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*UCRL-PRES-149818. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. 1 Understanding Radiation and Its Effects Prepared by Brooke Buddemeier, CHP LLNL Counter Terrorism and Incident Response Program Lawrence Livermore National Laboratory* brooke2@llnl.govbrooke2@llnl.gov (925) 423-2627 UCRL-PRES-149818-REV-2
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 2 Radiation is Energy The energy is given off by unstable (radioactive) atoms and some machines. For this talk, we will be focusing on ionizing radiation and its health effects.
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Ionizing Radiation Radiation with enough energy to remove an electron from its atom. It is energy in the form of particles or waves, given off by unstable (radioactive) atoms or by accelerated charged particles UCRL-PRES-149818. Understanding Radiation and it’s Effects. 3
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Ionizing vs. Non-ionizing Ionizing (can cause cancer) Non-ionizing AlphaSolar (visible light) BetaRadio broadcast GammaTV broadcast X-raysMicrowave Ultraviolet lightHeat (infrared) Fast neutronsLow frequency EMF Muons UCRL-PRES-149818. Understanding Radiation and it’s Effects. 4
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5 Radiation and Radioactive Material are a Natural Part of Our Lives We are constantly exposed to low levels of radiation from outer space, earth, and the healing arts. Low levels of naturally occurring radioactive material are in our environment, the food we eat, and in many consumer products. Some consumer products also contain small amounts of man-made radioactive material. no difference between radiation emitted by natural or man-made sources. Smoke Detector
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Artificial transmutations When one element is transformed into another element by the bombarding a nucleus with subatomic particles or small nuclei Fermi lab – Illinois (10.62 square miles!) UCRL-PRES-149818. Understanding Radiation and it’s Effects. 6
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7 Unstable Atoms Decay The number of “decays” that occur per unit time in the radioactive material tell us how radioactive it is. Units include Curies (Ci – 3.7 x 10 10 decays per sec – dps = 2.2 x 10 12 dpm, and Becquerels (decays per second). When an unstable atom decays, it transforms into another atom and releases its excess energy in the form of radiation. Sometimes the new atom is also unstable, creating a “decay chain”
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D eca y s e r I e s geoinfo.nmt.edu UCRL-PRES-149818. Understanding Radiation and it’s Effects. 8
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Band of Stability UCRL-PRES-149818. Understanding Radiation and it’s Effects. 9 chemwiki.ucdavis.edu
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Band of Stability cont. http://www.hasdeu.bz.edu.ro/softuri/fizica/mariana/Atomica/Table/lessons/11nuclear/nuclear.htm UCRL-PRES-149818. Understanding Radiation and it’s Effects. 10
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 11 Forms of Radiation When unstable atoms transform, they often eject particles from their nucleus. The most common of these are: Alpha Radiation High energy, but short range (travels an inch in air, not an external hazard) Beta Radiation Longer range (10 – 20 feet in air) and can be a skin and eye hazard for high activity beta sources. Gamma Rays (electromagnetic radiation) Often accompany particle radiation. This “penetrating” radiation is an external hazard and can travel 100s of feet in air. gamma
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Alpha particle α CharacteristicsRangeShieldingHazardsSources +2 charge 2 protons 2 neutrons Relatively large mass Very short range 1-2 inches in air Paper Outer layer of skin Internal Plutonium Uranium Radium Thorium Americium UCRL-PRES-149818. Understanding Radiation and it’s Effects. 12
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Beta particle β CharacteristicsRangeShieldingHazardsSources -1 charge Small mass Short range About 10’ in air Plastic safety glasses Thin metal Skin and eyes Can be internal Radioisotopes Activation products Sealed sources UCRL-PRES-149818. Understanding Radiation and it’s Effects. 13
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Gamma Ray γ CharacteristicsRangeShieldingHazardsSources No charge No mass Similar to x- rays Long range About 1100’ in air Lead Steel Concrete External (whole body) Can be internal X-ray Electron microscopes Sealed sources Accelerators Nuclear reactors radioisotopes UCRL-PRES-149818. Understanding Radiation and it’s Effects. 14
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Neutron particle η CharacteristicsRangeShieldingHazardsSources No charge Found in nucleus Extended range Water plastic External (whole body) Fission Reactor operation Sealed sources accelerators UCRL-PRES-149818. Understanding Radiation and it’s Effects. 15
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Penetration of radiation http://www.bcm.edu/bodycomplab/Radprimer/radpenetration.htm UCRL-PRES-149818. Understanding Radiation and it’s Effects. 16
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Uses for Radiation Medical Uses: Diagnostic X-rays and Diagnostic and Therapeutic Uses of Radioisotopes (ex.I-131) Academic and Scientific Applications: course work, laboratory demonstrations, experimental research, and a variety of health physics applications. Ex. C-14 dating UCRL-PRES-149818. Understanding Radiation and it’s Effects. 17
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Additional Uses of Radiation Industrial Uses: irradiation of foods, medical equipment and other substance. chem.duke.edu UCRL-PRES-149818. Understanding Radiation and it’s Effects. 18
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More Uses of Radiation Nuclear power plants -Electricity produced by nuclear fission Indian Point Nuclear Power Plant: One of New York State's Greatest Assets- aaenvironment.com UCRL-PRES-149818. Understanding Radiation and it’s Effects. 19
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6/9/2015 UCRL-PRES-149818. Understanding Radiation and it’s Effects. 20 How Unstable Is It? The “Half-Life” describes how quickly Radioactive Material decays away with time. It is the time required for half of the unstable atoms to decay. Some Examples: Some natural isotopes (like uranium and thorium) have half-lives that are billions of years, Most medical isotopes (like Technicium-99m) last only a few days
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 21 Some Isotopes & Their Half Lives ISOTOPE HALF- LIFE APPLICATIONS Uraniumbillions of years Natural uranium is comprised of several different isotopes. When enriched in the isotope of U-235, it’s used to power nuclear reactor or nuclear weapons. Carbon-14 5730 y Found in nature from cosmic interactions, used to “carbon date” items and as radiolabel for detection of tumors. Cesium-137 30.2 y Blood irradiators, tumor treatment through external exposure. Also used for industrial radiography. Hydrogen-3 12.3 yLabeling biological tracers. Irridium-19274 dImplants or "seeds" for treatment of cancer. Also used for industrial radiography. Molybdenum-9966 hParent for Tc-99m generator. Technicium-99m 6 hBrain, heart, liver (gastoenterology), lungs, bones, thyroid, and kidney imaging, regional cerebral blood flow, etc.
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 22 The Amount of Radioactivity is NOT Necessarily Related to Size Specific activity is the amount of radioactivity found in a gram of material. Radioactive material with long half-lives have low specific activity. 1 gram of Cobalt-60 has the same activity as 1800 tons of natural Uranium
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 23 What is a “Dose” of Radiation? When radiation’s energy is deposited into our body’s tissues, that is a dose of radiation. The more energy deposited into the body, the higher the dose. Radioactivity units measure the number of nuclear transformations (disintegrations) which occur in a certain time period
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Radiation Units – related to dose Curie (Ci) = 37,000,000,000 disintegrations per second (dps) = 2,200,000,000,000 dp minute Rem (Roentgen Equivalent to Man) is a unit of measure for radiation dose – estimates biological damage or health risk due to absorption of ionizing radiation Small doses expressed in mrem = 1/1000 rem. Sievert = 100 rem Rad (radiation absorbed dose) & R (Roentgens- measure exposure [ionization] of air by X-rays and gamma rays) are similar units that are often equated to the Rem UCRL-PRES-149818. Understanding Radiation and it’s Effects. 24
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Radioactive contamination Measures an amount of activity over a unit of surface area. E.g. 5000 dpm/100 cm 2 UCRL-PRES-149818. Understanding Radiation and it’s Effects. 25
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 26 Typical Doses Average Dose to US Public from All sources360 mrem/year Average Dose to US Public From Natural Sources300 mrem/year Average Dose to US Public From Medical Uses53 mrem/year Coal Burning Power Plant0.2 mrem/year Average dose to US Public from Weapons Fallout< 1 mrem/year Average Dose to US Public From Nuclear Power< 0.1 mrem/year Occupational Dose Limit for Radiation Workers5,000 mrem/yr Coast to coast Airplane roundtrip5 mrem Chest X ray8 mrem Dental X ray10 mrem Head/neck X ray20 mrem Shoe Fitting Fluoroscope (not in use now)170 mrem CT (head and body)1,100 mrem Therapeutic thyroid treatment (dose to the whole body)7,000 mrem
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Average Annual Radiation Exposure UCRL-PRES-149818. Understanding Radiation and it’s Effects. 27 lbl.gov
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RADON UCRL-PRES-149818. Understanding Radiation and it’s Effects. 28
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RADON EXPOSURE LIMITS UCRL-PRES-149818. Understanding Radiation and it’s Effects. 29 EPA recommends Radon levels should not be more than 4 picocuries per liter of air. A normal house contains ~ 1.5 pCi-L of air (1 pCi/L = 200 mrem/year Effective Dose Equivalent or 1.6 rem/y to the lungs)
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 30 Radiation is a type of energy; Contamination is material Exposure to Radiation will not contaminate you or make you radioactive. Contamination is Radioactive Material spilled someplace you don’t want it. Radioactive contamination emits radiation. Contact with Contamination can contaminate you with the material.
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 31 Our Bodies Are Resilient DNA damage is most important and can lead to cell malfunction or death. Our body has ~ 60 trillion cells Each cell takes “a hit” about every 10 seconds, resulting in tens of millions of DNA breaks per cell each year. BACKGROUND RADIATION causes only a very small fraction of these breaks (~ 5 DNA breaks per cell each year). Our bodies have a highly efficient DNA repair mechanisms
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Ways that radioactive material enters the body UCRL-PRES-149818. Understanding Radiation and it’s Effects. 32 peiweifoong.wordpress.com
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 33 Types of Exposure & Health Effects Acute Dose Large radiation dose in a short period of time Large doses may result in observable health effects Early: Nausea & vomiting Hair loss, fatigue, & medical complications Burns and wounds heal slowly Examples: medical exposures and accidental exposure to sealed sources Chronic Dose Radiation dose received over a long period of time Body more easily repairs damage from chronic doses Does not usually result in observable effects Examples: Background Radiation and Internal Deposition Inhalation
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 34 Dividing Cells are the Most Radiosensitive Rapidly dividing cells are more susceptible to radiation damage. Examples of radiosensitive cells are Blood forming cells The intestinal lining Hair follicles A fetus This is why the fetus has a exposure limit (over gestation period) of 500 mrem (or 1/10 th of the annual adult limit)
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Health Effects Radiation effects on cell chromosomes: Somatic effects: observed in the exposed individual Heritable effects: observed in future generations of exposed individual UCRL-PRES-149818. Understanding Radiation and it’s Effects. 35 Factors affecting biological damage Total radiation dose Dose rate Type of radiation Area of body exposed Cell sensitivity Individual sensitivity
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 36 At HIGH Doses, We KNOW Radiation Causes Harm High Dose effects seen in: Radium dial painters Early radiologists Atomic bomb survivors Populations near Chernobyl Medical treatments Criticality Accidents In addition to radiation sickness, increased cancer rates were also evident from high level exposures.
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 37 Effects of ACUTE Exposures Dose (Rads*)Effects 25-50 First sign of physical effects (drop in white blood cell count) 100 Threshold for vomiting (within a few hours of exposure) 320 - 360 ~ 50% die within 60 days (with minimal supportive care) 480 - 540 ~50 % die within 60 days (with supportive medical care) 1,000 ~ 100% die within 30 days * For common external exposures 1 Rad ~ 1Rem = 1,000 mrem
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 38 At LOW Doses, We PRESUME Radiation Causes Harm No physical effects have been observed Although somewhat controversial, this increased risk of cancer is presumed to be proportional to the dose (no matter how small). The Bad News:Radiation is a carcinogen and a mutagen The Good News: Radiation is a very weak carcinogen and mutagen! * Similar to those received by Atomic Bomb Survivors (≥10 rem)
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 39 Long-term Effects of Radiation Radiation is assumed to increase one’s risk of cancer The “normal” chance of dying of cancer is ~ 23% (~460 out of 2,000). Each rem is assumed to increase that risk by 0.05% (~1 chance in 2,000). The occupational radiation dose limit to the whole body is 5 rem/yr
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Common activities that cause 1 in a million chances of dying 10 mrem of radiation (cancer) smoking 1.4 cigarettes (lung cancer) eating 40 tablespoons of peanut butter Eating 100 charcoal broiled steaks spending 2 days in NYC (air pollution) driving 40 miles in a car (accident) flying 2500 miles in a jet (accident) canoeing for 6 miles UCRL-PRES-149818. Understanding Radiation and it’s Effects. 40
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Life Expectancy Lost Smoking 20 cigs a day 6 years Overweight (15%) 2 years Alcohol (US Ave) 1 year All Accidents 207 days All Natural Hazards 7 days Occupational dose (300 mrem/yr) 15 days From Industry Agriculture 320 days Construction 227 day Mining and quarrying 167 days Manufacturing 40 days Occupational dose (1 rem/yr) 51 days UCRL-PRES-149818. Understanding Radiation and it’s Effects. 41
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Risk-Loss of Life Expectancy Days of average life expectancy lost due to various causes Being an unmarried male3500 Smoking (1 pack/day)2250 Being an unmarried female1600 Being a coal miner1100 25% overweight777 Alcohol abuse (U.S. average)365 Being a construction worker227 Driving a motor vehicle207 All industries60 Radiation: 100 mrem/yr x 70 years10 Coffee6 UCRL-PRES-149818. Understanding Radiation and it’s Effects. 42
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Basic protective measures UCRL-PRES-149818. Understanding Radiation and it’s Effects. 43 nrc.gov
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Detecting Radiation Ionizing radiation is capable of knocking electrons off of atoms. Thus we can make instruments capable of “seeing” radiation. UCRL-PRES-149818. Understanding Radiation and it’s Effects. 44
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Geiger Counters An electric current is passed along the walls of a tube. A thin wire passes through the center of the tube (filled with argon) that easily loses electrons when hit with ionizing radiation. When this happens, an electric current can jump through the gas to the wire. This complete the circuit and the electricity causes a loud clicking sound or moves a needle on a dial. UCRL-PRES-149818. Understanding Radiation and it’s Effects. 45
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Scintillation counter Takes advantage of certain substances, such as ZnS, give off light when they are struck by high energy radiation. A photocell senses the flashes of light as radiation strikes and measures the number of decay events per unit time. UCRL-PRES-149818. Understanding Radiation and it’s Effects. 46 dehs.umn.edu
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Radiation affects photographic film similarly to the way light does. But, radiation can penetrate through materials that can stop light. People wear a film badge covered with plastic that prevents light from passing through, but not radiation. gammasonics.com UCRL-PRES-149818. Understanding Radiation and it’s Effects. 47 DOSIMETERDOSIMETER After use, the film is developed and the extent of darkening relates to amount of radiation exposure gammasonics.com
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e-radiography.net UCRL-PRES-149818. Understanding Radiation and it’s Effects. 48
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Skin-photographic film? When we are exposed to small amount of radiation our skin gets darker; suntan or sunburn. UCRL-PRES-149818. Understanding Radiation and it’s Effects. 49 We can’t detect radiation with our senses so a warning label has been developed and is commonly used.
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 50 Conclusion (1 of 2): Understanding Radiation and it’s Effects Radiation is energy given off by unstable atoms and some machines. Radioactive Material contains unstable atoms that give off radiation when they “decay.” Contamination is Radioactive Material spread someplace where you don’t want it.
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 51 Conclusion (2 of 2): Understanding Radiation and it’s Effects Radiation damages our cell’s DNA, fortunately our body has very efficient repair mechanisms. Large acute doses of radiation can cause sickness or even death. The severity of the effects are proportional to the dose. All exposures to presumed to increase the risk of cancer. The amount of “increased risk” is proportional to exposure. Very Small DOSE = Very Small RISK
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UCRL-PRES-149818. Understanding Radiation and it’s Effects. 52 References Risk, DNA, & Dose Effects: RadEFX(sm) Ionizing Radiation Health Effects Forum Copyright © 1994-1997 Baylor College of Medicine, All rights reserved. http://radefx.bcm.tmc.edu/ionizing/subject/risk/acute.htm Which cites several references, including: NCRP Report 98 "Guidance on Radiation Received in Space Activities," NCRP, Bethesda (MD) (1989). Health Effects Model for Nuclear Power Plant Accidence Consequence Analysis. Part 2, Scientific Basis for Health Effects Models. U.S. Nuclear Regulatory Commission, Report NUREG CR-4214, Rev. 1. Part II. Washington, D.C. NRC: 1989 Smithsonian, V26 No.9. December 1995; “RISK, Part 2: Safeguarding our cells” by James Trefil. Other Graphics and Info from: Uranium Information Centre Melbourne, Australia http://www.uic.com.au/index.htm DOE; Transportation Emergency Preparedness Program (TEPP) http://www.em.doe.gov/otem/program.html
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