polonium

☢ Polonium is a very rare, radioactive metal. There are 33 different isotopes of the element and all of the isotopes are radioactive. It exists in a variety of states, and has two metallic allotropes. It dissolves easily into dilute acids. It does not exist in nature in compounds, however it can be manipulated to form ones synthetically in the lab. It is used as an alloy with beryllium to act as a neutron source for nuclear weapons.
When combined with a low-atomic weight element (most commonly beryllium), Po-210 can be utilized as a neutron source. Alpha particles emitted from Po-210 are absorbed by the second element, emitting a neutron in the process. The polonium-beryllium pair was used in early nuclear weapons as a neutron initiator. The two elements were kept separated by materials such as nickel and gold until a chemical explosion caused a mixing of the two.
Nevada wells test positive for polonium
On Aug. 3, 2007, the U.S. Geological Survey (USGS) reported to well owners that 25 wells in Lahontan Valley in Churchill County, Nev., contained the carcinogenic, radioactive isotope polonium-210. Of these wells, 13 exceeded the U.S. Environmental Protection Agency’s (EPA) Maximum Contaminant Level for “gross alpha radioactivity” in a public water supply. The average polonium-210 concentrations in the wells exceeded typical groundwater concentrations
The concentration of Pb-210 has been measured at several altitudes in the atmosphere over the United Kingdom during 1968. The gradient into the lower stratosphere was less steep than observed by BURTON & STEWART (1960) and conformed to the diffusion models of JACOB & I ANDRE (1963) for the case of short washout times, and MACHTA The concentrations of Pb-210 and Po-210 in surface air and Pb-210 in rainwater have been measured continuously since 1961. The ratio of Po-210/Pb-210 exhibits a seasonal variation during 1962 and 1963: this might be attributed to artificial production of Pb-210 during the weapon tests of 1961-2. An estimate haa been obtained of the global deposition of Pb-210.
Polonium er et radioaktivt giftigt grundstof med atomnummer 84 i det periodiske system. Det har flere isotoper end noget andet element og de er alle radioaktive. Polonium ligner kemisk bismuth og tellur, og det findes i uran malm. Miniralet er ifølge NCRP Report No. 65, Management of Persons Accidentally Contaminated with Radionuclides (1980), anvendt i forbindelse med udvikling af kernevåben som en såkaldt moduleret neutron igangsætter først i Manhattanprojektets Dayton projekt og siden i Mound laboratoriets forskning frem til juni 1972.
Miljøforurening
/ Contamination, environmental pollution
Barium ; beryllium ; cerium ; cæsium ; jod ; krypton ; lanthanum ; molybdæn ; neptunium ; niobium ; plutonium ; radioaktivitet ; radium ; ruthenium ; strontium-90 ; tellur ; tritium ; uran ; xenon ; zirkonium.
Se også: Atomfysik ; Marie Curie ; kemi.

Litteratur og kilder

- http://www.ncrppublications.org/Reports/065
- http://moundmuseum.com/index.php?option=com_content&view=frontpage&Itemid=1
210-Polonium studies in some environmental and biological matrices of Domiasiat uranium deposit area, West Khasi Hills, Meghalaya, India. / Marbaniang DG, Poddar RK, Nongkynrih P, Khathing DT. Environ Monit Assess. 2010 Mar;162(1-4):347-53. Epub 2009 Feb 26.
- http://www.ncbi.nlm.nih.gov/pubmed/19242810
Artificial radioactive isotopes of polonium, bismuth, and lead : chapter IV : a new reaction with high energy deuterons . - Oak Ridge, Tenn. : Technical Information Division, Atomic Energy Commission, 1947. - 12 pp.
- http://www.archive.org/details/artificialradioa00univ
Polonium Uses: Submitted as coursework for Physics 241, Stanford University, Winter 2011 / Chris Yu. March 10, 2011.
- http://large.stanford.edu/courses/2011/ph241/yu1/
- http://www.geotimes.org/nov07/article.html?id=nn_polonium.html
Seiler, R.L., 2007, Methods and Data Used to Investigate Polonium-210 as a Source of Excess Gross-Alpha Radioactivity in Ground Water, Churchill County, Nevada: U.S. Geological Survey Open-File Report 2007–1231, 11 pp.
- http://nevada.usgs.gov/polonium/ofr20071231.pdf
Lead-2 1 0 and polonium-2 10 in the atmosphere. / D. H. Peirson, R. S. Cambray and G. S. Spicer, Atomic Energy Research Establishment, Hamell, Berkahire, U.K. Tellus XVIII (1966), 2 - http://www.tellusa.net/index.php/tellusa
Marie Curie: recipient of the 1911 Nobel Prize in Chemistry and discoverer of the chemical elements polonium and radium. / Friedrich C, Remane H. Angew Chem Int Ed Engl. 2011 May 16;50(21):4752-8. doi: 10.1002/anie.201008063. Epub 2011 Mar 29.
- http://www.ncbi.nlm.nih.gov/pubmed/21472933
Note by the secretary, Subject: part III – Weapons Progress Report to the Joint Committee, June – November 1953 . - 13 s.

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