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A Living Radon Reference Manual

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A Living Radon Reference Manual A LIVING RADON REFERENCE MANUAL Robert K. Lewis Pennsylvania Department of Environmental Protection Bureau of Radiation Protection, Radon Division and Paul N. Houle, PhD University Educational Services, Inc. Abstract This “living” manual is a compilation of facts, figures, tables and other information pertinent and useful to the radon practitioner, some of which can be otherwise difficult to find. It is envisioned as a useful addition to one’s desk and radon library. This reference manual is also intended to be a “living” document, where its users may supply additional information to the editors for incorporation in revisions as well as updates to this document on-line. Topics contained within the current version include radon chemistry and physics, radon units, radon fans, epidemiology, ambient radon, diagnostics, dosimetry, history, lung cancer, radon in workplace and radon statistics. In some cases motivations and explanations to the information are given. References are included. Introduction This reference manual is a compilation of facts, figures, tables and information on various aspects of radon science. It is hoped that this manual may prove useful to federal and state employees, groups such as AARST and CRCPD, and industry. There are numerous other reference manuals that have been produced on the various aspects of radon science; however, we hope that this manual will have a more “applied” use to all of the various radon practitioners who may use it. Many of the snippets on the various pages are highlights from referenced sources. The snippet will obviously only provide one with the briefest of information. To learn more about that item go to the reference and read the whole paper. It is our intent to continually update this manual with the help of all those mentioned above. Especially helpful would be remarks, comments and additions to the manual from anyone inclined to help. Please forward any contributions to [email protected]. The authors who will act as editors reserve all editorial rights. September 14, 2009 97 Table of Contents Introduction...............................................................................................................1-1 Chemistry..................................................................................................................2-1 Physics......................................................................................................................3-1 Units .........................................................................................................................4-1 Derivation of Rn/Tn working level............................................................................5-1 Radon-222 Dose Calculation.....................................................................................6-1 Dosimetry .................................................................................................................7-1 Effective Whole Body Dose Equivalent (EDE) .........................................................8-1 Risks From Indoor Radon-US EPA...........................................................................9-1 Radon-222 and Lung Cancer Risk Estimates ........................................................... 10-1 Epidemiology.......................................................................................................... 11-1 Lung Cancer............................................................................................................ 12-1 Lung Cancer Rate by State ...................................................................................... 13-1 NCRP Pie Chart ...................................................................................................... 14-1 History of Radon-222 Occupational Limits ............................................................. 15-1 Radon Geology ...................................................................................................... 16-1 Radon Decay Products ........................................................................................... 17-1 Radon Variability.................................................................................................... 18-1 Radon in the Workplace.......................................................................................... 19-1 Diagnostics ............................................................................................................. 20-1 Fan Selection .......................................................................................................... 21-1 Fan Comparison...................................................................................................... 22-1 Post-mitigation Radon Data..................................................................................... 23-1 Ambient Radon ....................................................................................................... 24-1 Radon Statistics....................................................................................................... 25-1 State Radon Data..................................................................................................... 26-1 State Radon Rankings ............................................................................................. 27-1 EPA State Rankings ................................................................................................ 28-1 PA Radon Analyzer Data vs. UK Data .................................................................... 29-1 International Radon Section .................................................................................... 30-1 10 CFR 20 Table..................................................................................................... 31-1 Other Radon Reference Manuals ............................................................................. 32-1 Radon in Water .............................................................................................In Progress Radon and Granite/Building Materials ..........................................................In Progress Radon Testing Equipment/Devices................................................................In Progress Mitigation Equipment ...................................................................................In Progress Thoron ..........................................................................................................In Progress Pertinent Web Sites.......................................................................................In Progress September 14, 2009 98 Chemistry of Radon Atomic Number: 86 Symbol: Rn Atomic Weight: 222.0176 Discovery: Fredrich Ernst Dorn 1898 or 1900 (Germany) discovered the element and called it radium emanation. Ramsay and Gray isolated the element in 1908 and named it niton. Word Origin: from radium. Radon was once called niton, from the Latin word nitens, which means “shining.” Isotopes: At least 20 isotopes of radon are known. Radon-220 is commonly called “thoron” and emanates naturally from radium-224, one of the decay products of thorium-232. Thoron is an alpha-emitter with a half-life of 55.6 sec. Radon-219 is commonly called “actinon” and emanates from radium-223, a decay product of actinium-227. It is an alpha-emitter with a half-life of 3.96 sec. Properties: Radon has a melting point of -71° C, boiling point of -61.8 °C, gas density of 9.73 g/l, specific gravity of the liquid state of 4.4 at -62°C, specific gravity of the solid state of 4 and usually a valence of 0 (it does form some compounds, however, such as radon fluoride). Radon is a colorless gas at normal temperatures. It is also the heaviest of the noble gases. When it is cooled below its freezing point it displays brilliant phosphorescence. The phosphorescence is yellow as the temperature is lowered, becoming orange-red at the temperature of liquid air. Inhalation of radon decay products presents a health risk. Radon build-up is a health consideration when working with radium, thorium or actinium. It is also an issue in uranium mines. September 14, 2009 99 Sources: It is estimated that each square mile of soil to a depth of 6 inches contains approximately 1 g of radium, which releases radon to the atmosphere. The average concentration of radon is about one in sextillion parts of air (1 radon atom in 1021 air atoms.). Radon naturally occurs in some spring waters. Element Classification: Inert Gas Density (g/cc): 4.4 (@ -62°C) Melting Point (°K): 202 Boiling Point (°K): 211.4 Appearance: heavy radioactive gas Specific Heat (@20°C J/g mol): 0.094 Evaporation Heat (kJ/mol): 18.1 First Ionizing Energy (kJ/mol): 1036.5 Lattice Structure: Face-Centered Cubic References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.) and http://chemistry.about.com/od/elementfacts/a/radon.htm September 14, 2009 100 Physics of Radon Atomic and Nuclear Structure Let’s first recognize that atoms consist primarily of electrons, protons and neutrons. Interestingly, the protons and neutrons exist in a very small central region called the nucleus, while the electrons orbit outside this region at quite a distance comparatively as seen in this drawing. The number of protons in the nucleus uniquely defines the element of which the atom is a part. For example, if there is only one proton in the nucleus of an atom, that atom is a hydrogen atom, no matter how many neutrons or electrons are also part of that
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