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CPT Joseph Hout, Assistant Professor, MSPH, REHS Winter, 2008

CPT Joseph Hout, Assistant Professor, MSPH, REHS Winter, 2008. Radiation. Learning Objectives. Be familiar with definitions used in class Know the sources for the various types of radiation discussed in class

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CPT Joseph Hout, Assistant Professor, MSPH, REHS Winter, 2008

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  1. CPT Joseph Hout, Assistant Professor,MSPH, REHS Winter, 2008 Radiation

  2. Learning Objectives • Be familiar with definitions used in class • Know the sources for the various types of radiation discussed in class • Be able to discuss characteristics as well as protection from alpha, beta, gamma, and x rays • Know radiation units • Know about radon and its cancer causing effects • Be able to discuss EPA carcinogenicty categories and give examples • Know how radon enters a home and how to protect against it

  3. Definitions • Ionizing radiation • Radiation capable of producing ions when interacting with matter • X rays, Alpha, Beta, Gamma, Cosmic rays • Nonionizing radiation • Radiation that does not have enough energy to remove an electron from an atom or molecule • UV light, Visible light, Infrared radiation, microwaves, radio and TV, power transmission

  4. Ionizing Radiation • 4 types of Ionizing radiation • Alpha particles • Beta particles • Gamma photons • X ray photons

  5. Ionizing Radiation • Alpha Particles • Large in Mass (+2) • Effects are short range (stopped by paper) • Hazardous - Inhalation and ingestion • Not part of the electromagnetic spectrum – has mass • Beta Particles • Relatively small mass and charge (-1) • Fast moving (stopped by thin metal or plastic) • Hazardous – inhalation, ingestion, skin burns • Not part of the electromagnetic spectrum –has mass

  6. Ionizing Radiation • Gamma Photons • Pure energy • Ionizing radiation at the high frequency end of spectrum • NO MASS • Very penetrating – external and internal radiation hazard • Travels at the speed of light • No charge • PRIMARY PROTECTION • Time • Distance • Shielding

  7. Ionizing Radiation • X Ray Photons • Similar to gamma • Penetrates less than gamma • PRIMARY PROTECTION • Time • Distance • Shielding

  8. Ionizing Radiation

  9. Ionizing Radiation • Radiation Damage - 4 things can happen • 1 – Pass through cell without causing damage • 2 – Damage the cell, but cell repairs itself • 3 – Damage the cell so repairs and replicates a damaged form • 4 – Kills the cell • Somatic effects appear in exposed person • Damage to cells that are NOT reproductive cells • Occur immediately or over years • Genetic effects can effect future generations • Reproductive cells • Can be inherited

  10. Carcinogenicity Categories • Class A – Human Carcinogen • RADON, Tobacco smoke Po210 • Class B1 – Probable human carcinogen • Limited evidence but not conclusive • UVA, UVB • Class B2 – Probable human carcinogen • Inadequate cause and effect evidence • UVA, UBV • Class C – Possible human carcinogen • Class D – Not classifiable as a human carcinogen • Class E – Evidence of non carcinogenicity

  11. Regulating Radiation • Nuclear Regulatory Commission • Nuclear Power Plants and Fuels • Department of Energy • Military • Argon National Lab, Fermi, Oak Ridge • EPA • Naturally occurring • Radon RECOMMENDATIONS

  12. Regulating Radiation • piC/L • A picocurie is a trillionth of a curie and represents about one radioactive particle disintegration every 27 seconds • Becquerel per meter3 (Bq/m3) • One becquerel per meter3 is one disintegration per second within a cubic meter • Absorbed dose – Gray (Gy) formerly Rad • Amount of energy absorbed • Equivalent Dose – Sievert (Sv) formerly REM • Makes different sources of radiation equivalent • Measures biological effect • Roentgen (R) – • Equivalent dose of ionizing radiation received by tissues and organs – takes in a quality factor for dangerous radiation

  13. Regulating Radiation • Radon – ALPHA EMITTER • All manmade Class A carcinogens are regulated • Radon regulated in mines since 1950s • Not regulated in homes because is not manmade • Standard of exposure • 4.0 pCi/l • Equates to 28 deaths per million per year • OSHA = 100 pCi/l

  14. Radon • Radon 222 is the decay product of radium 226. • Radium 226 is the decay product of Uranium 228. • Uranium is ubiquitous in the earth’s crust making Radium 226 and Radon 222 in almost all rock, soil, and water • Colorless, odorless, tasteless • Leaks into basements of houses, office, schools via • Foundation cracks • Sump pump wells • Drains • Well water

  15. Radon

  16. Radon • Protection • Test your house, work, school etc • Seal and Vent • Sub slab depressurization • Discharge above the highest eve • Post mitigation re test • Test location after work is completed • Test every two years

  17. Questions ?

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