 0.05 ml of Polonium-209 tracer (26.08 dpm ml-1). 210Po activity was determined by auto plating onto silver foil and counting using an alpha spectrometry system (Canberra model Alpha Analyst with a silicon-surface barrier detector). Lead that was collected via electrodeposition, formed lead sulphate (PbSO4) precipitation. This precipitate was wrapped onto plastic discs and counted for 210Pb beta activity using a gross alpha-beta counting system (Tennelec model LB-5100 low background gas-flowing anti-coincidence alpha/beta counter) after 1 month to allow bismuth ingrowths. The range of 210Po activities varied between 51.08 ± 15.1 and 742.08 ± 220.34 Bq/kg, whereas the activity of 210Pb ranged from 31.10 ± 4.20 to 880.23 ± 123.86 Bq/kg and 210Po/210Pb ratio value varied between sampling stations from 0.19 to 13.77. The contents of 210Po were also statistically positively correlated with the amount of total suspended particulate especially those recorded during heavy haze period events. (author)

  7. 210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

    In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210Po, in the marine environment. 210Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210Po and 210Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their 210Po and 210Pb content. The 210Po and 210Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg−1 dry weight (dw) and from 1.0 ± 0.3 Bq kg−1 to 35 ± 4.0 Bq kg−1 (dw), respectively. There were no significant differences in the activity concentrations of 210Po and 210Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210Po to humans was calculated to be 10,530 μSv year−1.

  8. /sup 210/Pb fluxes in acidified lakes

    The acidification of softwater lakes by atmospheric deposition of strong acids has occurred in several regions of the world; however, the rate of acidification of freshwater systems is generally unknown. The authors have tested the hypothesis that the /sup 210/Pb technique can be used to establish the chronologies of sediments in acidified lakes, with the purpose of establishing the rate of change of the chemical and perhaps biological composition of the water. Sediment cores were collected from four lakes near Sudbury, Ontario, Canada, that either were acidic (pH 4.2 to 4.4) or had been acidic, but were recently neutralized by the addition of calcium carbonate/calcium hydroxide. /sup 210/Pb flux was measured at five sites per lake. The whole lake fluxes in the Sudbury lakes were significantly lower than those of 11 nonacidic lakes -- 250 km to the southeast. Because it is unlikely that lead (Pb) is leached from the sediments, it is hypothesized that acidification results in alteration of the sedimentation mechanism, leading to reduced /sup 210/Pb (and stable Pb) retention in acidic lakes. Therefore, the /sup 210/Pb method is not suitable for establishing sediment chronologies in recently acidified lakes using existing models

  9. 48 CFR 12.210 - Contract financing.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contract financing. 12.210... financing. Customary market practice for some commercial items may include buyer contract financing. The contracting officer may offer Government financing in accordance with the policies and procedures in part 32....

  10. 48 CFR 210.001 - Policy.

    2010-10-01

    ... DEFENSE ACQUISITION PLANNING MARKET RESEARCH 210.001 Policy. (a) In addition to the requirements of FAR 10.001(a), agencies shall— (i) Conduct market research appropriate to the circumstances before— (A... 109-163); and (ii) Use the results of market research to determine— (A) Whether consolidation...

  11. 210Po/210Pb disequilibria in the shelf edge of the East China Sea

    The uranium-238 series radionuclides 210Pb (t1/2 = 22.3 yr) and its daughter 210Po (t1/2 = 138 days), are important tracers in the marine environment. They are especially useful for studies on material transport scavenging processes within relatively short times and on the mechanism of material transport from coastal zones to the open sea, because they are highly reactive to the particulate matter and is rapidly removal from the water column. In this study, we present measurements of 210Po and 210Pb concentrations in seawater and the calculated rates of removal of these radionuclides from the water column in the shelf edge of the East China Sea

  12. Forest fires as a source to polonium-210 and lead-210 in the atmosphere

    Research was performed on 210Po, 210Pb and other natural alpha emitter radionuclides released from vegetation by wildfires. In aerosols sampled in the vicinity of fires, the radionuclide activity concentrations per unit of air volume were systematically higher when there were higher particle loads in the air, suggesting that smoke particles were the vehicle for transport of radioactivity in the atmosphere. Exposure to these radionuclide through inhalation of smoke and radiation doses is discussed. (author)

  13. Variability of excretion rates of 210Pb and 210Po of humans at environmental levels

    Variability of the excretion rates of the nuclides 210Pb and 210Po at natural levels was studied in a group of samples collected from men maintained under the carefully controlled conditions of a metabolic ward. They consumed only the standard diet of the ward in which they had been resident for at least several months prior to this study. The mean urinary rates were about 0.1 to 0.5 pCi/day for both 210Pb and 210Po, while fecal rates ranged from 1 to 2.7 pCi/day for the two nuclides. For urinary 210Pb the coefficients of variation (ratio of standard deviation to mean) for three subjects ranged from 19 to 45 percent for eight continuous 24-hr samples compared to 11 to 13 percent for subsequently collected multiday samples (4 to 9 days each) for each subject. However, the standard errors of the means for the one day collections were about equal to the standard deviations of the pooled samples. Similar variability was noted for the 210Po data. Six day fecal collections from these time periods exhibited higher variabilities than did the urine, from about 12 percent to 50 percent for each of the nuclides. Multiday collections for 12 subjects showed mean coefficients of variation of about 16 percent for 210Pb and 13 percent for the 210Po for urine and 21 and 25 percent, respectively, in fecal collections. Since dietary intake was maintained fairly constant, excreta collections were carefully controlled, and the analytical precision was about 5 percent, these variabilities appear to be due to biological variations and are characteristic of the individuals studied. Some possible causes of these effects are discussed

  14. Normal dietary levels of radium-226, radium-228, lead-210, and polonium-210 for man

    A review of the literature and the results of some recent measurements on the levels in man's diet of the naturally occurring radionuclides 226Ra, 228Ra, 210Pb, and 210Po are presented. Intakes in other countries are similar to those in the United States, but in localized populations the 226Ra intake can be 8 or more pCi/day. The few data on 228Ra show that intake of this nuclide is about 80% that of 226Ra except in monazite areas where intakes of up to 160 pCi 228Ra/day are reported. Drinking water contributes less than 5% to daily intake except in special areas. For 210Pb, higher levels have been noted for Germany and the Union of Soviet Socialist Republics than for the United States. Persons in the Arctic who consume reindeer or caribou meat may ingest 210Pb at the rate of 10 to 40 pCi/day. Normal dietary levels of 210Po are about 20 to 30% higher than those of 210Pb, except in the Arctic. The levels of these nuclides in classes of foods are compared to show that the higher levels observed in certain diets are due to the levels in particular foods. Because of the high levels of 210Pb intake in Japan, total skeletal dose rates in that country are estimated to be more than twice those in the United States. The use of dietary intake for estimating metabolic parameters, such as intestinal absorption of 226Ra and 210Pb, is discussed

  15. Discharge of 210Po and 210Pb in coastal groundwater to the ocean

    The activities of 210Po and 210Pb were measured for the truly dissolved (<10 kDa) and colloidal (10 kDa - 0.45 ìm) phases in coastal ground water in 2010 and 2011. The sampling sites include the coast of a large tidal flat (Hampyeong Bay) and a volcanic island, Jeju, Korea, where submarine groundwater discharge (SGD) were reported to be higher than typical continental margins. The total dissolved fraction was separated into the colloidal and truly dissolved fractions using a tangential flow filtration (TFF) system (PLCGC Pellicon). The total 210Po and 210Pb activities in ground water were 1.0 - 18.2 dpm/100L (9.7±7.6 dpm/100L) an 2.9 - 29.1 dpm/100L (16.8±10.7 dpm/100L) in the Hampyeong Bay and Jeju Island samples, respectively. The total 210Po and 210Pb activities in groundwater were similar to or even slightly lower than those in the typical seawater. These lower activities seem to be due to the rapid adsorption of Po and Pb on to particles in the subterranean estuary. The proportions of the truly dissolved and colloidal phases were, respectively, 73±5% and 27±5% for 210Po, and 60±5% and 40±5% for 210Pb. This result is consistent with the earlier study that more than half of the some dissolved trace metals in coastal ground water are in the colloidal form. Thus, our result implies that the colloidal forms are important in controlling the behaviour of Po, Pb, and other trace metals in the subterranean estuary and SGD-associated fluxes to the ocean. (author)

  16. Correlation of unsupported 210Pb activity in soil and moss

    The activities of unsupported 210Pb, a naturally occurring radionuclide, were measured in samples of soil and terrestrial mosses collected in Serbia. Considering that clay particles in soil have a high affinity for Pb adsorption, and that mosses usually capture aerosol particles to obtain necessary nutrients, measurable amounts of airborne 210Pb, the daughter of 222Rn, can be registered in both soil and mosses. The objective of the present study was to determine if it is possible to compare the activity of unsupported 210Pb in soil and moss collected at the same sampling site, and to establish if a correlation exists between these measured values. - Highlights: • Samples of the soil and mosses were collected at same location. • Lead-210 was measured in mosses and soil. • Annual depositional flux of 210Pb is determined using 210Pb measured in soil. • Dependence of 210Pb in mosses of 210Pb atmospheric depositional flux can be observed

  17. Hair and feathers as indicator of internal contamination of 210Po and 210Pb

    The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

  18. Concentration of 210Po and 210Pb in the diet at the Marshall Islands

    The concentrations of 210Po and 210Pb have been determined in many local foods consumed by societies residing on different atolls in the Marshall Islands. The average daily intake of these two naturally occurring radionuclides from local and imported food is estimated to be 2.18 and 0.36 Bq, respectively. Local foods contribute 87% of the 210Po and 47% of the 210Pb associated with the diet. The items contributing the majority of the activity to the diet are derived from the marine environment and include parts of fish, invertebrates, seabirds and eggs of seabirds. The committed effective dose from ingestion of 210Po and 210Pb is 2 mSv/year (200 mrem/year). This pathway now contributes 83% of the natural background irradiation received by residents in the Marshall Islands. Because the naturally occurring radionuclides are omnipresent in terrestrial and marine foods at all atolls, the annual intake and computed dose can be considered as typical values for individuals with comparable diets and inhabiting other islands in the Pacific

  19. Hair and feathers as indicator of internal contamination of 210Po and 210Pb

    Holm, E. (ed.); Gwynn, J.; Zaborska, A.; Gaefvert, T. (Norwegian Radiation Protection Authority (Norway)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Henricsson, F. (Lund Univ., Lund (Sweden))

    2010-03-15

    The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

  20. Transfer analysis of 210Po and 210Pb in the terrestrial environment

    The transfer of 210Po and 210Pb between various compartments in the terrestrial environment has been analysed by using published data. The average activity concentration of 210Po in dry soil is 61 ± 14 Bq.kg-1 (median 44 Bq.kg-1). Ground water concentrations of 210Po in drilled wells might be as high as 6.5 Bq/l. But in regular drinking water it is just about 3-5 mBq/l. The uptake of radionuclides from soil to plant is usually given as the ratio of dry matter radionuclide-activity concentrations of plant (ACplant) and soil (ACsoil) respectively. This ratio is called the soil transfer factor: STF = ACplant/ACsoil. The soil transfer factor varies widely between various types of crops with an average of about 0.056±0.003. The activity concentrations in leafy plants are, however highly affected by the atmospheric deposition of 210Pb and 210Po. By comparing the activity concentrations in plants grown on an open field with those grown on a field sheltered by a polyethylene tent, it has been possible to estimate a deposition transfer factor: DTF = Difference of the dry matter activity concentration (Bq.kg-1) of plant grown in open field and plants grown in tent shelter, divided by the atmospheric deposition during the vegetation period (Bq.m-2). The deposition transfer factor for 210Pb thus estimated is in the order of 0.5-1.0 (m2.kg-1 dry matter) for leafy plants like grass and 0.1-0.5 for less leafy plant and straw. For various grains it is < 0.2 and for root fruits it is < 0.003 (m2.kg-1 dry matter). Corresponding values for 210Po are about a factor 3 times higher. The world average activity concentration of 210Po in fresh leafy vegetable is estimated to 320±190 mBq.kg-1, and in cereals and grain products 240±80 mBq.kg-1. The average activity concentration in milk products is 59 ± 13 mBq.kg-1 and in meat products about 70 ± 39 mBq.kg-1. The dietary intake of milk and meat products is 170 kg.a- which is the highest of all food items of terrestrial origin. The

  1. 21 CFR 172.210 - Coatings on fresh citrus fruit.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Coatings on fresh citrus fruit. 172.210 Section 172.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... CONSUMPTION Coatings, Films and Related Substances § 172.210 Coatings on fresh citrus fruit. Coatings may...

  2. 46 CFR 174.210 - Watertight doors in watertight bulkheads.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Watertight doors in watertight bulkheads. 174.210 Section 174.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.210 Watertight doors in...

  3. 19 CFR 210.10 - Institution of investigation.

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Institution of investigation. 210.10 Section 210.10 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN... § 210.10 Institution of investigation. (a)(1) The Commission shall determine whether the complaint...

  4. A record of atmospheric Pb-210 deposition in The Netherlands

    Beks, J.P.; Eisma, D.; Van Der Plicht, J.

    1998-01-01

    The deposition flux of total atmospheric 210Pb has been measured at two sites in The Netherlands: Texel from 1992 to 1996 and Groningen from 1989 to 1994. With predominant westerly oceanic winds, the annual 210Pb deposition is relatively low as 222Rn, the source for atmospheric 210Pb, is mainly exha

  5. 40 CFR 210.3 - Contents of notice.

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Contents of notice. 210.3 Section 210.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS PRIOR NOTICE OF CITIZEN SUITS § 210.3 Contents of notice. (a) Violation of noise control...

  6. 46 CFR 177.210 - Plans for sister vessels.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Plans for sister vessels. 177.210 Section 177.210... TONS) CONSTRUCTION AND ARRANGEMENT Plans § 177.210 Plans for sister vessels. (a) Plans are not required... MSC or with the cognizant OCMI, the vessel owner shall submit plans as described in § 177.202 of...

  7. 46 CFR 108.210 - Hospital space not required.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hospital space not required. 108.210 Section 108.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Accommodation Spaces § 108.210 Hospital space not...

  8. 22 CFR 210.635 - Drug-free workplace.

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Drug-free workplace. 210.635 Section 210.635 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 210.635 Drug-free workplace. Drug-free workplace means a site for...

  9. The 210Pb technique for dating sediments, and some applications

    The use of 210Pb for dating sediment in time scale 100-150 years is described. Various methods of determination of 210Pb concentration are reviewed and the problem of the initial 210Pb concentration using two models for interpretation of data is discussed. (author)

  10. 21 CFR 333.210 - Antifungal active ingredients.

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  11. Determination of polonium-210 in cigarettes from Syria

    Various Syrian cigarettes (Hamra long filter, Oreidt, Granata, Palmyra, Hamra short filter) were analyzed for their 210Po content. 210Po was precipitated on a silver plate after chemical separation and measured by α-spectroscopy. The concentration values found for 210Po ranged between 0.02 and 0.08 pCi g-1. (author)

  12. 9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.210 Section 113.210 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.210 Feline Calicivirus Vaccine, Killed Virus. Feline...

  13. 46 CFR 28.210 - First aid equipment and training.

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false First aid equipment and training. 28.210 Section 28.210....210 First aid equipment and training. (a) Each vessel must have on board a complete first aid manual... location. (b) First aid and cardiopulmonary resuscitation (CPR) course certification. Certification...

  14. 7Be, 210Pb, and 210Po in the surface air from the Arctic to Antarctica

    In the present study we have investigated the activity concentrations of 210Pb, 210Po as well as 7Be in surface air of the North and South Atlantic (1988–1989), the Arctic Ocean (1991), and along the coastline of Siberia (1994) during succeeding expeditions in the Swedish Polar Research program. During the cruises in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average air concentrations of 7Be was 0.6 ± 0.4 mBq/m3, 210Pb 40 ± 4 μBq/m3 and 210Po-38 ± 10 μBq/m3. During the Swedish-Russian Tundra Ecology-94 expedition along the Siberian coastline the average air concentrations of 7Be and 210Pb measured during May–July were 11 ± 3, and 2.4 ± 0.4 mBq/m3, and during July–September they were 7.2 ± 2 and 2.7 ± 1.1 mBq/m3 respectively. The results from measurements of the activity concentration of 210Pb in the air over the Arctic Ocean vary between 75 and 176 μBq/m3. In the air close to land masses, however, the activity concentration of 210Pb in the air increases to 269–2712 μBq/m3. The activity concentration of 7Be in the South Atlantic during the cruise down to Antarctica varied between 1.3 and 1.7 with an average of 1.5 ± 0.8 mBq/m3. The activity concentration of 210Pb in the South Atlantic down to Antarctica varied between 6 and 14 μBq/m3. At the Equator the activity concentration recorded in November 1988 was 630 μBq/m3 and in April 1989 it was 260 μBq/m3. The average activity concentration of 210Pb during the route Gothenburg–Montevideo in 1988 was 290 and on the return Montevideo–Gothenburg it was 230 μBq/m3. The activity concentration of 210Po in the South Atlantic down to Antarctica varied between 15 and 58 μBq/m3. At the Equator the activity concentration in November 1988 was 170 and in April 1989 it was 70 μBq/m3. The average activity concentration of 210Po during the route Gothenburg–Montevideo in 1988 was 63 and on the return Montevideo–Gothenburg it was 60 μBq/m3. The average of the activity concentrations in the

  15. Separation of 210Pb, 210Bi and 210Po by ion exchange and their Iiquid scintillation standardization; Separacion del 210Pb, 210Bi y 2I0Po mediante columna de cambio ionico y su calibracion por centelleo liquido

    Rodriguez, L.; Jimenez, A.; Grau, A.

    1996-07-01

    We applied the CIEMAT/NIST method and alpha/beta discrimination to ''210Pb samples in equilibrium with its daughters, by preparing homogeneous and gel samples. The stability of samples was tested in different available cocktails, HiSafe''TM II, HiSafe''TM III, Ultima-Gold''TM, Ultima-Gold''TM XR, Ultima-Gold''TM AB, Insta-Gel''R and e Insta-Gel''R lI. Also we analyzed the disequilibrium of the radioactive chain 210Pb+210Bi+210Po, achieving an excellent agreement between the results of the spectrum unfolding method and the experimental values. (Author) 13 refs.

  16. Distribution and behaviour of 210Po and 210Pb in soil samples of Goa, south west coast of India

    This paper deals with the distribution and behaviour of 210Pb and 210Po in soil samples of Goa. Soil samples were collected and analysed for 210Po and 210Pb radionuclides using standard radiochemical analytical techniques. The activity of 210Po in surface soil vary from 3.2 Bq kg-1 to 186.2 Bq kg-1 with a mean value of 57.4 Bq kg-1 and that of 210Pb vary from 29.6 Bq kg-1 to 253.4 Bq kg-1 with a mean value of 119.9 Bq kg-1. Depth profile study reveals that the activity of 210Po and 210Pb decreases with the increasing depth. The results obtained from these studies are discussed in detail and compared with the literature values reported for other environs. (author)

  17. Ingestion of 210 Pb and 210 Po through fish consumption in the Cananeia-Iguape system, Sao Paulo State, Brazil

    In this work the ingestion of 210 Pb and 210 Po in the Cananeia - Iguape System, coast south of the Sao Paulo State was estimated. After the dissolution of the fish muscle (by microwave) radiochemical methods were applied for the analysis of those radionuclides.210 Pb was detected by using a Geiger-Muller detector while 210 Po by alpha spectrometry. The estimates of individual ingestion of 210 Pb and 210 Po for the fish of higher economical importance for the population of the System were of 0.004 and 0.035 Bq.d-1, respectively. Although, the levels of individual ingestion of these radionuclides obtained in this work are below the recommended levels it is advisable a periodic monitoring of these radionuclides in estuarine samples, especially, for the organisms such as fish that can be used as bio-indicators of 210 Pb and 210 Po. (author)

  18. Assessment of 210Po and 210Pb in marine biota of the Mallipattinam ecosystem of Tamil Nadu, India

    To provide baseline data on background radiation levels for the future assessment of the impact of nuclear and thermal power stations, a systematic study was carried out in the Mallipattinam ecosystem of Tamil Nadu, India. Mallipattinam is located between the Kudankulam and Kalpakkam nuclear power plants and near to Tuticorin thermal power plant. Water, sediments, seaweeds, crustaceans, molluscs, and fish were collected to measure the concentrations of 210Po and 210Pb. The concentrations of 210Po and 210Pb in most samples are comparable to values reported worldwide. In fish, the concentrations of 210Po and 210Pb are in the range 16-190 Bq kg-1 and 8-153 Bq kg-1, respectively. The concentration factors of 210Po and 210Pb for the biotic components ranges from 103 to 106.

  19. Distribution of 210Pb and 210Po concentrations in wild berries and mushrooms in boreal forest ecosystems

    The activity concentrations and distribution of 210Pb and 210Po in wild berries and edible mushrooms were investigated in Finnish forests. The main study areas were located in Scots pine (Pinus sylvestris L.) forests in southern and northern Finland. The activity concentrations of 210Pb and 210Po in blueberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) samples decreased in the order: stems > leaves > berries (i.e. fruits). The activity ratios of 210Po/210Pb in the wild berry samples were mainly higher than one, indicating elevated activity concentrations of polonium in the samples. In mushrooms the activity concentrations of 210Pb and especially 210Po were higher than in fruits of the wild berries. The highest activity concentration of 210Pb was detected in Cortinarius armillatus L. (16.2 Bq kg-1 d.w.) and the lowest in Leccinum vulpinum L. (1.38 Bq kg-1 d.w.). The 210Po activity concentrations of the whole fruiting bodies ranged from 7.14 Bq kg-1 d.w. (Russula paludosa L.) to 1174 Bq kg-1 d.w. (L. vulpinum L.). In general, the highest activity concentrations of 210Po were recorded in boletes. The caps of mushrooms of the Boletaceae family showed higher activity concentrations of 210Po compared to the stipes. In most of the mushrooms analyzed, the activity concentrations of 210Po were higher than those of 210Pb. 210Po and 210Pb dominate the radiation doses received via ingestion of wild berries and mushrooms in northern Finland, while in southern Finland the ingested dose is dominated by 137Cs from the Chernobyl fallout.

  20. Natural radionuclides 210Po and 210Pb in the Delaware and Chesapeake Estuaries: modeling scavenging rates and residence times

    During the spring and summer months of 2012, 210Po and 210Pb activity were measured in the dissolved and particulate phases from the Delaware and upper Chesapeake estuaries. The upper Delaware estuary, near the freshwater end member, was characterized by high-suspended matter concentrations that scavenged dissolved 210Po and 210Pb. Box models were applied using mass balance calculations to assess the nuclides residence times in each estuary. Only 60% of the dissolved 210Po and 55% of the dissolved 210Pb from the Delaware estuary were exported to coastal waters. A large fraction of soluble 210Po and 210Pb within the estuary was either reversibly adsorbed onto suspended particles, trapped in sediment accumulation zones (such as intertidal marshes), bioaccumulated into phytoplankton and discharged to the coastal ocean. The upper Chesapeake estuary was largely characterized by sub-oxic bottom waters that contained higher concentrations of dissolved 210Po and 210Pb, hypothesized to be subjected to redox cycling of manganese. The Delaware and Chesapeake estuary mean residence times for 210Po differed significantly at 86 ± 7 and 126 ± 10 days respectively, while they were similar for 210Pb (67 ± 6–55 ± 5 days). The difference in residence times corresponds to the greater extent of biogeochemical scavenging and regeneration processes within the upper Chesapeake. - Highlights: • Estuarine 210Pb and 210Po data reveal key biogeochemical processes and rates. • Delaware Bay displays regional differentiation due to dominant particle reactions. •Chesapeake Bay displays vertical differentiation from deep sub-oxic redox cycling. • Parent (210Pb) grand-daughter (210Po) disequilibria evidence principle processes. • Net scavenging residence times calculated weeks (Delaware) to months (Chesapeake)

  1. Separation and electrodeposited of 210 Po

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D2EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N+2, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  2. Blastomogenic effect of 210Po on rats

    A single intraperitoneal administration of 210Po (0.3-20.0 μ Ci/kg) to rats induced development of tumors of thyroid gland (25% of cumulative incidence of tumors), kidneys (11.7%), mammary gland (9.2%), hypophysis (9.2%), large intestine (8.3%), liver, adrenal glands, ovaries, parathyroid gland, prostate, subcutaneous connective tissue and leukosis (8.3%). With the dose increase from 0.3 to 2.4 μ Ci/kg, the incidence of tumors increases from 25 to 50% of total number of rats with a latency period of 580-425 days, respectively. It can be assumed that the ''virtually ineffective'' dose of 210Po, as determined by the criterion of tumor occurrence in rats, constitutes 0.006 μ Ci/kg

  3. An assessment of 210Pb and 210Po in terrestrial foodstuffs from regions of England and Wales

    Based on data for nationally available foodstuffs, naturally occurring 210Pb and 210Po contribute significantly to the UK radiation dose from dietary intake. To provide a more complete overview of radiological implications to the public, samples of offal, cereal, fruit, root and green vegetables were collected from 11 sites, including regions of potential 210Pb and 210Po enhancement. Considerable variability was evident in levels of 210Pb and 210Po from all sites and in all food types investigated. Higher concentrations were typically found in offal and cereals. Lowest concentrations were generally found in root vegetables. Between sites, the only evidence of elevated concentrations of 210Po occurred at Helston (210Po 3.0 Bq kg-1 in bovine liver, no other offal sample exceeding 0.8 Bq kg-1), and Holyhead 210Po 0.4 Bq kg-1 in blackberries, no other fruit sample exceeding 0.1 Bq kg-1). Other foodstuffs from these sites did not show similar enhanced levels of 210Po. The maximum dose arising from consumption of 210Pb and 210Po in foods surveyed in this study is estimated to be around 120 μSv year-1 to adults. This compares with an estimated UK average consumption dose from all nuclides and foodstuffs of 300 μSv year-1 (broad range 100-1000 μSv year-1). (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. Assessment of soil contamination by (210)Po and (210)Pb around heavy oil and natural gas fired power plants.

    Al-Masri, M S; Haddad, Kh; Doubal, A W; Awad, I; Al-Khatib, Y

    2014-06-01

    Soil contamination by (210)Pb and (210)Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of (210)Pb and (210)Po were found to be the main source of surface soil contamination. The results showed that (210)Pb and (210)Po in fly-ash (economizer, superheater) is highly enriched with (210)Pb and (210)Po, while bottom-ash (boiler) is depleted. The highest (210)Pb and (210)Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, (210)Pb and (210)Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased. PMID:24602817

  5. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  6. Atmospheric environment for ASTP (SA-210) launch

    Johnson, D. L.

    1976-01-01

    A summary is presented of selected atmospheric conditions observed near ASTP/SA-210 launch time on July 15, 1975, at Kennedy Space Center, Florida. Values of ambient pressure, temperature, moisture, ground winds, visual observations (cloud), density, index of refraction, and wind/wind shear aloft are included. A final meteorological data tape for the ASTP launch, consisting of wind and thermodynamic parameters versus altitude, has been constructed.

  7. The Litvinenko 210polonium case. German experiences

    The high scientific standards of the BfS were necessary in order to characterize and evaluate the low activities of 210Po found during the deployment in Hamburg. The evaluation of the measurements enabled the BfS to offer effective radiation protection advice and to assist the police investigation. The majority of the 210Po traces were found in places that had been in skin contact with Kovtun, leading to the conclusion that Kovtun had most probably incorporated 210Po before his visit to Hamburg in October 2006. As yet, no formal charges have been brought by the German authorities against Kovtun and the costs of the operation remain under discussion. Strategies to improve the internal and external deployment communication of the ZUB are being developed and implemented to deal with both the real and the perceived threats that occur during such an incident. Open communication from the onset of a deployment is essential, both between the institutions involved and between deployment leaders and the press. This will save precious time and resources, lower anxiety in the public and emergency workers and could, in a culture of trust where radiation protection advice is listened to and followed, ultimately save lives. (orig.)

  8. Temporal changes of 210Po in temperate coastal waters

    The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green algae Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. Littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins

  9. Leaching of 210Po in human saliva from smokeless tobacco

    Use of smokeless tobacco (SLT) is associated with cancer of the oral cavity. 210Po, a known carcinogen present in SLT may leach into the saliva when the snuff is held in the mouth. Alpha emission from leached 210Po can cause oral tissue damage, especially in the presence of non healing ulcers seen frequently in snuff users' mouth. Leaching of 210Po from SLT in human saliva was determined for six popular US snuff brands. 210Po was leached into human saliva for 30 min, separated radiochemically and its activity was determined by α-counting. Approximately 2-10% of 210Po present in SLT was observed to leach. Annual exposure from leached 210Po, based on average daily consumption of 15 g of SLT, was calculated to range from 1.1 to 3.8 Bq year-1. (author)

  10. Uptake and kinetics of 226Ra, 210Pb and 210Po in big sage brush

    Root uptake of 226Pb and 210Po by mature sage brush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sage brush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 mo for A 2 y period. Significant levels of activity were detected in the vegetation beginning at the first sampling (81 d after soil injection for 226Ra, 28 d for 210Pb and 210Po). There was an exponential decrease in concentration to an apparent steady state value. Mean values (geometric) of the data pooled over the second year period indicated that steady-state Cr's for 226Ra, 210Pb and 210Po, as determined in mature sage brush, were 0.04, 0.009, and 0.08, respectively. Investigations were also carried out to verify the suitability of soil injection for uptake studies and to evaluate the time dependence of 226Ra leaching from sage brush leaves. The soil injection method was determined to produce, on the average, uptake equivalent to that produce by a uniform soil distribution, however, the variety of uptake for plants growing in injected soil was higher than for plants growing in uniformly contaminated soil. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of 226Ra, 210Po in vegetation as a function of time after soil spiking

  11. 210Po and 210Pb levels in mussels and fish from Slovenian market and the related dose assessment

    Polonium-210 (t1/2 = 138 d) is a decay product of uranium-radium decay chain and consequently widely spread in the environment. It enters organisms through direct uptake, ingestion or inhalation. It is a pure alpha emitter and its radiotoxicity is connected with the fact that emits alpha particles with relatively high energy of about 5.3 MeV. It is concentrated in the soft tissues such as mussel, liver and others, where significantly contributes to the internal dose. Beta emitter lead-210 (t1/2 = 22.17 years) is the second highest radiotoxic radionuclide from uranium-238 decay chain and decays, through bismuth-210 (t1/2 = 5.01 d) into 210Po. Therefore it is necessary to determine the 21Po in foods, especially in seafood, because of its accumulation capacity. 210Po and 210Pb were determined in mussels (Mytilus galloprovincialis) and fish (salmon, trout) from Slovenia market. Mussels were bought on the local market as well as from domestic producers. Fish of Slovenian origin were bought on the local market. Samples were freeze dried, homogenized and assayed for 210Po and 210Pb. First, radiochemical separation was performed, followed by alpha particle spectrometric measurement of 210Po and beta counting of 210Pb on a low background gas-flow proportional counter. The results obtained show that the activity concentrations of 210Po in mussels varied from 0.9 to 191 Bq/kg of fresh mass and for fish from 0.3 to 2.12 Bq/kg of fresh mass, while for 210Pb they varied from 1.5 to 6.9 Bq/k of fresh mass for mussels and in fish samples the activity concentrations were less than 1.9 Bq/kg of fresh mass. Combined annual ingestion doses due to 210Po and 210Pb for mussels and fish from the Slovenian market is assessed. (author)

  12. Scavenging and fractionation of particle-reactive radioisotopes 7Be, 210Pb and 210Po in the atmosphere

    Chen, Jinfang; Luo, Shangde; Huang, Yipu

    2016-09-01

    The scavenging and fractionation of 7Be, 210Pb, and 210Po in the atmosphere are investigated by measuring their activities in rainwater collected from 68 rain events during March 2004 to April 2006 at a coastal station of Xiamen, southeastern China. In addition to documenting the large temporal variations in activities, fluxes, and isotope ratios of 7Be, 210Pb and 210Po in rainwater and the role of rainfall intensity in radionuclide scavenging, our results show that an enhanced deposition of 7Be and 210Pb occurs in the spring than in other seasons and is attributed to the "funnel effect" due to the increased atmospheric vertical convective mixing in the spring. This latter hypothesis is further supported by the observed seasonal and inter-annual variations in 7Be/210Pb and 210Po/210Pb ratios showing that the weakening of vertical convective mixing or stratosphere-troposphere exchange (STE) at the study site is linked with the enhancement of summer monsoons. It appears that the rainfall intensity, in connection with the vertical (e.g., STE) and horizontal (summer monsoons) air transport, exerts an important control on the activities, fluxes, and isotope ratios of 7Be, 210Pb, and 210Po in the atmosphere. Application of the observational data to a theoretical model shows that there are significant fractionations among 7Be, 210Pb, and 210Po in the atmosphere, with the scavenging rate constant or reciprocal of the residence time of radionuclide in the atmosphere being 210Pb > 7Be > 210Po. A revised Poet et al. (1972)'s method is proposed for quantitative constraint on the scavenging behavior of radionuclide, aerosols, and aerosol-associated trace pollutants in the atmosphere.

  13. Polonium ({sup 210}Po) and lead ({sup 210}Pb) in marine organisms and their transfer in marine food chains

    Carvalho, Fernando P., E-mail: carvalho@itn.p [Instituto Tecnologico e Nuclear, Departamento de Proteccao Radiologica e Seguranca Nuclear, E.N. 10, 2686-953 Sacavem (Portugal)

    2011-05-15

    The determination of {sup 210}Po and {sup 210}Pb was performed in marine organisms from the seashore to abyssal depths, encompassing a plethora of species from the microscopic plankton to the sperm whale. Concentrations of those radionuclides ranged from low values of about 5 x 10{sup -1} Bq kg{sup -1} (wet wt.) in jellyfish, to very high values of about of 3 x 10{sup 4} Bq kg{sup -1} (wet wt.) in the gut walls of sardines, with a common pattern of {sup 210}Po > {sup 210}Pb.These radionuclides are primarily absorbed from water and concentrated by phyto- and microzooplankton, and then are transferred to the next trophic level along marine food chains. Investigation in epipelagic, mesopelagic, bathypelagic and abyssobenthic organisms revealed that {sup 210}Po is transferred in the marine food webs with transfer factors ranging from 0.1 to 0.7, and numerically similar to those of the energy transfer in the marine food chains. As {sup 210}Po preferentially binds to amino acids and proteins, its transfer in food chains likely traces protein transfer and, thus, {sup 210}Po transfer factors are similar to ecotrophic coefficients. {sup 210}Pb is transferred less efficiently in marine food chains and this contributes to increased {sup 210}Po:{sup 210}Pb activity ratios in some trophic levels.

  14. Correlation of /sup 210/Po and /sup 210/Pb enrichments in the sea-surface microlayer with neuston biomass

    Heyroud, M.; Cherry, R.D. (International Laboratory of Marine Radioactivity, Musee Oceanographique (Monaco))

    1983-01-01

    Samples of surface microlayer, bulk seawater from 20 cm depth and neustonic organisms inhabiting the top 5 cm of the sea, were collected at regular intervals over a period of 17 months at a site 3 km off Monaco and analysed for naturally occurring radionuclides /sup 210/Po and /sup 210/Pb. Enrichment of /sup 210/Po in the microlayer compared with bulk seawater was observed, and found to be correlated significantly with the neuston biomass per unit volume. Enrichment of /sup 210/Pb in the microlayer was also observed, but only under higher neuston biomass conditions. The /sup 210/Po: /sup 210/Pb ratio was always higher in the microlayer than in bulk seawater. Additional information was obtained from /sup 210/Po measurements made on the bulk seawater in which the neuston had been collected and in which it had stood for periods of 2 to 4 h. These showed the neuston lost /sup 210/Po to the water at a rate of about 1 pCi g/sup -1/ dry biomass h/sup -1/. A significant flux of /sup 210/Po from bulk seawater to the surface microlayer, and thence possibly to the atmosphere, is estimated. This flux will vary seasonally with the planktonic biomass. Under high biomass conditions a similar flux for /sup 210/Pb may also be significant.

  15. Studies on the distribution of 210Po and 210Pb in the ecosystem of Point Calimere Coast (Palk Strait), India

    A systematic study on the natural radionuclides such as 210Po and 210Pb in the environmental matrices of Point Calimere ecosystem has been undertaken to establish a baseline data on the radiation profile of Point Calimere environment. The environmental samples such as water, sediment and biota (seaweeds, crustaceans, molluscs and fish) have been subjected to analyses. It has been observed that the concentration of 210Po and 210Pb in the water samples of Point Calimere to be 0.5 mBq/l and 1.3 mBq/l, respectively. The soft tissues of the organisms accumulated higher 210Po content while shells and bones contained more 210Pb. The bivalve molluscs Meretrix casta have been identified to accumulate higher concentration of 210Po suggesting that they could serve as bio-indicator of radionuclides like 210Po in the Point Calimere ecosystem. The concentration factor of 210Po for the biotic components ranged from ∼103 to 106 while for 210Pb it ranged from ∼103 to 105

  16. The fractionation and determination procedures for the speciation of 210Pb and 210Po in soil samples

    A method for speciation and determination of 210Pb and 210Po in soil samples was developed. The speciation was carried out by fractionating the soil samples into five fractions which are water soluble or exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and bound to residue. After mineralisation, 10% solution of each fraction was used to spontaneously deposit polonium on a silver disk at 85-90 deg. C and pH 1.5, and 210Po was measured by α-spectrometry; the remain solution was used to separate lead by anion-exchange resin and purified by precipitation as PbS and PbSO4, and 210Pb was determined by a low background β-counter. The IAEA-327 reference material (soil) was studied for 210Pb and 210Po speciation. The results show that: (1) the average yields are 88.7 ± 6.4% for 210Pb and 93.8 ± 8.2% for 210Po; (2) if compared to the total 210Pb activity in the sample, 210Pb fractions are 0.95% in exchangeable form, 10.6% bound to carbonates, 14.3% bound to Fe-Mn oxides, 7.0% bound to organic matter and 67.2% bound to residue or acid soluble, and the corresponding values for 210Po are 0.17%, 0.97%, 21.0%, 0.47% and 77.4%, respectively; and (3) the obtained 210Pb concentration is in good agreement with the recommended value given by the IAEA

  17. Review of the distribution of 210Pb in the world oceans and 210Pb/226Ra ratio as scavenging tracer

    It was first shown by Rama et al. (1961) that 210Pb has a very short residence time and is remove quickly from the surface waters by suspended particulate matter. Since the first application of the daughter-parent pair in the 238U series (210Pb/226Ra) for deep-scavenging studies by Craig et al (1973), a number of vertical profiles from major ocean basins have been published to investigate the residence time and scavenging rates of 210Pb. The vertical distributions of 210Pb in the deep-ocean vary widely, depending on its supply rates (the atmospheric deposition rate of 210Pb and production from 226Ra) and the intensity of scavenging. The inventories of 210Pb in the 3 distinct zones of the deep ocean (epipelagic, mesopelagic and bathypelagic zones) will be assessed and compared to the total supply rates. The variations in the scavenging intensities in these three zones will be assessed and presented. The inventory of 210Pb in the euphotic zone will be compared to the global atmospheric fallout data and the relative contribution of advection, production from 226Ra and atmospheric depositional input to the 210Pb inventory will be discussed. Evaluation of the distinct differences between different ocean basins in the supply rates as well as the scavenging intensities of 210Pb is assessed and the results will be presented. Using the 210Pb/226Ra ratios in the water column the scavenging residence times obtained for different ocean basins will be compared. The utility of 210Pb-226Ra pair towards studying boundary scavenging, sediment focusing/erosion, and settling velocity of particles based on the water column profiles, sediment trap data and inventories of 210Pb in sediments will also be presented. The utility of 210Pb as a tracer for other lithogenic elements in the marine environment will be discussed and the results will be summarized. (author)

  18. Transfer of 226Ra, 228Ra, 210Pb and 210Po in aquatic organisms and food chain

    Objective: To find out the transfer regularities of 226Ra, 228Ra, 210Pb and 210Po, which are natural radionuclides in the aquatic organisms and food chain. Methods: Large amount of breed of representative aquatic products and their living waters and sediments were collected and treated according to routine experimental procedures. The contents of 226Ra, 228Ra, 210Pb and 210Po were detected in each sample. Measured data were analyzed statistically and pairwise comparisons were made to determine the differences between groups. Results: 226Ra, 228Ra and 210Pb were mainly deposited in the bones (or shells), their concentration factors (CF) ranged from 102 to 103; the CF ranged only from 100 to 102 in the flesh. 210Po was mainly deposited in the soft tissues, CF ranged from 102 to 104; especially in the stomachs and intestines of fishes, the value reached 104. The cooking process did not impinge significantly on the transfer of 226Ra, 228Ra and 210Pb in the food chain (P>0.05), but did significantly influence the transfer of 210Po, especially in the freshwater fishes and shrimps. Paired comparison test of the activities between raw flesh and cooked flesh showed very significant difference (P226Ra, 228Ra, 210Pb and 210Po. Even though the bones (or shells) of aquatic organisms contained relatively higher levels of 226Ra, 228Ra and 210Pb, the cooking process does not significantly increase the radioactive contents in the foodstuffs. However, the cooking process does significantly influence the transfer of 210Po. It does significantly increase the content of 210Po in foodstuffs

  19. Cascade ultrafiltering of 210Pb and 210Po in freshwater using a tangential flow filtering system

    A rapid method was developed using ultrafilters with a tangential flow filtering system for molecular size separation of naturally occurring 210Pb and 210Po in a freshwater sample. Generally, ultrafiltering of a large volume water sample for measuring the nuclides was too time consuming and not practical. The tangential flow filtering system made the filtering time short enough to adapt for in-situ ultrafiltering the large volume sample. In this method, a 20 liter water sample was at first passed through the 0.45 μm pore size membrane filter immediately after sample collection to obtain suspended particle matter [>0.45 μm particulate fraction (PRT)]. Two ultrafilters (Millipore Pellicon 2R) were used sequentially. The nuclides in the filtrate were separated into three fractions: high molecular mass (100 kDa-0.45μm; HMM), low molecular mass (10 k-100 kDa; LMM) and ionic (210Pb and 210Po in an oligotrophic lake, Lake Towada located in the northern area of Japan. (author)

  20. Allometric relationships of 210Po and 210Pb in mussels and their application to environmental monitoring

    Mussels from the Portuguese coast collected during several seasons of the year have shown 210Po and 210Pb body burdens (Bq mussel-1) that increased with mussels' body size but displayed significant decrease in radionuclide concentrations (Bq kg-1). For example, the increase of mussel size from 2.5 cm to 5.0 cm maximum shell length corresponded in average to a 50% decrease of 210Po activity concentration in soft tissues from 1065 Bq kg-1 (dw) to 540 Bq kg-1 (dw). A similar reduction in concentration was observed for 210Pb. The physiological condition of mussels, relating to fat and glycogen storage, had an effect on radionuclide concentrations, although the total body burden of radionuclide in mussels remained nearly constant throughout the year. These factors may play an important role in data interpretation for environmental monitoring programmes. Besides the mussel size and condition index, due to the inter-individual variation even inside narrow mussel size classes, the sample size, i.e., the number of specimens in one mussel sample is another key factor to be considered when obtaining environmentally representative radionuclide concentrations.

  1. 210Po and 210Pb concentration in drinking water of Bangalore and its surroundings

    Drinking water samples collected from different locations of Bangalore and its surrounding area were analysed for the activity concentrations of 210Po and 210Pb by employing radiochemical analysis. The measure concentration of 210Po varies from 0.46 to 36.46 mBq L-1 with a mean of 6.17 mBq L-1 and that of 210Pb ranges from 1.19 to 56.95 mBq L-1 with a mean of 13.98 mBq L-1. The activity concentrations of these radionuclides were found to be low at the place Kambasandra and high at Kalkere. The range and the mean value obtained in the present study are well within the guidance value of 100 mBq L-1 as prescribed by World Health Organization. From the measured concentrations of these radionuclides, the annual effective dose was calculated for different age groups: for babies (age below 1 y), children (age from 2 to 7 y) and adults (age from 17 y and above) using IAEA dose conversion factors and the prescribed water consumption rates. The total dose received is very much less than the ICRP recommended value of 1000 μ Sv y-1 for all age groups. (author)

  2. Distribution of polonium-210 in the human lung

    Polonium-210 has been measured in the tracheobronchial tree and parenchyma of cigarette smokers and nonsmokers in order to determine whether this α emitter is retained in smokers. The ratio of 210Po concentration in the tracheobronchial tree (T) to that in the lung parenchyma (P) in nonsmokers is T/P = 2.7 +- 0.5. The ratio in smokers is T/P = 1.1 +- 0.2. The difference in these ratios can be related to retention of 210Po, or its 210Pb precursor in the parenchymal tissue. About 5 pCi deposited and retained on alveolar surfaces and an average excess of 0.3 pCi 210Po retained on the tracheobronchial tree is estimated for smokers. Measurements in exsmokers result in a ratio (T/P) = 0.8 +- 0.4 and is possibly related to long-term retention of deposited 210Pb in alveolar tissue

  3. The Radiological Impact of 210Pb and 210Po Released from the Iron- and Steel-Making Plant ILVA in Taranto (Italy) on the Environment and the Public

    Guogang Jia

    2013-01-01

    Lead-210 and 210Po are naturally occurring radionuclides. Due to volatile characteristic of lead and polonium, environmental pollution of 210Pb and 210Po released from the coal power plant, steel-making industry and refractory material industry has been an exposure problem for the members of public. In this paper studies on the activity concentrations of 210Po and 210Pb in the raw materials, dust particles, surficial soils and atmospheric particulate samples collected in the area of the Iron-...

  4. The Litvinenko Polonium-210 case - German experiences

    This paper brings together the measurement results taken and the lessons learned by the German Federal Office for Radiation Protection during the polonium-210 incident in Hamburg in late 2006. The incident was pivotal in confirming the importance of the defence against nuclear hazards in Germany and for highlighting the role of communication in the success of a deployment. The background of the case is reviewed and an overview of the German defence against nuclear hazards is given. The various measurement tasks, both at the scene and in the laboratory, and their results are summarized along with the communication challenges experienced. The main conclusions are that the traces of polonium-210 found at the sites were of little radiological consequence and the German defence against nuclear hazards in Germany delivered an excellent and measured response to the incident. However, communication challenges still exist and communication with the public and the emergency responders has to be given high priority during future deployments in order to ensure their success. (author)

  5. The Litvinenko polonium-210 case - German experiences

    This paper brings together the measurement results taken and the lessons learned by the German Federal Office for Radiation Protection during the polonium-210 incident in Hamburg in late 2006. The incident was pivotal in confirming the importance of the defence against nuclear hazards in Germany and for highlighting the role of communication in the success of a deployment. The background of the case is reviewed and an overview of the German defence against nuclear hazards is given. The various measurement tasks, both at the scene and in the laboratory, and their results are summarized along with the communication challenges experienced. The main conclusions are that the traces of polonium-210 found at the sites were of little radiological consequence and the German defence against nuclear hazards in Germany delivered an excellent and measured response to the incident. However, communication challenges still exist and communication with the public and the emergency responders has to be given high priority during future deployments in order to ensure their success. (author)

  6. Study about excretion of 210 Po in urine

    The urine of mines's workers are analysed to detect the presence of 210 Po. The results was compared with the workers and with a control population. Cigarettes samples was analysed two and confirmed the 210 presence. The control population individuals were divided in smokers and non smokers and them urine was investigated the influence of the smoke in the 210 Po excretion. (L.M.J.)

  7. Atmospheric injections of polonium-210 from the recent volcanic eruptions

    The concentrations of 210Pb and 210Po in a total of 73 samples of individual rain and snow collected at Fayetteville (360N, 940W), Arkansas, were determined radiochemically during the period between October 1982 and January 1984. A clear seasonal pattern of variation of the 210Po/210Pb ratio in rain was observed: the ratio reaches a maximum during the months of November and December of January and February each year. The 210Po/210Pb ratio data obtained in our laboratories since 1971 were compared with the results of the studies on seasonal variation of the sulfate concentrations in the stratosphere reported by Sedlacek et al. (1983) and the following general trend was observed: the occurrence of a peak sulfate concentration in the stratosphere caused by a major volcanic eruption is followed by the occurrence of a peak 210Po/210Pb ratio in rain and snow samples collected several months later. Effect of the atmospheric injections of exess 210Po from major eruptions of volcanoes located in Alaska, Aleutian Islands, Kamchatka and Kurile Islands can be seen more clearly at Seattle (470N, 1220W), Washington, than at Fayetteville (360N, 940W), Arkansas. (author)

  8. Assessment of 210Po in foodstuffs consumed in Korea

    210Po in the daily diet in Korea was analyzed and the ingestion dose from an intake of 210Po was estimated by considering the dietary habit of a Korean person. The 210Po concentrations of a leafy vegetable (0.36 Bq x kg-1 for lettuce) in the terrestrial food were higher than those of grain, whereas Chinese cabbage had a lesser 210Po concentration (0.019 Bq x kg-1). The 210Po concentration of the animal product was similar to those detected in the grain and vegetable. The 210Po concentrations in the shell and crustaceous were high from 19.1 to 33.0 Bq x kg-1, however, its value fell in the overall range of the reported values. The effective dose from 210Po for an adult from the Korean population was about 269.4 μSv x y-1. Nearly 80% of the ingestion dose from the intake of 210Po was attributed to the consumption of seafood. It suggests that the marine food ingestion is a critical pathway for natural 210Po to the Korean population. (author)

  9. 210Po in Mytilus edulis in the Irish marine environment

    210Po is available to the Irish marine environment as a result of natural and anthropogenic processes. As it constitutes a significant portion of the radiation exposure of the population through the consumption of seafood, it is of interest to identify a suitable bio-indicator to monitor fluctuations of 210Po concentrations in the marine environment. Mytilus edulis was examined to assess the geographical variation in 210Po concentrations around the coast of Ireland. Temporal variations and the effect of mussel size on their 210Po contents at two sites, Sutton and Carlingford, were also examined. Chemical techniques for the separation of 210Po from mussels, seawater and suspended particulate are described. These methods use 209Po as a chemical yield monitor, microwave systems and Teflon bomb procedures for sample digestion. The concentration of 210Po in mussels around the coast was found to vary between 80±9 Bq kg-1 (dry wt.) at Seapark near Belfast and 468±32 Bq kg-1 (dry wt.) at Sutton in Dublin. The two sites at Sutton and Carlingford, which displayed similarities in terms of mussel morphology and 210Po concentration in water, exhibited significant temporal variations in mussel concentration. Furthermore, relationships derived from both sites indicate a strong linear dependency between mean 210Po content and mean mussel dry weight with higher concentrations of 210Po found in smaller mussels at a given site. Concentration ratios for mussels and water are also presented. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Geochemistry of 210Pb in the southeastern, US estuarine system

    This study was an attempt to determine the geochemical behavior of 210Pb in southeastern salt marsh estuaries. As a part of this study the 210Pb dating technique was applied to natural and anthropogenic deposits of the region. 210Pb activity of sediment and water from the Georgia coastal area was measured by alpha spectroscopy. The effects of grain size and carbon content of the sediment on 210Pb concentrations was evaluated and the activity of 210Pb in dissolved and particulate phases of rivers was measured as a function of salinity. Ages and sedimentation rates of sedimentary deposits were also determined for some deposits. 210Pb activity in dissolved and particulate phases of rivers showed no clear trends as functions of salinity. River particulate activities were three to four times higher than dissolved activities. The relationship between 210Pb activity in salt marsh sediments and grain size was highly significant. Direct application of the 210Pb method to date and determine sedimentation rates of natural and anthropogenic deposits was partially successful. The anthropogenic deposits, however, had to be dated on the basis of normalizing 210Pb activities to grain size (% silt and clay) and carbon content

  11. Radiolead (210)Pb and (210)Po/(210)Pb activity ratios in calcium supplements and the assessment of their possible dose to consumers.

    Strumińska-Parulska, Dagmara I

    2016-08-23

    This paper presents the results of pioneer study of the most popular calcium supplements as a potential additional source of radiolead (210)Pb in human diet. The analyzed calcium pharmaceutics contained organic or inorganic calcium compounds; some came from natural sources as mussels' shells, fish extracts, or sedimentary rocks. The idea was to investigate the naturally occurring (210)Pb activity in different calcium supplements and calculate the annual effective radiation dose from radiolead (210)Pb decay in consumed calcium supplement. The results showed (210)Pb concentrations in natural origin calcium supplements (especially sedimentary rocks) were significantly higher. The highest (210)Pb activity concentrations were determined in mineral tablets made from dolomite - 2.97 ± 0.18 mBq g(-1), while the lowest was observed in organic calcium compounds - both calcium lactate - 0.08 ± 0.01 and 0.13 ± 0.01 mBq g(-1). The highest annual radiation dose from (210)Pb taken with 1 tablet of calcium supplement per day was calculated for soluble calcium lactate sample - 1.19 ± 0.03 µSv year(-1), while the highest annual radiation dose from (210)Pb taken daily with 1 g of pure Ca for dolomite - 5.57 ± 0.34 µSv year(-1). PMID:27253716

  12. Distribution and biokinetic analysis of {sup 210}Pb and {sup 210}Po in poultry due to ingestion of dicalcium phosphate

    Casacuberta, N., E-mail: Nuria.Casacuberta@uab.es [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Traversa, F.L. [Departament d' Electronica, Escola Tecnica Superior d' Enginyeria, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Masque, P.; Garcia-Orellana, J. [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Anguita, M.; Gasa, J. [Departament de Ciencia Animal i dels Aliments, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Garcia-Tenorio, R. [Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla (Spain)

    2010-09-15

    Dicalcium phosphate (DCP) is used as a calcium supplement for food producing animals (i.e., cattle, poultry and pig). When DCP is produced via wet acid digestion of the phosphate rock and depending on the acid used in the industrial process, the final product can result in enhanced {sup 210}Pb and {sup 210}Po specific activities ({approx} 2000 Bq.kg{sup -1}). Both {sup 210}Pb and {sup 210}Po are of great interest because their contribution to the dose received by ingestion is potentially large. The aims of this work are to examine the accumulation of {sup 210}Pb and {sup 210}Po in chicken tissues during the first 42 days of life and to build a suitable single-compartment biokinetic model to understand the behavior of both radionuclides within the entire animal using the experimental results. Three commercial corn-soybean-based diets containing different amounts and sources of DCP were fed to broilers during a period of 42 days. The results show that diets containing enhanced concentrations of {sup 210}Pb and {sup 210}Po lead to larger specific accumulation in broiler tissues compared to the blank diet. Radionuclides do not accumulate homogeneously within the animal body: {sup 210}Pb follows the calcium pathways to some extent and accumulates largely in bones, while {sup 210}Po accumulates to a large extent in liver and kidneys. However, the total amount of radionuclide accumulation in tissues is small compared to the amounts excreted in feces. The single-compartment non-linear biokinetic model proposed here for {sup 210}Pb and {sup 210}Po in the whole animal takes into account the size evolution and is self-consistent in that no fitting parameterization of intake and excretions rates is required.

  13. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

    Gwynn, J.P.; Rudolfsen, G. [Norwegian Radiation Protection Authority, The Fram Centre, Tromsoe (Norway)

    2014-07-01

    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  14. 210Pb and 210Po concentrations in the Venice lagoon ecosystem (Italy) and the potential radiological impact to the local public and environment

    In order to evaluate the possible radiological impact to the local public and environment from a phosphogypsum stockpile, 210Po and 210Pb concentrations in river water, lagoon water, suspended matter, superficial sediment, algae and bivalves samples collected in Venice lagoon area have been investigated. The results show that the mean 210Po and 210Pb concentrations in river water are 1.42 ± 0.36 mBq x l-1 and 1.46 ± 0.39 mBq x l-1 with a mean 210Po/210Pb ratio of 0.98 ± 0.17 and about 60% of them are associated with the particulate; 210Po and 210Pb contribution from the phosphogypsum stockpile to the river water is negligible. Higher 210Po (2.61-5.67 mBq x l-1) and 210Pb (1.31-3.62 mBq x l-1) concentrations in the lagoon waters have been observed if compared with the literature values. About 60% of 210Po and 210Pb are found in the soluble form with a mean 210Po/210Pb ratio of 1.79 ± 1.47. 210Po and 210Pb concentrations in 28 out 37 sediment samples ranged from 26 to 45 Bq x kg-1 (dry weight), only 9 sediments with 210Po and 210Pb concentrations greater than 45 Bq x kg-1 are found and most of them are located 1-4 km near the phosphogypsum stockpile. The elevated 210Po and 210Pb concentrations in the sediments may be due to the contamination from the phosphogypsum stockpile. The mean 210Po/210Pb ratio (0.986 ± 0.049) in the sediments shows that 210Po and 210Pb exist in nearly secular equilibrium. 210Po and 210Pb concentrations in algae vary with different species. The mean 210Po and 210Pb concentrations in Gracilaria compress and Ulva laetevirens which show a similar behavior, are 3.18 ± 1.23 Bq x kg-1 and 2.42 ± 1.26 Bq x kg-1 (fresh weight), respectively, with a mean 210Po/210Pb ratio of 1.45 ± 0.34. The mean concentration factors with respect to the filtered water are 1096 ± 424 for 210Po and 1299 ± 680 for 210Pb. The mean 210Po and 210Pb concentrations in the soft part of Mytilus edulis are 23.2 ± 9.7 Bq x kg-1 and 0.537 ± 0.203 Bq x kg-1 (fresh

  15. Transfer of 210Po, 210Pb and 238U from some medicinal plants to their essential oils

    Essential oils were extracted from 35 medicinal plants used by Syrians, organic compounds were determined in these oils and concentrations of 210Po 210Pb and 238U were determined in the original plants and in the essential oils. The results showed that the highest activity concentrations of 210Po and 210Pb were found in leaves with large surfaces and in Sage were as high as 73.5 Bq kg−1 and 73.2 Bq kg−1, respectively. The activity concentration of 238U was as high as 4.26 Bq kg−1 in Aloe. On the other hand, activity concentrations of 210Po ranged between 0.2 and 71.1 Bq kg−1 in extracted essential oils for Rosemary and False yellowhead, respectively. The activity concentration of 210Pb reached 63.7 Bq kg−1 in Aloe oil. The activity concentrations of 238U were very low in all extracted oils; the highest value was 0.31 Bq kg−1 in peel of Orange oil. The transfer of 210Po and 210Pb from plant to its oil was the highest for Eugenia; 7.1% and 5.5% for 210Po and 210Pb, respectively. A linear relationship was found between the transfer factor of radionuclides from plant to its essential oil and the chemical content of this oil. - Highlights: • Natural radionuclides 210Po, 210Pb and 238U were determined in 35 medicinal plants and their essential oils. • The highest activity concentration of 210Po and 210Pb were 73.5 Bq kg−1 and 73.2 Bq kg−1 in Sage, respectively. • The transfer of 210Po and 210Pb from Eugenia plant to its oil was the highest amongst other plants. • The data obtained in this study can be considered the first reported data for medicinal plants and their oils in Syria

  16. Lead-210 and polonium-210 as marine geochemical tracers: review and discussion of results from the Laborador Sea

    Because of their suitable half-lives and their accurately measurable rates of supply to the oceans by decay of parent radionuclides, 210Pb and 210Po have become increasingly important as tracers in the study of marine geochemical processes. Short removal times characterize the behavior of both nuclides in the biologically productive surface layers of the sea. Release from particles at depth is efficient for 210Po but does not appear to be significant for 210Pb. Scavenging processes in the deep sea are revealed by 210Pb/226Ra and 210Po/210Pb disequilibriums. Adsorption by particles sinking in the water column and reaction at the seafloor both appear to be important removal mechanisms. Results from four stations in the Labrador Sea are shown to be consistent with many earlier observations. Significant 210Pb depletions, however, are found only at depths greater than 1500 m. Below 1500 m, 210Pb/226Ra ratios decrease steadily with depth to very low values in the Iceland-Scotland Overflow and Denmark Straits Overflow waters. The intense interaction of these water masses with the seafloor may account for this trend

  17. Compact Miniaturized Antenna for 210 MHz RFID

    Lee, Richard Q.; Chun, Kue

    2008-01-01

    This paper describes the design and simulation of a miniaturized square-ring antenna. The miniaturized antenna, with overall dimensions of approximately one tenth of a wavelength (0.1 ), was designed to operate at around 210 MHz, and was intended for radio-frequency identification (RFID) application. One unique feature of the design is the use of a parasitic element to improve the performance and impedance matching of the antenna. The use of parasitic elements to enhance the gain and bandwidth of patch antennas has been demonstrated and reported in the literature, but such use has never been applied to miniaturized antennas. In this work, we will present simulation results and discuss design parameters and their impact on the antenna performance.

  18. Separation and electrodeposited of {sup 210} Po; Separacion y electrodeposito de {sup 210} Po

    Ordonez R, E.; Iturbe G, J.L

    1991-12-15

    Presently work it was determined the selective separation of the {sup 210} Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D{sub 2}EHPA), it has been possible to isolate the {sup 210} Po of the rest of the radioactive elements that conform the family 4 N{sup +2}, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  19. Radiochemical analysis of Ra, 210Po, 210Pb, U and Th

    Full text: The analysis of isotopes of uranium, thorium, radium, 210Po and 210Pb is of great importance in fields where these isotopes are used as tracers or where dosimetric aspects are considered. Because of the emission of alpha, beta and gamma radiation from several of the isotopes a combined measurement strategy is often preferred (eg beta counting of 234Th followed by alpha spectrometry of 228,230,232Th). Also, due to their position in the natural decay chains it is sometimes an advantage to measure the concentration of the daughter products than the mother isotope itself (eg. 222Rn+daughters instead of analysing 226Ra directly). The presentation gives an overview of analytical techniques useful for separating the isotopes in a sequential manner from each other. (author)

  20. Normal dietary levels of 226Ra, 228Ra, 210Pb, and 210Po for man

    A review of the literature and the results of some recent measurements were presented on the levels in man's diet of the naturally-occurring radionuclides 226Ra, 228Ra, 210Pb, and 210Po. The mean intakes for standard U.S. diets for these nuclides are tabulated. Intakes in other countries are similar to those in the U.S., but in localized populations the 226Ra intake may be 8 or more pCi/day. The contents of 226Ra in diets chosen by individuals ranged from 0.4 to 7 pCi/day. The few data on 228Ra show intake of this nuclide to be about 80% that of 226Ra, except in monazite areas where intakes of up to 160 pCi/day 228Ra are reported, which may be 50 to 100 times that of 226Ra. Drinking water contributes less than 5% of the daily intake, except in special areas

  1. 14 CFR 221.210 - Suspension of tariffs.

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Suspension of tariffs. 221.210 Section 221...) ECONOMIC REGULATIONS TARIFFS Electronically Filed Tariffs § 221.210 Suspension of tariffs. (a) A fare, charge, rule or other tariff provision that is suspended by the Department pursuant to section 41509...

  2. 17 CFR 210.11-03 - Presentation of financial forecast.

    2010-04-01

    ... Information § 210.11-03 Presentation of financial forecast. (a) A financial forecast may be filed in lieu of the pro forma condensed statements of income required by § 210.11-02(b)(1). (1) The financial forecast... recent 12 month period in parallel columns with the financial forecast. (b) Such financial forecast...

  3. 5 CFR 930.210 - Reduction in force.

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Reduction in force. 930.210 Section 930... § 930.210 Reduction in force. (a) Retention preference regulations. Except as modified by this section, the reduction in force regulations in part 351 of this chapter apply to administrative law judges....

  4. 7 CFR 58.210 - Dry storage of product.

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Dry storage of product. 58.210 Section 58.210... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION, GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1...

  5. 43 CFR 46.210 - Listing of Departmental categorical exclusions.

    2010-10-01

    ..., procurement contracts (e.g., in accordance with applicable procedures and Executive Orders for sustainable or... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Listing of Departmental categorical exclusions. 46.210 Section 46.210 Public Lands: Interior Office of the Secretary of the...

  6. 12 CFR 210.29 - Agreement of receiving bank.

    2010-01-01

    ... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Agreement of receiving bank. 210.29 Section 210.29 Banks and Banking FEDERAL RESERVE SYSTEM BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM COLLECTION OF CHECKS AND OTHER ITEMS BY FEDERAL RESERVE BANKS AND FUNDS TRANSFERS THROUGH FEDWIRE...

  7. 17 CFR 210.4-07 - Discount on shares.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Discount on shares. 210.4-07..., PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT COMPANY ACT OF 1940, INVESTMENT ADVISERS ACT OF 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Rules of General Application § 210.4-07...

  8. 31 CFR 210.4 - Authorizations and revocations of authorizations.

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Authorizations and revocations of authorizations. 210.4 Section 210.4 Money and Finance: Treasury Regulations Relating to Money and Finance... corporate action, or the appointment of a receiver, conservator, or liquidator for the RDFI. In any...

  9. 20 CFR 637.210 - Incentive bonus program applications.

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Incentive bonus program applications. 637.210... UNDER TITLE V OF THE JOB TRAINING PARTNERSHIP ACT Program Planning and Operation § 637.210 Incentive bonus program applications. (a) Any State seeking to receive an incentive bonus under this title...

  10. Biomass Burning and Polonium-210 in the Atmosphere: a Review

    Carvalho, Fernando P. [Instituto Superior Tecnico/Campus Tecnologico e Nuclear/(IST/CTN), Universidade de Lisboa, Estrada Nacional 10 - ao km 139,7 - 2695-066 Bobadela LRS (Portugal)

    2014-07-01

    Naturally-occurring radionuclides, such as those of uranium series, are part of the lithosphere and hydrosphere and plants do accumulate them up to a certain extent being the activity concentrations in plants generally low, less than 10 Bq/kg (dry weight). Forest and vegetation fires, as well as biomass burning for energy production, release large amounts of carbon, particulate materials, and gaseous compounds into the atmosphere including the naturally-occurring radionuclides present in plants. Near forest fires, and at local and regional scales, surface aerosol sampling followed by radionuclide analysis showed enhanced radionuclide concentrations, especially those of {sup 210}Po. In surface air with smoke from wild fires {sup 210}Po concentration attained 70 mBq/m{sup 3}, more than 2000 times above {sup 210}Po background in surface air, and aerosols displayed {sup 210}Po/{sup 210}Pb concentration ratios up to 12, i.e., about 20 times higher than the average concentration ratio in surface air. Taking into account the amount of plant biomass burned every year, the total activity of {sup 210}Po released into the atmosphere from this source is able to disrupt the usual {sup 210}Po/{sup 210}Pb concentration ratios in atmosphere and atmospheric depositions. A review of atmospheric polonium sources is presented. (authors)

  11. 42 CFR 414.210 - General payment rules.

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false General payment rules. 414.210 Section 414.210 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for Durable...

  12. 21 CFR 175.210 - Acrylate ester copolymer coating.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  13. 210Polonium content of small cetaceans from Southeastern Brazil

    The 210Po concentration of muscle and liver samples obtained from dolphins stranded on beaches in the Southeastern region of Rio de Janeiro State was analyzed in the present study. The samples were primarily obtained from “Franciscana” (Pontoporia blainvillei) and “Guiana” dolphins (Sotalia guianensis); however, samples from four other species were also evaluated. The 210Po concentration of muscle samples obtained from “Franciscana” dolphins (66.7 ± 6.7, n = 8) Bq kg−1 w.w. was greater than that of “Guiana” dolphins (25.3 ± 5.7, n = 8) Bq kg−1 w.w. due to differences in the diets of these species. Alternatively, the 210Po concentrations of liver samples obtained from different species were statically equivalent. Compared to the results described in the literature, the muscle samples evaluated in the present study displayed lower 210Po concentrations, except for those obtained from “Franciscana” dolphins, which exhibited similar values. For “Franciscana” and “Guiana” dolphins, a clear relationship between the 210Po concentration of muscle and liver samples and the size of the dolphin was not observed. - Highlights: ► 210Po was determined in liver and muscle samples from twenty-four dolphins stranded. ► Higher 210Po concentration on muscle was observed on that specie which feeds on larger fish. ► No clear correlation between 210Po concentration on muscle and dolphin size was observed.

  14. Biomass Burning and Polonium-210 in the Atmosphere: a Review

    Naturally-occurring radionuclides, such as those of uranium series, are part of the lithosphere and hydrosphere and plants do accumulate them up to a certain extent being the activity concentrations in plants generally low, less than 10 Bq/kg (dry weight). Forest and vegetation fires, as well as biomass burning for energy production, release large amounts of carbon, particulate materials, and gaseous compounds into the atmosphere including the naturally-occurring radionuclides present in plants. Near forest fires, and at local and regional scales, surface aerosol sampling followed by radionuclide analysis showed enhanced radionuclide concentrations, especially those of 210Po. In surface air with smoke from wild fires 210Po concentration attained 70 mBq/m3, more than 2000 times above 210Po background in surface air, and aerosols displayed 210Po/210Pb concentration ratios up to 12, i.e., about 20 times higher than the average concentration ratio in surface air. Taking into account the amount of plant biomass burned every year, the total activity of 210Po released into the atmosphere from this source is able to disrupt the usual 210Po/210Pb concentration ratios in atmosphere and atmospheric depositions. A review of atmospheric polonium sources is presented. (authors)

  15. 42 CFR 495.210 - Meaningful EHR user attestation.

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Meaningful EHR user attestation. 495.210 Section... INCENTIVE PROGRAM Requirements Specific to Medicare Advantage (MA) Organizations § 495.210 Meaningful EHR... EHR user. (b) Qualifying MA organizations are required to attest within 60 days after the close of...

  16. Determination of lead 210 atmospheric fluxes in Syria

    Lead 210 atmospheric fluxes were determined by collecting 51 profiles from Syrian soil during 1998. Lead 210 fluxes in Syria calculated from lead 210 inventory in soil ranged from 15 Bq.m-2.y-1 and 407 Bq.m-2.y-1 with an average value of 128 Bq.m-2.y-1. the highest fluxes were found to be in Hama area due to the Gaab fault, which is considered as a radon source in the area. In addition, fluxes were also high in most sites, which are located in Syria valleys and around the lakes. Moreover, the study has indicated that there is no linear relation between lead 210 flux values and other parameters such as annual rainfall and bulk density of the soil. On the other hand, an effect, of those two factors on lead 210 distribution with depth has been observed. In addition, the results of variable lead 210 fluxes from site to another have proved that it is necessary, in order to obtain a representative mean value of lead 210 flux obtained in this study is within the worldwide range for lead 210 flux. (Author)

  17. 17 CFR 210.6-05 - Statements of net assets.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Statements of net assets. 210... Statements of net assets. In lieu of the balance sheet otherwise required by § 210.6-04 of this part, persons may substitute a statement of net assets if at least 95 percent of the amount of the person's...

  18. 49 CFR 210.25 - Measurement criteria and procedures.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Measurement criteria and procedures. 210.25... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD NOISE EMISSION COMPLIANCE REGULATIONS Inspection and Testing § 210.25 Measurement criteria and procedures. The parameters and procedures for the measurement...

  19. 47 CFR 10.210 - CMAS participation election procedures.

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false CMAS participation election procedures. 10.210... Election to Participate in Commercial Mobile Alert System § 10.210 CMAS participation election procedures... attesting to that fact. (c) CMS providers shall file their election electronically to the docket....

  20. 19 CFR 210.53 - Motion filed after complaint.

    2010-04-01

    ....53 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Temporary Relief § 210.53 Motion filed after complaint. (a) A... § 210.58 for review of the complaint and informal investigatory activity will begin to run anew from...

  1. 226Ra, 210Pb and 210Po levels in marine biota and surface coastal sediments from the Red sea, Sudan

    This paper presents data on 226Ra, 210Pb and 210Po activity concentration levels in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (flamingo bay) of Port Sudan harbour. The analyses were performed adopting a simple time efficient method combining alpha-spectrometry, liquid scintillation and Cerenkov counting technique. generally speaking, surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported form different coastal areas around the globe. There is surface enrichment of 210Pb and 210Po with respect to their progenitor 226Ra as it is evident form the activity ratios of 210Pb/226Ra (3.03±1.79) and 210Pb/226Ra (2.23±1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2 Bq/kg and 21.9 Bq/kg dry weight, respectively. Similarly, the highest concentration of 210Po was met in the favites at 38.7 Bq/kg followed by brown algae, cytoseria sp., at 32.6 Bq/kg. There is no variation seen among algal species for 210Pb uptake, however, converse to radium and polonium, favites (coral) was found to contain the minimum concentration of lead (3.88). In most species there is preferential accumulation of polonium over its parent radium as indicated by 210Po:226Ra activity ratio with cytoseria (brown algae) showing the highest value at 8.81. On the other hand, 210Po:220Pb activity concentration ratio revealed that coral species favites (9.97) and the brown algae sargassum (1.85) have a greater tendency to accumulate 210Po over220Pb, while in the rest of the species; this ratio is less than unity. (Author)

  2. Study of polonium-210 in tobacco in Tunisia

    Polonium-210 is a radio-isotopes natural α emitter, it cans be found in tobacco with a significant range. The high activity of 210Po in tobacco and cigarettes causes the absorption of a high dose of alpha radiation that caused probably lung cancer, the objective of this study is to estimate the activity of 210Po in tobacco matrix. Thirteen samples of cigarettes consumed in tunisia were experimented to determine the activity of this radionuclide. The PIPS, a silicon semiconductor, is used as on α spectrometry detector for the detection of 210Po in all of our samples. The final results showed a high radioactivity of 210Po from 11.77 to 25.31 mBq/g. We conclude that the effective annual average is estimated at 106.53 μSv / year.

  3. Estimation of 210Po in marine organisms at Mumbai, India

    210Po was estimated in the edible muscle of fifteen different marine species collected from Trans-Thane Creek area (Trombay) and Thane. Daily intake of 210Po and its radiation dose to human beings due to consumption of marine organisms collected from this particular area were assessed. Estimation of 210Po was carried out using radiochemical separation and alpha spectrometric technique. The concentration of 210Po was found to vary from 0.18 to 10.9 Bq kg-1wet wt in different biota species and maximum concentrations were observed in bivalves.The daily intake and individual dose of 210Po to human beings through biota consumption was calculated and found to be 31.89mBq d-1 and 19.44μSv yr-1 respectively. (author)

  4. Po-210 and Pb-210 concentration factors for zooplankton and faecal pellets in the oligotrophic South-West Pacific

    In a previous study on zooplankton sampled from very low productivity waters of French Polynesia, their Po-210 concentrations were found to be unexpectedly elevated, compared to values measured in marine zooplankton from various other geographical regions of the world. For the French Polynesian samples their Po-210 concentrations also increased appreciably as their biomass declined. A simple conceptual and mathematical model, that incorporated the established role of zooplankton faecal pellets in the removal of Po-210 and particle-reactive radionuclides and stable metals from the water column, could capture the shape of this empirical relationship between Po-210 concentration and their biomass and also explained the biomass-related mechanism that increases Po-210 concentrations in zooplankton. Similarly, a field investigation in the Timor Sea showed that a range of particle-reactive elements showed elevated water concentrations as particle removal rates, as inferred from Th-234: U-238 disequilibria, reduced in the euphotic zone. However, in these previous studies simultaneous in situ measurements of a range of parameters valuable in assessment of the role of zooplankton in the biogeochemical cycling of particle-reactive elements like Po-210 and Pb-210 were not made. Here we report preliminary results of a field study, that was undertaken in the oligotrophic waters of the South-West Pacific between New Caledonia and Fiji, where we simultaneously measured a) zooplankton biomass and their faecal pellet production rates, b) Po-210 and its progenitor Pb-210 in water, zooplankton and their faecal pellets and c) particle flux rates using U-238:Th-234 disequilibria, to further assess the role of zooplankton in Po-210 and Pb-210 biogeochemistry in the euphotic zone of oligotrophic systems. Zooplankton sampled from the oceanic region of the SW Pacific between Fiji and New Caledonia had biomasses ranging from 0.1 to 7.1 mg dw/m3, with a median value of 3.6 and mean of 2.65 mg

  5. Po-210 and Pb-210 concentration factors for zooplankton and faecal pellets in the oligotrophic South-West Pacific

    In a previous study on zooplankton sampled from very low productivity waters of French Polynesia, their Po-210 concentrations were found to be unexpectedly elevated, compared to values measured in marine zooplankton from various other geographical regions of the world. For the French Polynesian samples their Po-210 concentrations also increased appreciably as their biomass declined. A simple conceptual and mathematical model, that incorporated the established role of zooplankton faecal pellets in the removal of Po-210 and particle-reactive radionuclides and stable metals from the water column, could capture the shape of this empirical relationship between Po-210 concentration and their biomass and also explained the biomass-related mechanism that increases Po-210 concentrations in zooplankton. Similarly, a field investigation in the Timor Sea showed that a range of particle-reactive elements showed elevated water concentrations as particle removal rates, as inferred from Th-234: U-238 disequilibria, reduced in the euphotic zone. However, in these previous studies simultaneous in situ measurements of a range of parameters valuable in assessment of the role of zooplankton in the biogeochemical cycling of particle-reactive elements like Po-210 and Pb-210 were not made. Here we report preliminary results of a field study, that was undertaken in the oligotrophic waters of the South-West Pacific between New Caledonia and Fiji, where we simultaneously measured a) zooplankton biomass and their faecal pellet production rates; b) Po-210 and its progenitor Pb-210 in water, zooplankton and their faecal pellets; and c) particle flux rates using U-238:Th-234 disequilibria, to further assess the role of zooplankton in Po-210 and Pb- 210 biogeochemistry in the euphotic zone of oligotrophic systems. Zooplankton sampled from the oceanic region of the South-West Pacific between Fiji and New Caledonia had biomasses ranging from 0.1 to 7.1 mgDW/m3, with a median value of 3.6 and mean

  6. Assessment Activity of 210Po and 210Pb in the Edible Tissues of Cultured Seabass (Lates calcariferat Peninsular Malaysia

    Noorliza Zakaria

    2013-01-01

    Full Text Available Analysis levels of 210Po and 210Pb were determined in the edible tissue of sea bass (Lates calcarifer from 14 cages in the west and east coast Peninsular of Malaysia. The concentrations level in fish were found varies from 1.35 ± 0.22 to 6.20 ± 0.99 Bq/kg dry weight210Po and 3.30 ± 2.69 to 51.71 ± 19.26 Bq/kg dry weight 210Pb. The level of this radionuclide was much related to the anthropogenic activities at the sampling locations neighbouring area, differences in metabolisms of fish and food intake pattern for each cage. Then the calculated daily intake value due to fish consumption was to be 7.69 mBq/d/person210Po and 35.90 mBq/d/person210Pb, which lower than those reported in others countries. In addition, the collective doses of210Po and210Pb were estimated to be 0.001mSv/year and 0.009 mSv/year, respectively. This suggests that the dose received by Malaysian due to consumption of fish is rather small, and did not deteriorate human’s health and safe for consumption.

  7. Seasonal monitoring of radionuclides, 210Polonium and 210Lead in marine macrophytes at Kudankulam, Gulf of Mannar, India

    Evaluation of radioecology around nuclear site is important to ensure that it will not create an unacceptable risk to the public or to the environment. In light of this, the present study was aimed at quantifying the levels of natural 210Po and 210Pb in ten species of marine macrophytes collected along the coastline of Kudankulam. Non-parametric Kruskal-Wallis ANOVA revealed a significant variation in the accumulation of 210Po and 210Pb between species based on site and season (p<0.05). The 210Po activity varied between 25.2 - 50.6 Bq Kg-1 fresh and it ranged from 12.5 - 23.4 Bq Kg-1 fresh for 210Pb, respectively. 210Po:210Pb ratio was calculated to be greater than unity in all the species. The ecological sensitivity of sea grasses to the radiation exposure and the safeness of the environment was analysed by calculating the external and internal dose rate. The hazard quotient for the plants was lesser than the global bench mark dose rate of 10 μGyh-1. (author)

  8. Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes

    The activity of 210Po and 210Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759 ± 277 Bq kg-1 for 210Po (range 460-1470 Bq kg-1 dry weight), and 45 ± 19 Bq kg-1 for 210Pb (range 23-96 Bq kg-1 dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that 210Po and 210Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210 ± 75 Bq kg-1 (dry weight) for 210Po and 10 ± 4 Bq kg-1 (dry weight) for 210Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of 210Po and man

  9. Evaluation of uncertainty and detection limits in {sup 210}Pb and {sup 210}Po measurement in water by alpha spectrometry using {sup 210}Po spontaneous deposition onto a silver disk

    Fernandez, Pedro L., E-mail: pedroluis.fernandez@unican.es [Department of Medical and Surgical Sciences (Medical Physics Section), Faculty of Medicine, University of Cantabria, 39011 Santander (Cantabria) (Spain); Gomez, Jose; Rodenas, Carmen [Department of Medical and Surgical Sciences (Medical Physics Section), Faculty of Medicine, University of Cantabria, 39011 Santander (Cantabria) (Spain)

    2012-04-15

    An easy and accurate method for the determination of {sup 210}Pb and {sup 210}Po in water using {sup 210}Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of {sup 210}Pb, {sup 210}Bi and {sup 210}Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of {sup 210}Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between {sup 210}Pb and {sup 210}Bi and the second after a sufficient time for the ingrowth of {sup 210}Po from {sup 210}Pb to be significant. As shown, for a recommended time interval of seven months between {sup 210}Po measurements, the applicability of the proposed method is limited to water samples with a {sup 226}Ra to {sup 210}Pb activity ratio C{sub Ra}/C{sub Pb}{<=}4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L{sup -1} for {sup 210}Pb in water samples with an initial activity of {sup 210}Po in the range 0-200 mBq L{sup -1}, and between 0.6 and 8.5 mBq L{sup -1} for {sup 210}Po in water samples with an initial activity of {sup 210}Pb in the same range. - Highlights: Black-Right-Pointing-Pointer {sup 210}Pb and {sup 210}Po measurement in water by {sup 210}Po spontaneous deposition onto silver disks. Black-Right-Pointing-Pointer {sup 210}Pb and {sup 210}Po determination based on {sup 210}Po measurement in two different aliquots. Black-Right-Pointing-Pointer Evaluation of characteristic limits in radioactivity

  10. Polonium 210 content in foodstuffs produced in Bulgaria

    A study of the content of polonium-210 in a variety of foodstuffs produced in Bulgaria in 1970 revealed peak radionuclide concentration in wheat - 6.7 pCi/kg, followed by prunes - 2.2 pCi/kg, cabbage - 1.86 pCi/kg, peppers - 1.64 pCi/kg. The content of polonium-210 in onions, meat and potatoes was low (0.5, 0.8 and 0.9 pCi/kg accordingly). All other food products studied - milk, bread, beans, eggs, tomatoes, apples, pears, grapes and drinking water - appeared to have approximately equal polonium-210 concentration - from 1.21 to 1.35 pCi/kg. The daily intake of polonium-210 with food and water amounted accordingly to 1.61, 1.79 and 2.08 pCi/kg in preschool children, in school children and in senile individuals. The major part (68 - 82 per cent) of incorporated polonium-210 was eliminated with the stools. In all age groups the amount of polonium-210 removed daily from the body with the excreta corresponded to the intake, i.e. the balance of polonium-210 was in a state of equilibrium. The age factor in all three groups exerted no effect on the radionuclide intake and elimination from the body. (Ch.K.)

  11. Quantitative determination of 210Po in geochemical samples

    To test the usefulness of 210Po in soils as a means of detecting buried U mineralization, methods for the determination of 210Po were investigated and adapted for routine production of 210Po data from geochemical samples. A number of conditions affecting autodeposition and detection of 210Po were investigated. The optimum area of deposition with a 450 mm2 solid state detector was found to be 300 mm2. Convenience dictated room temperature over-night deposition times, although increased temperature increased speed and efficiency of deposition. A clear inverse relationship was observed between volume of solution and deposition efficiency with stirring times of less than 2 hours. For routine analysis, soil and rock powders were dissolved by leaching 1 g samples in teflon beakers successively with conc. HNO3, HF, and HNO3-HClO4, evaporating the solution to dryness between leaches, and taking the residue up in 20 mL 0.5 M HCl. The 210Po was deposited on 19 mm diameter Ni discs and counted with an alpha spectrometer system employing 450 mm2 ruggedized surface barrier detectors. The method achieved 90 percent recovery of 210Po from solution and a detection efficiency of 30 percent. With a counting time of 3 hours, the method is capable of detecting 0.2 pCi of 210Po per gram of sample

  12. A record of atmospheric 210Pb deposition in The Netherlands

    The deposition flux of total atmospheric 210Pb has been measured at two sites in The Netherlands: Texel from 1992 to 1996 and Groningen from 1989 to 1994. With predominant westerly oceanic winds, the annual 210Pb deposition is relatively low as 222Rn, the source for atmospheric 210Pb, is mainly exhaled by the continents. The daily fluctuations in 210Pb deposition are determined by the almost random daily fluctuations in precipitation and the concentration in groundlevel air. The variations in annual 210Pb deposition flux appear to be mainly correlated with the number of heavy rains or thunder storms. This explains the variations in annual deposition at short distance. The average 210Pb deposition at Groningen (1987-1994) is 200 mBq m-2 day-1. The 210Pb deposition over the North Sea is estimated to be 115 mBq m-2 day-1 in the same period. The deposition velocity in Groningen is 1.0 cm s-1, which is similar to measurements in Virginia and Connecticut. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  13. Bioaccumulation of 210Pb in the Kaveri River ecosystem, India

    Data on the concentrations of 210Pb in water, sediment and biota (plankton, weed, snail, bivalve, prawn and fish) of the Kaveri River ecosystem at Tiruchirappalli in South India are presented. The highest level of 210Pb activity was observed in the sediment (15.5 Bq kg-1 dry) and the lowest activity in water (2.7 mBq l-1). The root of the aquatic weed, Eichhornia crassipes, showed a higher activity (1.17 Bq kg-1 wet) than its shoot (0.22 Bq kg-1 wet). Among the biotic components, the shells and bones of animals accumulated higher 210Pb than their tissues and muscle. Among animals, the freshwater mussel, Lamellidens marginalis was identified to accumulate more 210Pb in its soft tissues (0.79 Bq kg-1 wet) and shell (6.55 Bq kg-1 wet) than prawns (muscle 0.65 Bq kg-1 wet; exoskeleton: 1.06 Bq kg-1) wet and fish (muscle: 0.24 Bq kg-1 wet; bone: 1.37 Bq kg-1 wet). The concentration factors (CFs) of 210Pb in biotic components ranged from ∼ 101 to ∼ 103 with higher CFs observed for shells and bones. It is shown that 210Pb undergoes a seasonal variation in surface deposition with minimum values in summer and maximum values in winter. The significance of the results of 210Pb in the abiotic and biotic environment of Kaveri River is discussed. (Author)

  14. The atmospheric depositional fluxes of 7Be, 210Pb and 210Po to Xiamen and Qingdao, China

    7Be (half life t1/2 = 54.3 d) is produced by the spallation of atmospheric oxygen and nitrogen with cosmic rays. 210Pb (t1/2= 22.3 a) in air is produced by decay from 222Rn (t1/2= 3.8d) which emanates into the atmosphere from the earth's surface. 210Po (t1/2= 138 days) in air is produced from the decay of 210Pb through 210Bi (t1/2=5.0 days). 7Be, 210Pb and 210Po is easily absorbed to aerosols and removed to land and ocean through precipitation and dry fallout. The atmospheric depositional fluxes of 7Be, 210Pb and 210Po to Xiamen and Qingdao were measured in this paper. The samples were collected with plastic vessels fixed on the top of the Oceanography Building of Xiamen University and the Environmental Engineering Building of Oceanography University of China in Qingdao of China. The sampling period is one month normally. The 7Be and 210Pb were measured using HPGe-γ spectrometer after concentration by Fe(OH)3 co-precipitation method, but the 210Po was counted with α spectrometer after the sample is digested and electroplated onto a silver planchet. From March to October 2004 at Xiamen, the depositional fluxes of 7Be varied from 0.58 to 2.78 Bq m-2 d-1 and the average is 1.99 Bq m-2 d-1, 210Pb varied from 0.24 to 0.86 Bq m-2 d-1, and the average is 0.60 Bq m-2 d-1; 210Po varied from 0.02 to 0.13 Bq m-2 d-1 and the average is 0.06 Bq m-2 d-1. The 7Be/210Pb activity ratio is between 0.67 and 5.53 and the average is 3.48. The flux of 7Be is lower in April, June and October; the flux of 210Pb in June is lower than other periods. The 7Be/210Pb activity ratio is -the highest in may while it is the lowest in April. From May to November 2004 at Qingdao, the depositional fluxes of 7Be varied between 1.54 and 2.60 Bq m-2 d-1 with the average 2.08 Bq m-2 d-1; 210Pb varied between 0.33 and 0.73 Bq m-2 d-1 with the average 0.55 Bq m-2 d-1; 210Po varied between 0.03 and 0.19 Bq m-2 d-1 with the average 0.08 Bq m-2 d-1. The 7Be/210Pb activity ratio is between 2.81 and 6.62 and

  15. Accumulation of 210Po by benthic marine algae

    The accumulation of polonium 210Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210Po. The algae collected in open sea, revealed greater concentration factors of 210Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

  16. Lead-210 content of food samples in India

    The paper presents results of measurements made on cereals and composite meal samples collected from Bombay market for their lead-210 content. The details of sampling and analytical chemistry procedures are also given. The Pb-210 contents of most of these samples were in the range of 1-5 pCi/kg of cereals samples. The concentrations in composite meal samples were mostly in the range of 1-3.5 pCi of 210Pb per composite meal. The assessment of daily intake of this isotope through food-stuffs has been made. (orig.)

  17. Temporal and spatial distribution patterns of 210Po/210Pb and their implication in biogeochemical cycle along coastal region of China

    The natural radionuclide 210Po and 210Pb were analyzed in samples of atmospheric deposition (dry+wet), river water, tidal flat sediments and seawater along the coastal region of China. The results showed that the atmospheric deposition fluxes of 210Po and 210Pb with a similar trend in yearly time scale, changing seasonally with a higher value in spring and winter. As the river input (XLJ, fresh water end- number of the Chanjiang River), approximately 86% and 78% of the total 210Po and 210Pb in the water column were in particulate phrase, demonstrating that 210Po and 210Pb was easily absorbed and scavenged by the riverine particles. Except in Feb., Apr. and Oct., the ratio 210Po/210Pb of water column was less than 1.0 showing a deficiency 210Po relative to 210Pb. In surface sediments of east Chongming tidal flat of the Changjiang Estuary, the activities of 210Po and 210Pb were decreasing with the height of tidal flat (from land to seaward), due to the variations of the sediments grain size, the vegetational areas and the hydrodynamics force. Although a bit different from 2009 to 2010, the ratios of 210Po/210Pb were over 1.0 in both of two years, suggesting that 210Po was absorbed onto organic matter in the frequent bioturbation processes. In the coastal water, all the results showed a 210Po-deficiency relative to 210Pb in Yellow Sea since the atmospheric deposition source and bio-scavenge in water column. (author)

  18. 234Th, 210Pb, 210Po and stable Pb in the central equatorial Pacific: Tracers for particle cycling

    Murray, J.W.; Paul, B.; Dunne, J.P.; Chapin, T.

    2005-01-01

    Samples were collected during the 1992 US JGOFS EqPac Survey I and II cruises from 12??N to 12??S at 140??W in the central equatorial Pacific for water column profiles of dissolved, particulate and total 234Th, 210Pb and 210Po and total acid soluble stable Pb and sediment trap fluxes of 234Th, 210Pb and 210Po. Survey I occurred in February/March with moderate El Nino conditions while Survey II was conducted in September/October when there was a well developed cold-tongue. 234Th, 210Pb and 210Po are all particle reactive yet they partition differently between dissolved and particulate phases. Fractionation factors (the ratios of the distribution coefficients) show that the selectivity for suspended and sediment trap particles follows Th>Po>Pb. Scavenging residence times (??) for 234Th, 210Pb and 210Po ranged from 25 to 100 d, 3 to 8 years and 100 to 500 d, respectively. These particle reactive tracers have very different distributions in the water column, which reflect differences in their sources and sinks. The deficiency of 234Th relative to 238U was fairly uniformly distributed meridionally, though deficiencies were higher during Survey II when there was higher new production. Excess 210Pb relative to 226Ra was very asymmetrical with much higher excess values north of the equator. The distributions were similar for Surveys I and II. The deficiency of 210Po relative to 210Pb had a symmetrical distribution about the equator for both Survey I and II but the deficiencies were larger during Survey I when upwelling was smaller. Stable Pb was generally higher at the surface than at 250 m and there was no meridional trend from 12??N to 12??S. A mass balance for 210Pb was used to determine the atmospheric input of 210Pb. The average values for Surveys I and II were 0.12 and 0.32 dpm cm-2 year-1, respectively. There was no general increase in atmospheric input of 210Pb north of the equator but there was a strong maximum at 2-3??N during Survey I coincident with the

  19. Enhancement of 210Po and 210Pb arising from phosphate industry in the Syrian coast

    Phosphate industry is considered to be one of the potential sources of natural radionuclide in Syria. Most of the phosphate processed ore is exported in large quantities via one of the Syrian main ports (Tartous) situated on the east part of the Mediterranean Sea (34 deg. 54 N, 35 deg. 52 E). Loading activities into ships have been carried out for more than 20 years. Dust carrying radioactivity is elevated and transported to the surroundings; most of the port area is affected. The impact of these loading activities on the marine environment has been evaluated. 210Po and other natural radionuclides in seawater, sediment and marine organisms have been determined

  20. Geochronology of recent sediments from the Cariaco Trench (Venezuela) by Alpha Spectrometry of 210Pb (210Po)

    210Pb concentration in marine sediments of the Cariaco Trench (North-East of Venezuela) was measured through the analysis of 210Po alpha emissions, which can be assumed to be in secular equilibrium with 210Pb. The analysed sediment core has a length of 1.9 m. The results allowed to apply the CF:CS dating model (Constant Flux and Constant Supply). The sedimentation rate was estimated to be 0.25 cm/y. As far as we know this is the first α- dating carried out in the country, performed with an alpha spectrometer recently funded by the IAEA.

  1. 27 CFR 555.210 - Construction of type 4 magazines.

    2010-04-01

    ..., FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.210..., dugout, box, trailer, or a semitrailer or other mobile magazine. (a) Outdoor magazines—(1)...

  2. Second order focusing property of 210deg cylindrical energy analyzer

    It was confirmed experimentally that a 210deg cylindrical energy analyzer with drift spaces has second order focusing. The properties of the analyzer is deeply dependent on the fringing field around the entrance and exit of the cylinders. (author)

  3. 19 CFR 210.31 - Requests for admission.

    2010-04-01

    ... TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.31 Requests for admission. (a... or deny unless he states that he has made reasonable inquiry and that the information known to...

  4. Biogeochemical factors affecting the presence of 210Po in groundwater

    Seiler, R.L.; Stillings, L.L.; Cutler, N.; Salonen, L.; Outola, I.

    2011-01-01

    The discovery of natural 210Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among the highest reported levels in the USA. There is little spatial or depth variability in 210Pb activity in study-area sediments and mobilization of a few percent of the 210Po in the sediments would account for all of the 210Po in water. Stable-isotope measurements indicate SO4 reduction has occurred in all 210Po contaminated wells. Sulfide species are not accumulating in the groundwater in much of Lahontan Valley, probably because of S cycling involving microbial SO4 reduction, abiotic oxidation of H2S to S0 by Mn(IV), followed by microbial disproportionation of S0 to H2S and SO4. The high pH, Ca depletion, MnCO3 saturation, and presence of S0 in Lahontan Valley groundwater may be consequences of the anaerobic S cycling. Consistent with data from naturally-enriched wells in Florida, 210Po activities begin to decrease when aqueous sulfide species begin to accumulate. This may be due to formation and precipitation of PoS, however, Eh–pH diagrams suggest PoS would not be stable in study-area groundwater. An alternative explanation for the study area is that H2S accumulation begins when anaerobic S cycling stops because Mn oxides are depleted and their reduction is no longer releasing 210Po. Common features of 210Po-enriched groundwater were identified by comparing the radiological and geochemical data from Nevada with data from naturally-enriched wells in Finland, and Florida and Maryland in the USA. Values of pH ranged from 9 in Nevada wells, indicating that pH is not critical in determining whether 210Po is present. Where U is present in the sediments, the data suggest 210Po levels may be elevated in aquifers with (1) SO4-reducing waters with low H2S

  5. Cluster and factor analysis methods in the study of data on concentrations of 210Pb, 210Bi, 210Po and a number of stable elements in atmospheric aerosols

    We have performed cluster and factor analyses of results of determinations of the content of long-lived radon decay products (210Pb, 210Bi, 210Po) and 15 stable elements in atmospheric aerosols of the air near the surface. Using cluster analysis, we have isolated the test samples which are substantially different from the rest. Analysis of the factor loadings for a homogeneous group of filters has shown specificity in the behavior of the long-lived radon decay products and their strong intercollection. We have shown the absence of a number of technogenetic sources of nuclides of this group in the studied region. We note a correlation between the factor determining the variability of the long-lived radon decay products and the factor determining the content of stable lead and the mineral component

  6. Po-210 distribution in uranium-mill circuits

    Greater than 99% of all incoming Po-210 reports to the tailing piles for both the acid and the alkaline leach uranium circuits. Leached Po-210 may be carried along on small particles rather than dissolved in solution. There does not appear to be any radiologically significant buildup or accumulation in the acid leach circuit, but there are noteworthy amounts in the molybdenum recovery solution

  7. RAPID DETERMINATION OF {sup 210} PO IN WATER SAMPLES

    Maxwell, S.

    2013-05-22

    A new rapid method for the determination of {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of {sup 210}Po in water samples have typically involved spontaneous auto-deposition of {sup 210}Po onto silver or other metal disks followed by counting by alpha spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of {sup 210}Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate {sup 210} Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid

  8. 210Po and Se speciation in Mytilus galloprovincialis

    Marine and freshwater microorganisms (algae, bacteria) as well as higher organisms such as mussels and fish metabolise polonium and selenium, and can accumulate them into cellular components. Selenium is a essential trace element for humans and animals, since it forms part of several enzymes, while 210Po is highly radiotoxic due to its high specific activity - 1.7 x 1014 Bq/g. Polonium has no known biological role and is involved in metal metabolism regarding its chemical-physical similarities with essential metals such as selenium. It follows the same biochemical pathways as selenium when considering the biochemistry of polonium. The aim of our study was to investigate distribution of 210Po and Se between soluble (supernatant) and insoluble (sediment) part of mussels from Slovenian market after enzymatic hydrolysis. 210Po and Se in supernatant are considered as bioavailable. We investigated the tissue of Mytilus galloprovincialis which lives attached on hard substrata, being filter feeders exposed to ambient seawater. These particular mussels are primarily used as food and also as indicators of environmental pollution, due to their ability to accumulate high levels of different contaminant (heavy metals, hydrocarbons and pesticides). The mussels were purchased on a local market as well as from a domestic producer. Samples were freeze dried and homogenized. After enzymatic hydrolysis of sample with Protease XIV, separation and determination of 210Po and Se in supernatant and sediment were performed. Measurements of 210Po were performed by alpha spectrometry while for Se measurements HG-AFS was used. The results obtained show that polonium in the soluble part of mussels tissue has similar pattern as selenium when Se increases also 210Po level increases, indicating the similar biochemistry of polonium and selenium. The soluble part of Se represented from 62 to 77 % of the total content, while soluble part of 210Po represented from 38 to 50 %. Extraction balance

  9. Radionuclides (210Pb, 226Ra, 210Po e 137Cs) in the Cananeia-Iguape coastal system: environmental studies

    This work was developed in the Cananeia-lguape Coastal System, coast south of the State of Sao Paulo, with the aim of monitoring the levels of some natural radionuclides (210Pb, 210Po, 226Ra ) and artificial (137Cs) and to study the sedimentary dynamics of the area. For this, some studies and determinations were carried out, such as: sedimentation rates, concentration factors, bio-indicators and ingestion for the human population of some of these radionuclides. For the obtaining of the levels of these radionuclides, radiochemical and instrumental methodologies were developed and applied in reference samples of the International Agency of Atomic Energy (IAEA). After this, the methodologies were applied in samples of sediments, aquatic organisms and water of the channels collected in several points. In the sediments, the levels of (210Pb, 226Ra and 137Cs varied from 6.1 to 167.5 Bq.kg-1 from 4.1 to 28.5 Bq.kg-1 and from MDC (0.28) to 6.1 Bq.kg-1 respectively. More significant correlations were observed among the percentage of mud (silt-clay) in the sediments and the levels of these radionuclides. These data were used for sedimentation rate studies in the points of sampling in the System. The sedimentation rates obtained with the values of unsupported (210Pb and 137Cs for the Ponta do Arrozal (T1), Ponta do Frade (T2), Valo Grande (T3) and Carapara-BOCA River (T4) were of 5.02 and 5.00 mm.a-1, 2.30 and 3.82 mm.a-1, 14.59 and 15.74 mm.a-1, 3.41 and 5.00 mm.a-1 respectively. The sedimentation rates obtained with unsupported 210Pb and the 137Cs in the cores(T1, T2, T3 and T4) showed a good agreement. The sedimentation rates obtained along the System reflect the dynamics intern of the channels, that presents general tendency the one accentuated deposition process, with pronounced contribution of sediments of continental origin, for the drainages Mandira and Ribeira of Iguape Rivers, by the high biological production of the System as well as the pronounced erosion of the

  10. Calibration and measurement of 210Pb using two independent techniques

    An experimental procedure has been developed for a rapid and accurate determination of the activity concentration of 210Pb in sediments by liquid scintillation counting (LSC). Additionally, an alternative technique using γ-spectrometry and Monte Carlo simulation has been developed. A radiochemical procedure, based on radium and barium sulphates co-precipitation have been applied to isolate the Pb-isotopes. 210Pb activity measurements were done in a low background scintillation spectrometer Quantulus 1220. A calibration of the liquid scintillation spectrometer, including its α/β discrimination system, has been made, in order to minimize background and, additionally, some improvements are suggested for the calculation of the 210Pb activity concentration, taking into account that 210Pb counting efficiency cannot be accurately determined. Therefore, the use of an effective radiochemical yield, which can be empirically evaluated, is proposed. 210Pb activity concentration in riverbed sediments from an area affected by NORM wastes has been determined using both the proposed method. Results using γ-spectrometry and LSC are compared to the results obtained following indirect α-spectrometry (210Po) method

  11. Some aspects of the bioaccumulation of polonium-210 and lead-210 in the gill of the fish Macrodon ancylodon (Block and Schneider, 1801)

    210Po and its grandfather 210Pb are natural radionuclides from the 238U family. The former is of considerable radio-biological relevance because of its very easy absorption by almost all living organisms and because of its high radiotoxicity, being considered as the major contributor to α-irradiation in the great majority of organisms. On the contrary, the low energy β-emitter 210Pb is less efficiently absorbed; its biological importance results from the fact that it decays to 210Po, being one of the sources of the latter in all living beings. The concentrations of 210Po and 210Pb in the gills of Macrodon ancylodon (known as 'pescadinha') from Sepetiba Bay (80 Km SW of Rio de Janeiro, Brazil) were determined monthly, looking for: eventual variations along the time of their respective bioaccumulation; variations of their relative bioaccumulation (210Po/210Pb ratios); and correlations between levels of 210Po and 210Pb and biometric parameters such as length and weight. Thus, the concentrations of 210Po and 210Pb in gills of M. ancylodon were determined monthly during respectively 16 and 12 months. The overall mean concentrations of 210Po and 210Pb were respectively of 22.41 +/- 14.57 mBq/g (range : 12.69 +/- 4.76 mBq/g in May 98 to 34.84 +/- 15.72 mBq/g in January 98) and 2.48 +/- 1.92 mBq/g (range : 1.62 +/- 0.85 mBq/g in September 97 to 4.89 +/- 2.85 mBq/g in May 97). Statistical analysis of the radiometric parameters (210Po activity, 210Pb activity and 210Po/210Pb ratio) showed that there was no detectable dependence of 210Po or 210Pb accumulation along the time. However, the 210Po/210Pb ratios were higher during summer and winter (approximately 22), and lower during spring and autumn (approximately 10). This suggested that some seasonal variations must indeed occur and these might be related to the heavy rainfalls that occur during summer and winter. On the other hand, no correlations could be observed between the biometric parameters (weight and length) and

  12. Biogeochemical factors affecting the presence of 210Po in groundwater

    Research highlights: → 210Po activities in numerous domestic wells in Fallon NV exceed 500 mBq/L. → 210Po levels in sediment are not the primary determinant on levels in groundwater. → δ34S measurements indicate SO4 reduction occurred in all 210Po contaminated wells. → 210Po contaminated wells are anoxic, have high pH and low Ca. → Po mobilization probably involves an anaerobic S cycle in which H2S dissolves MnO2. - Abstract: The discovery of natural 210Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among the highest reported levels in the USA. There is little spatial or depth variability in 210Pb activity in study-area sediments and mobilization of a few percent of the 210Po in the sediments would account for all of the 210Po in water. Stable-isotope measurements indicate SO4 reduction has occurred in all 210Po contaminated wells. Sulfide species are not accumulating in the groundwater in much of Lahontan Valley, probably because of S cycling involving microbial SO4 reduction, abiotic oxidation of H2S to S0 by Mn(IV), followed by microbial disproportionation of S0 to H2S and SO4. The high pH, Ca depletion, MnCO3 saturation, and presence of S0 in Lahontan Valley groundwater may be consequences of the anaerobic S cycling. Consistent with data from naturally-enriched wells in Florida, 210Po activities begin to decrease when aqueous sulfide species begin to accumulate. This may be due to formation and precipitation of PoS, however, Eh-pH diagrams suggest PoS would not be stable in study-area groundwater. An alternative explanation for the study area is that H2S accumulation begins when anaerobic S cycling stops because Mn oxides are depleted and their reduction is no longer releasing 210Po. Common features of 210Po

  13. Assessment of 210Po and 210Pb in lichen, moss and soil around Can coal-fired power plant, Turkey

    This paper deals with determination of 210Po and 210Pb activity concentrations using epigeic moss (Hypnum cupressiforme), bushy soil (fruticose) lichen (Cladonia rangiformis) and surface soil samples in the area around Can coal-fired power plant, northwest Turkey. Mean activity concentrations of 210Po and 210Pb were found to be 303.9 and 425.8 Bq kg-1 for moss, 161.6 and 259.1 Bq kg-1 for lichen, and 79.9 and 91.5 Bq kg-1 for soil samples at dry weight, respectively. We propose that distance and altitude of sampling site may be of significant parameters of distribution of both radionuclides. (author)

  14. 210Po and 210Pb trophic transfer within the phytoplankton–zooplankton–anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea)

    The transfer of 210Po and 210Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of 210Po and 210Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on 210Po, 210Pb activity concentrations and 210Po/210Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is connected to local specific pelagic habitats and hydrodynamics. The sampling strategy suggests that 210Po bioaccumulation in the GoL remains at a constant level from the first (dominated by phytoplankton) to the second trophic level (zooplankton), while 210Pb bioaccumulation shows an increase in winter. Based on stable N isotope ratios and 210Po activity concentrations measured in anchovies and sardines, we evidence 210Po bio-magnification along the trophic food web of these two planktivorous pelagic fishes. - Highlights: • 210Po and 210Pb activity concentrations in plankton vary up to a factor of two in the Gulf of Lion (East vs West). • 210Po and 210Pb variability is connected to local specific pelagic habitats. • Bio-magnification of 210Po is evidenced in anchovy/sardine foodwebs

  15. A study of 210Pb and 210Po levels in various food components and computation of ingestion dose to the resident community at Kalpakkam, Tamilnadu, India

    210Pb is a member of 238U series and a beta (Emax: 0.017 MeV) and gamma (0.047 MeV) emitting isotope with half-life of 22 years. 210Po, the last radioactive member of 238U series, is an alpha emitter (5.3 MeV) having a half-life of 138.4 days which reportedly delivers a significantly high dose to human population via. ingestion route. According to Clayton and Bradley (1995) about 18% of the average internal dose to the population is due to ingestion of 210Po along with its precursor 210Pb. The main source of 210Pb and 210Po in the environment is 222Rn gas, a daughter product of 226Ra, which diffuses into the atmosphere from rocks and soil where it ultimately decay to 210Pb, 210Bi and then to 210Po in the atmosphere. 210Pb and 210Po attach themselves further electrostatically to aerosol particles, transported back to earth's surface to soil, plant and aquatic environments by dry deposition and washout and both are directly taken up by plants, either from the soil through the root system or by foliar sorption from the air. Besides these radionuclide are also generated in plants from 226Ra assimilated from soil and water. This paper presents the distribution of 210Pb and 210Po activities in food of plant origin and food of animal origin in addition to salt and drinking water collected in and around Kalpakkam. The ingestion dose received due to the intake of 210Pb and 210Po via. dietary sources by the public at Kalpakkam, was computed using the 210Pb and 210Po activity data in the analysed matrices

  16. A New Method of Separating 210Pb from Ra-DEF for a Radioactive Equilibrium Experiment.

    Wai, C. M.; Lo, J. M.

    1984-01-01

    Background information, procedures, and results are provided for an experiment in which lead-210 is separated from bismuth-210 and polonium-210 by means of solvent extraction of their diethyldithiocarbamate complexes. The method involves a simple extraction procedure which allows complete separation of lead-210 from commercially available…

  17. Radionuclides in human hair as indicators of exposure to uranium series radionuclides - Polonium-210 and lead-210 in human hair as indicators of exposure to uranium series radionuclides

    Polonium-210 and lead-210 were determined in samples of human hair from people living in several regions of Portugal with different radioactivity levels in soils and water. Activity concentration ratios of 210Po/210Pb in the hair were always higher than unity, suggesting that hair is an excretion route for these radionuclides from the human body, especially for 210Po. 210Po activity concentration in the hair increased with the age of people indicating that the source of 210Po body burden is 226Ra deposited in bone, and that this deposit increases with the age of individuals. Furthermore, 210Po activity concentration in the hair was significantly higher in uranium mine workers than in members of the public at large in granite regions, and these ones higher than in people living in low background sedimentary regions, indicating that 210Po concentration in the hair reflected radioactivity levels of the regional environment. 210Pb activity concentrations in the hair seemed more constant throughout life of humans, although reflecting also 210Pb levels in the environment. A relationship is established between 210Po concentration in the hair and 210Po total body burden. (authors)

  18. Po-210 and other radionuclides in terrestrial and freshwater environments

    Gjelsvik, Runhild; Brown, Justin (eds.) (Norwegian Radiation Protection Authority (Norway)); Holm, Elis (Univ. of Lund (Sweden)); Roos, Per (Risoe DTU (Denmark)); Saxen, Ritva; Outola, Iisa (STUK - Radiation and Nuclear Safety Authority (Finland))

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  19. Po-210 and other radionuclides in terrestrial and freshwater environments

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  20. The Radiological Impact of 210Pb and 210Po Released from the Iron- and Steel-Making Plant ILVA in Taranto (Italy on the Environment and the Public

    Guogang Jia

    2013-01-01

    Full Text Available Lead-210 and 210Po are naturally occurring radionuclides. Due to volatile characteristic of lead and polonium, environmental pollution of 210Pb and 210Po released from the coal power plant, steel-making industry and refractory material industry has been an exposure problem for the members of public. In this paper studies on the activity concentrations of 210Po and 210Pb in the raw materials, dust particles, surficial soils and atmospheric particulate samples collected in the area of the Iron- and Steel-Making Plant ILVA Taranto (Italy were made. These data have been used to evaluate the source-term, distributions, inventories, mass balance, biological availability, ecological migration processes and public exposure risk of 210Pb and 210Po in the concerned environment.

  1. Incorporation of 210Pb and 210Po to Poultry through the Addition of Dicalcium Phosphate (DCP) to the Diet

    Casacuberta, N.; Masqué, P.; Garcia-Orellana, J.; Gasa, J.; Anguita, M.

    2008-08-01

    Due to the replacement of calcium by uranium in the phosphorite, sedimentary phosphate rock contains high concentrations of 238U (i.e. from 1500 Bqṡkg-1 in Morocco to 4000 Bqṡkg-1 in Tanzania ores). Dicalcium Phosphate (DCP) is produced by the wet acid digestion of the phosphorite, and is used as a source of calcium and phosphorus for livestock feed supplement. If the phosphorite acid digestion is made with hydrochloric acid, DCP may present specific activities of about 103 Bqṡkg-1 of 238U and some of its decay chain daughters. In particular, due to its radiological implications, the presence of 210Pb and 210Po in DCP is of special relevance. The aim of this work was to investigate the potential incorporation of these radionuclides to poultry through its diet. Three different diets were therefore prepared with different contents of both DCP and 210Pb and 210Po. Diet A was used as a blank, and had a 2.5% in weight of monocalcium phosphate (MCP); diet B, with a 5% in weight of DCP; and diet C, with a 2.5% of DCP. Concentrations of 210Pb were 0.93, 101.4 and 51.2 Bqṡkg-1; whereas concentrations of 210Po were 0.92, 74 and 36 Bqṡkg-1 of food for diets A, B and C, respectively. Accumulation of 210Pb and 210Po was analysed at several times during poultry growth in samples of bone, liver, kidney, muscle, excrements as well as entire animals, with a total of 30 broilers fed with the 3 different diets. Results showed clear enhancements in the accumulation of both 210Pb and 210Po in chicken for diets B and C, and in particular in liver and bone. However, total accumulation of radionuclides in chicken, and especially in edible parts, is low compared to its expulsion through excrements. These results are interpreted in terms of the potential dose through consumption of chicken.

  2. Some aspects of polonium-210 and lead-210 bioaccumulation in the gills of the fish Macrodon ancylodon ( Block and Schneider, 1801)

    The concentrations of 210 Po and 210 Pb and the ratios between these radionuclides have been determined monthly from February 1997 to May 1998 in the gills of the fish Macrodon ancylodon, collected in the bay of Sepetiba (State of Rio de Janeiro). The variations in the biological accumulation of 210 Po and 210 Pb were analysed along the time and correlated to the weight and length of the fishes. (author)

  3. Assessment of radiation dose from 210Pb and 210Po due to chewing tobacco leaves and smoking cigarettes - an Indian scenario

    The study of 210Pb and 210Po content in tobacco and its products is essential because of their elevated concentrations. The cumulative alpha-radiation dose delivered to humans from inhaled 210Po in cigarette smoke becomes significant. 210Pb is another element of interest since it is the precursor to 210Po in the radioactive decay chain of 238U. Further, in India the ingestion dose due to these radionuclides becomes significant because of chewing tobacco leaves. In the present study, the concentrations of these two radionuclides were determined in dried tobacco leaves and some branded cigarettes. 210Pb was determined by counting the beta activity of 210Bi with a low background beta counter after radiochemical separation and precipitation. 210Po was determined by alpha counter after radiochemical separation and deposition of polonium on silver disc. 210Pb and 210Po concentrations in dry tobacco leaves ranged from 6.0 to 30.5 mBq/g (mean 15.8 mBq/g) and 5.6 to 29.3 mBq/g (mean 12.7 mBq/g). The average annual committed effective dose for the tobacco chewers (10 g/day) was estimated to be 95.5 μSv/y (39.9 μSv/y from 210Pb and 55.6 μSv/y from 210Po). 210Pb and 210Po concentrations in branded cigarettes ranged from 11.0 to 18.4 mBq/cigarette (mean 41.2 mBq/cigarette) and 10.5 to 16.6 mBq/cigarette (mean 13.1 mBq/cigarette). The average annual committed effective dose for the smokers (20 cigarettes per day) was estimated to be 149.8 μSv/y (39.8 μSv/y from 210Pb and 110.0 μSv/y from 210Po). (author)

  4. The effect of CaNa2EDTA on excretion of 210PB, 210Po and stable lead in cases of chronic lead intoxication

    The study describes the effect of CaNa2EDTA on the excretion of the naturally occurring radionuclides 210Pb, 210Po and stable lead in workers' urine. The CaNa2EDTA was administered intravenously to workers in the morning for five days. The results show that CaNa2EDTA mobilises biologically active 210Pb, 210Po and stable lead, appreciably increasing their concentration in urine. (author)

  5. Natural levels of {sup 210}Po in human urine

    Diaz-Frances, I.; Manjon, G.; Mantero, J.; Diaz, J. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); Garcia-Tenorio, R. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); National Accelerator Centre, P.O. Box 41092 Seville (Spain)

    2014-07-01

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a {sup 210}Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. {sup 210}Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the {sup 222}Rn. The total amount of natural {sup 210}Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to {sup 222}Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of {sup 210}Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. {sup 210}Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation {sup 210}Po, followed by its auto-deposition on copper planchets for proper measure. Daily {sup 210}Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the

  6. Natural levels of 210Po in human urine

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a 210Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. 210Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the 222Rn. The total amount of natural 210Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to 222Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of 210Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. 210Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation 210Po, followed by its auto-deposition on copper planchets for proper measure. Daily 210Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the highest 210Po content in recent products. The use of urine to

  7. /sup 210/Pb in a tropical coastal lagoon sediment core

    Paez-Osuna, F.; Mandelli, E.F. (Universidad Nacional Autonoma de Mexico, Sinaloa. Inst. de Ciencias del Mar y Limnologia)

    1985-03-01

    Excess /sup 210/Pb in a core from a Mexican Coastal Lagoon, which has no connection with the sea shows a small but measurable decay over the length of the core; when different approaches were compared significant differences in the values for the sedimentation rate are obtained. The best coefficient correlation was calculated when corrected /sup 210/Pb activity for the uneven distribution of organic matter and cumulative inorganic weight is considered. Time frames in the sedimentary column were in agreement between the /sup 210/Pb calculated time and the appearance of shell fragments probably associated with the disturbances caused by the 1961 hurricane Tara. The surface accumulation rate is equivalent to a mean deposition of 262.5 g m/sup -2/ yr/sup -1/ of organic matter which is minor but comparable to some salt marshes of United States.

  8. An emergency bioassay method for 210Po in urine

    A rapid method was developed to efficiently measure 210Po in urine samples in an emergency situation. Polonium-210 in small urine samples (10 mL) was spontaneously deposited on a stainless steel disc in 1 M HCl at room temperature for 4 h in a polyethylene bottle. The metallic disc was then counted for 4 h by alpha spectrometry. The developed method allowed the preparation of large sample batch in a short time. The method meets the requirements for an emergency bioassay procedure. - Highlights: • A new method was developed to rapidly measurement 210Po in urine. • The method is easy to perform and does not require highly qualified staffs. • Large sample batches can be simultaneously prepared. • The method meets the requirements for an emergency bioassay method

  9. Sedimentation rates in Manila Bay from 210Pb profiles

    Manila Bay is one of the water systems affected by red tide occurrences. In an effort to provide an age control to the cyst produced by the red tide causative organism, Pyrodinium bahamense var compressum, several cores were collected from the bay and analyzed for lead-210 (210Pb) by alpha spectrometry. The surface activity ranges from 1.31 dpm/g to 4.56 dpm/g with an average at 3.32 dpm/g. The derived 210Pb vertical profiles indicate a marked increase of 5x to 10x in sedimentation rate in the last ten years in the deeper portions of the bay. This is probably due to the elevated sediment yield of rivers after the eruption of Mt. Pinatubo in 1991 as can be seen in the profiles of the three cores. (Author)

  10. Radiological Dispersal Polonium-210, and Lessons for Public Health

    On November 23, 2006, Alexander Litvinenko died in London as a result of being poisoned with Polonium-210. Public health authorities in the United Kingdom (UK) subsequently found Polonium-210 contamination at a number of locations in and around London. UK authorities have determined that citizens of 48 countries other than the UK, including the United States, may have been exposed to this contamination. UK authorities asked the CDC to contact approximately 160 individuals who may have been exposed to Po-210. These citizens have been advised that their risk of adverse health effects is likely to be low, but, if they are concerned, they should contact their primary health care provider. In turn, physicians are referred to state and local public health departments or CDC for further information on Po-210, including where they can seek testing of 24 hour urine samples for Po-210, if desired. CDC posted guidance for members of the public and physicians on its web site, and it responded to numerous inquiries from national media. Working with our UK colleagues, CDC developed guidelines for judging when a measurement of Po-210 in urine was or was not a level of concern. Because the death of Mr. Litvinenko is an ongoing criminal investigation, one of the major challenges of this response to what is a radiological dispersal device event has been the inability to obtain all of the technical detail desired to perform assessments. This has complicated the ability to communicate effectively with citizens and members of the public health community. These and other lessons learned from this response will help prepare the public health community to respond more effectively to future contamination events involving radioactive dispersal in the environment.(author)

  11. Dosimetric consideration of polonium-210 for Tiruchirappalli public

    This paper deals with the committed effective dose equivalent from polonium-210 to the public of Tiruchirappalli district in south India on consumption of cereals, vegetables and animal food. It is demonstrated that the activity of 210Po is non-uniformly distributed between cereals, vegetables and animal food. Among cereals, the green gram recorded a higher activity of 210Po (0.62 Bq.kg-1) than the others tested. The study also recorded a relatively enhanced activity in raw rice (0.90 Bq.kg-1) than in boiled rice (0.03 Bq.kg-1). Among vegetables, the tubers accumulated more 210Po than the shoot growing vegetables. The muscle of prawn (Macrobrachium rosenbergii) recorded the highest level of 210Po activity (13.9 Bq.kg-1) among the animal food. With reference to dosimetry, the animal food was identified to contribute higher radiation dose (0.38-29.5 μSv.y-1) than the cereals (0.05 - 1.9 μSv.y-1) and vegetables (0.05 - 1.9 μSv.y-1). Among animal food, the fish contributed a substantial level of α radiation dose to man. Though activity in raw rice was higher than the activity in boiled rice, the dose delivered from raw rice was substantially low since the average consumption of this rice represents only 7 kg.y-1 when compared to the consumption of boiled rice (108 kg.y-1). From the dose estimates made, it was evident that the total dose received by the general public (2.7 μSv.y-1) from 210Po was well below the dose limit of 1mSv.y-1. (author)

  12. 210Po radiation dose due to cigarette smoking

    The level of 210Po in eight brands of cigarettes and four brands of bidis popular in and around Nagercoil town was determined to evaluate the annual effective dose. The 210Po activity in a full cigarette ranged from 32.8±3.6 to 68.4±5.9 mBq and from 34.3±3.5 to 62.9±5.8 mBq in a bidi. In tobacco, the highest 210Po content was recorded in the brand C4 (23.0±1.2 mBq) whereas for bidis it was the highest in the brand B2 (21.1±1.1 mBq). The activity in mainstream varied from 15.2±0.75 to 36.8±2.1 mBq in a cigarette and from 20.7±3.1 to 39.8±4.0 mBq in a bidi. With regard to 210Po activity concentration, not much specificity was noted with respect to the tobacco brand. The data showed a relatively wide range of activity concentration of 210Po in the different cigarette/bidi brands and even within the same brand. The bidis showed a higher activity when compared to cigarettes. The popular brands concentrated more activity than the fine brands. Smokers who smoke one pack (10 cigarettes/bidis) per day may inhale about 100-300 mBq d-1 (0.1-0.3 Bq d-1) of 210Po. In this study, radiation dose values in the range of 153.5-372.9 μSv Y-'1 from cigarettes and from 209.2 to 402.7 μSvY-1 from bidis was estimated for the whole body. (author)

  13. Behaviour of polonium-210 during anode slimes processing

    Refinery slimes produced during the electrorefining of copper anodes often contain recoverable quantities of gold, silver and the platinum group metals, platinum and palladium. The treatment process selected to recover precious metals from the slimes depends on the concentration of other impurities. Polonium-210 will be present in the refinery slimes when uranium-bearing minerals (e.g. uraninite) are associated with the copper mineralogy. The production of pure precious metals from copper anode slimes containing polonium-210 involves a variety of steps including impurity removal, smelting to produce a dore metal and then refining. Gold and silver are recovered by electrorefining processes. Platinum group metals accumulate in the gold electrolyte and are recovered by precipitation. To ensure that specifications are met in the final products, it is necessary to identify and closely monitor where the impurities, including polonium-210, are partitioning during processing. Although measurement of polonium-210 activity using alpha spectrometry identifies relative amounts of the radionuclide in the various streams, it does not give any indication of the form it may be in. By studying the chemistry and deportment of its neighbours in the periodic table (Pb,Bi,Se and Te) it may be possible to make some conclusions regarding polonium-210 behaviour. Examination of the solid phases produced during anode slimes treatment were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Elemental analyses of solid and liquor streams were carried out using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES). This paper attempts to develop a relationship between the behaviour of polonium-210 and other impurities during precious metals recovery based on the results of these studies

  14. Concentrations of 210Po in fish and shellfish from southern region of Japan and evaluation of 210Po intake from seafood for Japanese people

    Concentrations of 210Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of 210Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and 210Po was analyzed. The phytoplankton occupied only 4.4% of 210Po in seawater and a large fraction of 210Po was observed in the particulate form. (orig.)

  15. Concentrations of {sup 210}Po in fish and shellfish from southern region of Japan and evaluation of {sup 210}Po intake from seafood for Japanese people

    Momoshima, N.; Sugihara, S. [Kyushu Univ., Fukuoka (Japan). Radioisotope Center; Nakao, H. [Kyushu Univ., Fukuoka (Japan). Graduate School of Sciences

    2012-07-01

    Concentrations of {sup 210}Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of {sup 210}Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and {sup 210}Po was analyzed. The phytoplankton occupied only 4.4% of {sup 210}Po in seawater and a large fraction of {sup 210}Po was observed in the particulate form. (orig.)

  16. Modelling the evolution of 210Pb and 210Po size distributions in the atmosphere

    The study of radon (222Rn and 220Rn) decay products in the atmosphere is important for estimating air ionization, assessing the inhalation doses to humans and for understanding atmospheric transport processes. The decay products 218Po, 214Pb (T1/2 < 1 hour), 212Pb (T1/2 ∼ 10.6 hrs) are short lived and 210Po (T1/2 ∼ 13 days), 210Pb (T1/2 ∼ 22 years) are long lived. Within a short time after their formation, the decay product atom combine with air constituents to form molecular clusters which then get attached to existing aerosol particles. The activity size distributions of the short-lived components in the atmosphere show two major modes, namely fine and coarse modes. The long-lived components predominantly occur in the coarse mode. Several studies have been carried out on the decay product activity distributions to estimate their atmospheric residence times. An important aspect that has received little attention is the upward size evolution of the decay products due to the persistent coagulation of the coarse mode particles. The present study aims at the development of first principle model for progeny attachment dynamics to a coagulating aerosol, which will provide insight in understanding the evolution of activity size distribution. A theoretical model is formulated by considering the processes such a constant formation of background aerosols, attachment of progeny atoms to the aerosol, coagulation, physical decay, and deposition. A set of integro-differential equations for attached and unattached fractions are formulated and are solved by a comprehensive numerical approach. Comparative studies of the activity size distributions, the degree of mixing of radioactivity within particles are carried out for short-lived and long lived species. The results are in agreement with the observations which show that the mode of the activity size distribution strongly depends on the effective life time of the progeny species in the atmosphere. The size dependence of

  17. Levels of polonium-210 in some beverages and in tobacco

    Colangelo, C.H.; Huguet, M.R.; Palacios, M.A.; Oliveira, A.A. [Gerencia de Seguridad Radiologica y Nuclear, Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    1992-07-01

    The objective of the present work is the estimation of the Polonium-210 content in some beverages and in tobacco, in order to assess the corresponding collective doses to the population in Argentina. Yerba mate, an autochton plant of South America, tea leaves, their infusion and ground coffee were analyzed as well as tobacco. Collective doses due to annual consumption of the beverages described, resulted in values from 6 man.Sv to 1200 man.Sv. Results for Polonium-210 in tobacco ranged from 10 Bq kg{sup -1}. Doses due to the use of tobacco were not assessed since an appropriate metabolic model was not found. (author)

  18. Levels of polonium-210 in some beverages and in tobacco

    The objective of the present work is the estimation of the Polonium-210 content in some beverages and in tobacco, in order to assess the corresponding collective doses to the population in Argentina. Yerba mate, an autochton plant of South America, tea leaves, their infusion and ground coffee were analyzed as well as tobacco. Collective doses due to annual consumption of the beverages described, resulted in values from 6 man.Sv to 1200 man.Sv. Results for Polonium-210 in tobacco ranged from 10 Bq kg-1. Doses due to the use of tobacco were not assessed since an appropriate metabolic model was not found. (author)

  19. Variations of 210Po and 210Pb in various marine organisms from Western English Channel: contribution of 210Po to the radiation dose

    Measurements of 210Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg-1 (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg-1 (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. 210Po/210Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 103 and 5.0 x 103) and for molluscs, with highest CFs (>105) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to 210Po received by the marine organisms (0.05 μG h-1 for macroalgae, between 0.70 and 1.5 μG h-1 for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 μSv y-1)

  20. Variations of {sup 210}Po and {sup 210}Pb in various marine organisms from Western English Channel: contribution of {sup 210}Po to the radiation dose

    Connan, O. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)], E-mail: olivier.connan@irsn.fr; Germain, P.; Solier, L.; Gouret, G. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)

    2007-10-15

    Measurements of {sup 210}Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg{sup -1} (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg{sup -1} (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. {sup 210}Po/{sup 210}Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 10{sup 3} and 5.0 x 10{sup 3}) and for molluscs, with highest CFs (>10{sup 5}) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to {sup 210}Po received by the marine organisms (0.05 {mu}G h{sup -1} for macroalgae, between 0.70 and 1.5 {mu}G h{sup -1} for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 {mu}Sv y{sup -1})

  1. 17 CFR 210.2-07 - Communication with audit committees.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Communication with audit..., INVESTMENT ADVISERS ACT OF 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Qualifications and Reports of Accountants § 210.2-07 Communication with audit committees. (a) Each registered public accounting firm...

  2. Polonium-210 in the total environment of Goa

    The paper deals with the distribution of 210Po in total environment of Goa. The activity concentration of 210Po in food, diet, water and air samples of the region were measured and the annual effective dose due to ingestion of this radionuclide was estimated. The activity of 210Po in soil and sand samples vary from 3.2 Bq kg-1 to 186.2 Bq kg-1 with a mean value of 57.4Bq kg-1 and from 0.94 Bq kg-1 to 3.7 Bq kg-1 with the mean value of 1.8 Bq kg-1 respectively. Among food samples fish and prawn shows higher concentration of 210Po. The Committed Effective Dose Equivalent due to ingestion of non veg meal, veg meal, breakfast and potable water were found to be 94.6 μSv y-1, 49.1 μSv y-1, 10.5 μSv y-1 and 4.2 μSv y-1 respectively. All the results are compared with the reported literature values and discussed in detail in this paper. (author)

  3. 20 CFR 210.7 - Verification of service claimed.

    2010-04-01

    ... CREDITABLE RAILROAD SERVICE § 210.7 Verification of service claimed. Service claimed by an employee, which is not credited in the records of the Board, must be verified to the satisfaction of the Board before it... claimed, the employee may submit affidavits and other evidence in support of the service claimed in...

  4. 10 CFR 72.210 - General license issued.

    2010-01-01

    ... for Storage of Spent Fuel at Power Reactor Sites § 72.210 General license issued. A general license is hereby issued for the storage of spent fuel in an independent spent fuel storage installation at power... NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF...

  5. 12 CFR 611.210 - Director qualifications and training.

    2010-01-01

    ... Association Board of Directors § 611.210 Director qualifications and training. (a) Qualifications. (1) Each bank and association board of directors must establish and maintain a policy identifying desirable... board members, explaining how the desired qualifications were identified. The policy must...

  6. 27 CFR 26.210 - Liquor dealer registration and recordkeeping.

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Liquor dealer registration... TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE... Recordkeeping § 26.210 Liquor dealer registration and recordkeeping. Every person bringing liquors into...

  7. 17 CFR 210.5-03 - Income statements.

    2010-04-01

    ..., PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT COMPANY ACT OF 1940, INVESTMENT ADVISERS ACT OF... parties shall be disclosed as required under § 210.4-08(k). A public utility company using a uniform... of debt discount and expense. 9. Non-operating expenses. State separately in the income statement...

  8. 19 CFR 210.27 - General provisions governing discovery.

    2010-04-01

    ... PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.27 General... the other parties during the discovery process or in writing. (2) A duty to supplement responses also... to the best of the signer's knowledge, information, and belief formed after a reasonable inquiry,...

  9. 40 CFR 1065.210 - Work input and output sensors.

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Work input and output sensors. 1065... Ambient Conditions § 1065.210 Work input and output sensors. (a) Application. Use instruments as specified... sensors, transducers, and meters that meet the specifications in Table 1 of § 1065.205. Note that...

  10. Volatility of 210Po in the gross alpha determination

    Světlík, Ivo; Belanová, A.; Vršková, M.; Hanslík, E.; Ivanovova, D.; Marešová, J.; Tomášková, Lenka; Nováková, Tereza

    Roč. 286 , č. 2 ( 2010 ), s. 547-551. ISSN 0236-5731 R&D Projects: GA AV ČR IAAX00130801 Institutional research plan: CEZ:AV0Z10480505 Keywords : gross alpha * 210Po * polonium recovery Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 0.777, year: 2010

  11. 210Po activity concentrations in mussels at Aegean Turkish Coast

    In Turkey mussels (Mytilus galloprovincialis) are consumed in relatively large quantities. Therefore, analyses of mussel samples from different sampling sites in Aegean Sea were performed in order to evaluate the ingestion of 210Po and 210Pb by the Turkey population. Polonium analyses were performed with a complete dissolution of the sample in mineral acids. Polonium isotopes were plated onto a copper discs in 0.5 M HCl solution in the presence of ascorbic acid using a technique modified from Flynn (1968). The alpha activity measurements of polonium isotopes plated on copper discs were performed with ZnS(Ag) detector. The highest concentrations was found in Karaburun mussels as 254 Bq.kg-1 and the lowest one was at Inciralti as 18 Bq.kg-1. Based on these 210Po activity concentrations, annual dose equivalent rates delivered to biological tissues in mussels would vary widely, from 136 to 10 mSv.y-1. It is concluded that in mussels living in the Aegean Sea a wide range of internal radiation dose exists and it is essentially sustained by 210Po food-chain transfer. (author)

  12. Size distribution measurements of stable Pb and 210Pb

    High volume impactor measurements were taken to define the particle size distribution of atmospheric stable Pb and 210Pb. This was done in an effort to establish if a particle size effect could be responsible for the differences in wet and dry deposition values of stable Pb and 210Pb. Duplicate impactor tests were run on the roof of the Environmental Measurements Laboratory (EML) and at the Regional Baseline Station in Chester, NJ, to determine the feasibility of collecting flow controlled impactor samples over extended sampling periods. The test results indicate that 210Pb is associated more with smaller particles than is the stable Pb (63% vs 53%, on the average for particles less than 0.58 μm). This difference, although not large, is beyond the experimental error. The duplicate samples gave results that are in good agreement. The differences observed between the total air concentrations at the urban and rural sites are as expected, since 210Pb has a natural source while Pb is of anthropogenic origin

  13. 17 CFR 210.12-09 - Valuation and qualifying accounts.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Valuation and qualifying... § 210.12-09 Valuation and qualifying accounts. Column A—Description 1 Column B—Balance at beginning of... D—Deductions—describe Column E—Balance at end of period 1 List, by major classes, all valuation...

  14. Restructuring of an Ir(210 electrode surface by potential cycling

    Khaled A. Soliman

    2014-08-01

    Full Text Available This study addresses the electrochemical surface faceting and restructuring of Ir(210 single crystal electrodes. Cyclic voltammetry measurements and in situ scanning tunnelling microscopy are used to probe structural changes and variations in the electrochemical behaviour after potential cycling of Ir(210 in 0.1 M H2SO4. Faceted structures are obtained electrochemically as a function of time by cycling at a scanrate of 1 V·s−1 between −0.28 and 0.70 V vs SCE, i.e., between the onset of hydrogen evolution and the surface oxidation regime. The electrochemical behaviour in sulfuric acid solution is compared with that of thermally faceted Ir(210, which shows a sharp characteristic voltammetric peak for (311 facets. Structures similar to thermally-induced faceted Ir(210 are obtained electrochemically, which typically correspond to polyoriented facets at nano-pyramids. These structures grow anisotropically in a preferred direction and reach a height of about 5 nm after 4 h of cycling. The structural changes are reflected in variations of the electrocatalytic activity towards carbon monoxide adlayer oxidation.

  15. 33 CFR 160.210 - Methods for submitting an NOA.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Methods for submitting an NOA... Conditions, and Certain Dangerous Cargos § 160.210 Methods for submitting an NOA. (a) Submission to the..., vessels must submit NOA information required by § 160.206 (entries 1 through 9 in Table 160.206) to...

  16. Po-210 in the coastal waters at Kalpakkam

    The occurrence of patches of monazite in the beach sands at Kalpakkam is significant in the context of preoperational surveillance at site and the adjoining coastal marine environment. The paper gives data on Po-210 concentrations in the coastal marine environment - sea water, silt, pelagic and benthic fishes, intertidal biota (mollusca, crustacea and macrophytes) and discusses their relevance to population exposure

  17. 48 CFR 1852.210-70 - Brand name or equal.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Brand name or equal. 1852... 1852.210-70 Brand name or equal. As prescribed in 1810.011-70(a), insert the following provision: Brand Name or Equal (DEC 1988) (a) As used in this provision, “brand name” means identification of...

  18. Lead-210 in the Australian environment, 1964--70

    Extensive monitoring studies have been made of fission products arising from nuclear weapon tests and of naturally occurring radionuclides in the Australian environment. Methods are described for the sampling and radiochemical measurement procedures for lead-210 in air, precipitation, and drinking water. The results of measurements in Australia to the end of 1970 are reported. (U.S.)

  19. 29 CFR 553.210 - Fire protection activities.

    2010-07-01

    ... OF THE FAIR LABOR STANDARDS ACT TO EMPLOYEES OF STATE AND LOCAL GOVERNMENTS Fire Protection and Law Enforcement Employees of Public Agencies Exemption Requirements § 553.210 Fire protection activities. (a) As... activities” also refers to employees who work for forest conservation agencies or other public...

  20. 17 CFR 210.12-26 - Certificate reserves.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Certificate reserves. 210.12... 1934, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT COMPANY ACT OF 1940, INVESTMENT ADVISERS... Certificate reserves. Column A—Description 1 Column B—Balance at beginning of period (1)—Number of...

  1. Pb-210 in beans grown in normal background environments

    Mingote, Raquel M.; Nogueira, Regina A., E-mail: mingote@cnen.gov.br, E-mail: rnogueira@cnen.gov.br [Centro Regional de Ciencias Nucleares do Centro-Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil)

    2013-07-01

    A survey was carried out on the activity concentration of {sup 210}Pb in common beans (Phaseolus vulgaris L.) grown in normal background environments in Brazil. The Carioca beans and the black type were analyzed, which contribute with 90% of the Brazilian market share of the common beans. To this study 18 bean samples sowing in the Middle-Western and Southern regions of Brazil during the years 2010-2011 were analyzed. The proportion per bean type was similar to the national production: most of the Carioca beans (n=13; 72%) and black beans (n=5; 28%). Other 17 values of {sup 210}Pb activity concentration in beans grown in Southeastern region available in the GEORAD, a dataset of radioactivity in Brazil, were added to the statistic analysis of the data. Considering the information contained in censored observations (60%), representative value of {sup 210}Pb activity concentration in beans was estimated by using robust ROS, a censored data analysis method. The value 0.047 Bq kg{sup -1} fresh wt. obtained here is according to {sup 210}Pb activity concentration in grains reported by UNSCEAR 0.05 Bq kg{sup -1}. (author)

  2. 40 CFR 180.210 - Bromacil; tolerances for residues.

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromacil; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.210 Bromacil; tolerances for residues. (a) General. Tolerances are established for residues of the...

  3. Vertical distribution of 210Pb around Uraniferous coal-fired power plant in Western Turkey

    Monitoring of 210Pb in soil, water, sediment and biological materials has been increasing in several pollution studies in recent years. The 210Pb in soils generated in situ by the decay of 226Ra is termed supported 210Pb and is in equilibrium with 226Ra. 210Pb activity in excess of the fraction which is derived from decay of the in situ 226Ra is called unsupported 210Pb. The amount of unsupported or atmospherically derived 210Pb in a soil can be calculated by measuring both the 210Pb and 226Ra activities and subtracting the 226Ra supported 210Pb component from the total 210Pb in the sample. We have determined the deposition rates of 210Pb from the atmosphere in Yatagan Region by measuring their inventories in core samples of cultivated and uncultivated soils.Yatagan is located in Western Turkey in a region where there are three CPPs operating with uraniferous coal. Energy production from coal is one of the major sources of increased natural radioactivity in the atmosphere. Soil samples were stored for a period of 2-3 half-lives (9 - 14 months) of 210Po (t1/2 =138 d) before analysis to allow build-up of 210Pb from 210Pb . The determination of the 210Po activity by alpha-counting provided an indirect measurement of the 210Pb activity. Measurements of 210Po were made through its 5.30 MeV alpha particle emission, using 208Po (5.11 MeV alpha emission, t1/2 = 2.9 yr) as the internal tracer. Measurements were made by silicon surface-barrier detector. The 210Pb activity concentrations in cultivated and uncultivated bulk soil cores varied between 83 Bq kg-1 - 22 Bq kg-1 and 250 Bq kg-1 - 55 Bq kg-1, respectively. (authors)

  4. A method for rapid determination of 210Pb radioactivity in environmental water

    Background: There are three methods for determination of 210Pb radioactivity concentration in environmental water. One is detecting p rays of 210Bi guided by the EJT 859-1994, one is detecting α rays of 210Po for 210Pb radioactivity, and the other is using gamma ray spectrometer to determinate the radioactivity of 210Pb. But the first method can not give an exact recovery rate of 210Pb, the second one is a time-consuming process, and the third one is unable to detect 210Pb in water samples because of its detection limit. This paper describes a method of rapid determination of 210Pb in environmental water with the anion exchange. Purpose: To determine the radioactivity of 210Pb in water samples rapidly. Methods: The stable Pb carrier is added to the water samples for the recovery rate in the chemical and physical process. 210Pb and Pb carrier in the water samples are adsorbed and concentrated by Fe(OH)3 co-precipitation undergoing heating. 210Pb and its carrier are isolated from most interference by an anion exchange. The PbSO4 precipitation has been purified via being precipitated for three times. The PbSO4 precipitation has been stored in the environmental temperature for one month. And then, the p rays of 210Bi and the daughter of 210Pb are detected to determine the radioactivity concentration of 210Pb. Results: This method provides a stable and reliable result and costs less time than the method that detects α rays of 210Po for 210Pb radioactivity. Conclusions: The method for rapid determination of 210Pb is a practical and reliable method and used to analyze water samples in Yunnan province. (authors)

  5. Assessment of committed effective dose due to the ingestion of 210Po and 210Pb in consumed Lebanese fish affected by a phosphate fertilizer plant

    Ingestion of radionuclides through seafood intake is a one of the sources contributing to the internal effective dose in the human organism. In order to evaluate the internal exposure and potential risks due to 210Po and 210Pb associated with fish consumption, these radionuclides were measured in commonly consumed fish species from a clean area and an area subjected to the impact of a Lebanese phosphate fertilizer plant. The highest concentration of 210Pb was 98.7 Bq/kg fresh weight while 210Po activity concentrations varied from 3.6 Bq/kg to 140 Bq/kg. A supplementary radiation exposure was detected; the highest committed effective dose due to 210Po and 210Pb was found to be 1110 μSv/y and 450 μSv/y, respectively. Moreover, the average mortality and morbidity risks due to the fish consuming were estimated. - Highlights: • Enrichment in 210Po and 210Pb in fish affected by a phosphate fertilizer plant. • Significant human exposure associated with the ingestion of fish. • Estimation of potential risks due to 210Po and 210Pb via fish consumption

  6. Biomonitoring of Po-210 and Pb-210 using lichens and mosses around a uraniferous coal-fired power plant in western Turkey

    Ugur, A.; Ozden, B.; Sac, M.M.; Yener, G. [Ege University, Izmir (Turkey). Inst. of Nuclear Science

    2003-05-01

    Studies were realized over a wide area around the coal-fired power plant (CPP) located at Yatagan , Gokova, Turkey, to evaluate the possible increase of natural radioactivity level due to the operation of the plant. The lichens Rhizoplaca melanophthalma, Cladonia convoluta, Cladonia pyxidata and the mosses Grimmia pulvinata, Hypnum cupressiforme were investigated for potential use as bioindicators for Po-210 and Pb-210 deposition. The maximum Po-210 and Pb-210 activities were observed around the hill close to ash stacks. The capture efficiency was the highest in one of the moss species, G. pulvinata with the activity concentration ranges of 600 {+-} 19 - 1228 {+-} 36 and 446 {+-} 15 - 650 {+-} 21 Bq kg{sup -1} for Po-210 and Pb-210, respectively. Soil samples were also collected and analysed in order to investigate any possible contamination in soil profiles due to CPPs and to determine unsupported Pb-210 flux. The Pb-210 and Ra-226 concentrations in uncultivated soil profiles varied between 58 {+-} 2 and 258 {+-} 6 Bq kg{sup -1}, 50 {+-} 5 and 58 {+-} 5 Bq kg{sup -1}, respectively. The unsupported Pb-210 inventory in the core was calculated to be 3312 Bq m{sup 2}. The corresponding annual Pb-210 flux of 103 Bq m{sup -2} yr{sup -1} is high with compare to estimates of the atmospheric flux given in literature for the same region.

  7. Particle-reactive radionuclides (234Th, 210Pb, 210 as tracers for the estimation of export production in the South China Sea

    P. H. Santschi

    2011-12-01

    Full Text Available The time-series station, SEATS (18° N, 116° E in the South China Sea was visited six times during October 2006–December 2008 to carry out seawater sampling and floating trap deployments for the determination of distributions and fluxes of POC, PIC, PN, 234Th, 210Pb, and 210Po in the upper 200 m of the water column. Radionuclide deficiencies resulted in removal fluxes from the euphotic layer of 1.1×103–1.8×103 dpm m−2d−1 and 7.1–40.2 dpm m−2d−1 for 234Th and 210Po, respectively. Due to atmospheric input, an excess of 210Pb relative to 226Ra is commonly observed in the upper water column. Sinking fluxes of total mass, POC, PIC, PN, 234Th, 210Pb, and 210Po measured at the euphotic depth were low in summer-fall and high in winter-spring, reflecting the seasonal variability of biological pumping. Excluding the suspiciously low primary productivity data point in July 2007, a relatively high e-ratio of 0.28–0.69 was estimated by the ratio of the POC flux at the euphotic depth and the integrated primary productivity. The ratios of 234Th, 210Pb, and 210Po to organic carbon, inorganic carbon, and nitrogen in the sinking particles were combined with the disequilibria of 234Th–238U, 210Pb–226Ra, and 210Po–210Pb to estimate export fluxes of POC, PIC, and PN from the euphotic layer. Compared with measured fluxes by the sediment trap and estimated fluxes by other approaches, it is concluded that the export production in the South China Sea, ranging from 1.8 to 21.3 mmol-C m−2d−1, can be reasonably estimated using 234Th, 210Pb, and 210Po as carbon proxies.

  8. 210Po in Nevada groundwater and its relation to gross alpha radioactivity

    Seiler, R.L.

    2011-01-01

    Polonium-210 (210Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. 210Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high 210Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous 210Po is unsupported by 210Pb, indicating that the 210Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are 234/238U, 222Rn, and 210Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with 210Po activity. The only applicable drinking water standard for 210Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. 210Po was not volatile in a Nevada well, but volatile 210Po has been reported in a Florida well. Additional information on the volatility of 210Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had 210Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10−4 (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of 210Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded.

  9. Health Risk Evaluations for Ingestion Exposure of Humans to Polonium-210

    Scott, Bobby R.

    2007-01-01

    The incident in London during November 2006 involving a lethal intake by Mr. Alexander Litvinenko of the highly-radioactive, alpha-particles-emitting polonium-210 (Po-210) isotope, presumably via ingestion, sparked renewed interest in the area of Po-210 toxicity to humans. This paper is the result of assembling and interpreting existing Po-210 data within the context of what is considered a reliable risk model (hazard-function [HF] model) for characterizing the risk of death from deterministi...

  10. Lead Precipitation Fluxes at Tropical Oceanic Sites Determined From ^(210)Pb Measurements

    Settle, D. M.; Patterson, C C; Turekian, K K; Cochran, J. K.

    1982-01-01

    Concentrations of lead, ^(210)Pb, and ^(210)Po were measured in rain selected for least influence by local sources of contamination at several tropical and subtropical islands (Enewetak; Pigeon Key, Florida; and American Samoa) and shipboard stations (near Bermuda and Tahiti). Ratios expressed as ng Pb/dpm ^(210)Pb in rain were 250–900 for Pigeon Key (assuming 12% adsorption for ^(210)Pb and no adsorption for lead), depending on whether the air masses containing the analyzed rain came from th...

  11. 13 CFR 108.210 - Minimum capital requirements for NMVC Companies.

    2010-01-01

    ... NMVC Companies. 108.210 Section 108.210 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Company § 108.210 Minimum capital requirements for NMVC Companies. You must have Regulatory Capital of at least $5,000,000 and Leverageable Capital of at least $500,000 to become a NMVC Company....

  12. 7 CFR Appendix C to Part 210 - Child Nutrition Labeling Program

    2010-01-01

    ... significantly to the meat/meat alternate component of meal pattern requirements of 7 CFR 210.10, 225.20, and 226...) The statement of the product's contribution toward meal pattern requirements of 7 CFR 210.10, § 220.8... product for noncompliance with the meal pattern requirements of 7 CFR 210.10, § 220.8 or §...

  13. 40 CFR 80.210 - What sulfur standards apply to gasoline downstream from refineries and importers?

    2010-07-01

    ... gasoline downstream from refineries and importers? 80.210 Section 80.210 Protection of Environment... Gasoline Sulfur Gasoline Sulfur Standards § 80.210 What sulfur standards apply to gasoline downstream from... downstream from refineries and import facilities, including gasoline at facilities of distributors,...

  14. 7 CFR 330.210a - Administrative instructions listing approved packing materials for plant pests.

    2010-01-01

    ... materials for plant pests. 330.210a Section 330.210a Agriculture Regulations of the Department of... PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant Pests § 330.210a Administrative instructions listing approved packing materials for plant pests. (a)...

  15. 17 CFR 210.6A-04 - Statements of income and changes in plan equity.

    2010-04-01

    ... changes in plan equity. 210.6A-04 Section 210.6A-04 Commodity and Securities Exchanges SECURITIES AND..., Savings and Similar Plans § 210.6A-04 Statements of income and changes in plan equity. Statements of income and changes in plan equity filed under this rule shall comply with the following provisions:...

  16. 30 CFR 210.204 - How do I submit facility data?

    2010-07-01

    ... you submit facility data by paper copy, send it to the applicable address given in § 210.202(c)(2). ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I submit facility data? 210.204 Section... MANAGEMENT FORMS AND REPORTS Production and Royalty Reports-Solid Minerals § 210.204 How do I submit...

  17. 17 CFR 210.8-06 - Real estate operations acquired or to be acquired.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Real estate operations acquired or to be acquired. 210.8-06 Section 210.8-06 Commodity and Securities Exchanges SECURITIES AND... Statements of Smaller Reporting Companies § 210.8-06 Real estate operations acquired or to be acquired....

  18. 17 CFR 210.3-14 - Special instructions for real estate operations to be acquired.

    2010-04-01

    ... General Instructions As to Financial Statements § 210.3-14 Special instructions for real estate operations... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Special instructions for real estate operations to be acquired. 210.3-14 Section 210.3-14 Commodity and Securities Exchanges...

  19. 30 CFR 210.153 - What reports must I submit for Indian gas valuation purposes?

    2010-07-01

    ... valuation purposes? 210.153 Section 210.153 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... Geothermal Resources § 210.153 What reports must I submit for Indian gas valuation purposes? (a) General. For Indian gas valuation, under certain conditions under § 206.172 of this chapter, lessees must submit...

  20. 20 CFR 405.210 - How to request review of an initial determination.

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How to request review of an initial determination. 405.210 Section 405.210 Employees' Benefits SOCIAL SECURITY ADMINISTRATION ADMINISTRATIVE REVIEW PROCESS FOR ADJUDICATING INITIAL DISABILITY CLAIMS Review of Initial Determinations by a Federal Reviewing Official § 405.210 How to request...

  1. 17 CFR 210.8-01 - Preliminary Notes to Article 8.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Preliminary Notes to Article 8... ADVISERS ACT OF 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Article 8 Financial Statements of Smaller Reporting Companies § 210.8-01 Preliminary Notes to Article 8. Sections 210.8-01 to 210.8-08...

  2. 27 CFR 44.210 - Return of shipment to factory or export warehouse.

    2010-04-01

    ... factory or export warehouse. 44.210 Section 44.210 Alcohol, Tobacco Products and Firearms ALCOHOL AND... Shipments of Tobacco Products and Cigarette Papers and Tubes by Manufacturers and Export Warehouse Proprietors Miscellaneous Provisions § 44.210 Return of shipment to factory or export warehouse....

  3. 27 CFR 24.210 - Classes of wine other than standard wine.

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Classes of wine other than standard wine. 24.210 Section 24.210 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.210 Classes of wine other than standard...

  4. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  5. 49 CFR 210.29 - Operation standards (moving locomotives and rail cars).

    2010-10-01

    ... cars). 210.29 Section 210.29 Transportation Other Regulations Relating to Transportation (Continued... REGULATIONS Inspection and Testing § 210.29 Operation standards (moving locomotives and rail cars). The operation standards for the noise emission levels of moving locomotives, rail cars, or consists...

  6. 17 CFR 210.6-09 - Statements of changes in net assets.

    2010-04-01

    ... assets. 210.6-09 Section 210.6-09 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... Companies § 210.6-09 Statements of changes in net assets. Statements of changes in net assets filed for... income taxes applicable to such amounts; and (d) net increase (decrease) in net assets resulting...

  7. Biogeochemistry of lead-210 and polonium-210 in fresh waters and sediments. Final report, 1 September 1985-31 August 1987

    The objective was to investigate the behavior of toxic metals in lakes and streams using the naturally occurring radioactive metals lead-210 and polonium-210 as tracers. The radionuclides were measured as a function of position and time in a Massachusetts lake, its sediments and pore waters, and associated streams. A mass balance for the epilimnion showed that lead-210 direct uptake by bottom sediments was inconsequential. Below the epilimnion, a steep temperature/density gradient limited vertical transport. Anoxic conditions caused remobilization of iron and lead-210, which reprecipitated at the oxycline and returned to the bottom via settling. Below the oxycline, lead-210 and iron distributions resulted from constant release from anoxic sediments and dilution in the water column. Sediment lead-210 distributions were caused by sedimentation and Fickian transport

  8. Biomonitoring of {sup 210}Po and {sup 210}Pb using lichens and mosses around coal-fired power plants in Western Turkey

    Sert, Emel, E-mail: emel.sert@mail.ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Ugur, Aysun, E-mail: aysun.ugur@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Ozden, Banu, E-mail: banu.ozden@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Sac, Mueslim Murat, E-mail: muslum.murat.sac@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey); Camgoez, Berkay, E-mail: berkay.camgoz@ege.edu.tr [Ege University, Institute of Nuclear Sciences, 35100 Bornova, Izmir (Turkey)

    2011-06-15

    Mosses and lichens are useful biological indicators of environmental contamination for a variety of metals and radionuclides of both natural and artificial origin. These plants lack a well-developed root system and rely largely on atmospheric deposition for nourishment. Therefore in the study, different lichens (Cladonia convoluta, Cladonia foliacea) and mosses (Homalothecium sericeum, Hypnum lacunosum, Hypnum cupressiforme, Tortella tortuosa, Didymodon acutus, Syntrichia ruralis, Syntrichia intermedia, Pterogonium graciale, Isothecium alopecuroides, Pleurochatae squarrosa) were collected around the Yatagan (Mugla), Soma (Manisa), Seyitoemer - Tuncbilek (Kuetahya) coal-fired power plants and investigated for potential use as biomonitors for {sup 210}Po and {sup 210}Pb deposition. While the activity concentrations of {sup 210}Po and {sup 210}Pb in lichens are in the ranges of 151 {+-} 7-593 {+-} 21 and 97 {+-} 5-364 {+-} 13 Bq kg{sup -1}, for mosses the ranges for {sup 210}Po and {sup 210}Pb are 124 {+-} 5-1125 {+-} 38 and 113 {+-} 4-490 {+-} 17 Bq kg{sup -1}, respectively. In the study, the moss samples were observed to accumulate more {sup 210}Po and {sup 210}Pb compared to lichens. While the most suitable biomonitor was a moss species (H. lacunosum) for Yatagan (Mugla), it was another moss species (S. intermedia) for Soma (Manisa) and Seyitoemer - Tuncbilek (Kuetahya) sites. {sup 210}Po concentrations were found higher than {sup 210}Pb concentrations at the all sampling stations. - Highlights: > Lichens and mosses have been used as biomonitors of 210Po and 210Pb deposition. > The morphology of lichens and mosses does not vary with seasons. > Lichens and mosses retain and accumulate pollutants deposited from the atmosphere. > Canopy is an important factor causing differences in the concentrations of radionuclides.

  9. 210Pb and 210Po, manganese and iron cycling across the O2/H2S interface of a permanently anoxic fjord: Framvaren, Norway

    Swarzenski, Peter W.; McKee, Brent A.; Sorenson, Kai; Todd, James F.

    1999-01-01

    Vertical profiles of dissolved and particulate 201Po and 210Pb were measured across the redox transition zone at Station F1 in Framvaren Fjord, Norway. In this fjord, a sharp decrease in pH above the O2/H2S interface facilitates the aerobic dissolution of MnO2. In contrast, Fe(II) concentrations begin to increase only at the O2/H2S interface depth. Activity profiles reveal that dissolved 210Po and 210Pb are sequestered efficiently by particulates in surface waters. As polonium-210 and lead-210 activities descend down into the aerobic manganese reduction (AMR) zone, they are remobilized during the reductive dissolution of the carrier phase oxyhydroxides. Both 210Po and 210Pb are highly enriched at the O2/H2S interface where an active community of microbes, such as anoxygenic phototrophs (e.g., Chromatium, Chlorobium sp.), thrives. The coincident peaks in 210Po and 210Pb and microbial biomass suggest a strong biological influence on the behavior of these radionuclides. There is a strong covariance between the vertical distribution of Mn and Pb, indicating that their redox cycling is closely coupled and is likely microbially mediated.

  10. Spatial and temporal variability of 210Po and 210Pb in mussels (Mytilus galloprovincialis) at the Turkish Coast of the Aegean Sea

    In this study, the activity concentrations of 210Po and 210Pb were determined in mussel samples (Mytilus galloprovincialis) collected from the Turkish coast of the Aegean Sea. The samples were collected seasonally for a period of two years (2004-2006) at six coastal stations (Canakkale, Dikili, Foça, Çe°me, Didim, Bodrum). Mussels were separated into several groups according to their size (1-4, 4-6, >6 cm). The results showed that 210Po concentrations in mussels varied between 53±4 and 1960±60 Bq kg-1 dw. The highest activity 210Po concentrations were determined in winter samples of mussels with a shell length of 4-6 cm from Didim. In general, it was observed that the 210Pb concentration levels in mussels were lower than 210Po concentrations. The 210Po/210Pb activity concentration ratios exceeded unity for all mussel samples and averaged 26.0. The inter-site difference seen in 210Po concentrations can be due to both the natural background levels of sites and industrial activities. (author)

  11. 210Po inhalation due to smoking. A dose estimation

    Smoking is the second reason for developing lung cancer. Our goal was to determine how the amount of 210Po in the tobacco is distributed among the cigarette parts and what percentage reaches the respiratory system, calculating the effective dose. 210Po from tobacco, filter and ash samples were measured from seven Romanian cigarette brands by alpha spectrometry. The obtained average results were 13.97 ± 1.75 mBq/cigarette in the tobacco; 1.61 ± 0.25 mBq/cigarette in the filter and 3.33 ± 0.29 mBq/cigarette in the ash. The dose originating from active smoking was estimated to have an average of 8.36 ± 0.91 μSv/year, while the passive smoking dose reaching the respiratory system was 5.92 ± 0.49 μSv. (author)

  12. Levels of 210Po in some beverages and in tobacco

    The objective of the present work is the estimation of the 210Po content in some beverages and in tobacco, in order to assess the corresponding collective doses to the population in Argentina. Yerba mate, tea leaves, their infusions and ground coffee were analyzed, as well as tobacco. Collective doses due to the annual consumption of the beverages described were found to be from 6 man.Sv to 1200 man.Sv. Results for 210Po in tobacco ranged from 10 Bq*kg-1 to 80 Bq*kg-1. Lung doses due to the use of tobacco vary from 75 μSv*y-1 to 600 μSv*y-1. (author) 14 refs.; 1 fig.; 5 tabs

  13. 210Pb dating of sediments from Havana Bay

    The study of sedimentation rates and age of marine sediments has been performed through many years using natural and artificial radioactive isotopes. Polluted sediments were collected in three sampling points in the Havana Bay. Sedimentation rates were estimated using two different radiometric approaches: the depth profiles of 137Cs and 210Pb. The maximum activity 137Cs might indicate the proximity of the 1964's. The unsupported 210Pb has been measured to apply both the Constant Initial Concentration Method (CIC) and the Constant Rate of Supply Method (CRS) Dating Models. The results show values for sedimentation rate ranging from 0.2 up to 1.3 cm x y-1 increasing with time which manifests the importance of the achievement of a project of dredging. (author)

  14. Management of response to the polonium-210 incident in London

    On the 23 November 2006, Alexander Litvinenko died in London allegedly from poisoning by 210Po, an alpha particle emitter. The spread of radioactive contamination, arising from the poisoning and the events leading up to it, involved many locations in London. The potential for intakes of 210Po arising from the contamination posed a public health risk and generated significant public concern. The scale of the event required a multi-agency response, including top level UK Government emergency response management arrangements. The Health Protection Agency (HPA) had a leading role in co-ordinating and managing the public health response. This paper reviews the management of the incident response and the issues involved. (author)

  15. Properties of polyphosphate: AMP phosphotransferase of Acinetobacter strain 210A.

    Bonting, C F; Kortstee, G J; Zehnder, A J

    1991-01-01

    Polyphosphate:AMP phosphotransferase, an enzyme which catalyzes the phosphorylation of AMP to ADP at the expense of polyphosphate, was purified more than 1,500-fold from Acinetobacter strain 210A by streptomycin sulfate precipitation and by Mono-Q, Phenyl Superose, and Superose column chromatography. Streptomycin sulfate precipitation appeared to be an effective step in the purification procedure. During the following chromatographic steps, there was a 29-fold increase in specific activity bu...

  16. Management of response to the polonium-210 incident in London

    On the 23 November 2006, Alexander Litvinenko died in London allegedly from poisoning by 210Po, an alpha particle emitter. The spread of radioactive contamination, arising from the poisoning and the events leading up to it, involved many locations in London. The potential for intakes of 210Po arising from the contamination posed a public health risk and generated significant public concern. The scale of the event required a multi-agency response, including top level UK Government emergency response management arrangements. The Health Protection Agency (HPA) had a leading role in co-ordinating and managing the public health response. This paper reviews the management of the incident response and the issues involved. The fatal poisoning of Mr Litvinenko with 210Po, and the associated public health hazard from the spread of contamination to many locations across London, was an unprecedented event. Fortunately, no one else is known to have suffered any acute effects. Results from the programme of individual monitoring showed that whilst more than 100 people had measurable intakes of 210Po, only 17 had assessed doses in excess of 6 mSv. The highest dose of about 100 mSv gives rise to an increased risk of fatal cancer of about 0.5%, compared with the natural incidence of about 25%. The incident required a co-ordinated and sustained multi-agency emergency response. The Health Protection Agency, as the lead on public health matters played a significant role in this. Whilst inevitably some lessons have been identified, the response is considered to have been very effective and to have benefited from the wide spectrum of experience and expertise developed through normal work, together with the effort put into emergency preparedness and the various emergency response. (author)

  17. 137Cs and 210Pb distribution in Manila Bay sediment

    Two radionuclides were measured in surface sediment samples taken from geographically distributed sections of Manila Bay, namely cesium-137 (137Cs) and lead-210 (210Pb). Results indicated a noticeable change in the radioactivity concentration levels in sediments collected in 2005 and 2010, with a median concentration of 1.0 and 2.64 Bq kg-1, respectively. Higher levels of 137Cs radioactivity were measured in the northern and inner portion of the bay adjacent to major river systems, agricultural and highly industrialized urban areas. 137Cs isotope increased in activity in most of the samples especially in the northwestern areas of Bataan and Pampanga with five times more than the activity from the first sampling measurements. Nevertheless, radioactivity concentrations observed in surface sediments along the bay are within the range of radioactivity in several areas monitored in the Northern Hemisphere. The country has been frequented by tropical cyclones and storms that have caused erosion, which may have introduced elevated material input in the bay. In addition, wind-driven circulation especially in the shallower areas of the bay is a possibility for the substantial sediment movement and accumulation along this coast. Conversely, areas with higher 137Cs have lower values of 210Pb. In an undisturbed environment, 210Pb deposition values are assumed nearly constant. Hence, changes in the radioactivity concentration levels of these radionuclides can be an indicator of pollution input from land-based sources, sediment movement and reworking in the coastal areas. At present, there is very limited information on the radioactivity level of various radioisotopes in Manila Bay.The data obtained are benchmark values against which changes that will be occurring in the bay can be assessed. (author)

  18. 210Pb method for estimating the rate of carbonate sand sedimentation

    Holmes, Charles W.

    1981-01-01

    The plot of 210Pb activity against depth in carbonate sands on the Virgin Island Bank is a negative asymmetric hyperbolic curve. As depth increases, an initial rapid decrease in 210Pb activity caused by the decay of unsupported 210Pb and 226Ra is followed by increasing activity as a result of 210Pb achieving equilibrium with in growing 230Th. As this curve is time dependent, an estimate of the relative ages in carbonate sequences and the rates of net carbonate accumulation can be made. The ease of 210Pb activity determinations makes this procedure an attractive method in obtaining carbonate sand accumulation rates.

  19. Deposition of atmospheric 210Pb and total beta activity in Finland

    The seasonal and regional variation of the atmospheric 210Pb deposition in Finland was studied. The 210Pb activity concentration in precipitation shows a decreasing trend from southeastern Finland north-westwards. An average deposition of 40 Bq/m2 during a 12 months period was observed. The deposition of 210Pb shows a seasonal variation with minimum in spring and maximum in autumn and winter. The specific activity of 210Pb (activity of 210Pb per unit mass of stable lead) in the atmosphere has returned to the level prior to World War II owing to the reduced lead emissions into the atmosphere. (author)

  20. A record of atmospheric 210Pb accumulation in the industrial city

    Buraeva, E A; Stasov, V V; Zorina, L V; Shramenko, B I

    2013-01-01

    The deposition flux of total atmospheric 210Pb in the industrial city Rostov-on-Don, Russia from 2002 to 2010 has been measured. The variations in annual 210Pb deposition flux appear to be mainly correlated with the number of rains and significant amount of anthropogenic 210Pb, polluted into the surface layer of air in the home-heating period. The average 210Pb deposition is 1.75 mBq/m3. Several meteorological parameters which are strongly associated with the fluctuations of concentrations of 210Pb are identified. These results are useful to provide typical information on the atmosphere radioactivity in an industrial city.

  1. Human absorption and retention of polonium-210 from caribou meat

    The gastrointestinal (GI) absorption factors and the biological retention times for polonium were determined for a group of 14 volunteers - seven men and seven women - from Saskatoon, Saskatchewan, Canada. Each volunteer consumed 2.0 kg of caribou meat containing known amounts of naturally occurring 210Po. Urine and faecal samples were collected for up to 65 days after meat consumption and analysed for 210Po. The average GI absorption factor for the 14 volunteers was 56±4% (range = 31-71%), not significantly different from the ICRP value of 50%. About 3% of absorbed polonium underwent prompt excretion by the urinary pathway. The remainder was retained by the body with a half-time >100 days, compared to the ICRP value of 50 days. The effect of these findings increases the dose estimate for ingestion of 210Po in food by a factor of 1.5 to 3.5. Thus, background doses to people consuming caribou and reindeer may be higher than previously thought. (author)

  2. Excess polonium-210 in the coastal atmosphere originating from marine biogenic material

    YANG Weifeng; CHEN Min; HUANG Yipu; LIU Guangshan; JIA Chengxia

    2006-01-01

    The depositional fluxes of atmospheric polonium-210 were measured at one site in Xiamen from August 2001 to March 2002. With predominant marine air mass, the depositional fluxes of atmospheric polonium-210 ranged from 0.01 to 0.09 Bq/(m2·d), with an average of 0.04 Bq/(m2·d). The seasonal pattern showed elevated polonium-210 fluxes in summer and autumn rather than in winter. Atmospheric depositional fluxes of polonium-210 showed a good correlation with beryllium-7 (r2=0.85) and lead-210 fluxes (r2=0.71), indicating their similar removal mechanism from atmosphere. The relationship between the polonium-210 depositional fluxes and the precipitation amount demonstrated that the precipitation dominates the polonium-210 removal from the atmosphere. The observed high activity ratios of polonium-210 to lead-210 indicated the occurrence of excess polonium-210 in coastal atmosphere, which may originate from marine surface waters either by indirect (foam), or more likely, direct (air-sea exchange) input of marine biogenic material into the atmosphere. This source is even more important than the in situ decay of lead-210.

  3. Lead-210 and Beryllium-7 fallout rates on the southeastern coast of Brazil

    Sanders, Christian J., E-mail: zinosanders@yahoo.com [Universidade Federal de Fluminense (UFF), Departamento de Geoquimica, Outeiro de Sao Joao Baptista s/n, Morro do Valonguinho Centro, Niteroi, RJ (Brazil); Smoak, Joseph M. [University of South Florida (USF), Environmental Science, St. Petersburg, FL (United States); Cable, Peter H. [Tulane University, Department of Earth and Environmental Sciences, New Orleans, LA (United States); Patchineelam, Sambasiva R. [Universidade Federal de Fluminense (UFF), Departamento de Geoquimica, Outeiro de Sao Joao Baptista s/n, Morro do Valonguinho Centro, Niteroi, RJ (Brazil); Sanders, Luciana M. [Istituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro 22780 (Brazil)

    2011-12-15

    Total {sup 210}Pb and {sup 7}Be fallout rates were measured on the coastal region of Niteroi, Brazil. The monthly depositional flux of {sup 210}Pb and {sup 7}Be varied by a factor of 26, from 1.7 to 43.3 mBq cm{sup -2} year{sup -1} and {approx}27, from 7.5 to 203.5 mBq cm{sup -2} year{sup -1}, respectively. The relatively large oscillations in the depositional flux of {sup 210}Pb at this study site were likely due to variations in air mass sources, while the {sup 7}Be fluctuations may be driven by a combination of weather conditions. Local geology could support the periodic high fluxes of {sup 210}Pb from continental air masses, as shifting oceanic wind sources were affirmed by the uncorrelated {sup 210}Pb and {sup 7}Be fallout activities and {sup 7}Be/{sup 210}Pb ratios. The {sup 210}Pb atmospheric deposition was found to be in agreement with local sediment inventories, an important consideration in geochemical studies that estimate sedimentation processes. - Highlights: > Fallout rates of {sup 210}Pb and {sup 7}Be indicate depositional flux during a 12-month period. > Oscillations in {sup 210}Pb and {sup 7}Be fallout are driven by geology ({sup 210}Pb) and weather. > Regional trends in {sup 7}Be and {sup 210}Pb fluxes used in geochemical processes.

  4. Distribution of Po-210 in two species of predatory marine fish from the Brazilian coast

    Polonium-210 (210Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher 210Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg−1 for G. brasiliensis and it was 6 mBq kg−1 for C. microlepidotus. The activity concentrations varied significantly between the species and among organs. -- Highlights: • We analyzed the distribution of 210Po in two species of predator marine fish. • 210Po tends to accumulate in some organs, which make this radionuclide radiotoxic. • The consumption of small quantities of fish can represent high potential of 210Po exposure. • Data about 210Po bioaccumulation in tropical predator marine fish are limited

  5. Sequential determination of U and Th isotopes, 226Ra, 228Ra, 210Pb, and 210Po in mushroom

    For this study, mushroom samples were collected in Brazil at the Sao Paulo Metropolitan Region and at the Pocos de Caldas Plateau (PC; a region of elevated natural radioactivity, which houses the first Brazilian uranium mine). This paper discusses a sequential methodology to determine natural series radionuclides in mushrooms, such as uranium (238U and 234U) and thorium (232Th, 230Th, and 228Th) isotopes, radium-226, radium-228, as well as lead-210 and polonium-210; using Alpha Spectrometry, Gamma Spectrometry, and Total Alpha and Beta Counting. The method involves total sample dissolution in a closed system in order to avoid loss of Polonium and employment of specific chromatographic resins for radionuclide purification. A subsequent interpretation of the results can provide information on pollutants present in mushrooms and infer possible contamination in the areas sampled as well as allow an association of measured concentrations to radioactive anomalies in the Plateau. (author)

  6. Fetal doses from plutonium-239 and polonium-210

    The transfer of 239Pu and 210Po from the maternal circulation to the developing embryo and fetus was studied in rodents. The highest concentrations of both isotopes were measured in the yolk sac. In utero doses to haemopoietic tissue have been calculated taking account of transfer to the blastocyst/egg cylinder, yolk sac, liver and bone marrow. From animal data, the concentration ratios relative to maternal liver for these tissues were taken to be 0.1, 2, 0.01 and o.02, respectively for 239Pu; and 1, 2, 0.1 and 0.1, respectively, for 210Po. These concentration ratios were applied to periods of human gestation of 0-2.5 weeks, 2.5-6 weeks, 6-12 weeks and 12-38 weeks, and used to calculate fetal tissue doses for chronic maternal intake by ingestion of 1 kBq 239Pu or 2 kBq 210Po in the year of pregnancy (1 ALI for a member of the public). On this basis, the total in utero dose to haemopoietic tissue was about 1 μSv from 239Pu and 60 μSv from 210Po compared with red bone marrow doses to the mother in the year of 19 μSv from 239Pu and 160 μSv from210Po. The yolk sac and bone marrow dominated in utero doses from both nuclides. For 239Pu, because of its long half life, an important consideration was activity present in the offspring at birth and committed dose equivalents to red bone marrow in the child and mother. The total dose to haemopoietic tissue in the offspring to age 70 years, including in utero doses, was calculated as 13 μSv compared with a maternal dose to red bone marrow of 1400 μSv. For both isotopes the risk of leukaemia in the year of pregnancy was estimated to be of the same order for mother and fetus. For 239Pu, the overall risk to 70 years of age was two orders of magnitude higher for the mother than her offspring. For 239Pu, an acute intake of 1 kBq by ingestion during the period of yolk sac haemopoiesis would result in the highest in utero dose, estimated at about 20 μSv. However, activity at birth would be lower and the overall risk would be

  7. Carbon and nitrogen cycling in the Zhubi coral reef lagoon of the South China Sea as revealed by 210Po and 210Pb

    Highlights: → 210Po/210Pb disequilibria were used to trace export of POC and PON in a coral lagoon. → Recycling of POC and PON were quantified by a mass balance budget in a coral lagoon. → 210Po excess could be used to qualify the degradation of particulate organic matter. → Degradation rate constant of POM was much more in the lagoon than in the open sea. - Abstract: The radionuclides 210Po and 210Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mgC m-2 d-1. However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from 210Po/210Pb disequilibria, are 43 mgC m-2 d-1 and 13.8 mgN m-2 d-1, respectively. The deficit of 210Po relative to 210Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mgC m-2 d-1 and 121 mgN m-2 d-1 were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m-1, respectively. Thus, 210Po and 210Pb can quantify the cycling of carbon and nitrogen in this coral lagoon.

  8. Preparation of low level sealed 210Pb source for random pulse generator

    We have developed the random pulse generator (RPG) that utilizes alpha-particle detection with pin photodiode (PPD). In order to support an expected large market of RPG, a steady production system of weak (about 100 Bq) alpha sealed source is necessary, and, for such alpha-source, 210Pb-210Po source is the best candidate on a viewpoint of environmental radioactivity impact. Two methods for such 210Pb-210Po sealed source preparation, namely direct deposition from isopropyl alcohol solution (IPA solution) of 210Pb-210Po nitrate (D-IPA method) and the 210Pb-210Po hydroxides precipitation (PPT method), were experimentally examined. In the former D-IPA method, an aliquot of IPA solution of 210Pb-210Po nitrate was directly dropped in a sealed cap for PPD and dried by heating. Then, a polycarbonate (PC) solution of 1/1 mixture of dichloromethane and dichloroethane was dropped on the source to make a thin (about 0.1 mg/cm2) film for radioactivity sealed. In the PPT method, 210Pb-210Po hydroxide was filtrated on a PC membrane filter (Nuclipore 0.1 μm) and the membrane filter was dissolved in a 1/1 mixture of dichloromethane and dichloroethane. The sealed 210Pb-210Po sources were prepared directly by dropping an aliquot of the solution into the PPD cap followed by its evaporation. The sealed sources thus prepared were subjected to 1m height fall-down test, air blowing test, and water immersion test. It was confirmed that no radioactive contaminants were coming off from the sealed source through these tests. (author)

  9. Assay methods for U-238, Th-232, and Pb-210 in lead and calibration of Bi-210 bremsstrahlung emission from lead

    Orrell, John L; Arnquist, Isaac J; Eggemeyer, Tere A; Glasgow, Brian D; Hoppe, Eric W; Keillor, Martin E; Morley, Shannon M; Myers, Allan W; Overman, Cory T; Shaff, Sarah M; Thommasson, Kimbrelle S

    2015-01-01

    Assay methods for measuring 238U, 232Th, and 210Pb concentrations in refined lead are presented. The 238U and 232Th concentrations are determined using isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) after anion exchange column separation of dissolved lead samples. The 210Pb concentration is inferred through {\\alpha}-spectroscopy of a daughter isotope, 210Po, after chemical precipitation separation on dissolved lead samples. Subsequent to the 210Po {\\alpha}-spectroscopy assay, a method for evaluating 210Pb concentrations in solid lead samples was developed via measurement of bremsstrahlung radiation from \\b{eta}-decay of a daughter isotope, 210Bi, by employing a 14-crystal array of high purity germanium (HPGe) detectors. Ten sources of refined lead were assayed. The 238U concentrations were <34 microBq/kg and the 232Th concentrations ranged <0.6-15 microBq/kg, as determined by the ICP-MS assay method. The 210Pb concentrations ranged from ~0.1-75 Bq/kg, as inferred by the 210Po ...

  10. Seasonal and vertical changes of molecular size distribution of lead-210 and polonium-210 in an oligotrophic lake, lake Towada in Japan

    Lead-210 and 210Po are naturally occurring long-lived radionuclides in the 238U decay series. These nuclides are easily measurable, and have been used as tracers of non-conservative material cycling in aquatic systems because of reactivity with particles in water. To deepen our understandings of the behaviors and cycling of these nuclides in lake systems, it is important to know the existing forms (speciation) of these nuclides in the water and seasonal variations of the speciation, including their material balances. We report here a detailed study of molecular size distributions and their seasonal variations for 210Pb and 210Po in the water column of an oligo-trophic lake, Lake Towada in the northern area of Japan, Aomori Prefecture. The samples were separated to four fractions; particulate phase (>0.45 μm), 0.45 μm - 100 kDa, 100 10 kDa and 210Pb and 210Po in the epi-limnion over thermocline (20 - 25 m) were higher than those in the hypo-limnion. Fluctuations of total concentrations of both nuclides in water could attribute to concentration variation of them in particulate phase. The pattern of seasonal variation of particulate 210Pb were reverse to that of the 210Po was similar to that of the particulate phase. (author)

  11. Populational exposure to 210Pb and 210Po in two cities with various industrial activities in the south-west of Romania

    In the present work, we proposed to estimate the contribution of the thermal power plants (TPP) relying in fossil fuel to the modification of the natural radioactive background and implicitly to the population's exposure in two urban centers - district residences - Timisoara and Deva. In the range of natural radioelements released in the atmosphere we considered as critical, 220Pb and 210Po for the following reasons: (i) radiolead is one of the long lived daughters of 222Rn in secular equilibrium with its daughter 210Bi. It is a beta active hard element, generator of Typo, an alpha active element with high energy. 210Pb, and 210Po are in the group of very high radiotoxicity; 210Bi high radiotoxicity; (ii) during the technological process of coal combustion of thermal power plants, there take place an accumulation of radiolead in the fly ash by a concentration rate of about 3 to 50. (author)

  12. A sequential and fast method for low level of 226Ra , 228Ra, 210Pb e 210Po in mine effluents and uranium processing plant

    Due to biological risk and long half lives, the radionuclides 228Ra, 226Ra, 210Pb and 210Po should be frequently monitored to check for any environmental contamination around mines and uranium plants. Currently, the methods used for the determination of these radionuclides take about thirty days to reach the radioactive equilibrium of the 210Pb and 226Ra daughter's. The evaluation of effluent discharges and leakage of deposits to water bodies in monitoring programs, require quick answers to implement corrective measures. Thereby fast determination methods must be implemented. This work presents a fast and sequential method to, in three days, determine accurately and sensitively, 226Ra, 228Ra, 210Pb, 210Po, in water and effluent samples

  13. Calibration of an HPGe detector and self-attenuation correction for 210Pb: Verification by alpha spectrometry of 210Po in environmental samples

    Saïdou; Bochud, François; Laedermann, Jean-Pascal; Buchillier, Thierry; Njock Moïse, Kwato; Froidevaux, Pascal

    2007-08-01

    In this work the calibration of an HPGe detector for 210Pb measurement is realised by a liquid standard source and the determination of this radionuclide in solid environmental samples by gamma spectrometry takes into account a correction factor for self-attenuation of its 46.5 keV line. Experimental, theoretical and Monte Carlo investigations are undertaken to evaluate self-attenuation for cylindrical sample geometry. To validate this correction factor, 210Po (at equilibrium with 210Pb) alpha spectrometry procedure using microwave acid digestion under pressure is developed and proposed. The different self-attenuation correction methods are in coherence, and corrected 210Pb activities are in good agreement with the results of 210Po. Finally, self-attenuation corrections are proposed for environmental solid samples whose density ranges between 0.8 and 1.4 g/cm 3 and whose mass attenuation coefficient is around 0.4 cm 2/g.

  14. Distribution of some chemical elements between dissolved and particulate phases in the ocean. Research period: August 1, 1975--July 31, 1976. [Fallout /sup 210/Po and /sup 210/Pb diffusion in oceans

    1976-01-01

    Progress is reported on studies on the distributions of fallout /sup 210/Pb and /sup 210/Po in dissolved and particulate states in the Gulf of Maine and a transect of the equatorial North Atlantic Ocean. The ratio of /sup 210/Pb//sup 226/Ra and /sup 210/Po//sup 210/Pb in seawater and suspended particulate matter in samples collected from 10 stations in the tropical and eastern North Atlantic and two stations in the Pacific was also determined. (CH)

  15. Polonium-210 and lead-210 in the Southern Polar Ocean: Naturally occurring tracers of biological and hydrographical processes in the surface waters of the Antarctic Circumpolar Current and the Weddell Sea; Polonium-210 und Blei-210 im Suedpolarmeer: Natuerliche Tracer fuer biologische und hydrographische Prozesse im Oberflaechenwasser des Antarktischen Zirkumpolarstroms und des Weddellmeeres

    Friedrich, J.

    1997-11-01

    In this thesis the distribution of {sup 210}Po and {sup 210}Pb in the upper 600 m of the Antarctic Circumpolar Current and the Weddell Sea was investigated along north-south transects in austral spring and autumn. {sup 210}Po and {sup 210}Pb can serve as sensitive tracers for the special hydrographic conditions of the Antarctic Circumpolar Current and the Weddell Sea as well as for biological processes during phytoplankton blooms. The {sup 210}Po/{sup 210}Pb disequilibrium was used as a tracer for particle export. This tracer integrates export on a timescale of 276 days because of the 138 day half-life of {sup 210}Po and complements the {sup 234}Th/{sup 238}U disequilibrium as another tracer for plankton production and export on a shorter timescale of several weeks. (orig.) [Deutsch] In der vorliegenden Arbeit wurde die Verteilung von Blei-210 und seinem Enkelnuklid Polonium-210 im Antarktischen Zirkumpolarstrom und im Weddellmeer bis 600 m Tiefe in mehreren meridionalen Transekten im australen Fruehjahr und Herbst waehrend der `Polarstern`-Expeditionen ANT-X/6 und ANT-XI/4 untersucht. Die Verteilung von {sup 210}Pb und {sup 210}Po wird von mehreren Faktoren beeinflusst, sowohl durch die Advektion von Wassermassen im Antarktischen Zirkumpolarstrom und im Weddellmeer als auch von biologischen Prozessen z.B. innerhalb einer Planktonbluete. Bevor die Verteilungsmuster von {sup 210}Pb und {sup 210}Po jedoch als Tracer fuer einen Prozess genutzt werden koennen, muss der Effekt der einzelnen Faktoren auf die Verteilung betrachtet werden. (orig.)

  16. Polonium-210 in cartilaginous fishes (Chondrichthyes) from south-eastern Australian waters

    A study was made of the concentration of the naturally occurring radionuclide polonium-210 in the livers of cartilaginous fishes (chondrichthyans) caught in the waters of Port Phillip Bay, Victoria, Australia in 1991. Five elasmobranch species had 210Po concentrations in the range 1-31 Bq kg-1 (wet weight) and one holocephalian species, the elephant fish (Callorhynchus milii), was exceptional with a 210Po range of 60-270 Bq kg-1 (n-3, mean 180 Bq kg-1). Lead-210 was present at 0.1-1.1 Bq kg-1 and activity concentration ratios of 210Po:210Pb were all greater than 1, indicating that the 210Po could not all have grown in from in situ decay of 210Pb within the chondrichthyan liver. The concentration of 210Po in the livers appeared to be species related. Concentrations of the trace metals Cu, Fe and Zn showed no correlation with the 210Po and were not species-related. The mean concentration of 210Po measured in Port Phillip Bay water was 0.32 mBq kg-1. This yields concentration factors of 3.2 x 103 to 8.4 x 105 for unsupported 210Po in the livers of the chondrichthyans. The total 210Po (using Q=20) exposes the livers to a weighted absorbed dose of up to 140 mGy year-1 (16 μGy h-1), which is >99% of the total internal dose and three orders of magnitude greater than the external dose based on estimated levels of 40K. 18 refs., 3 tabs., 2 figs

  17. Sedimentation and lateral transport of 210Pb over the East China Sea Shelf

    210Pb is an effective tracer of constraining particle transport and sedimentation in shelf regions. To reveal the spatial pattern of 210Pb over the East China Sea (i.e. ECS) Shelf, 210Pb in the surface sediments were examined at 11 stations, as well as 234Th and 210Pb in the water column at four stations. Overall, the plume zone of the Yangtze River along the coastline is a source area of 210Pb for the outer shelf, exporting 0.46 dpm cm-2 year-1 at least, which accounts for about 25 % of 210Pb input into this region. In the southern ECS Shelf to the north of the Taiwan Strait, the focusing factor (f) values are higher than unity, indicating a sink area of 210Pb. Boundary scavenging of 210Pb contributes 0.36 dpm cm-2 year-1 to this sink area on the basis of a mass balance model evaluation. Lateral transport of 210Pb to this region, quantified by 234Th and 210Pb in the water column, varied from 3.34 to 6.39 dpm cm-2 year-1 with an average of 4.83 dpm cm-2 year-1, also supporting its sink characteristic. To the southwest of the Cheju Island, the f values were less than unity, revealing a source region of 210Pb. The average export flux of 210Pb from this region was 1.64 dpm cm-2 year-1. Therefore, 210Pb sedimentation/settling showed significantly heterogeneous sedimentation of particulate matter over the ECS Shelf. (author)

  18. Assessment of the potential impact of the phosphate industry along the Syrian Coast by evaluating 210Po and 210Pb levels in sediment, seawater and selected marine organisms

    Phosphate industry is considered to be one of the potential sources of natural radionuclides in Syrian environment. Most of the phosphate ore is exported in large quantities via one of the main Syrian ports (Tartous) situated on the east coast of the Mediterranean Sea (34 54 North , 35 52 East). The impact of the loading cargoes on the marine environment has been evaluated. 210Po and 210Pb in seawater, sediment and marine organisms have been determined. Results have shown a significant enhancement of these two radionuclides in sediment and surface water inside the port area. The highest 210Po and 210Pb concentrations observed in sediment were found to be 170 Bq.kg-1and 64 Bq.kg-1 respectively. While, 210Pb and 210Po concentrations in surface water ranged from 5 to 20 m Bq.l-1 and 0.93 to 3.23 m Bq.l-1. In addition, other naturally occurring radionuclides were also determined in the collected sediment samples and relatively higher values (226Ra = 33.2 Bq.kg-1 and 234Th = 88 Bq.kg-1) were observed for those samples collected from inside the port. However, the effect of loading cargoes on the near marine environment was found to be mainly related to wind direction where air particulate carrying radioactivity either being blown to lands or sea. Moreover, comparable values of 210Po and 210Pb for all marine organisms (algae, crab and fish) have been observed and it is not recommended to use these organisms for evaluating the effect of phosphate industry on marine environment. This is due to the fact that marine organisms accumulate 210Po and 210Pb in their body. Two core samples were also collected in order to investigate the history of pollution in the port. Results have shown a complex relation for unsupported 210Pb with depth, where the constant supply dating method can not be applied. This is due to the fact that two sources for unsupported 210Pb being observed in the port area; viz. radon gas and phosphate dust carrying radioactivity including 210Pb. However, depth

  19. A route for polonium 210 production from alpha-particle irradiated bismuth-209 target

    A method is proposed for production of polonium-210 via the 209Bi(α,3n)210 At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 x 10-13 mol) from macroscopic amount of Bi (2.8 x 10-2 mol).

  20. 7Be and 210Pb radioactivity and implications on sources of surface ozone at Mt. Waliguan

    ZHENG Xiangdong; WANG Guojiang; TANG Jie; ZHANG Xiaochun; YANG Wei; H. N. Lee; WANG Changsheng

    2005-01-01

    Beryllium-7 (7Be) and lead-210 (210Pb) radioac- tivity in aerosols collected, from October 2002 to January 2004 at Mt. Waliguan, by the Global Atmospheric Watch (GAW) Station, Qinghai Province is presented. The data were analyzed together with simultaneously measured surface ozone concentrations. We found that short time variations of 7Be and 210Pb were linked to alternations of synoptic weather around the Mt. Waliguan region. 210Pb showed the lowest concentration in summer while 7Be showed no obvious sea- sonal changes. Relatively high 7Be and 210Pb radioactivity was observed at Mt. Waliguan when compared with the ob- servations at other mountain sites in other parts of the world. Surface ozone and 7Be showed a consistent seasonal variation. Surface ozone correlated fairly well with 7Be/210Pb ratio. This suggested that vertical transport from higher altitudes of the atmosphere has predominant effects on the budget of surface ozone at Mt. Waliguan.

  1. Geochemical fractionation of 210Pb in oxic estuarine sediments of Coatzacoalcos River, Gulf of Mexico

    210Pb activities were analyzed in surface sediments from the Coatzacoalcos River (Gulf of Mexico) to evaluate its distribution according to sediment grain size and in different geochemical compartments by using sequential extraction techniques. The geochemical fractionation experiments provided compatible results: by using the Tessier's method more than 90% of the 210Pb activity in the samples was found the residual fraction (primary and secondary minerals) and the remaining (210Pb content was found in comparative amounts in the reactive, the silicate, and the pyrite fractions (accounting together for >80%), and the rest was found in the residual fraction. The grain size fractionation analyses showed that the 210Pb activities were mostly retained in the clay fraction, accounting up to 60-70% of the 210Pb total activity in the sediment sample and therefore, it is concluded that the separation of the clay fraction can be useful to improve the analysis of low 210Pb content sediments for dating purposes. (author)

  2. Studies on the bioaccumulation of polonium-210 in the fishes of Trichirappalli city

    The activity concentration of 210Po were determined in the muscle of fishes collected from Trichirappalli city. The highest 210Po content were found in the fish Ayeelai (Corvphane hippurus) 8.7 Bq/kg and Kelanga (Eliops saurus) 4.2 Bq/kg. The minimum 210Po activity was found in fish Sangara 0.60 Bq/kg (Lautinus campecharus) and Mrigal 0.34 Bq/kg (Cirrhimus mrigala). The 210Po concentration high level activity found in the Kauveri water 0.78 mBq/l. The sediment maintained level of 210Po 8.9 Bq/kg. The dosimetry study was also calculated on average consumption of fish by the people from Trichirappalli city. The Ayeelai fish (Corvphane hippurus) recorded higher CEDE from 210Po 681 Sv/y and the results were discussed. (author)

  3. Transfer of {sup 40}K, {sup 238}U, {sup 210}Pb, and {sup 210}Po from soil to plant in various locations in south of Syria

    Al-Masri, M.S. [Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)], E-mail: scientific1@aec.org.sy; Al-Akel, B.; Nashawani, A.; Amin, Y.; Khalifa, K.H.; Al-Ain, F. [Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)

    2008-02-15

    Transfer factors of {sup 40}K, {sup 238}U, {sup 210}Pb, and {sup 210}Po from soil to some agriculture crops in various locations in south of Syria (Dara'a and Assuwaydaa districts) have been determined. Soil and vegetable crops (green pepper, cucumber, tomato, and eggplant), legumes crops (lentil, chickpea, and broad bean), fruit trees (apple, grape, and olives) and cereals (barley and wheat) were collected and analyzed for {sup 238}U, {sup 210}Pb, and {sup 210}Po. The results have shown that higher transfer factors (calculated as Bq kg{sup -1} dry wt. plant material per Bq kg{sup -1} dry wt. soil) for {sup 210}Po, {sup 210}Pb and {sup 238}U were observed in vegetable leaves than fruits and cereals leaves; the highest values of transfer factor (TF) for {sup 238}U were found to be 0.1 for straw of chickpea. Transfer factors for {sup 210}Po varied between 2.8 x 10{sup -2} and 2 in fruits of eggplant and grain of barley, respectively. In addition, several parameters affecting transfer factors of the radionuclides were evaluated. The results can be considered as base values for TF of natural radionuclides in the region.

  4. Extreme accumulations of natural polonium-210 in certain marine organisms

    Concentration levels of polonium-210 reported for sea water are reviewed, and activities accumulated by various marine plant and animal species are discussed. Special mention is made of detailed studies of one giant algae upon whose outer surfaces intense accumulations of polonium have been discovered recently. Some concentrations found in two organisms intimate with algae, the abalones and the sea hares, are reported. Concentrations are listed pertaining to organisms selected from the open ocean in order to show that intense polonium concentrations are not restricted to organisms living near the continents where precursors of polonium originate. A brief discussion of conditions on one of the marine mammals, the dolphin, next is made. Then comments are made upon a benthic species (the sable fish) that prefers to live close to the deep sea floor, presumably so as to eat detritus. They also eat many of the smaller organisms that compete for the natural deep sea fallout of food, and many of these live in close contact with the muds and clays of the sea floor that are rich in radium. Some of the behavior and anatomical features and polonium-210 distribution in one of the most interesting and valuable of fishes, the North Pacific albacore (Thunnus alalunga) is described. This species has been used previously to tell us something about nuclear fallout distributions in the North Pacific Ocean during the past decade and repeatedly has directed attention to features of this ocean that might hardly be detected otherwise. (U.S.)

  5. Relationship Between 210Pb Concentrations in Solid Wastes and Plants from Uranium Mill Tailings

    Full text: The exploitation and treatment of uranium ore at the Urgeirica mine (north of Portugal) have led to the accumulation of large amounts of soild wastes (mill tailings) in dams (tailing ponds). These solid wastes containing natural radionuclides could be dispersed by the action of atmospheric agents and contaminate the environment. To minimize the dispersion of these radionuclides into the environment the dams were revegetated with pines (Pinus pinea) and eucalyptes (Eucalyptus globolus). The objective of this study is to know the 210Pb behaviour in what concerns its transfer from the uranium mill tailings to these plants, through the analysis of relationships between 210Pb concentrations in the solid wastes and the plants. Solid wastes and plant samples were randomly collected at the dams and the 210Pb activity concentration in solid wastes and plant (aerial part and roots) samples were determined by gamma spectrometry. The results obtained for pines show a good correlation between 210Pb concentrations in the solid wastes and roots. No correlation was found to 210Pb concentrations in the solid wastes and needles. The 210Pb concentration data for eucalyptes show a quite good correlation between 210Pb concentrations in the solid wastes and leaves. Concentration ratio data, solid wastes/roots and solid wastes/needles for pines are on the same order of magnitude. The 210Pb uptake by pines (roots and needles) and eucalyptes (leaves) show that 210Pb concentration ratios decrease at low 210Pb concentrations in the solid wastes and appear relatively constant at higher 210Pb concentrations in the solid wastes. Data presented for 210Pb in this paper, will be compared with those obtained for 226Ra on the same samples. (author)

  6. Recent aquatic ecosystem response to environmental events revealed from 210Pb sediment profiles

    The 210Pb dating method was first introduced by , and since then has been applied to study sediment from lakes, estuaries and coastal marine environments. Hundreds of studies around the world have used 210Pb as a geochronological tool in aquatic ecosystems. However little attention has been paid to the potential of this naturally occurring isotope as an environmental tracer of ecological events. Here we report three instances in which 210Pb profiles measured on undisturbed sediment cores from lakes, rivers and fjords show us the potential of 210Pb profile as a tracer of natural and anthropogenic processes. The methodology used here is a suite of techniques combining biogeochemistry (micro-electrodes), paleomagnetism (susceptibility), sediment characteristics (LOI) and visualization (SPI and X-ray) applied to the interpretation of 210Pb profiles. We measured 210Pb profiles on sediments from a river, Cruces River (Chile), which recorded a clear shift in the water chemistry caused by a pulp mill effluent to the river. Here metal mobilization and remobilization of the tracer may be the cause of the observed profile. We also measured 210Pb profiles in sediment from two fjords of Southern Chile (Pillan and Renihue), the sudden deposition change of fresh 210Pb with depth observed could very well be the result of bioturbation but it occurred in a seafloor area deprived of bioturbators. In this case, 210Pb recorded the onset of aquaculture activities (fish farming) that took place two decades ago. Finally, 210Pb profiles measured in two lakes in the 'pampa Argentina': Epecuen and Venado showed a particular shape with depth. These profiles apparently registered a sudden depositional event with recent 210Pb material, probably related to strong shifts in precipitation and drought cycles in that part of the world. These three examples show that 210Pb profiles provide valuable information not only on geochronology, but also related to natural and anthropogenic short term

  7. Estimation of sediment loading in Asian coastal area using 210Pb inventory in mangrove sediment

    Full text: Concentrations of 210Pb in coastal sediment are generally controlled by local atmospheric 210Pb flux and fine sediment input to coastal area, because the 210Pb has high affinity to inorganic fine particles and 210Pb inventory in coastal sediment is coincided with sediment loading to the area. Thus the 210Pb level in coastal sediment is good index of sediment loading to coastal zones. However, in subtropical/tropical coastal area, such as S-E Asian coast, sediment loading is widely variable due to seasonal difference of precipitation and coastal sediment discharge among rainy/dry season. Secondly, the S-E Asian coastal areas are mostly covered with mangroves those entrap the sediment particle supplied from river to adjacent coastal waters. Since the entrapped fine sediment particles include not only the excess 210Pb supplied from local atmosphere but also the accumulated sediment particles by terrestrial input, thus the 210Pb inventory exceeds largely compared to the atmospheric supply. Thus the 210Pb inventory balance in mangrove area is expected to reflect drastically the local sediment loading conditions in S-E Asia. We studied the 210Pb balance in subtropical mangrove coastal water in Japan and found that the 210Pb was useful natural tracer to evaluate the coastal sediment load. However, limited data are reported about the mangrove coastal area. In this study, we collected mangrove sediment cores at the Japan and Viet Nam and analyzed the 210Pb concentrations in sections of different depth and location. By comparing with the atmospheric flux, we estimate the balance of the 210Pb in the area and evaluate the sediment loading to the studied mangrove area. (author)

  8. 210Pb and 210Po in sediments and suspended matter in the Tagus estuary, Portugal: Local enhancement of natural levels by wastes from phosphate ore processing industry

    Results of analyses of uranium series radionuclides in phosphate ore and in wastes released by the phosphate fertilizer industry confirm their potential for the enhancement of environmental radioactivity levels. Therefore, concentrations of 210Pb and 210Po were measured in bottom sediments and suspended matter in the Tagus estuary, Portugal, to assess the enhancement of radioactivity due to wastes from the phosphate industry. The concentration of 210Pb in surface sediments in the estuary increased inversely with sediment grain-size; conversely, increased percentage of sand has a dilution effect on the concentration of 210Pb measured in bulk sediment samples. By normalizing the data to the 210Pb in sediments was found to be 68 ± 19 Bq kg-1 (dry wt.) in background sediments. Higher 210Pb levels, up to 1580 Bq kg-1 (dry wt.), were measured in some bulk sediment samples. It was verified that this radionuclide has been introduced by the discharge of wastes from a phosphate fertilizer plant but enhanced concentrations are localized near the point of discharge. In other zones of the estuary, the concentrations of 210Pb in sediments and suspended matter were generally below those measured in the zone of phosphatic releases at the Barreiro Peninsula. Concentrations higher than the predicted average concentration of unsupported 210Pb from natural sources (atmospheric deposition, river input) were also measured in the upper estuary, both in bottom sediments and in suspended matter. It is suggested that these relatively elevated concentrations are due to the highly efficient scavenging of soluble naturally-occurring unsupported 210Pb onto suspended matter and to co-precipitation with iron-manganese hydroxides in the fresh water-salt water mixing zone

  9. Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry

    A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an α emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a (β emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author)

  10. MicroRNA-210 promotes sensory axon regeneration of adult mice in vivo and in vitro.

    Hu, Yi-Wen; Jiang, Jing-Jing; Yan-Gao; Wang, Rui-Ying; Tu, Guan-Jun

    2016-05-27

    Axon regeneration as a critical step in nerve repairing and remodeling after peripheral nerve injury relies on regulation of gene expression. MicroRNAs are emerging to be important epigenetic regulators of gene expression to control axon regeneration. Here we used a novel in vivo electroporation approach to transfect microRNA-210 (miR-210) or siRNAs to adult mice dorsal root ganglion (DRG) neurons, measured the axon length 3days after sciatic nerve crush or dissociated DRG cultures in vitro to detect the effect of miR-210 in sensory axon regeneration. Importantly, we found that miR-210 overexpression could promote sensory axon regeneration and inhibit apoptsosis by ephrin-A3 (EFNA3). In addition, inhibition of endogenous miR-210 in DRG neurons impaired axon regeneration in vitro and in vivo, the regulatory effect of miR-210 was mediated by increased expression of EFNA3 because downregulation of EFNA3 fully rescued axon regeneration. We thus demonstrate that miR-210 is a new physiological regulator of sensory axon regeneration, and EFNA3 may be the functional target of miR-210. We conclude that miR-210 may play an important role in sensory axon regeneration. PMID:27102143

  11. Root uptake of lead by Norway spruce grown on Pb-210 spiked soils

    Hovmand, M.F.; Nielsen, Sven Poul; Johnsen, I.

    2009-01-01

    The root uptake of lead (Pb) by trees and the transfer of Pb by leaf litter deposition to the forest floor were investigated through a pot experiment with Norway spruce. Natural Pb and radio isotopic lead (210Pb) were determined in needles and twigs and in the pot soil spiked with 210Pb. Calculat......The root uptake of lead (Pb) by trees and the transfer of Pb by leaf litter deposition to the forest floor were investigated through a pot experiment with Norway spruce. Natural Pb and radio isotopic lead (210Pb) were determined in needles and twigs and in the pot soil spiked with 210Pb...

  12. Determination and distribution of 210Po in tobacco plants from Poland

    One of the most radiotoxic elements, 210Po in different parts of tobacco plant from Poland was determined. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of 210Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. It was indicated that 210Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, 210Po concentration in tobacco leaves from Poland are higher than that in the other countries. (author)

  13. The role of Pb-210 dating in sediment based erosion studies

    As sediments can accumulate unsupported lead-210 by different processes, there are uncertainties concerning the appropriateness of procedures for calculating lead-210 dates. The applicability of CRS (constant rate of Pb-210 supply) models and CIC (constant initial Pb-210 concentration) models is considered. Variants of both models can be devised to take account of postdepositional processes such as sediment mixing and redistribution. It is argued that the CRS model should be the primary dating model at a wide range of sites and that empirical testing should be built into dating strategies

  14. Content of Pollonium 210 in tobacco leaves depending on their quality (class)

    Content of polonium 210 was studied in the leaves of six varieties of Bulgarian oriental tobacco according to their class. Tobacco that had to be examined was kept for more than three years for equilibrium between polonium 210 and lead 210 to be reached. Tobacco leaves of higher classes contained smaller quantities polonium 210 compared with those of lower classes (III-V classes). This is due to leaves of the upper and middle parts of the plant with a shorter vegetation period belonging to higher tobacco classes; radionuclide penetration by the root. The established divergence from this relationship was due to some other reasons such as mechanical damage, etc. (A.B.)

  15. Lung cancer induced in hamsters by low doses of alpha radiation from 210Po

    Lung cancers have been induced in 9 to 53 percent of hamsters given multiple intratracheal instillations of polonium-210 in amounts yielding lifetime exposures of 15 to 300 rads to the lungs. Cigarette smokers have previously been estimated to receive 20 rads to areas of the bronchial epithelium from deposited polonium-210. This finding thus supports the hypothesis that alpha radiation resulting from the polonium-210 or lead-210 present in cigarette smoke may be a significant causative factor in human lung cancer. (U.S.)

  16. Geochronology of lake sediments using 210Pb with double energetic window method by LSC: An application to Lake Van

    In this study the age and sediment accumulation rates of the lake sediment were calculated by using the 210Pb concentrations through the sediment core. The specific activity of 210Pb for each sediment section was determined by LSC with double energetic window method which relies on the direct determination of 210Pb without waiting for the in growth of 210Po from 210Pb. For the successful determination of this radionuclide two counting windows were optimized to eliminate the overlapping of the beta spectra of 210Pb and 210Bi. - Highlights: • LSC method was used to construct the geochronlogy of Lake Van. • Age and accumulation rates of the lake sediment were calculated by using the 210Pb concentrations. • 210Pb activity was determined by LSC with double energetic window method. • The sedimentation rate varies significantly from 0.4 to 0.7 mm yr−1

  17. Baseline concentration of {sup 210}Po in Sargassum from the Northern Gulf

    Uddin, S.; Bebhehani, M.; Talebi, L. [Kuwait Institute for Scientific Research (Kuwait)

    2014-07-01

    The concentration of the {sup 210}Po is of enormous interest because of its large contribution to the natural radiation dose received by marine organisms and human populations consuming seafood. In fact natural {sup 210}Po is responsible for higher radiation doses to humans consuming marine products than is plutonium and other man-made radionuclides. Many marine organisms are capable of concentrating {sup 210}Po in their tissues. {sup 210}Po is an alpha emitter in the {sup 238}U series, with 138-d half-life, that is supplied to seawater from atmospheric inputs and river runoff, however, the main source of {sup 210}Po in the environment is {sup 222}Rn exhalation from the ground. Assessing the impact of radionuclides in the environment requires the establishment of baseline levels in the environmental compartments. The objective of this study was to establish baseline levels in Sargassum. Two most common species of Sargassum found in the northern Gulf were analysed for {sup 210}Po. These macro-algae were collected from three different locations during January 2013. This study sets the baseline for {sup 210}Po concentration in northern Gulf, {sup 210}Po is absorbed from water and concentrated by Phytoplankton and macro-algae. This concentrated {sup 210}Po can then be passed along to the next trophic level of the marine food web. The {sup 210}Po concentration measured in Sargassum boveanum (4.405 - 4.952 BqKg{sup -1}) was significantly higher (p>0.084) than Sargassum oligocystum (3.838 - 4.358 BqKg{sup -1}). The {sup 210}Po concentration in these seaweeds from the Arabian/Persian Gulf were substantially lower than those found in various Phytoplankton and macro-algae species from other regions; this may be due to the lower background {sup 210}Po concentration in the Kuwait marine waters (0.282 - 0.382 mBq l{sup -1}). The {sup 210}Po concentrations in seawater measured at the 3 stations during January 2013 were less than those reported previously from the same region

  18. 210Po content in human urine of people living in south of Spain

    The death of the former secret service agent Alexander Livitnenko in 2006 due to a lethal intake of 210Po, presumably via ingestion, sparked renewed interest in the field of 210Po toxicity to humans. 210Po occurs widely in nature and is an important component of man' s natural radiation background. The main route of 210Po intake by the human body is the ingestion with foodstuffs, although ingestion with drinking water especially of underground origin represents another route of 210Po intakes. Inhalation of 222Rn released from the soil also contributes in 210Po body burden. However, the body burden of 210Po in normal human body may differ from one person to another depending upon the mode life including diet habits, origin of drinking water, residence place (radon exposure rate) and also smoking habits. Therefore, many factors may affect the 210Po intake and lead to variations in the body burden in different individuals, and consequently in their urine. To see the influence of the diet habits in the amount of 210Po excreted by urine, some volunteers in Seville (south of Spain) follow defined diets during approximately one month, with daily urine collection followed by 210Po determination by alpha-particle spectrometry. Depending on the type of diet ingested by the different volunteers, it was observed differences approaching even an order of magnitude in their levels of 210Po in urine. This fact difficult enormously the adoption of a predefined value of this nuclide in urine with natural origin with the consequence difficulties for screening through urine the possible anthropogenic intake of this element. (author)

  19. The use of Po-210 a geochronometer at Corumbatai river basin, Brazil

    The geochronology of 210Pb allows to measure the rate of accumulation of sediments in the environment (Koide et al., 1973), the recent pollution history for heavy metals, i.e. the rate of affluence of pollutants, as well the rates of regional erosion and growth of saline swamps (Evans and Rigler, 1980; McCafferty and Thomson, 1980; Battarbee et al., 1985; Christensen and Goetz, 1987). The 210Pb atoms are removed from atmosphere by precipitation, entering directly into lakes and reservoirs through the rain or indirectly by the superficial drainage in the basin hydrographic, mechanisms that finalize after deposition in the bottom of lakes and oceans when are incorporated into the column of sediments, being subjected to chemical changes. However, besides possessing 210Pb originated from the atmosphere, the sediments also contain 210Pb generated by the decay of 226Ra. The 210Pb originated in the atmosphere and present in the sediments has been referred to as 'non-supported' 210Pb and the 210Pb resultant of 226Ra decay present in the sediment has been referred to as 'supported' 210Pb. In order to determine the sedimentation rate and to establish a chronological evaluation at the Corumbata river basin, Sao Paulo State, Brazil, on using the unstable lead (210Pb) present in bottom sediments, in this work was quantified the 210Po, 'grandson' of 210Pb. Such nuclide presents a half-life of 138.4 days and declines for the stable 206Pb, emitting an alpha particle of 5.3 MeV of energy (Eakins and Morrison, 1978) (au)

  20. CPLOAS_2 V2.10 verification report.

    Groth, Katrina M.

    2014-07-01

    A series of test cases designed to verify the correct implementation of several features of the CPLOAS_2 program are documented. CPLOAS_2 is used to calculate the probability of loss of assured safety (PLOAS) for a weak link (WL)/strong link (SL) system. CPLOAS_2 takes physical properties (e.g., temperature, pressure, etc.) of a WL/SL system and uses these properties and definitions of link failure properties in probabilistic calculations to determine PLOAS. The features being tested include (i) six aleatory distribution forms, (ii) five numerical procedures for the determination of PLOAS (i.e., one quadrature procedure, two simple random sampling procedures, and two importance sampling procedures), and (iii) time and environmental margin calculations. All tests were performed with CPLOAS_2 version 2.10.

  1. MD210 Note: Creation of Hollow Bunches in the PSB

    Oeftiger, Adrian; Findlay, Alan James; Hancock, Steven; Rumolo, Giovanni; CERN. Geneva. ATS Department

    2016-01-01

    MD210 aims for the creation of longitudinally hollow bunches in the CERN PS Booster. The first three sessions have been carried out using the radial loop feedback system in order to drive the beam on a dipolar parametric resonance (instead of the phase loop). It has been found that the damping by the phase loop inhibits the excitation of the resonance to a major extent. The hollow distributions generated under these circumstances fail to reach a satisfying bunching factor. Nonetheless, proving the principally successful application of this technique to the PS Booster promises good results once the phase loop system supports trim functions. The approach, actions and detailed results of the first three MD sessions are presented in this paper.

  2. Cahors - 210, avenue Jean Jaurès

    Guyard, Laurent

    2016-01-01

    Lien Atlas (MCC) :http://atlas.patrimoines.culture.fr/atlas/trunk/index.php?ap_theme=DOM_2.01.02&ap_bbox=1.373;44.401;1.505;44.512 En 2012, un diagnostic réalisé au 210 av. Jean Jaurès avait révélé des niveaux antiques, conduisant à une fouille préventive qui s’est déroulée d’avril à septembre 2013. Le terrain est situé dans le fond de la vallée du Lot, au-dessus d’alluvions récentes et au pied de la colline où s’est installée la ville antique de Divona-Cahors, à 200 m au sud du théâtre antiq...

  3. Seasonal variation and source areas of airborne lead-210 at Ny-Ålesund in the High Arctic

    Paatero, Jussi; Buyukay, Murat; Holmén, Kim; Hatakka, Juha; Viisanen, Yrjö

    2010-01-01

    High-volume aerosol particle samples were collected onto glass-fibre filters at Mount Zeppelin Global Atmosphere Watch station, Ny-Ålesund, Svalbard, in 2001–05. The filters were assayed for lead-210 (210Pb) by measuring the alpha particles of its in-grown daughter nuclide polonium-210 (210Po). The observed 210Pb activity concentrations at Mount Zeppelin vary between <4 and 1060 mBq m-3, with an arithmetic mean of 130 mBq m-3 and a median of 74 mBq m-3. The lowest 210Pb activit...

  4. The pulsating variable star population in DDO210

    Ordoñez, Antonio J.; Sarajedini, Ata

    2016-01-01

    We have probed the pulsating variable star content of the isolated Local Group dwarf galaxy, DDO210 (Aquarius), using archival Advanced Camera for Surveys/Hubble Space Telescope imaging in the F475W and F814W passbands. We find a total of 32 RR Lyrae stars (24 ab-type; 8 c-type) and 75 Cepheid variables. The mean periods of the ab-type and c-type RR Lyrae stars are calculated to be = 0.609 ± 0.011 and = 0.359 ± 0.025 d, respectively. The light-curve properties of the fundamental mode RR Lyrae stars yield a mean metallicity of = -1.63 ± 0.11 dex for this ancient population, consistent with a recent synthetic colour-magnitude diagram analysis. We find this galaxy to be Oosterhoff-intermediate and lacking in high-amplitude, short-period ab-type RR Lyrae, consistent with behaviour recently observed for many dwarf spheroidals and ultrafaint dwarfs in the Local Group. We find a distance modulus of μ = 25.07 ± 0.12 as determined by the RR Lyrae stars, slightly larger but agreeing with recent distance estimates from the red giant branch tip. We also find a sizable population of Cepheid variables in this galaxy. We provide evidence in favour of most if not all of these stars being short-period classical Cepheids. Assuming all of these stars to be classical Cepheids, we find that most of these Cepheids are ˜300 Myr old, with the youngest Cepheids being offset from the older Cepheids and the centre of the galaxy. We conclude that this may have resulted from a migration of star formation in DDO210.

  5. Polonium-210 and lead-210 in food and tobacco products: a review of parameters and an estimate of potential exposure and dose

    Food-chain transport of Pb-210 and Po-210 from soil to edible plant parts and from animal feed to meat and milk were evaluated from a review of literature. The degree of transfer was characterized by estimating concentration factors (unweighted arithmetic means) as well as the transfer coefficients B/sub v/, B/sub r/ (unweighted geometric means, f/sub m/ and f/sub f/ (unweighted arithmetic means). Global dietary intake of Pb-210 and Po-210 was also summarized, and 50-year dose estimates to target organs calculated. The greatest estimated ingestion doses were those to populations with large dietary complements of animal protein in the form of seafood (Japan) or caribou/reindeer muscle and organ meats (Arctic Eskimos and Lapps). The magnitude of this latter source illustrates the importance of simple food chains in generating significant exposures to populations dependent upon them. The origin and magnitude of inhalation exposure and dose from tobacco products was also assessed. For the majority of internal organs evaluated, the dose resulting from smoking commercially available tobacco products is comparable to or greater than the dose estimates for ingestion of naturally occurring dietary Pb-210 and Po-210

  6. 17 CFR 210.6-03 - Special rules of general application to registered investment companies.

    2010-04-01

    ... ACT OF 1933, SECURITIES EXCHANGE ACT OF 1934, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT... information as to investment securities which cannot be offered for public sale without first being registered... application to registered investment companies. 210.6-03 Section 210.6-03 Commodity and Securities...

  7. 29 CFR 2530.210 - Employer or employers maintaining the plan.

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Employer or employers maintaining the plan. 2530.210... Administration as Related to Benefits § 2530.210 Employer or employers maintaining the plan. (a) General... service with the employer or employers maintaining the plan shall be taken into account for purposes...

  8. 19 CFR 210.70 - Forfeiture or return of complainant's temporary relief bond.

    2010-04-01

    ... provided for in the temporary relief order, proceedings to determine whether the complainant's bond should... relief bond. 210.70 Section 210.70 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION... Forfeiture or return of complainant's temporary relief bond. (a)(1) If the Commission determines that one...

  9. MiR-210: A potential therapeutic target against radiation-induced enteropathy

    A previously undescribed and robust miR210 overexpression is shown in intestinal samples obtained from patients with radiation enteropathy and fibrotic cultured cells. In addition, miR-210 overexpression is repressed by antifibrotic treatment combining pentoxifylline and α-tocopherol

  10. 17 CFR 210.5-04 - What schedules are to be filed.

    2010-04-01

    ...—Valuation and qualifying accounts. The schedule prescribed by § 210.12-09 shall be filed in support of valuation and qualifying accounts included in each balance sheet but not included in Schedule VI. (See § 210... portion of whose business is that of acquiring and holding for investment real estate or interests in...

  11. 41 CFR 102-85.210 - What if a customer agency has to relocate?

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What if a customer agency has to relocate? 102-85.210 Section 102-85.210 Public Contracts and Property Management Federal... customer agency has to relocate? If the agency or GSA determines relocation is necessary at the...

  12. Evaluation 210Ro flow of natural radionuclides in the sediments of the Black Sea

    Гулін, Сергій Борисович; Єгоров, Віктор Миколайович; Мірзоєва, Наталя Юріївна; Сидоров, Ілля Геннадійович; Гуліна, Лариса Вікторівна; Лазоренко, Галина Євдокимівна

    2016-01-01

    The flows of natural radionuclide 210Po from the surface of the Black Sea to its bottom sediments were evaluated. They depend on mass accumulation rates as total suspended matter and its biogenic component. It was shown that 210Po might be used as an indicator of quality of organic matter in marine environments.

  13. 19 CFR 210.6 - Computation of time, additional hearings, postponements, continuances, and extensions of time.

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Computation of time, additional hearings, postponements, continuances, and extensions of time. 210.6 Section 210.6 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Rules of General Applicability §...

  14. 30 CFR 210.202 - How do I submit sales summaries?

    2010-07-01

    ... for these submissions. (2) If you submit sales summaries by paper copy, mail them to one of the... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I submit sales summaries? 210.202... MANAGEMENT FORMS AND REPORTS Production and Royalty Reports-Solid Minerals § 210.202 How do I submit...

  15. Atmospheric concentrations and deposition fluxes of 7Be and 210Pb at Rokkasho village, Japan

    Biweekly atmospheric concentrations and deposition fluxes of 7Be and 210Pb were measured at Rokkasho, Aomori Prefecture, Japan, from March 2000 to March 2006, to clarify their regional features. The atmospheric concentration of 7Be was low in summer and winter and high in spring and fall, and that of 210Pb was low in summer and high in winter. Negative correlations were between the atmospheric 7Be or 210Pb concentrations and precipitation in the sampling periods, and that suggested that both nuclides were removed from the atmosphere mainly by wet deposition (rain or snow). The deposition fluxes of 7Be and 210Pb were low in summer and high in winter to spring. Deposition fluxes of 7Be and 210Pb positively correlated to precipitation. From the results of the power spectral analysis by fast Fourier transform, annual periodicities of 7Be and 210Pb deposition at Rokkasho could be classified as a double peak distribution pattern and single peak distribution pattern, respectively. Backward trajectories for 72 h were calculated every 6 h in order to clarify the relation of air mass transport course and atmospheric concentrations of 210Pb. The results showed that atmospheric 210Pb concentrations were strongly affected by air mass from the northern Asian continental area above 40degN. (author)

  16. Concentration and distribution of 210Po in rats exposed to radon

    Objective: To study the concentration and distribution of 210Po in rats exposed to radon and its daughters. Methods: Fifteen male wistar rats were randomly divided into three groups, including one control group and two radon exposed groups with the cumulative doses of 100 WLM (low dose) and 200 WLM (high dose), respectively. Tissue samples containing 210Po were spontaneously deposited onto silvery discs with the diameter of 20 mm by means of wet ashing and electrodeposition. The concentration of 210Po in tissues were measured by α spectroscopy, and tissue burden were calculated. Results: The concentrations of 210Po were significantly different among the three dose groups in femur, liver, sex gland and hair (P210Po were different between the exposed groups and the control group in lung and soleus muscle (P210Po in lung, spleen and hair were higher than that in liver, bone and sex gland, the lowest was in intestine. The tissue burdens of liver, bone and sex gland were significantly different from those in other organs or tissues. Conclusions: 210Po was mainly distributed in lung, liver, spleen, femur and sex gland. The concentrations of 210Po in organs or tissues and the tissue burdens were correspondingly increased with the exposure dose of radon and its daughters. The results of this experiment provide a dosimetric basis for further studies on the carcinogenic effect of radon and its daughters. (authors)

  17. 40 CFR 158.210 - Experimental use permit data requirements for product chemistry.

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Experimental use permit data requirements for product chemistry. 158.210 Section 158.210 Protection of Environment ENVIRONMENTAL PROTECTION... Experimental use permit data requirements for product chemistry. All product chemistry data, as described...

  18. Activity levels of polonium-210 in tobacco and cigarette in Iran

    Polonium-210 (210Po) is a natural contaminant of tobacco and its products. Due to its volatility and inherent adsorption properties, 210Po is one of the major potential sources of human exposure through smoking. This paper reports measurements on 210Po and 210Pb levels in domestic as well as imported tobacco to Iran through α-spectrometry technique. The fate of 210Po radionuclide has been also followed from tobacco farm through curing procedure in factory. The activity levels of 210Po in Iranian domestic and imported cigarettes is found to be on the average as 38.4±0.8 mBq/g with a range of 30.3-51.3 mBq/g and 20.0±0.6 mBq/g with a range of 18.6-21.7 mBq/g, respectively. These levels are considerably higher than those reported in many other parts of the world. In the case of tobacco produced in Iranian northern province of Guilan, drying in closed compartments by fossil fuel and elevated inventories of 210Po in soil due to over application of phosphate-rich fertilizers seems to be the main causes of these elevated activity levels.

  19. 23 CFR 972.210 - Federal lands bridge management system (BMS).

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands bridge management system (BMS). 972.210....210 Federal lands bridge management system (BMS). In addition to the requirements provided in § 972... CFR 650, subpart C, National Bridge Inspection Standards (NBIS). (b) The BMS shall be designed to...

  20. 23 CFR 973.210 - Indian lands bridge management system (BMS).

    2010-04-01

    ... “Guidelines for Bridge Management Systems,” AASHTO, 1993, is available for inspection as prescribed at 49 CFR... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands bridge management system (BMS). 973.210... PROGRAM Bureau of Indian Affairs Management Systems § 973.210 Indian lands bridge management system...

  1. 30 CFR 210.104 - Must I submit these production reports electronically?

    2010-07-01

    ... electronically? 210.104 Section 210.104 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR... production reports electronically? (a) You must submit Forms MMS-4054 and MMS-4058 electronically unless you... which either party may contract. (2) Web-based reporting—Reporters/payors may enter report data...

  2. 30 CFR 210.54 - Must I submit this royalty report electronically?

    2010-07-01

    ... electronically? 210.54 Section 210.54 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR... Must I submit this royalty report electronically? (a) You must submit Form MMS-2014 electronically... with which either party may contract. (2) Web-based reporting—Reporters/payors may enter report...

  3. The 210Pb budget of the North Sea. Atmospheric input versus sediment flux

    Atmospheric deposition is one of the main sources of 210Pb in the North Sea water. Annual variations of this flux are large in the Netherlands. Translated to the North Sea area the atmospheric deposition is 42 Bq.m-2.y-1. In the 210Pb budget of the North Sea, supply by rivers, as artificial supply by power plants and fertilizer plants, does not play a great role. Fishery activities is not a good scavenger in the total 210Pb budget. From measurements of 36 box-cores in the North Sea the average 210Pb flux to the sediment is estimated 150 Bq.m-2.y-1. Fluxes to the sediment smaller than 10% of the atmospheric flux, occur in the sandy areas of the Southern Bight and Dogger Bank. Large fluxes, up to 50 times the atmospheric deposition, occur mainly in the fine grained deposition areas of the Skagerrak and the Norwegian Trench. The net lateral flux accounts for 1/3 part of the flux to the sediment: the North Sea is a true sink for 210Pb. The radon flux from the sediment supplies 1/3 of the 210Pb flux to the sediment. Based on the 210Pb budget total mass accumulation in the North Sea is 1100 x 109 kg.y-1, this is an order of magnitude higher than figures obtained from transport of suspended matter and from 210Pb sedimentation rates. (author)

  4. 9 CFR 2.10 - Licensees whose licenses have been suspended or revoked.

    2010-01-01

    ... suspended or revoked. 2.10 Section 2.10 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... have been suspended or revoked. (a) Any person whose license has been suspended for any reason shall....12. (b) Any person whose license has been revoked shall not be licensed in his or her own name or...

  5. 19 CFR 210.9 - Action of Commission upon receipt of complaint.

    2010-04-01

    .... 210.9 Section 210.9 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Commencement of Preinstitution Proceedings... compliance with the applicable sections of this chapter. (b) Informal investigatory activity. The...

  6. 33 CFR 155.210 - Discharge removal equipment for vessels less than 400 feet in length.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Discharge removal equipment for vessels less than 400 feet in length. 155.210 Section 155.210 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION...

  7. Using natural radionuclides 210Po and 210Pb in GEOTRACES data from the North Atlantic to estimate particulate and biologically reactive trace element scavenging and regeneration

    Rigaud, Sylvain; Church, Thomas

    2016-04-01

    Central to understanding the coupling of oceanic carbon and nutrient cycles are trace elements that can limit ocean production and ultimately climate change. These include elements that are both lithogenic (particle reactive) and biogenic (biologically reactive) central to particle scavenging, exchange and bioavailability. The natural 210Po and 210Pb radionuclide (granddaughter/parent) pair provides the radiometric means to model particle scavenging and exchange in the ocean on monthly to annual time scales. Data on dissolved (0.2 μm, >53μm) 210Po (t1/2= 138.4 d) and 210Pb (T1/2 = 22.3 y) are available from seven complete water profiles during two U.S. GEOTRACES cruises that transited the North Atlantic during fall 2010 and 2011. The transects correspond to a wide range of marine environments: coastal slopes at the western and eutrophic up-welling at the eastern margins, Saharan dust sources from the east, hydro-thermal vents in the TAG plume on the Mid-Atlantic Ridge, and oligotrophic gyres in both the western and eastern basins. Steady state box modeling at each depth interval was employed to estimate radionuclide exchange rates at the fine-large particle and fine particulate-dissolved interface, in terms of biological uptake, and net of radioactive support or decay. By proxy, the results should predict the rates of biological (210Po) and particle reactive (210Pb) trace element adsorption and resorption, vertical particulate and carbon export, and respective residence times. The model results show the contrasting chemical behaviour of the two nuclides over the large range of oceanic conditions encountered in the North Atlantic. In the surface ocean, 210Po scavenging is linearly correlated with the concentration of particulate organic carbon (POC) in large particles, supporting the role of biogenic particles in 210Po bioaccumulation and export. At depth, 210Po exhibits significant widespread deficit with respect to 210Pb, which could in part be attributed to in

  8. A faster sample preparation method for determination of polonium-210 in fish

    In order to facilitate Health Canada’s study on background radiation levels in country foods, an in-house radio-analytical method has been developed for determination of polonium-210 (210Po) in fish samples. The method was validated by measurement of 210Po in a certified reference material. It was also evaluated by comparing 210Po concentrations in a number of fish samples by another method. The in-house method offers faster sample dissolution using an automated digestion system compared to currently used wet-ashing on a hot plate. It also utilizes pre-packed Sr-resin® cartridges for rapid and reproducible separation of 210Po versus time-consuming manually packed Sr-resin® columns. (author)

  9. Determination of 210Po in Slovak mineral waters by sorption on ZnS(Ag)

    In determining of 210Po it was followed according to the Czech technical standard CSN 75 7626 Water quality - Determination of polonium-210. The aim of this work was to optimize the conditions for sorption of 210Po on ZnS (Ag) from acidic environment from the model solutions. The effect of pH of the sample, its volume and the presence of NaCl on the sorption of 210Po on ZnS (Ag) was studied. Three types of filters for filtering ZnS (Ag), Synpor, paper and glass fiber filters were tested. Bulk activity of 210Po was determined in the samples of Slovak mineral waters and healing waters as well as in water samples from antimony mine (mine Rufus) near the village Poproc (rural Kosice district). (author)

  10. Bioaccumulation of polonium-210 in fish of the Kaveri river system

    Concentration of naturally occurring radioactive nuclide polonium-210 was determined in selected species of fish from the Kaveri river system at Tiruchirappalli. It is shown that 210Po is non-uniformly distributed within these fishes. Concentrations of 210Po in the muscle of fish ranged from 3.3 to 8.2 Bq/kg (wet weight). Concentration factors of Po210 in edible portion of fish from river water worked out to be 2.5 x 103 to 6.3 x 103. Radiation dose to public due to consumption of fish from the Kaveri river varied from 5.1 to 27.3 μSv/y. The results have implications that fish represents an important source of supply of 210Po to humans. (author). 16 refs., 2 tabs

  11. Investigations of the potential bioavailability of 210Po in some foodstuffs

    Extraction of 210Po from lamb's liver, pig's kidneys, mussel flesh and brown crabmeat with a series of solvent systems has been used to gain some insight into the uncertainty about the gastrointestinal absorption factor for Po incorporated into foodstuffs. By extracting the tissues with diethyldithiocarbamate dissolved in chloroform, and also in methanol, it has been shown that 210Po is more effectively extracted from lamb's liver and crabmeat than it is from each of the other tissues. A similar pattern of extractability is also evident for aqueous solutions of citric acid on crabmeat and mussel flesh. Of particular note is the low extractability by dimethylsulphoxide (3%) of 210Po in mussel flesh as opposed to 24% extractability of 210Po from crabmeat. 210Po-binding macromolecules of about 10 kDa have been released from crabmeat and mussel flesh by digestion with pepsin

  12. Estimation of 210Po in Cauvery river and ground water from south interior Karnataka state, India

    The study is carried out for the estimation of 210Po concentration in Cauvery River and Ground water from south interior Karnataka State region. 210Po is generated from Uranium decay series and is highly toxic element. The water samples were collected from Cauvery river belt of south interior Karnataka. These samples were processed using radiochemical analysis. As per WHO standards 210Po concentration in drinking water should not exceed 100 mBql-1. The concentration of 210Po ranges from 0.36 mBql-1 to 3.97 mBql-1 in river water samples and has a mean value of 1.98 mBql-1. In ground water samples the 210Po concentration ranges from 1.89 mBql-1 to 4.87 mBql-1 and mean value is 3.22 mBql-1. (author)

  13. Excess unsupported sup(210)Pb in lake sediment from Rocky Mountain lakes

    Sediment cores from four high-altitude (approximately 3200 m) lakes in Rocky Mountain National Park, Colorado, were dated by sup(210)Pb chronology. Background (supported) sup(210)Pb activities for the four cores range from 0.26 to 0.93 Beq/g dry weight, high for typical oligotrophic lakes. Integrated unsupported sup(210)Pb ranges from 0.81 (a typical value for most lakes) to 11.0 Beq/cmsup(2). The sup(210)Pb activity in the surface sediments ranges from 1.48 to 22.2 Beq/g dry weight. Sedimentation from Lake Louise, the most unusual of the four, has 22.2 Beq/g dry weight at the sediment surface, an integrated unsupported sup(210)Pb=11.0 Beq/cmsup(2), and supported sup(210)Pb=0.74 Beq/g dry weight. sup(226)Ra content of the sediment is insufficient to explain either the high unsupported sup(210)Pb or the sup(222)Rn content of the water column of Lake Louise, which averaged 96.2 Beq/L. We concluded that sup(222)Rn-rich groundwater entering the lake is the source of the high sup(222)Rn in the water column. This, in turn, is capable of supporting the unusually high sup(210)Pb flux to the sediment surface. Groundwater with high sup(222)Rn may control the sup(210)Pb budget of lakes where sediment cores have integrated unsupported sup(210)Pb greater than 2 Beq/cmsup(2)

  14. A study on the radioactivity profile of Polonium-210 in different freshwater habitats

    The present study is an attempt to understand the distribution pattern of Polonium-210, a natural alpha emitter in three distinct freshwater systems namely lotic (running water), lentic (standing water) and semi-lentic (impounded water) of the Kaveri river system, Tiruchirappalli (10.48 degN latitude and 78.42 degE longitude). Measurements were made on the 210Po levels of water, sediment and selected biota (net plankton, weed, snail, bivalve, prawn and fish) collected from the three different habitats. Analysis of the results indicate that a lentic system tends to accumulate 210Po at a relatively higher level compared to a lotic system in all environmental matrices tested. The semi-lentic system maintained an intermediate level between the lotic and the lentic habitat. In water, dissolved concentrations of 210Po ranged from 0.77 mBq.l-1 (lotic system) to 1.8 mBq.l-1 (lentic system). As in water, 210Po concentration in sediment was also significantly higher in lentic habitat (59.9 Bq.kg-1 dry wt.) than in lotic habitat (20.8 Bq.kg-1 dry wt.). The aquatic organisms demonstrated differential accumulation of 210Po with enhanced bioaccumulation in soft tissues and muscle. The 210Po activity in the biota fell within the range 1.6 to 140.1 Bq.kg-1 wet wt. The bivalve mollusca, Parrevsia favidens was identified to concentrate higher levels of 210Po in their soft tissues, suggesting, that these organisms could serve as sentinel organisms for 210Po in a riverine system. The significance of the results of 210Po in the abiotic and biotic components are discussed. (author)

  15. Fluxes of 238U Series Radionuclides in the Industrial Production of Dicalcium Phosphate and the Biokinetic Analysis of 210Pb and 210Po in Poultry Tissue Due to its Ingestion

    NORM derived from the wet acid digestion of phosphate rock might represent a serious problem facing the phosphate industry. The aim of this work is to discuss both: (a) the fluxes of the 238U series radionuclides (U and Th isotopes, 226Ra, 210Pb and 210Po) during the DCP production process and, (b) the accumulation of 210Pb and 210Po in chicken tissues due to the ingestion of DCP. Industrial samples were collected from different production steps at a factory in Spain that uses phosphate rock from Morocco. The results showed that whereas uranium is equally distributed within products and by-products, thorium and 210Po are mainly eliminated through the sludges and 210Pb is mostly found in the final product (DCP). The 210Pb and 210Po results in chicken tissues and faeces after animals were bred with different amounts of DCP for 42 days have shown that about 95% of the ingested 210Pb and 210Po was immediately excreted. From the amount accumulated in tissues it was observed that whereas 210Pb is mostly found in bones, 210Po accumulates in the liver and kidneys. A one compartment non-linear kinetic model has been developed in order to determine the variation of the total activity of 210Pb and 210Po accumulated in the chicken body throughout its 6 weeks life. This model correctly reproduces experimental results and also allows calculating of transfer rates for 210Pb and 210Po, useful for first order models, that is, under stationary metabolic conditions. (author)

  16. Enrichment of {sup 210}Po and {sup 210}Pb in ash samples from oil shale-fired power plants in Estonia

    Ozden, B. [University of Tartu, Institute of Physics/Ege University, Institute of Nuclear Sciences (Estonia); Vaasma, T.; Kiisk, M.; Suursoo, S.; Tkaczyk, A.H. [University of Tartu,Institute of Physics (Estonia)

    2014-07-01

    Energy production in Estonia is largely dependent on the oil shale industry. Oil shale is a fossil fuel typically characterized by relatively high mineral composition, modest organic fraction (varying between 10 and 65%), high ash content (usually 45% to 50%), and average lower heating value of 8.4 MJ/kg{sup -1}. Oil shale-fired power plants account for 85% of Estonian electricity production and produce up to 6 million tons of oil shale ash annually. This ash contains elevated amounts of natural radionuclides (from the {sup 238}U and {sup 232}Th series and {sup 40}K), which were bound to oil shale during its formation. These radionuclides become enriched in ash fractions during the combustion process and are partially emitted to the atmosphere via fly ash and flue gases. Oil shale-fired electricity production is foreseen to remain a dominant trend in Estonia, suggesting that the radionuclide emissions to the atmosphere will continue in the future. The natural radionuclides {sup 210}Po and {sup 210}Pb, with half-lives of 138 days and 22.3 years respectively, originate from the radioactive decay of radionuclides of {sup 238}U series present in the earth's crust. These radionuclides are also built up artificially in the environment due to waste discharge from phosphate, oil, and gas industries, combustion of fossil fuels and other energy production as technically enhanced natural radionuclides. There are few studies on oil shale power plants influence on the levels of natural radioactivity in the surrounding areas. Realo, et al. reported that the annual doses from fly ash depositions over a 30 year period are in the range 90 - 200 μSv a{sup -1}. A study previously initiated by the University of Tartu, Institute of Physics (IPh) evaluated enrichment in the activity concentrations of {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 232}Th, {sup 228}Ra and {sup 40}K in ash samples collected from Eesti Power Plant's circulating fluidized bed (CFB) boiler. According

  17. Transfer of the uranium decay products, polonium-210 and lead-210, through the lichen-caribou-wolf food chain in northern Canada (manuscript report)

    The main purpose of this study is to investigate the accumulation and transfer of polonium-210 and lead-210 in the arctic food chain, lichen-caribou-wolf, in the Northwest Territories. Polonium-210 arises from lead-210 decay and is a widespread alpha-emitting radionuclide. It seeks soft tissue and has the potential to accumulate in the food chain. Caribou, wolves and other wildlife may become exposed to enhanced levels of these two uranium-series radionuclides if the proposed uranium mine near Baker Lake, Northwest Territories, proceeds. Baker Lake lies at the crossroads of the ranges of the Beverly, the Kaminuriak and the Wager Bay caribou herds. Therefore, it is important to establish baseline concentrations and natural food chain transfer of uranium series radionuclides, in this study. This information can be used for baseline data before any further mining development takes place. This study will also provide data regarding the statistical uncertainty attached to transfer coefficients. This can help ensure reliable and appropriate future monitoring of environmental change. With the participation of the hunters of Baker Lake, caribou and wolf samples were collected and analyzed for polonium. Results indicate that polonium-210 activity in caribou tissues were somewhat higher than previous data reported from Alaska. Transfer coefficients for polonium-210 from caribou to wolf were near unity for many tissues. However, polonium-210 does not appear to cross the placenta in caribou. Further study includes lichen collections and collection of further caribou samples from the beverly herd in order to determine transfer from lichens to caribou in both the Baker Lake and Snowdrift areas in the Northwest Territories. (author). 26 refs., 3 tabs

  18. 17 CFR 210.2-02T - Accountants' reports and attestation reports on internal control over financial reporting.

    2010-04-01

    ... attestation reports on internal control over financial reporting. 210.2-02T Section 210.2-02T Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION FORM AND CONTENT OF AND REQUIREMENTS FOR FINANCIAL... attestation reports on internal control over financial reporting. (a) The requirements of § 210.2-02(f)...

  19. 28 CFR 5.210 - Amount of detail required in information relating to registrant's activities and expenditures.

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Amount of detail required in information relating to registrant's activities and expenditures. 5.210 Section 5.210 Judicial Administration... § 5.210 Amount of detail required in information relating to registrant's activities and...

  20. 76 FR 7818 - Correction to Notice Soliciting Comments on Proposed Voluntary Product Standard PS 2-10 and...

    2011-02-11

    ... Standard PS 2-10 (75 FR 66734). The title of the notice incorrectly gave the title of Proposed Voluntary... Voluntary Product Standard PS 2-10 and Reopening of Comment Period AGENCY: National Institute of Standards... Register requesting comments on Proposed Voluntary Product Standard PS 2-10. The title of the...

  1. 12 CFR 550.210 - Must I conduct another review of an account after I accept it?

    2010-01-01

    ... Fiduciary Account § 550.210 Must I conduct another review of an account after I accept it? After you accept a fiduciary account for which you have investment discretion, you must conduct a prompt review of... after I accept it? 550.210 Section 550.210 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT...

  2. Radioactive contamination in human by polonium-210 in food from marine origin

    Food from marine origin is considered as one of the sources that most contributes to internal radioactive contamination in humans by polonium-210 (210Po). This work intended to check whether a single ingestion of the mussel Perna perna should result in a detectable increase of radioactive contamination in the consumer. The mussel was bought at a fish market localized in the city of Niteroi, RJ, Brazil. It was cooked as usually, and its content in 210Po determined after acid mineralization, spontaneous electrodeposition on stainless steel disks and alpha counting. Non-smoking volunteers maintained for two weeks a normal diet, but completely avoiding fish and seafood. Then, they ate 200 g of cooked mussel, and collected total faeces and urine every day during ten days. 210Po level in faeces samples showed a 900% increase at the first day after ingestion, and reached normal levels after 3-4 days. In urine samples, the increase of 210Po was much lower (50%) and reached a maximum at the fifth day. Such data showed a short time permanence of 210Po in the intestine. Most of ingested 210Po (∼91%) was eliminated in up to 5 days through faeces. A small amount was absorbed (∼5-10%), part of it being eliminated in urine, and the remaining contaminated the human body. (author)

  3. Indoor air as an important source for 210Pb accumulation in man

    A pilot study was performed with measurements in a German, inhabited, two-family house, to obtain data on the correlation between the equilibrium equivalent radon concentration Ceq and the 210Pb concentration CPb in indoor air. Aerosol samples were collected in various rooms of the house under conditions of low ventilation. The data indicate a linear correlation between Ceq and CPb. A regression analysis, assuming such a relationship, resulted in the following equation: CPb (in mBq.m-3)=8.2x10-3 Ceq (in Bq.m-3) + 0.32. From this relationship it follows that in environments with enhanced radon concentrations direct inhalation of 210Pb is an important source for 210Pb accumulation in man. It was estimated that at an indoor 222Rn concentration of 1,000 Bq.m-3, the 210Pb uptake from inhalation amounts 32 mBq.d-1 of which 62% originates from the direct inhalation of 210Pb. Only the remaining third can be attributed to inhaled short-lived radon progeny and to radon gas dissolved in body tissues. It is shown that, in addition to ingestion and even for elevated indoor radon concentrations, direct inhalation of indoor 210Pb is a further important source of uncertainty, when in vivo measurements of the 210Pb activity in the human body are used as a measure of cumulative radon exposure. (author)

  4. Determination of 210 Pb in mineral spring waters of Aguas da Prata city

    Concentration levels of 210 Pb have been analyzed in 12 mineral spring waters of Aguas da Prata city. The 210 Pb concentration was determined through 210 Bi, by measuring the gross beta activity of the 210 Pb Cr O4 precipitate after separation from interfering elements by complexation with nitrile tri acetic acid at basic pH. The 210 Bi beta activity was carried out in a low background gas flow proportional counter. Concentrations ranging from lower limit of detection to 1240 mBq/L were observed for 210 Pb. The radiochemical procedure adopted presented a chemical yield around 85% and a lower limit of detection of 4,9 mBq/L. Dose calculations were performed in order to evaluate the importance of this radionuclide to the radiation exposure due to the ingestion of these waters. Based upon measured concentrations, committed effective doses up to 1,1 mSv/y and committed doses to the bone up to 1.7 x 101 mSv/y were observed for 210 Pb. (author). 64 refs, 6 figs, 7 tabs

  5. Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig.

    Arnaud P J Giese

    Full Text Available Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino-2-((methylaminomethylpropane-1-thiol on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy to each ear. Auditory Brainstem Responses (ABRs were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing.

  6. Evaluation of the 210Po method at the Midwest uranium deposit, northern Saskatchewan, Canada

    Vertical profiles of 210Po in soils near the Midwest uranium deposit and an associated surficial radioactive sandstone boulder train in northern Saskatchewan show a high 210Po background in air-dried forest litter (24 pCi/g) and Ah horizon soil (11 pCi/g) relative to lower soil horizons (210Po signal from the radioactive boulders in the near-surface soil horizons. Only in the Bf and C horizons can the existence of the radioactive boulders be inferred from 210Po determinations. For comparative purposes profiles for 226Ra, U, Ni, and other trace elements are also presented. Escape of most of the Rn from near surface soils into the atmosphere, homogenization and decay of Rn, and precipitation of decay products back onto surface soils satisfactorily explain the field observations discussed here. Compared to the highly anomalous 222Rn signal in soil gases over this boulder train the 210Po contrast is very weak and is of little use for prospecting for this type of boulder train. The relatively high 210Po background in surficial materials relative to lower soil horizons dictates that great care be taken with the 210Po method; the deepest possible horizons should be sampled. (orig.)

  7. Baseline concentration of 210Po in Kuwait’s commercial fish species

    Highlights: ► The study reports baseline concentration of 210Po in commercial fish species of Kuwait. ► Radionuclide conc. in commercial fish is critical for food chain transfer. ► With nuclear plants coming-up in Gulf baseline is critical. - Abstract: This baseline study highlights the 210Po variation in whole fishes with different feeding habits. Whole-body 210Po concentrations were determined in ten important commercial fish species found in the northern Arabian Gulf to serve as baseline data. Primarily, 210Po is absorbed from water, concentrated by phytoplankton and microzooplankton, and then transferred to the next trophic level along the marine food chain. The lowest concentration of 210Po was measured in larger carnivorous fishes like hamoor (0.089 Bq kg−1), while the highest was found in the fishes that feed on algae, zooplanktons and detritus, like battan (3.30 Bq kg−1). The baseline data can be used to understand both the trophic transfer of 210Po in the marine food chain and the 210Po concentration factors in fish from the Arabian Gulf.

  8. Primary electron transfer in reaction centers of YM210L and YM210L/HL168L mutants of Rhodobacter sphaeroides.

    Yakovlev, A G; Vasilieva, L G; Khmelnitskaya, T I; Shkuropatova, V A; Shkuropatov, A Ya; Shuvalov, V A

    2010-07-01

    The role of tyrosine M210 in charge separation and stabilization of separated charges was studied by analyzing of the femtosecond oscillations in the kinetics of decay of stimulated emission from P* and of a population of the primary charge separated state P(+)B(A)(-) in YM210L and YM210L/HL168L mutant reaction centers (RCs) of Rhodobacter sphaeroides in comparison with those in native Rba. sphaeroides RCs. In the mutant RCs, TyrM210 was replaced by Leu. The HL168L mutation placed the redox potential of the P(+)/P pair 123 mV below that of native RCs, thus creating a theoretical possibility of P(+)B(A)(-) stabilization. Kinetics of P* decay at 940 nm of both mutants show a significant slowing of the primary charge separation reaction in comparison with native RCs. Distinct damped oscillations in these kinetics with main frequency bands in the range of 90-150 cm(-1) reflect mostly nuclear motions inside the dimer P. Formation of a very small absorption band of B(A)(-) at 1020 nm is registered in RCs of both mutants. The formation of the B(A)(-) band is accompanied by damped oscillations with main frequencies from ~10 to ~150 cm(-1). Only a partial stabilization of the P(+)B(A)(-) state is seen in the YM210L/HL168L mutant in the form of a small non-oscillating background of the 1020-nm kinetics. A similar charge stabilization is absent in the YM210L mutant. A model of oscillatory reorientation of the OH-group of TyrM210 in the electric fields of P(+) and B(A)(-) is proposed to explain rapid stabilization of the P(+)B(A)(-) state in native RCs. Small oscillatory components at ~330-380 cm(-1) in the 1020-nm kinetics of native RCs are assumed to reflect this reorientation. We conclude that the absence of TyrM210 probably cannot be compensated by lowering of the P(+)B(A)(-) free energy that is expected for the double YM210L/HL168L mutant. An oscillatory motion of the HOH55 water molecule under the influence of P(+) and B(A)(-) is assumed to be another potential

  9. Atmospheric deposition patterns of 210Pb and 7Be in Cienfuegos, Cuba

    The radiometric composition of bulk deposition samples, collected monthly for one year, February 2010 until January 2011, at a site located in Cienfuegos (22° 03′ N, 80° 29′ W) (Cuba), are analysed in this paper. Measurement of 7Be and 210Pb activity concentrations were carried out in 12 bulk deposition samples. The atmospheric deposition fluxes of 7Be and 210Pb are in the range of 13.2–132 and 1.24–8.29 Bq m−2, and their mean values are: 56.6 and 3.97 Bq m−2, respectively. The time variations of the different radionuclide have been discussed in relation with meteorological factors and the mean values have been compared to those published in recent literature from other sites located at different latitudes. The annual average flux of 210Pb and 7Be were 47 and 700 Bq m−2 y−1, respectively. Observed seasonal variations of deposition data are explained in terms of different environmental features. The atmospheric deposition fluxes of 7Be and 210Pb were moderately well correlated with precipitation and well correlated with one another. The 210Pb/7Be ratios in the monthly depositions samples varied in the range of 0.05–0.10 and showed a strong correlation with the number of rainy days. - Highlights: • We evaluated for first time in Cuba the atmospheric deposition fluxes of 7Be and 210Pb. • The annual average flux of 210Pb and 7Be were 47 and 700 Bq m−2 y−1, respectively. • The atmospheric deposition fluxes of 7Be and 210Pb are correlated with precipitation. • 7Be and 210Pb present similar removal behaviour from the atmosphere

  10. Etiology of epilepsy a prospective study of 210 cases

    Walter Oleschko Arruda

    1991-09-01

    Full Text Available The objective of this study was to establish the etiology of epilepsy in 210 chronic epileptics (110 female, 100 male, aged 14-82 years (34.2±13.3. Patients less than 10 years-old and alcoholism were excluded. All underwent neurological examination, routine blood tests, EEG and CT-scan. Twenty patients (10.5% were submitted to spinal tap for CSF examination. Neurological examination was abnormal in 26 (12.4%, the EEG in 68 (45.5%, and CT-scan in 93 (44.3%. According to the International Classification of Epileptic Seizures (1981, 101 (48.1% have generalized seizures, 66 (31.4% partial seizures secondarily generalized, 25 (11.8% simple partial and complex partial seizures, and 14 (6.6% generalized and partial seizures. Four patients (2.0% could not be classified. In 125 (59.5% patients the etiology was unknown. Neurocysticercosis accounted for 57 (27.1% of cases, followed by cerebrovascular disease 8 (3.8%, perinatal damage 5 (2.4%, familial epilepsy 4 (1.9%, head injury 4 (1.9%, infective 1 (0.5%, and miscelanea 6 (2.8%.

  11. The pulsating variable star population in DDO210

    Ordoñez, Antonio J

    2015-01-01

    We have probed the pulsating variable star content of the isolated Local Group dwarf galaxy, DDO210 (Aquarius), using archival Advanced Camera for Surveys/$Hubble$ $Space$ $Telescope$ imaging in the F475W and F814W passbands. We find a total of 32 RR Lyrae stars (24 ab-type, 8 c-type) and 75 Cepheid variables. The mean periods of the ab-type and c-type RR Lyrae stars are calculated to be $\\langle$P$_{\\mathrm{ab}}\\rangle = 0.609\\pm0.011$ and $\\langle$P$_{\\mathrm{c}}\\rangle = 0.359\\pm0.025$ days, respectively. The light curve properties of the fundamental mode RR Lyrae stars yield a mean metallicity of $\\langle$[Fe/H]$\\rangle$ = -1.63$\\pm$0.11 dex for this ancient population, consistent with a recent synthetic colour-magnitude diagram analysis. We find this galaxy to be Oosterhoff-intermediate and lacking in high-amplitude, short-period ab-type RR Lyrae, consistent with behavior recently observed for many dwarf spheroidals and ultra-faint dwarfs in the Local Group. We find a distance modulus of $\\mu = 25.07\\pm ...

  12. Scientific Opinion on Flavouring Group Evaluation 210 Revision 2 (FGE.210Rev2): Consideration of genotoxic potential for α,β-unsaturated alicyclic ketones and precursors from chemical subgroup 2.4 of FGE.19

    Beltoft, Vibe Meister; Nørby, Karin Kristiane

    Safety Authority was requested to evaluate the genotoxic potential of 14 flavouring substances in Flavouring Group Evaluation 210 (FGE.210). In FGE.210, the Panel concluded that the genotoxic potential could not be ruled out for any of the flavouring substances. In FGE.210 Revision1, the Panel.......226 and 07.231] the concern for genotoxicity remains and additional data were requested. The Flavour Industry has submitted additional genotoxicity data for allyl a-ionone [FL-no: 07.061], that are evaluated in the present revision of FGE.210 (Revision 2). Based on these new data the Panel concluded that...

  13. Evaluation of the contribution of smoking to total blood polonium-210 in Saudi population

    A preliminary study of 210Po concentrations in the blood of some smokers and nonsmokers is presented in order to evaluate the contribution of smoking to total blood 210Po in Saudi population. Blood samples were collected from 30 volunteers and analyzed by high resolution α-spectrometry using a radiochemical technique. The technique is based on the separation of polonium from other components of the sample by wet ashing with an HNO3/H2O2 oxidizing mixture and spontaneous deposition on a silver disc under the relevant conditions for α-particle counting. The results indicated that a significant fraction (about 30%) of blood 210Po is related to smoking

  14. Sedimentation rates in Kagoshima Bay, Southwestern Japan, using the 210Pb method

    Yokota K; Inoue M.; Kofuji H.; Maeda H.

    2012-01-01

    To understand the pattern of sedimentation rates as fundamental physical parameter of coastal environment, the 210Pb dating method was applied to core samples collected from Kagoshima Bay, Southwestern Japan. The sedimentation rate varied at each location within the bay (0.08–0.30 g·cm−2·y−1), and the rate at the bay-head area was less than that at the centre of the bay. The inventory of ex210Pb has a lower value in the bay-head area. The low ex210Pb inventory at Stn.5' is considered to be du...

  15. Recent aquatic ecosystem response to environmental events revealed from 210Pb sediment profiles.

    Mulsow, S; Piovano, E; Cordoba, F

    2009-01-01

    The (210)Pb dating method was first introduced by Goldberg (1963), and since then has been applied to study sediment from lakes, estuaries and coastal marine environments. Hundreds of studies around the world have used (210)Pb as a geochronological tool in aquatic ecosystems. However little attention has been paid to the potential of this naturally occurring isotope as an environmental tracer of ecological events. Here we report three instances in which (210)Pb profiles measured on undisturbed sediment cores from lakes, rivers and fjords show us the potential of (210)Pb profile as a tracer of natural and anthropogenic processes. The methodology used here is a suite of techniques combining biogeochemistry (micro-electrodes), paleomagnetism (susceptibility), sediment characteristics (LOI) and visualization (SPI and X-ray) applied to the interpretation of (210)Pb profiles. We measured (210)Pb profiles on sediments from a river, Cruces River (Chile), which recorded a clear shift in the water chemistry caused by a pulp mill effluent to the river. Here metal mobilization and remobilization of the tracer may be the cause of the observed profile. We also measured (210)Pb profiles in sediment from two fjords of Southern Chile (Pillan and Reñihue), the sudden deposition change of fresh (210)Pb with depth observed could very well be the result of bioturbation but it occurred in a seafloor area deprived of bioturbators. In this case, (210)Pb recorded the onset of aquaculture activities (fish farming) that took place two decades ago. Finally, (210)Pb profiles measured in two lakes in the "pampa Argentina": Epecuen and Venado showed a particular shape with depth. These profiles apparently registered a sudden depositional event with recent (210)Pb material, probably related to strong shifts in precipitation and drought cycles in that part of the world. These three examples show that (210)Pb profiles provide valuable information not only on geochronology, but also related to

  16. Nuclear pore complex assembly and maintenance in POM121- and gp210-deficient cells

    Stavru, Fabrizia; Nautrup-Pedersen, Gitte; Cordes, Volker C;

    2006-01-01

    So far, POM121 and gp210 are the only known anchoring sites of vertebrate nuclear pore complexes (NPCs) within the lipid bilayer of the nuclear envelope (NE) and, thus, are excellent candidates for initiating the NPC assembly process. Indeed, we demonstrate that POM121 can recruit several...... depletion of POM121 from human fibroblasts, which do not express gp210, further suggest that NPCs can assemble or at least persist in a POM121- and gp210-free form. This points to extensive redundancies in protein-protein interactions within NPCs and suggests that vertebrate NPCs contain additional membrane...

  17. Estimating emission source of lead using 210Pb specific activity (210Pb/Pb) and zinc as tracers in Slovenian forest soils

    Specific activity of 210Pb (210Pb/Pb) is a good indicator for distinguishing local and remote emission sources of Pb deposited on some forest floors in Slovenia. Another parameter (zinc in soil) gives additional information on possible emission sources and distance of Pb transported from the source. The procedure based on 210Pb activity measurements and non-destructive Pb and Zn determination is rather simple, and not necessary any chemical pre-treatments with strong acids. The soils investigated in this study were collected from several temperate forest sites (Zirovski Vrh, Idrija, Kocevski Rog, Pohorje, Gorisnica, Rakitna, Hotavlje, Otovci, Ptujska gora and Puce) in Slovenia where high level of Pb contamination has been known in some places. Regression analyses of the results suggest an applicability of the proposed procedure for estimating emission sources and atmospheric transportation of Pb. (author)

  18. Polonium-210 and lead-210 in the Southern Polar Ocean: Naturally occurring tracers of biological and hydrographical processes in the surface waters of the Antarctic Circumpolar Current and the Weddell Sea

    In this thesis the distribution of 210Po and 210Pb in the upper 600 m of the Antarctic Circumpolar Current and the Weddell Sea was investigated along north-south transects in austral spring and autumn. 210Po and 210Pb can serve as sensitive tracers for the special hydrographic conditions of the Antarctic Circumpolar Current and the Weddell Sea as well as for biological processes during phytoplankton blooms. The 210Po/210Pb disequilibrium was used as a tracer for particle export. This tracer integrates export on a timescale of 276 days because of the 138 day half-life of 210Po and complements the 234Th/238U disequilibrium as another tracer for plankton production and export on a shorter timescale of several weeks. (orig.)

  19. Temporal evolution of natural radionuclides distributions 238U, 234Th, 226Ra, 228Ra, 210Pb and 210Po in the Bransfield strait, Antarctica peninsula

    Research on the distribution of natural radionuclides in Antarctica is rare and thus, there is great interest in to know their occurrence and factors related to its mobilization, transference and accumulation in this extremely fragile environment. Natural radionuclides have been used intensively as tracers in the ocean, helping to better understand processes as sinking and particle resuspension, water masses mixture and oceanic circulation. 234Th (t½ = 24.1 days) is a particle-reactive radionuclide produced continuously in seawater by the decay of its soluble precursor conservative with salinity 238U (t½ = 4.5 109 years). Since 234Th presents relatively short half-life, it is used to quantify processes that occur in temporal scale varying from days to weeks. The disequilibrium 234Th/238U in the surface ocean has been applied to estimate carbon fluxes exported via sinking material. The flux of particles biologically productive out of the euphotic zone in the Southern Ocean has special attention due to its importance in the control of CO2 atmospheric concentrations. The radionuclides 210Pb (t½ = 22.3 years) and 210Po (t½ = 138 days) are also particle-reactive. The disequilibrium 210Po/210Pb has been used to estimate fluxes of particles exported in the ocean in the time scale of weeks. The long-lived Ra isotopes, 226Ra (t½ = 1,600 years) and 228Ra (t½ = 5.75 years) are soluble in seawater, presenting unique properties that make them excellent tracers of water masses. This research work had the aim to study the distributions of natural radionuclides 238U, 234Th, 22'6Ra, 22'8Ra, 210Pb and 210Po in the Bransfield Strait during 2 samplings carried out in the 2011 Austral Summer (OPERANTAR XXIX and XXX). (author)

  20. Po-210 high levels in aquatic plants of the Carapebus sandbank, RJ, Brazil

    210 Po concentration have been determined in one green alga and in five freshwater plants grown in a pond of the Carapebus restinga (state of Rio de Janeiro). The alga Chara sp showed elevated concentration of 210 Po, similar to that observed in marine algae. All the other plants had the lowest concentration of 210 Po in the stems and the highest in the roots. Intermediate values were observed in the leaves. The unexpected high concentration of 210 Po in the roots, even superior to reported values for roots of plants from high radioactive background areas, must be due to the elevated levels of this radionuclide in associated soils that are known to be rich in humic organic material. There seem to have no translocation of this radionuclide from the roots to the other parts of the plants. (author)

  1. Determination of sedimentation rate in Thane creek using 210Pb dating

    Sediments are good representatives of the geochemical history of a particular area. They can be regarded as good archives of environmental processes and their effects. Therefore, the study of sediments in coastal areas has great importance for the understanding of the interaction between human activities and marine systems. The sedimentation process can be correlated with time by assessing decays of radionuclides like 210Pb, 137Cs and 14C in different layers of it. 210Pb and its environmental cycle have been commonly used as environmental tracer in many environmental studies. For assessment of chronological history of pollution in the Mumbai region, sediment samples were collected from Thane creek and sedimentation rates were estimated by measurement of 210Po activity which is in equilibrium with 210Pb

  2. Levels of polonium-210 in the grapevine leaves in Alasehir district in Turkey

    The objective of present work is the estimation of Po-210 (polonium) content in the edible grapevine leaves (Vitis viniferae, L.cv Sultana syn.) collected from Gediz plain in Western Turkey. Alasehir District in Gediz plain is one of the most important wine culture region of Turkey. Grapevine leaves are important food material for Dolma in Turkish cuisine. Dolma is a name applied to such vegetables as grapevine leaves, cabbage leaves and green peppers stuffed ground meat or spiked rice. Levels of Po-210 in the grapevine leaves had not been analyzed before in Turkey. In this study, after wet ashing of grapevine leaves, Po-210 was spontaneously plated onto a copper disc from dilute hydrochloric acid medium and deposited activity was measured. The results for Po-210 in the grapevine leaves are compared with the other foodstuff values in the literature

  3. 19 CFR 210.50 - Commission action, the public interest, and bonding by respondents.

    2010-04-01

    ... action; (2) Consult with and seek advice and information from the U.S. Department of Health and Human... terminations by settlement agreement, consent order, or arbitration agreement under § 210.21 (b), (c) or...

  4. Lead-210 as a radiotracer of coastal processes in studies along the Brazil coastal

    In this work, we review environmental radioactivity studies, using 210Pb, over the past 15 years along various areas of the Brazilian Coast. Included in these studies sediment accumulation rates, mixing zones, atmospheric fallout, sediment focusing and boundary scavenging have been studied. To validate, our 210Pb geochronologies, we have measured artificially fallout nuclides such as 137Cs, 239+240Pu and recorded pollution records, such as with heavy metals, with known mining history and have been used to confirm our 210Pb geochronologies. Activities reported are also in agreement with duplicate analyses taken at the USGS geochemistry laboratory. Sedimentary deposit in mangrove of the Ilha Grande have been compared with near by tide gauge record. Result indicated the accretion rates are keeping pace with sea level rise. This relation, between 210Pb sediment accumulation rates at local sea level rise, has proven to be important in area where tide gauges are not available to determine local sea level rise

  5. Radiometric determination of 210Pb in powder samples by the method of standard additions

    The method of standard additions is a well known procedure in chemistry for the measurements of trace substances. The use of this method is described in the radiometric determination of 210Pb activity via the γ-ray at 46.5 keV emitted in about 4% of the decays. Standard additions of 210Pb activity are absorbed on anion exchange resin which is then mixed with the sample. The procedure used to extract the area of the photopeak from the continuum on which it is superimposed, is described in detail. The value of the 210Pb activity is calculated using the slope and intercept of the best straight line fitting the count-rate data plotted against added activity. Results obtained on four standard ore samples indicate that this method yields results of comparable accuracy to other methods such as β-ray spectrometry of the prompt 210Bi daughter. This method, however, avoids the tedious chemical separations required. (author)

  6. The concentrations of 226 Ra and 210 Pb in food cultivated in Pocos de Caldas

    The aim of this study is to determine the average concentrations of 226 Ra and 210 Pb in vegetables widely cultivated in the region, mainly potatoes, carrots, beans and corn which are the main agricultural products (considering production and human consume) in the region and estimation of the average transfer factors soil-foodstuff for both radionuclides. The total 226 Ra and 210 Pb content in the soil was determined by gamma spectrometry. The exchangeable fraction was obtained by ammonium acetate solution extraction. The 226 Ra was analysed by the classical radon emanation procedure and the 210 Pb was isolated by a radiochemical procedure and determined by radiometry of its daughter 210 Bi beta emissions with a Geiger Mueller counter. (author)

  7. Particle mediated transport of Pb-210 through the epilimnion of Lake Michigan

    Concentrations of Pb-210 were measured on four size fractions of suspended particulate material and a dissolved fraction (500-111, 111-21, 21-6, 6-1 and 2/yr indicating a steady-state system with respect to Pb-210. During such dynamic particle events as the spring diatom bloom and the late summer calcium carbonate precipitation, however, Pb-210 fluxes increased by a factor of approx.2 over the steady-state flux. The 6-1 μm size fraction contained the largest percentage of the particulate Pb-210 standing crop-60% in April increasing to 98% during August through November. The importance of these particle events on trace metal transport through the water column are discussed

  8. 44 CFR 19.210 - Military and merchant marine educational institutions.

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Military and merchant marine... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Coverage § 19.210 Military and merchant... the merchant marine....

  9. Role of p21 RAS in p210 bcr-abl transformation of murine myeloid cells.

    Mandanas, R A; Leibowitz, D S; Gharehbaghi, K; Tauchi, T; Burgess, G S; Miyazawa, K; Jayaram, H N; Boswell, H S

    1993-09-15

    The p21 RAS product has been implicated as part of the downstream signaling of certain nonreceptor tyrosine kinase oncogenes and several growth factor receptor-ligand interactions. We have reported that the chronic myelogenous leukemia oncogene p210 bcr-abl transforms a growth-factor-dependent myeloid cell line NFS/N1.H7 to interleukin-3 (IL-3) independence. In these p210 bcr-abl-transformed cells (H7 bcr-abl.A54) and in two other murine myeloid cell lines transformed to IL-3 independence by p210 bcr-abl, endogenous p21 RAS is activated as determined by an elevated ratio of associated guanosine triphosphate (GTP)/guanosine diphosphate (GDP), assayed by thin-layer chromatography of the nucleotides eluted from p21 RAS after immunoprecipitation with the Y13-259 antibody. Treatment of p210 bcr-abl-transformed cells with a specific tyrosine kinase inhibitor herbimycin A resulted in diminished tyrosine phosphorylation of p210 bcr-abl and associated proteins, without major reduction in expression of the p210 bcr-abl protein itself. Inhibition of p210 bcr-abl-dependent tyrosine phosphorylation resulted in a reduction of active p21RAS-GTP complexes in the transformed cells, in diminished expression of the nuclear early response genes c-jun and c-fos, and in lower cellular proliferation rate. To further implicate p21 RAS in these functional events downstream of p210 bcr-abl tyrosine phosphorylation, we targeted G-protein function directly by limiting the availability of GTP with the inosine monophosphate dehydrogenase inhibitor, tiazofurin (TR). In p210 bcr-abl-transformed cells treated for 4 hours with TR, in which the levels of GTP were reduced by 50%, but GDP, guanosine monophosphate, and adenosine triphosphate (ATP) were unaffected, p210 bcr-abl tyrosine phosphorylation was at control levels. However, expression of c-fos and c-jun nuclear proto-oncogenes were strongly inhibited and p21 RAS activity was downregulated. These findings show that p210 bcr-abl transduces

  10. Study of 7Be and 210Pb as radiotracers of African intrusions in Malaga (Spain)

    The relationship between the particulate matter in the atmosphere of Malaga and the origin of air masses with special attention to African intrusions was analyzed. The concentrations of PM10 and the activities of some radionuclides (7Be and 210Pb) as tracers of these intrusions are discussed. The origin of these radiotracers is completely different. 210Pb is a good tracer of air masses traveling close to the ground and come from inland areas. On the other hand, the production of 7Be is very low in the vicinity of the Earth's surface, and increases with altitude, making it a great tracer of stratospheric air masses in the troposphere. Studies of radionuclide activities in aerosol particles provide a means for evaluating the integrated effects of transport and meteorology on the atmospheric loadings of substances with different sources. Measurements of aerosol mass concentration and specific activities of 7Be and 210Pb in aerosols at Malaga (36° 43′ 40″ N; 4° 28′ 8″ W) for the period 2009–2011 were used to obtain the relationships between radionuclide activities and airflow patterns by comparing the data grouped by air mass trajectory. The average concentration values of 7Be and 210Pb over the 3-year period have been found to be 5.05 and 0.55 mBq m−3, respectively, with mean aerosol mass concentration of 53.6 μg m−3. Taking into account the outbreaks of the daily values limits of PM10 in the study period (2009–2011), the origin of air masses is studied to explain three different situations of both radionuclides 7Be and 210Pb: 1) high concentrations of 7Be and low concentrations of 210Pb; 2) high concentrations of 210Pb and low concentrations of 7Be and 3) high concentrations of 7Be and 210Pb. - Highlights: • Time series of 7Be, 210Pb and PM10 recorded at Malaga (Spain) are analyzed over a 3-y period. • Three different scenarios in the concentrations of 7Be and 210Pb were observed. • High activities of 7Be indicated dust intrusions

  11. Measurement and Meteorological Analysis of 7Be and 210Pb in Aerosol at Waliguan Observatory

    ZHENG Xiangdong; WAN Guojiang; CHEN Zunyu; TANG Jie

    2008-01-01

    Beryllium-7 (7Be) and lead-210 (210Pb) activities were measured from October 2002 to January 2004 at Waliguan Observatory (WO: 36.287 N, 100.898 E, 3816 m a.s.l (above sea level) in northwest China. 7Be and 210Pb activities are high with overall averages of 14.7 3.5 mBq m-3 and 1.8 0.8 mBq m-3 respectively. For both 7Be and 210Pb, there are significant short-term and seasonal variations with a commonly low value in summer (May-September) and a monthly maximum in April (for 7Be) and in December (for 210Pb). The ratio of 7Be/210Pb showed a broad maximum extending from April to July, coinciding with a seasonal peak in surface ozone (O3). The seasonal cycles of 7Be and 210Pb activities were greatly influenced by precipitation and thermal dynamical conditions over the boundary layer, especially for 210Pb. The vertical mixing process between the boundary layer and the aloft air modulates the variations of 7Be and 210Pb at WO in summer. It is indicated that air mass had longer residence time and originated from higher altitudes at WO in the spring-summer time and the winter in 2003. During an event with extremely high weekly-averaged 7Be concentration (24.8 mBq m-3) together with high O3 levels and low water mixing ratio, we found that air masses had been convectively transported a long distance to WO from high latitude source regions in central Asia, where significant subsiding motions were observed. In another case with the extreme 210Pb activity of 5.7 mBq m-3 high CO2 level and specific humidity (in winter), air masses had come from south China and north Indian regions where 222Rn activities were high. This study, using 7Be and 210Pb as atmospheric tracers, has revealed that complex interactions of convective mixing from the upper troposphere and long-range transports exist at WO.

  12. Polonium-210 in mussels and fish from the Baltic-North Sea estuary

    Dahlgaard, H.

    1996-01-01

    Polonium-210 has been measured in Danish fish meat caught in the North Sea, the Kattegat and the Baltic in 1991-1994. Average values of 0.35, 0.65 and 0.96 Bq Po-210 kg(-1) fresh weight were observed for cod, herring and plaice fillets, respectively. The difference between species is statisticall...... in fish and mussels may represent a natural baseline. Copyright (C) 1996 Elsevier Science Ltd....

  13. Determination of (210)Po in calcium supplements and the possible related dose assessment to the consumers.

    Strumińska-Parulska, Dagmara I

    2015-12-01

    The aim of this pioneer study was to investigate the most popular calcium supplements as a potential additional source of polonium (210)Po in human diet. The analyzed calcium pharmaceutics contained organic or inorganic calcium compounds; some from natural sources as mussels' shells, fish extracts, or sedimentary rocks. The objectives of this research were to investigate the naturally occurring (210)Po activity concentrations in calcium supplements, find the correlations between (210)Po concentration in medicament and calcium chemical form, and calculate the effective radiation dose connected to analyzed calcium supplement consumption. As results showed, (210)Po concentrations in natural origin calcium supplements (especially sedimentary rocks) were higher than the other analyzed. Also the results of (210)Po analysis obtained for inorganic forms of calcium supplements were higher. The highest (210)Po activity concentrations were determined in mineral tablets made from sedimentary rocks: dolomite and chalk - 3.88 ± 0.22 and 3.36 ± 0.10 mBq g(-1) respectively; while the lowest in organic calcium compounds: calcium lactate and calcium gluconate - 0.07 ± 0.02 and 0.17 ± 0.01 mBq g(-1). The annual effective radiation doses from supplements intake were estimated as well. The highest annual radiation dose from (210)Po taken with 1 tablet of calcium supplement per day was connected to sample made from chalk - 2.5 ± 0.07 μSv year(-1), while the highest annual radiation dose from (210)Po taken with 1 g of pure calcium per day was connected to dolomite - 12.7 ± 0.70 μSv year(-1). PMID:26318774

  14. 17 CFR 210.12-12 - Investments in securities of unaffiliated issuers.

    2010-04-01

    ..., however, that an amount not exceeding five percent of the total of Column C may be listed in one amount as... to net assets (§§ 210.6-04.19 or 210.6-05.4). 4 Column C shall be totaled. The total of column C... effect that, on the last interest or dividend date, only partial interest was paid or partial...

  15. Ingestion of 210Po by public residing in and around Kalpakkam through dietary source

    The distribution of naturally occurring radionuclide Polonium-210 (210Po) activity in dietary source of Kalpakkam, Nuclear Power Plant, Tamil Nadu and its nearby region was studied. The 210Po was analyzed in the food materials consumed by the male and female individuals (he/she) living in the study area of Kalpakkam (nuclear power plant) was done by 24-hr Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was done by collecting the food materials such as, cereals, fruits, nuts, leafy vegetables, other vegetables, fish, meat and milk collected from the study area. The DDS was done by collecting the food materials including the beverages consumed in 24 h from different age groups of male and female individuals living in surroundings of Kalpakkam. The intake and ingestion dose of the radionuclide 210Po was estimated. The mean concentration of 210Po in DDS (n= 33) was found to be 36 mBq.kg-1 of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into 8 food groups. The mean concentration of 210Po in 8 food groups namely leafy vegetables was 288 mBq.kg-1 (n=4), vegetables 33 mBq.kg-1 (n=12), fish 7294 mBq.kg-1 (n=5) and cereal 34 (n=1) mBq.kg-1 of fresh weight respectively. The remaining food categories such as nuts (n=1), fruits (n= 4), meat food (n= 2) and milk (n= 2) are below detection limit of 30 mBq.kg-1 fresh weight. The annual intake and ingestion dose due to 210Po was estimated by DDS and MBS in adults, adolescents and children. Thereby, discussing the risk level of 210Po ingestion to the local inhabitants in Kalpakkam region. (author)

  16. Polonium-210 in mussels and fish from the Baltic-North Sea estuary

    Dahlgaard, H.

    Polonium-210 has been measured in Danish fish meat caught in the North Sea, the Kattegat and the Baltic in 1991-1994. Average values of 0.35, 0.65 and 0.96 Bq Po-210 kg(-1) fresh weight were observed for cod, herring and plaice fillets, respectively. The difference between species is statistically...... in fish and mussels may represent a natural baseline. Copyright (C) 1996 Elsevier Science Ltd....

  17. Use of lead-210 as a novel tracer for lead (Pb) sources in plants

    Handong Yang; Peter G. APPLEBY

    2016-01-01

    Lead (Pb) released from anthropogenic sources and stored in environmental repositories can be a potential source for secondary pollution. Here we develop a novel approach for tracking Pb from atmospheric deposition and other sources in the environment using fallout 210Pb as a tracer, and apply the method to samples collected from Richmond Park, London, the UK. The mean ratio of 210Pb to total Pb in atmospheric depositions collected from a site adjacent to the park during August–October 2012 w...

  18. Pb-210 and Pu-239,240 in nearshore Gulf of Mexico sediments

    Pb-210, Ra-226, and Pu-239,240 activities were measured in nearshore Gulf of Mexico sediments. Sediment cores were collected from the Mississippi delta, and the western Gulf of Mexico shelf. Mississippi delta cores which exhibit significantly higher sedimentation rates show larger inventories of Pb-210. The measured Pu levels from the western shelf are lower than from the delta at comparable depths. In three of the western shelf cores, the observed Pu inventory is considerably less than predicted from atmospheric flux. Therefore, Pu is not being removed to the sediment, or is being released following deposition. A key difference between these isotopes is that Pu exists in a less particle-reactive state. The ratio of excess Pb-210 to Pu levels increases with water depth in the delta and the western shelf. Water depth acts as an integrator of depth-sensitive processes. Pu scavenging is more sensitive to these processes. A sub-surface Pu maximum has been observed. Excess Pb-210 and Pu levels correlate well with sedimentation rates. This suggests that particle flux is important in removal of Pb-210 and Pu to the sediment. The flux of Mn out of the sediment is correlated with inventory data, suggesting that redox cycling of Mn may play a role in increasing Pb-210 and Pu sediment inventories. It is unclear whether the effects of increased sedimentation rates and increased Mn fluxes can be evaluated independently. Mixing of surface sediment correlates with inventory data. Increased sediment mixing allows for additional scavenging of Pb-210 and Pu from overlying waters. Mixing of sediment at depths below the mixed surface layer may play a role in increasing sediment inventories of Pb-210 and Pu

  19. Dating hapuka otoliths using 210 Pb/226 Ra, with comments on dating orange roughy otoliths

    It is shown that Hapuka otoliths cannot be reliably dated using the 210 Pb/ 226 Ra method because contrary to previous assumptions, excess 210 Pb is incorporated into the outer layers of otoliths which have been taken from old fish, though the 226 Ra incorporation remains normal. This is shown to apply also to Orange Roughy otoliths. Ages based on calculations using previously published methods will be artificially old. (author). 13 refs., 2 tabs., 3 figs

  20. A study on Polonium-210 distribution in the Koraiyar river ecosystem, Tiruchirappalli - India

    The present work reports the distribution of naturally occurring alpha emitting radionuclide 210Po in the environmental matrices of Koraiyar river. Koraiyar is a seasonal river and it is situated 5 Km West of Tiruchirappalli. Environmental samples such as water, sediment, plankton, weeds (Eichhornia crassipes), crab (Barytelphusa jacguemonti), gastropods (Pila virens and Bellamya dissimilis) and fishes (Anabas testudineus, Catla catla, Clarias batrachus, Channa punctatus, Macrognathus acculeatus, Mystus vittatus and Oreochromis mossambicus) were collected and subjected to the analyses of 210Po activity. The concentration of 210Po in water sample and sediment sample was 0.75 mBq/l and 3.1 Bq/Kg respectively. The roots and shoots of aquatic weeds and plankton sample showed concentration of 3.4, 1.2 and 22.2 Bq/Kg respectively. The concentration of 210Po in crab muscle and exoskeleton was 43.92 Bq/Kg and 11.34 Bq/Kg respectively. In soft tissue of gastropods the 210Po activity ranged from 38.16 (B. dissimilis) to 88.74 Bq/Kg (P. virens) and 2.9 to 9.45 Bq/Kg in shell. The 210Po activity in fishes ranged from 8.87 (Macrognathus acculeatus) to 45.29 (Clarias batrachus) Bq/Kg in muscle and 4.76 to 25.09 Bq/Kg in bone. Concentration factor of 210Po in edible portion of fish from river water ranged from 1.3 x 103 to 6.0 x 104. Among the samples analysed P. virens accumulated higher concentrations of 210Po and it could serve as a bioindicator organism in the absence of any bivalve mollusc. (author)

  1. Metabolism and toxicity of polonium 210 and SiO2

    Synergistic effects of quartz dust and of Po-210 have been investigated in lungs and kidneys of rats. The substances (50mg silicone per animal, 5 (or 10)μCi of Po-210 per kg bodyweight) were introduced intratracheally in a single dose. Exposure times were 7 and 12 month. Postmortem the following quantities were determined: weight of lung and kidneys, Po-210 content, hydroxyproline contents of the lungs. Autoradiographic and histopathological investigations were carried out. It was found that synergistic effects increase mortallity. The most frequent cause of death was renal lesions. Po-210 behaves as a nephrotoxic agent, causing damages to all kidney structures, it mainly attacks the epithelium of convoluted renal tubules of nephrons. The cancerogenic effects of Po-210 are enhanced in the presens of quartz. Po-210 predominantly accumulates in the kidney cortex. Po content of lungs and kidneys was still high after 7 month. Po-retention was highest in kidneys not subjected to quartz, in lungs the opposite effect was observed. Hydroxyproline contents are moderately increased in Po-contaminated lungs

  2. Growth rates in modern speleothems from Santana Cave, Brazil, by the 210Pb-method

    The Santana Cave is located at the Upper Ribeira Touristic State Park (PETAR-Parque Estadual Turístico do Alto Ribeira) in southern São Paulo State, Brazil. This paper describes 210Pb activity concentration data in soda straw stalactites samples collected at Salão das Flores in Santana Cave that is a fossil tributary of the cave river. Non-expensive alpha counting following some analytical steps for extracting and depositing 210Po were used for providing the 210Pb data. In the analyzed samples, 210Pb values of increasingly older samples fitted an exponential curve, thus suggesting that the production of 210Pb has been constant with time. Also, the near-ideal fit indicated that the growth was uniform and there was no break in the continuous growth. The soda straw growth rates were determined from the best fit to the exponential curve through the 210Pb activity concentration. The results of the measurements allowed estimate a longitudinal rate corresponding to 1.3 mm/yr and a lateral rate of 0.01 mm/yr, which permitted calculate times of 70 years and 317–498 years for their formation, respectively. The lateral growth rate is compatible with values from studies of chemical weathering rates held under laboratory and natural conditions.

  3. Detection of 210Pb in the lungs of smokers by in-vivo gamma spectrometry

    Since mainstream smoke is highly enriched in 210Pb, alpha radiation from inhaled cigarette smoke particles has been proposed as a cancer-producing agent in cigarette smokers. 210Po and 210Pb have been observed in tobacco, cigarette smoke and in the lungs of smokers. Since 210Pb is highly enriched in mainstream smoke, there have been estimates of yearly excesses of 210Pb in the lungs of one-pack-a-day smokers of 3 to 10 pCi (0.11 to 0.37 Bq). The ORNL Whole Body Counter was used to verify this estimate by the methodology of high-resolution, in vivo gamma spectrometry. Measurements were made on 113 adult male non-radiation workers who have either smoked at least one pack of cigarettes per day for at least five years, or have never smoked cigarettes. An analysis-of-variance table was generated based on the Pb-ratio for each individual which revealed that there was no statistically significant increase in the amount of 210Pb in the lungs of smokers over those of non-smokers. Sources of error are also discussed

  4. Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration.

    Lax, Pedro; Esquiva, Gema; Altavilla, Cesare; Cuenca, Nicolás

    2014-03-01

    Cannabinoids have been demonstrated to exert neuroprotective effects on different types of neuronal insults. Here we have addressed the therapeutic potential of the synthetic cannabinoid HU210 on photoreceptor degeneration, synaptic connectivity and functional activity of the retina in the transgenic P23H rat, an animal model for autosomal dominant retinitis pigmentosa (RP). In P23H rats administered with HU210 (100 μg/kg, i.p.) from P24 to P90, ERG recordings showed an amelioration of vision loss, as compared to vehicle-administered animals. Under scotopic conditions, the maximum a-wave amplitudes recorded at P60 and P90 were higher in HU210-treated animals, as compared to the values obtained in untreated animals. The scotopic b-waves were significantly higher in treated animals than in untreated rats at P30, P60 and P90. This attenuation of visual deterioration correlated with a delay in photoreceptor degeneration and the preservation of retinal cytoarchitecture. HU210-treated animals had 40% more photoreceptors than untreated animals. Presynaptic and postsynaptic elements, as well as the synaptic contacts between photoreceptors and bipolar or horizontal cells, were also preserved in HU210-treated P23H rats. These results indicate that HU210 preserves cone and rod structure and function, together with their contacts with postsynaptic neurons, in P23H rats. These data suggest that cannabinoids are potentially useful to delay retinal degeneration in RP patients. PMID:24495949

  5. A century old record of lead-210 fallout on the Greenland ice sheet

    Systematic measurements of the stable oxygen isotope ratio (δ18O) and artificial radioactivity (total β) on a 77 m ice core the DYE 3 location in S.E. Greenland provided precise age indices to study the fallout of lead-210 during the last century. The results obtained on the Dye 3 core and those of similar studies conducted on two other ice cores from the Greenland locations, Camp Century and North Central, are discussed in relation to the average fallout of 210Pb and the probable contributions made by natural and artificial sources in the atmosphere. The results indicate that: (i) the fallout of 210Pb observed over a period of 100 years has not remained constant, an assumption usually made in geochronological studies; (ii) the fallout of 210Pb over the period 1886-1930 is observed to be higher at least by a factor of two than that observed in the period 1930-1975; (iii) the higher 210Pb fallout observed over the period 1886-1930 coincides with high volcanic activity in this period; (iv) there is no evidence for significant production of 210Pb due to testing of nuclear weapons in the three decades: 1950s to 1970s. (author) 28 refs

  6. Calibration and measurement of {sup 210}Pb using two independent techniques

    Villa, M. [Centro de Investigacion, Tecnologia e Innovacion, CITIUS, Universidad de Sevilla, Av. Reina Mercedes 4B, 41012 Sevilla (Spain)], E-mail: mvilla@us.es; Hurtado, S. [Centro de Investigacion, Tecnologia e Innovacion, CITIUS, Universidad de Sevilla, Av. Reina Mercedes 4B, 41012 Sevilla (Spain); Manjon, G.; Garcia-Tenorio, R. [Departamento de Fisica Aplicada II, E.T.S. Arquitectura, Universidad de Sevilla, Av. Reina Mercedes 2, 41012 Sevilla (Spain)

    2007-10-15

    An experimental procedure has been developed for a rapid and accurate determination of the activity concentration of {sup 210}Pb in sediments by liquid scintillation counting (LSC). Additionally, an alternative technique using {gamma}-spectrometry and Monte Carlo simulation has been developed. A radiochemical procedure, based on radium and barium sulphates co-precipitation have been applied to isolate the Pb-isotopes. {sup 210}Pb activity measurements were done in a low background scintillation spectrometer Quantulus 1220. A calibration of the liquid scintillation spectrometer, including its {alpha}/{beta} discrimination system, has been made, in order to minimize background and, additionally, some improvements are suggested for the calculation of the {sup 210}Pb activity concentration, taking into account that {sup 210}Pb counting efficiency cannot be accurately determined. Therefore, the use of an effective radiochemical yield, which can be empirically evaluated, is proposed. {sup 210}Pb activity concentration in riverbed sediments from an area affected by NORM wastes has been determined using both the proposed method. Results using {gamma}-spectrometry and LSC are compared to the results obtained following indirect {alpha}-spectrometry ({sup 210}Po) method.

  7. Improved optimum condition for recovery and measurement of 210Po in environmental samples

    An improved laboratory technique for measurement of polonium-210(210Po) in environmental samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian Nuclear Agency. To further improve this technique, a study with the objectives to determine the optimum conditions for 210Po deposition and; evaluate the accuracy and precision results for the determination of 210Po in environmental samples was carried-out. Polonium-210 which is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples has been efficiently plated onto one side of the silver disc in the spontaneous plating process for measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl ammonium chloride and the plating temperature at 90 degree Celsius. The plating was carried out in 80 ml HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 209Po tracers in the CRM IAEA-385 and environmental samples were 85 % - 98% whereby the efficiency of the new technique is a distinct advantage over the existing techniques. Therefore, optimization of deposition parameters is a prime importance to achieve accuracy and precision results as well as economy and time saving. (author)

  8. Pb-210 concentrations in cigarettes tobaccos and radiation doses to the smokers

    Cigarette smoking is a source of radiation exposure due to the concentrations of natural radionuclides in the tobacco leaves. From the health point of view, measurement of 210Pb and 210Po contents in cigarette tobacco is important to assess the radiological effects associated with the tobacco smoking for the smokers. In the present study, activity concentrations of 210Pb, which is a 210Po precursor in the 238U-decay series, were measured in cigarette tobaccos. Samples of nine different commonly sold brands of cigarette tobaccos were analysed by employing a planar high purity germanium (HPGe) low background detector. Activity concentrations of 210Pb were measured from its gamma peak at 47 keV. Mean activity concentration of 210Pb was measured to be 13 ± 4 Bq kg-1 from all samples analysed. The annual committed effective dose for a smoker and the collective committed effective dose corresponding to annual cigarettes production were estimated to be 64 ± 20 μSv and 0.6 x 102 man-Sv, respectively. (authors)

  9. Polonium-210 in mussels and fish from the Baltic-North Sea estuary

    Polonium-210 has been measured in Danish fish meat caught in the North Sea, the Kattegat and the Baltic in 1991-1994. Average values of 0.35, 0.65 and 0.96 Bq 210Po kg-1 fresh weight were observed for cod, herring and plaice fillets, respectively. The difference between species is statistically significant, whereas no effect of salinity could be observed. There is a high variation giving SD values in the range 70-100%. Mytilus edulis soft parts were analysed for 210Po from 11 Danish locations ranging from full North Sea salinity to Baltic 8 per mille water. Significantly increasing 210Po concentrations with a decreasing 'condition index' were observed. Concentrations at two former phosphate industry sites were not statistically different from the other locations. The average 210Po concentration in the M.edulis soft parts was 149 Bq kg-1 dry ± 55% SD (n = 41). The present levels of 210Po in fish and mussels may represent a natural baseline. (author)

  10. Residence times of surface water and particle-reactive 210Pb and 210Po in the East China and Yellow seas

    228,226Ra, 210Pb, and 210Po were measured in the surface waters of the East China and Yellow seas. Using mass balance equations for the Ra isotopes. The authors estimated the total flux of diffusion from sediments and desorption from suspended particles to be 0.1 dpm 226Ra cm-2 a-1 and 1 dpm 228Ra cm-2 a-1, and residence times to be 2-3 years for the waters on the East China Sea Shelf and 5-6 years for Yellow Sea waters. Box-model calculations yielded generally congruent scavenging residence times for 210Pb and 210Po in the waters of ∼2 months on the shelf and ∼7 months in the Kuroshio Current. These suggest that reactive heavy metals and pollutants discharged through rivers from the continent to the East Asian continental shelf are largely deposited on the bottom sediments prior to transport to the pelagic ocean by lateral mixing

  11. Milanés 210, un patrimonio matancero

    Ramón Félix Recondo Pérez

    2010-01-01

    Full Text Available Cada año, desde el 2003, el Consejo Nacional de Patrimonio Cultural convoca al Premio Nacional de Conservación y Restauración, a entregarse cada 18 de abril, Día Internacional de los Monumentos, con el objetivo de estimular la protección y el rescate del patrimonio edificado, histórico y natural de la nación. En la versión del 2010, nuestra provincia, Matanzas, estuvo representada en la categoría de Conservación por la edificación ubicada en la calle Milanés 210, vivienda del ilustre Doctor y Pedagogo Mario Emilio Dihigo Llanos y diseñada por el eminente arquitecto Enrique Marcet Palomino, cuyo legado en obras hasta nuestros días dignifica nuestra ciudad. No sería justo detallarles el valor urbano arquitectónico y contextual de la edificación sin entrar a resaltar la significación histórica del Dr. Dihigo, pues es precisamente su vida y su obra la que le aporta valor histórico a la edificación, y es por ello que en este artículo, antes de precisar valores técnico-constructivos y de ubicación de esta edificación de estilo neocolonial, representativa de modernismo matancero, a manera de introducción, haciendo un poco de historia, los familiarizamos con la figura de este prestigioso hijo de Matanzas. Valoramos además en nuestro trabajo, la necesidad del respeto al patrimonio, como libro abierto de nuestra historia, y significamos que la preservación de este inmueble es hoy realidad gracias a la sensibilidad y el respeto de las personas que lo habitan, no sólo por la figura de Dihigo, sino además por el reconocimiento al genio y la manera de hacer y construir de una época de buenas prácticas. Lleva este artículo intrínseco el homenaje también a esa familia de arquitectos, que a criterio del autor, supieron ganarse un espacio en el buen hacer de la creación arquitectónica del pasado reciente matancero, los Marcet Beato.

  12. Radioactivity of cigarettes and the importance of (210)Po and thorium isotopes for radiation dose assessment due to smoking.

    Kubalek, Davor; Serša, Gregor; Štrok, Marko; Benedik, Ljudmila; Jeran, Zvonka

    2016-05-01

    Tobacco and tobacco smoke are very complex mixtures. In addition to various chemical and organic compounds they also contain natural radioactive elements (radionuclides). In this work, the natural radionuclide activity concentrations ((234)U, (238)U, (228)Th, (230)Th, (232)Th, (226)Ra, (210)Pb and (210)Po) of nine different cigarette samples available on the Slovenian market are reported. In addition to (210)Po, the transfer of thorium isotopes from a cigarette to a smoker's body and lungs have been determined for the first time. Cigarette smoke and exhaled air from smokers' lungs were collected from volunteer smokers (C-4 brand) to determinate what quantity of (210)Po and thorium isotopes is transferred from the tobacco to the smoker's lungs. Cigarette ash and smoked filters were also collected and analysed. Among the determined isotopes, (210)Pb and (210)Po showed the highest activity concentrations. During the smoking of one cigarette approximately 22% of (210)Po (and presumably its predecessor (210)Pb), 0.6% of (228)Th, 24% of (230)Th, and 31% of (232)Th are transferred from the cigarette and retained in the smoker's body. The estimated annual effective dose for smokers is 61 μSv/year from (210)Po; 9 μSv/year from (210)Pb; 6 μSv/year from (228)Th; 47 μSv/year from (230)Th, and 37 μSv/year from (232)Th. These results show the importance of thorium isotopes in contributing to the annual effective dose for smoking. PMID:26942842

  13. Effects of knockdown of miR-210 in combination with ionizing radiation on human hepatoma xenograft in nude mice

    Solid tumors usually develop local hypoxia, which renders them resilient to radiotherapy. MiR-210 is the most consistently and robustly induced miRNA under hypoxia and functions as a micro-controller of a wide range of cellular responses to hypoxia. Hence, it is important to investigate the effect of knockdown of miR-210 in tumorigenesis and evaluate the efficacy of knockdown of miR-210 in combination with radiotherapy on human tumor xenograft in nude mice. SMMC-7721 Cells with stable integration of the anti-sense miR-210 were generated through lentiviral-mediated gene transfer and were subcutaneously implanted into nude mice. Mice were monitored for tumor growth and survival after radiotherapy. MiR-210 expression in tumor tissues was assessed by real-time Reverse transcription-Polymerase Chain Reaction (RT-PCR). Protein expression of HIF-1α and miR-210 targeted genes in human hepatoma xenograft was assessed by Western blot. Tumors were analyzed for proliferation, apoptosis, and angiogenesis biomarkers by immunohistochemistry staining. Tumor growth was delayed in miR-210 downregulated xenograft. Knockdown of miR-210 increased protein expression of miR-210 targeted genes, but decreased HIF-1α protein in hepatoma xenograft. Knockdown of miR-210 in combination with radiotherapy is more effective than radiotherapy alone or miR-210 knockdown therapy alone in suppressing tumor growth and extending survival duration. Combined therapy decreased Ki-67-positive cells and CD31-positive cells and increased TUNEL-positive cells in tumor xenograft. Knockdown of miR-210 in combination with radiotherapy showed an enhanced anti-tumor effect on human hepatoma xenograft. Our experiments demonstrated specific inhibition of miR-210 expression might be a means to enhance the effectiveness of radiotherapy to human hepatoma

  14. Determination of the latest sediment accumulation rates and pattern by performing 210Pb models and 137Cs technique in the Lake Bafa, Mugla, Turkey

    The sediment chronology was determined using Lead-210 (210Pb) and Cesium-137 (137Cs) dating method. Profile distributions of Polonium-210 (210Po) and 210Pb were evaluated with regarding to sediment porosity, core location, bottom currents and prevalent winds. Max. 210Po and 210Pb activity concentrations are found as 193.83 ± 4.43 and 187.84 ± 4.84 Bq kg-1 respectively. According to vertical radionuclide (210Po/210Pb) ratios, sediments especially in east part of the lake are rich with respect to the fecal pellets. Residence time of the 210Pb is calculated as 1.9 months in the lake. Average sedimentation rate (0.359 ± 0.012 cm year-1) in central area is higher than the near shore (0.137 ± 0.006 cm year-1) one in Lake Bafa. (author)

  15. Polonium-210 in dried fin fishes of Tuticorin, Southeast coast of India

    Tuticorin is one of the major sea-ports and fish-landing centres in the southeastern coast of India. Most of the fishes landed in this coast are consumed fresh and 40% of the fishes are used in the dried form. 210Po (t1/2 = 138.4 days) in marine food has received much interest from the scientific community because of its high toxicity and the radioactive dose it delivers to marine organisms and human beings when compared to anthropogenic radionuclides released into coastal waters. Although many studies have been conducted in fresh fishes from various coasts concerning 210Po, sufficient data are not available for value-added dried marine fish products. In the present study, 210Po and 210Pb were quantified in some commercially important dried fishes and their exposure to humans studied. Polonium-210 was determined after wet digestion and counted using an alpha probe. Overall, the concentration of 210Po in the dried fish muscle tissue ranged from 1.45 ± 0.82 to 559.23 ± 5.45 Bq kg-1. The highest concentration in the muscle tissue was recorded for the species Stolephorus brevisensis (559.23 ± 8.9 Bq kg-1) belonging to the group Clupeidae and the lowest in Harpodon sp. (Bombay duck). The 210Po dose receive by the public due to consumption of the dried fishes was found to be in the range of 25.2-350.3 μSV yr-1 and the fish samples were found to be radiologically safe. (author)

  16. 210Po accumulations in marine organisms from the Spanish East Coast

    One of the most radiotoxic natural radionuclides is 210Po. Its presence in the environment is mainly due to the 222Rn decay. The 222Rn is diffused, as a descendent of the natural Uranium chain, from the ground to the atmosphere and its daughters are deposited on the surface of the earth. Recent publications in the literature show anchovies (Engraulis encrasilocus) as the marine species with highest levels of 210Po. The aim of this work is the study of the 210Po concentrations in anchovies and other fish species from an area where radon contents is very high due to the influence of a coastal lagoon (measured radon contents in coastal lagoon water, by scintillation counter, shows 790 ±90 Bq m-3) that flows in the sea. The samples are being collected from different local markets and ports from March 2012. The fish samples were weighed and oven dry to a constant weigh at 70℃ and then thoroughly mixed. 208Po tracer was added to the samples which were digested using nitric and hydrochloric acid, after that samples were dissolved with hydrochloric acid and spontaneously plated onto a silver disc. 210Po is measured by á-particle spectrometry with a Si detector. The ratio between 210Po and 208Po peaks is used to determine the activity concentration of 210Po in the sample. First results of 210Po concentration in anchovies in the interesting area vary between 202 ± 22 Bq Kg-1 and 400 ± 49 Bq Kg-1 (d.w). (author)

  17. Accurate measurements of {sup 210}Pb in industrial wastes for environmental radiation risk assessment purpose

    Bonczyk, Michal; Michalik, Boguslaw [Central Mining Institute, Silesian Centre for Environmental Radioactivity, Plac Gwarkow 1, 40-166 Katowice (Poland)

    2014-07-01

    Lead {sup 210}Pb is a naturally occurring radioactive nuclide element of the uranium ({sup 238}U) radioactive series. It is produced as a result of the decay of so-called short-lived progenies of {sup 222}Rn, i.e. {sup 214}Po (99.98%) and {sup 214}Bi by {sup 219}Tl (0.02%). Activity concentration of lead {sup 210}Pb could vary independently from parent radionuclides due to its physical and chemical properties, especially, due to its half-life (T{sub 1/2} = 22,3 years). Hence, its behaviour in natural environment is very complex and difficult in forecasting. Lead {sup 210}Pb in substantial amount occurs in mining, gas and oil extraction industry wastes, which are deposited in natural environment very often. Due to lack of secular equilibrium proper radiation risk assessment requires accurate concentration of {sup 210}Pb in such materials. The laboratory measurements seem to be the only reliable method in environmental radioactivity monitoring. One of the methods is gamma-ray spectrometry, which is very fast and cost-effective method to determine {sup 210}Pb concentration. On the other hand, the self-attenuation of gamma ray from {sup 210}Pb (46,5 keV) is significant and not depends only on sample density as well the chemical composition (sample matrix) is crucial. Current work describes how the self-attenuation correction factors in the case of {sup 210}Pb concentration analysis in mining wastes are important when environmental radiation risk assessment is carried out. The measurements were done for such industrial wastes as mine sediments which contain significant amount of elements with high Z-number (Barium, Lead, etc.) Experimentally obtained correction factors range between 0.51-6.96 cm{sup 2}/g. Neglecting this factor can cause a significant error or underestimations in radiological risk assessment. (authors)

  18. Polonium-210 in marine mussels (bivalve molluscs) inhabiting the southern coast of India

    The present study focused on the determination of the alpha-emitter, 210Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of 210Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010–2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in 210Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p < 0.05). The dose rate assessment for mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to 210Po was found to be lesser than the global benchmark dose rate of 10 μGy h−1. The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1–34.9 μSv y−1. The measurement contributes to the furthering of knowledge of 210Po, since no data exist in this region. - Highlights: • Polonium-210 was quantified in two species of Mytilid mussels inhabiting southern coast of India. • Polonium-210 activity showed significant variation among size classes, between seasons and sampling site. • The internal dose rate to mussels and the dose assessment to the adult population were performed

  19. Distributions of 137Cs and 210Pb in moss collected from Belarus and Slovakia

    In the present work, moss samples collected in Slovakia and Belarus were assayed with respect to gamma-emitting radionuclides. The results for 137Cs and 210Pb are discussed. Moss was used for the first time in Belarus, as a biological indicator of radioactive environmental pollution in consequence of the Chernobyl accident in 1986. In Belarus, the maximum activity of 137Cs was observed in the Gomel region near Mazyr (6830 Bq/kg) and the minimum activity in the Vitebsyevsk Region near Luzhki-Yazno (5 Bq/kg). “Hot spots” were also observed near the towns Borisow and Yuratsishki. The results of measurements of 137Cs in moss samples collected in 2000, 2006 and 2009 in the same localities of Slovakia are presented and compared with the results of air monitoring of 137Cs carried out in Slovakia from 1977 until 2010. Measurements of the 210Pb concentration in moss samples collected over the territory of Slovakia showed, that the median value exceed 2.3 times median value of 210Pb obtained for Belarus moss. For that reason, the inhalation dose for man from 210Pb and 137Cs in Slovakia is more than twice as high as in Belarus, in spite of the initially very high 137Cs exposure in the latter country. -- Highlights: ► Belarus moss was used as a biological indicator of 137Cs and 210Pb. ► Comparison with concentration of 137Cs and 210Pb in moss from Slovakia. ► Moss samples reflect the original distribution of Chernobyl fallout in Belarus. ► Regular decrease of the annual average activity of 137Cs in surface air in Slovakia. ► Median concentration of 210Pb in moss from Belarus is 2.3 times lower than in Slovakia

  20. Po 210 in the Turkish coast of the Aegean sea ecosystem

    Full text: Po 210 is a natural radionuclide which constitutes the major source of natural radiation received by humans through the consumption of food and contributes more to the total radiation dose than environmental levels of anthropogenic radionuclides, such as Cs 137 and Pu 239, 240. For Turkish Coast of Aegean Sea Ecosystem, although there some investigations presently available on some natural radionuclides and gross radioactivity concentrations, data on Po 210 in the sea water, bottom sediment and marine biota are very scarce. The aim of the present study is to improve our knowledge about the levels of radioactive polonium along Aegean Turkish Coastal zone and also assess its enhancement from the fosil fuel industry like coal-fired power plants (CPPs), oil industry and from phosphate industry, all located along the coast and also from the discharge of a number streams and rivers in the region. This paper introduces an extensive set of data and related results on Po 210 in surface sea water, bottom sediments, fishes and mussels (Mytilus galloprovincialis) obtained from 6 stations (Canakkale, Dikili, Foca, Ceshme, Didim and Bodrum) along the coast in the period of 2004-2005. In the bottom sediments, Po 210 concentration varies between 21±1 and 214±24 Bq kg-1 dry wt with an average value of 70±7 Bq kg-1. The concentrations in surface water of the sea during the sampling period are around 0.016±0.001 Bq l-1. Amongst the fishes, small pelagic plankton feding fish like anchovy (Engraulis encrasicolus) and sardine (Sardine plichardus) tend to accumulate more Po 210. The concentration of Po 210 in mussels (Mytilus galloprovincialis) varies between 55±5 and 2288±124 Bq kg-1 which is in general higher than those given in literature for other countries. The highest Po 210 concentration belongs to Didim mussels for winter time with a shell length of 4-6 cm

  1. The polonium 210 in aerosols: contribution to the study of savannah fires and volcano emissions

    Natural sources plan a fundamental role on the emission of the species causing climatic variations. The aim of this study is, on the one hand, to estimate fluxes of different components emitted by biomass burning and volcanoes, and on the other hand, to trace these components in time and space. We used 210Po, last decay product in the 238U series, as a tracer, as it is one of the characteristic species emitted by these sources: it is highly enriched in these plumes compared to the usual atmosphere and the 210Po radioactivity is not affected by chemical transformation. We have shown that the contribution of biomass burning on the 210Po concentration in local background atmosphere is minor during the dry season, compared to that of Saharan soil dusts despite of the importance of this source in the global budget of 210Po (10%). However, the good correlation observed between the 210Po concentration and that of carbonaceous aerosols and of CO2 in biomass burning plumes reveals that 210Po can be used as a reference of the components emitted by biomass burning. We have estimated the contribution of the Indonesian volcanoes which represent about 5 to 30 % of the global volcanic budget of trace metals. Atmospheric transport of these volcanic plumes was simulated using the 210Po as a tracer. Due to the characteristic atmospheric circulation in this region, vertical transport is predominant over meridian dispersion, which is moderated by the convergence of the trade winds. The impact of these volcanic emissions on the atmospheric concentration of the trace metals remains a local effect when the volcanic activity is out of cataclysmal eruptions. (author)

  2. Study of the particulate matter transfer and dumping using 210 Po et le 210 Pb. Application to the Gulf of Biscary (NE Atlantic Ocean) and the Gulf of Lion (NW Mediterranean Sea) continental margins

    210 Po and 210 Pb activities and fluxes were measured on seawater, sediment-trapped material collected during one year and sediment. Focalization of 210 Pb is clearly noticed on the Cap-Ferret canyon (Gulf of Biscary) and the Lacaze-Duthiers canyon (western part of the Gulf of Lion). In both sites, 210 Pb fluxes in traps and sediment are always higher than 210 Pb flux available from atmospheric and in situ production. On the contrary, Grand-Rhone canyon and its adjacent open slope exhibit a 210 Pb budget near equilibrium in the near-bottom sediment traps, but focalization is important in the sediment. For the entire Gulf of Lion margin, focalization of 210 Pb in the sediment occurred principally between 500 and 1500 m water depth on the slope, and on the middle shelf mud-patch. 210 Po and 210 Pb have been used in the Cap Ferret and Grand-Rhone canyons to characterize the origin of the particulate trapped material. Two main sources feed the water column. The first source, localized in surface waters, is constituted by biogenic particles from primary production and lithogenic material. The second source, deeper, is due to resuspension at the shelf break and/or on the open slope. In each site, 210 Po and 210 Pb activities of the trapped particles did not show any relations with the major constituents. Quantity of particles appeared to be the main factor regulating adsorption processes of these nuclides. Sedimentation rates based on 210 Po profiles decreased with increasing water depth, from 0.4 ti 0.06 cm y-1 on the Cap Ferret canyon (400 to 3000 m water depth) and from 0.5 to 0.05 cm y-1 for the entire Gulf of Lion margin (50 to 2000 m water depth). (author)

  3. Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

    Radon gas (222Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to (222Rn and its progeny in epidemiological studies. Measurements of implanted 210Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210Po in spongy, porous materials (210Po volume traps). Other approach is in-vivo measurements of 210Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210Po concentration in glasses exposed to 222Rn using alpha spectrometry

  4. Determination of 210Pb, 210Po, 226Ra, 228Ra and uranium isotopes in drinking water in order to comply with the requirements of the EU ‘Drinking Water Directive.

    Vasile, M; Loots, H; Jacobs, K; Verheyen, L; Sneyers, L; Verrezen, F; Bruggeman, M

    2016-03-01

    The European Union published in 2013 a new Drinking Water Directive with stricter requirements for measuring natural radioactivity. In order to adhere to this, a method for sequential separation of 210Pb, 210Po, 238U and 234U in drinking water was applied using UTEVA® and Sr resins. Polonium-210, 238U and 234U were quantified using alpha-particle spectrometry and 210Pb using liquid scintillation counting. Radium-226 and 228Ra were determined using 3M Empore Radium RAD Disks, and their quantification was done using a Quantulus™ 1220 liquid scintillation counter. PMID:27358946

  5. Ingestion dose from 210Po due to the consumption of packaged drinking water

    Humans are chronically exposed to naturally occurring radionuclides from uranium and thorium series via inhalation and ingestion. With increased interest in radiological assessment a study was taken up for assessing natural radioactivity in drinking water. Drinking water is an important route of intake of naturally occurring 210Po. 210Po being a very important radionuclide from Uranium series with high specific activity causes significant internal dose. In our study 210Po in PDW was concentrated with calcium phosphate and spontaneously deposited onto silver planchette and subsequently measured by alpha spectrometry. The concentration of 210Po in the bottled water ranged from 0.11 mBq.l-1 to 2.9 mBq.l-1. The highest concentration was observed in that sample that was reportedly sourced from mountain regions. Based on the concentration of 210Po in each water sample, the annual intake rate (1.68L/d), and the Dose Coefficient (1.2 X 10-6 Vs./Bq) recommended by the International Commission on Radiological Protection (ICRP, 1996), the annual committed effective doses to the adult population was estimated. The annual effective doses ranged between 0.10-2.16 μSv/yr. (author)

  6. Galvanic deposition of 210Po at a rotating nickel disk electrode

    With increasing environmental concerns over the mining and milling of uranium for nuclear power production, the radiochemical determination of 210Po and 210Pb in environmental samples is assuming greater importance. The procedures for both 210Po and 210Pb determinations usually employ the galvanic deposition of 210Pb into the deposition solution. After an appropriate sample preparation, currently accepted plating procedures call for the deposition solution to be 0.5 N in HCl with 2 ml of 40% citric acid and 1 g of hydroxylamine hydrochloride added. This prevents ions such as Fe2+ from interfering in the deposition. The nickel electrode is either suspended in the deposition solution on a glass hook or secured in the bottom of a deposition cell with a removable screw cap. Plating is then carried out for one, two, or more hours at between 50 and 800C. In this study no attempt has been made to change the chemical composition of the deposition solution, only the plating hydrodynamics were modified. This paper presents a new plating technique using a rotating nickel disk electrode which achieves uniformly thin plates at ambient deposition temperatures in one hour or less, depending on the sample activity

  7. Lead precipitation fluxes at tropical oceanic sites determined from 210Pb measurements

    Concentrations of lead, 210Pb, and 210Po were measured in rain selected for least influence by local sources of contamination at several tropical and subtropical islands (Enewetak; Pigeon Key, Florida; and American Samoa) and shipboard stations (near Bermuda and Tahiti). Ratios expressed as ng Pb/dpm 210Pb in rain were 250--900 for Pigeon Key (assuming 12% adsorption for 210Pb and no adsorption for lead), depending on whether the air masses containing the analyzed rain came from the Caribbean or from the continent, respectively; about 390 for the northern Sargasso Sea downwind from emissions of industrial lead in North America; 65 for Enewetak, remote from continental emissions of industrial lead in the northern hemisphere; and 14 near Tahiti, a remote location in the southern hemisphere where industrial lead emissions to the atmosphere are much less than in the northern hemisphere. (The American Samoa sample yielded a higher ratio than Tahiti; the reason for this is not clear but may be due to local Pb sources). The corresponding fluxes of lead to the oceans, based on measured or modeled 210Pb precipitation fluxes, are about 4 ng Pb/cm2y for Tahiti, 10 for Enewetak, and 270 for the Sargasso Sea site, and between 110 to 390 at Pigeon Key

  8. Determination of 210Pb at ultra-trace levels in water by ICP-MS

    210Pb (t 1/2 = 22.26 years) is one of the most difficult naturally occurring radionuclides to analyze directly via radiometric measurement due to its low-energy radioactive decay. In this work, inductively coupled plasma mass spectrometry (ICP-MS) was investigated as a possible alternative to radiometric counting for the determination of 210Pb. The formation of isobaric and polyatomic (molecular) interferences was studied and various strategies (i.e. co-precipitation, extraction chromatography, and derivatization) were tested to assess their usefulness in reducing these interferences. In addition, the potential of these strategies as pre-concentration methods was demonstrated. A 210Pb pre-concentration of >300-fold and recoveries of 63-73% were obtained using a combined co-precipitation and extraction chromatography protocol followed by derivatization using an ethylating reagent. The abundance sensitivity at m/z = 210 in the presence of stable Pb was also investigated for three types of mass spectrometers (sector-field (ICP-SFMS), quadrupole-based (ICP-QMS), and quadrupole-based with a dynamic reaction cell (ICP-QMS (DRC))). Finally, the method was applied to determine 210Pb in water samples and a detection limit of 90 mBq L-1 (10 pg L-1) was obtained

  9. 210Po in marine organisms: a wide range of natural radiation dose domains

    Marine biota is able to concentrate 210Po to high levels, as 103-105 relative to sea water concentration. 210Po concentrations in mixed zooplankton reaches 34-51 Bq.kg-1 (fresh wt), special groups such as copepods reaching even higher concentrations ∼ 90 Bq.kg-1, whereas gelatinous zooplankton display ∼ 1 Bq.kg-1. Epipelagic teleosts feeding on plankton displayed the highest concentrations found in fish muscle, 2-21 Bq.kg-1. Contrasting with this, demersal teleosts and elasmobranchs display lower 210Po concentrations, in the ranges 0.5-7 Bq.kg-1 and 0.2-1.7 Bq.kg-1, respectively. Much higher concentrations can, however, be measured in fish liver, gonad, bone and piloric caecca, and small mesopelagic fish can reach ∼ 800 Bq.kg-1 on a whole-body basis. Due to these 210Po activity concentrations, dose equivalent rates delivered to biological tissues in marine organisms can vary widely, from 0.4 mSv.y-1 in gelatinous plankton up to 5.6 x 103 mSv.y-1 in the gut wall of sardines. It is concluded that in organisms living in the same ocean layer a wide range of internal radiation doses exists and it is essentially sustained by 210Po food-chain transfer. (author)

  10. Polonium-210 in marine mussels (bivalve molluscs) inhabiting the southern coast of India.

    Khan, M Feroz; Wesley, S Godwin; Rajan, M P

    2014-12-01

    The present study focused on the determination of the alpha-emitter, (210)Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of (210)Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010-2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in (210)Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to (210)Po was found to be lesser than the global benchmark dose rate of 10 μGy h(-1). The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1-34.9 μSv y(-1). The measurement contributes to the furthering of knowledge of (210)Po, since no data exist in this region. PMID:25042075

  11. Atmospheric deposition patterns of (210)Pb and (7)Be in Cienfuegos, Cuba.

    Alonso-Hernández, Carlos M; Morera-Gómez, Yasser; Cartas-Águila, Héctor; Guillén-Arruebarrena, Aniel

    2014-12-01

    The radiometric composition of bulk deposition samples, collected monthly for one year, February 2010 until January 2011, at a site located in Cienfuegos (22° 03' N, 80° 29' W) (Cuba), are analysed in this paper. Measurement of (7)Be and (210)Pb activity concentrations were carried out in 12 bulk deposition samples. The atmospheric deposition fluxes of (7)Be and (210)Pb are in the range of 13.2-132 and 1.24-8.29 Bq m(-2), and their mean values are: 56.6 and 3.97 Bq m(-2), respectively. The time variations of the different radionuclide have been discussed in relation with meteorological factors and the mean values have been compared to those published in recent literature from other sites located at different latitudes. The annual average flux of (210)Pb and (7)Be were 47 and 700 Bq m(-2) y(-1), respectively. Observed seasonal variations of deposition data are explained in terms of different environmental features. The atmospheric deposition fluxes of (7)Be and (210)Pb were moderately well correlated with precipitation and well correlated with one another. The (210)Pb/(7)Be ratios in the monthly depositions samples varied in the range of 0.05-0.10 and showed a strong correlation with the number of rainy days. PMID:25233214

  12. Increase of {sup 210}Po levels in human semen fluid after mussel ingestion

    Kelecom, Alphonse, E-mail: lararapls@hotmail.co [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil); Programs in Environmental Science and Marine Biology, Universidade Federal Fluminense, Niteroi, RJ (Brazil); Gouvea, Rita de Cassia dos Santos [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil)

    2011-05-15

    Polonium-210 ({sup 210}Po) radioactive concentrations were determined in human semen fluid of vasectomized non-smoker volunteers. The {sup 210}Po levels ranged from 0.10 to 0.39 mBq g{sup -1} (mean: 0.23 {+-} 0.08 mBq g{sup -1}). This value decreased to 0.10 {+-} 0.02 mBq g{sup -1} (range from 0.07 to 0.13 mBq g{sup -1}) after two weeks of a controlled diet, excluding fish and seafood. Then, volunteers ate during a single meal 200 g of the cooked mussel Perna perna L., and {sup 210}Po levels were determined again, during ten days, in semen fluid samples collected every morning. Volunteers continued with the controlled diet and maintained sexual abstinence through the period of the experiment. A 300% increase of {sup 210}Po level was observed the day following mussel consumption, with a later reduction, such that the level returned to near baseline by day 4.

  13. Study of the particulate matter transfer and dumping using {sup 210} Po et le {sup 210} Pb. Application to the Gulf of Biscary (NE Atlantic Ocean) and the Gulf of Lion (NW Mediterranean Sea) continental margins; Etude du transfert et du depot du materiel particulaire par le {sup 210} Po et le {sup 210} Pb. Application aux marges continentales du Golfe de Gascogne (NE Atlantique) et du Golfe du Lion (NW Mediterranee)

    Radakovitch, O.

    1995-07-07

    {sup 210} Po and {sup 210} Pb activities and fluxes were measured on seawater, sediment-trapped material collected during one year and sediment. Focalization of {sup 210} Pb is clearly noticed on the Cap-Ferret canyon (Gulf of Biscary) and the Lacaze-Duthiers canyon (western part of the Gulf of Lion). In both sites, {sup 210} Pb fluxes in traps and sediment are always higher than {sup 210} Pb flux available from atmospheric and in situ production. On the contrary, Grand-Rhone canyon and its adjacent open slope exhibit a {sup 210} Pb budget near equilibrium in the near-bottom sediment traps, but focalization is important in the sediment. For the entire Gulf of Lion margin, focalization of {sup 210} Pb in the sediment occurred principally between 500 and 1500 m water depth on the slope, and on the middle shelf mud-patch. {sup 210} Po and {sup 210} Pb have been used in the Cap Ferret and Grand-Rhone canyons to characterize the origin of the particulate trapped material. Two main sources feed the water column. The first source, localized in surface waters, is constituted by biogenic particles from primary production and lithogenic material. The second source, deeper, is due to resuspension at the shelf break and/or on the open slope. In each site, {sup 210} Po and {sup 210} Pb activities of the trapped particles did not show any relations with the major constituents. Quantity of particles appeared to be the main factor regulating adsorption processes of these nuclides. Sedimentation rates based on {sup 210} Po profiles decreased with increasing water depth, from 0.4 ti 0.06 cm y-1 on the Cap Ferret canyon (400 to 3000 m water depth) and from 0.5 to 0.05 cm y-1 for the entire Gulf of Lion margin (50 to 2000 m water depth). (author). 243 refs.

  14. Determination of 210Pb activity concentration in ground-level air by gamma-ray spectrometry in Tripoli, Libya

    210Pb activity concentration at ground-level air of Tripoli was determined by gamma-ray spectrometric analysis of 20 particulate samples collected. Each sample, the air filtered through chlorinated vinyl polychloride Petrianow was 78,000 m3 on average. Activity concentrations of 210Pb were ranging from 78-186 μBq x m-3. Estimated effective dose to adult from inhaled 210Pb was calculated to be 2.7 μSv x y-1. (author)

  15. HU210-induced downregulation in cannabinoid CB1 receptor binding strongly correlates with body weight loss in the adult rat.

    Dalton, Victoria S; Wang, Hongqin; Zavitsanou, Katerina

    2009-07-01

    In vitro autoradiography was used to examine changes in cannabinoid CB1 receptors (targeted with [(3)H] CP55,940) in rats treated with the potent cannabinoid agonist HU210. Animals were administered with HU210 (25, 50, 100 microg/kg) for 4 or 14 days or received a single 100 microg/kg injection of HU210 and sacrificed 24 h later. The acute dose resulted in a decrease in binding in the caudate putamen and hippocampus. A dose dependent, region-specific reduction (P HU210. PMID:19169813

  16. Retention and tissue distribution of 210Pb (NO3)2 administered orally to infant and adult monkeys

    The retention and tissue distribution of 210Pb were studied in 10-day-old, 150-day-old, and adult monkeys. Lead-210 nitrate was administered to the monkeys by gavage after a 12 hr fast and 210Pb excreted in urine and feces was monitored for 96 hr. All monkeys were necropsied 96 hr after dosing and the 210Pb concentrations of various tissues were deermined. The data demonstrated that infant monkeys retained 64.5 and 69.8% of the orally administered 210Pb at 10 and 150 days of age, respectively, while adult monkeys retained 3.2% of the 210Pb dose. Blood 210Pb levels 96 hr after dosing did not vary significantly between age groups. Of the 210Pb contained in blood, 98 to 99% was found in blood cells and 1 to 2% in blood plamsa; 5 to 8% of the Pb in blood cells was bound to blood cell membranes. None of these parameters varied significantly with age. The percentage of the lead dose excreted in urine did not vary significantly between age groups. Analysis of tissues for 210Pb revealed that both the tissue Pb concentrations and tissue Pb : blood Pb ratios were significantly higher in the bone structure of infants than adults. Brain Pb : blood Pb ratios were significantly greater in 10-day-old infants than 150-day-old infants or adults

  17. The average concentrations of 226Ra and 210Pb in foodstuff cultivated in the Pocos de Caldas plateau

    The average concentrations of 226Ra and 210Pb in vegetables cultivated in the Pocos de Caldas plateau, mainly potatoes, carrots, beans and corn and the estimation of the average transfer factors soil-foodstuff for both radionuclides, were performed. The total 226Ra and 210Pb content in the soil was determined by gamma spectrometry. The exchangeable fraction was obtained by the classical radon emanation procedure and the 210Pb was isolated by a radiochemical procedure and determined by radiometry of its daughter 210Bi beta emissions with a Geiger Muller Counter. (M.A.C.)

  18. 238U, 226Ra and 210Pb in some vent waters of the Galapagos spreading center

    The concentrations of 226Ra, 238U and 210Pb have been measured in waters from the Mussel Bed and the Rose Garden thermal fields at the Galapagos spreading center over a temperature range of approx.2.5--16 0C. The 226Ra-T plots yield slopes of 0.112 and 0.036 dpm/kg 0C for the Mussel Bed and the Rose Garden respectively yielding a global hydrothermal 226Ra flux less than 5% of that required to sustain the oceanic inventory. 238U concentration in waters 0C is the same as that in ambient sea water whereas water hotter than approx.9 0C shows a decreasing trend with temperature to zero 238U at approx.29 0C. 210Pb concentration in Mussel Bed increases with temperature, and extrapolated to approx.350 0C yields a 210Pb concentration considerably less than that expected from 222Rn decay and basalt alteration

  19. Spectroscopy and measurement of electromagnetic moments in sup(198,200,210)Po

    The quadrupole coupling constants for the 210Po Isup(π)=8+, 11-, 13- isomers in Bi have been measured, and Q(11-)=82(2) fm2 and Q(13-)=90(2) fm2 normalized to Q(210Po8+)=57 fm2 are deduced. In beam γ-spectroscopy of sup(198,) 200Po showed the (πh2sub(9/2) 8+) π(hsub(9/2)isub(13/2) 11-) and (visub(13/2) 12+) isomers. The B(E2 8+->6+) and Q(8+) in 198Po to 210Po are discussed, a sudden drop is found for the B(E2) in 198Po. The B(E3, 11-->8+) rises very steeply in the light Po isotopes. (orig.)

  20. Pb-210 behaviour in environmental samples from the Cuban east in 1993

    A method based in alpha and beta gross counting, is applied to research behaviour, during 1993, of Pb-210 in atmospheric depositional samples of six sites of the Cuban east. In five of these points, located distant from Cuban centers, the average Pb-210 aport to measured beta activity is predominant (80 +- 20 %) and maximum (> 50 % annual) is observed in coincidence with the first rain full peak. Such regularity may be explained, if assumption is made that principal source of Pb-210 are the continental air masses penetrating the insular atmosphere in winter and that mentioned radionuclide is deposit later with the spring rainfalls. In the sixth point, located at industrial zone, the alpha-beta activities rates are abnormally high, with maximums of 1.5 and 2.4 faced with peak raining and wet months respectively and probably originated by the input atmosphere of rich s in alpha emisors particles from industrial processes