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State of Connecticut Radiation Professional Volunteer Program (CT-RPVP)

State of Connecticut Radiation Professional Volunteer Program (CT-RPVP). LESSON 1. Principles of Radiation and Radiation Protection. Objectives. Describe the two forms of radiation and give examples of each Distinguish between radiation exposure and radioactive contamination

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State of Connecticut Radiation Professional Volunteer Program (CT-RPVP)

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  1. State of Connecticut Radiation Professional Volunteer Program (CT-RPVP) LESSON 1 Principles of Radiation and Radiation Protection

  2. Objectives • Describe the two forms of radiation and give examples of each • Distinguish between radiation exposure and radioactive contamination • Describe the relationships between radiation exposure, radiation absorbed dose, and dose equivalent • Understand how time, distance and shielding are used to minimize radiation exposure

  3. Photon and ParticleRadiation • Radiation, as the term is used in this course, consists of: • photons • and • subatomic particles • Radiation is emitted from the nuclei of radioactive atoms (or radioisotopes) and is capable of causing the ionization of atoms. For this reason, this type of radiation is often referred to as “ionizing radiation” Photon Radiation Radioactive Atom Particle

  4. Photon Radiation • X- and gamma rays are released from the nuclei of a radioactive atoms as packets of energy, or photons • X rays are similar to gamma but have lower energy 4

  5. Subatomic Particle Radiation • Alpha, and beta radiations are subatomic particles ejected from the nuclei of atoms undergoing radioactive decay • Neutron radiation consists of free neutrons produced during nuclear fission, a reaction which takes place in reactors of nuclear power plants and atomic bombs following detonation + + (N) Alpha (α) Beta (β) Neutron (N) 5

  6. Test Your knowledge • Which of the following can be used to in place of “radioactive atom” A) Radiation B) Radioisotope C) Photon D) Subatomic Particle

  7. Sources of Radiation • Man-Made, such as x-rays generated from a medical x-ray machine, and gamma rays from radiation therapy equipment • or • Naturally-Occurring, such as cosmic rays from space, and gamma radiation from radon gas 7

  8. Shielding from Radiation • Protective shielding varies with the type of radiation α Skin, paper, 1 to 4 inches of air [Alpha] Less than ¼ inch metal, glass, concrete, 1 to 18 feet air β [Beta] 2 to 12 inches lead, 3 to 18 inches steel, 1 to 6 feet of concrete, tens to hundreds of yards in air X, γ and n [X-, Gamma rays and Neutrons] 8

  9. Cannot be seen Cannot be smelled But, can be Cannot be felt Cannot be tasted Radiation Detection • easily detected by instruments 9

  10. Exposure vs. Contamination • Exposure to radiation occurs after entering an area in which there is a radiation source • After leaving the area, the exposure no longer happens • Contamination occurs when radioactive material is on the body surface (external contamination) or is in the body (internal contamination) • Decontamination of external areas is accomplished by removing clothing and washing the affected areas 10

  11. Measuring Radiation • Exposure to radiation results in the absorption of a radiation dose • The unit for exposure is the roentgens (R) • The unit for absorbed dose is the Radiation Absorbed Dose (rad) • The unit for dose equivalent is the Roentgen equivalent man (rem) • For practical purposes, 1 R (exposure) = 1 rad (absorbed dose) = 1 rem or 1000 mrem (dose equivalent) 11

  12. Daily sources of radiation Normal annual exposure from natural radiation Approx.0.3 rem/yr • Radon gas 0.165 rem • Human body 0.03 rem • Rocks, soil 0.02 rem • Cosmic rays 0.02 rem Normal annual exposure from man-made radiation Between0.030 -0.070 rem/yr • 1 chest X-ray0.010 rem • Consumer products 0.010 rem • Air travel round trip (NY-LA)0.005 rem • Watching color TV 0.001 rem • Nuclear industry < 0.001 rem 12

  13. Test You knowledge Radon gas can enter homes from surrounding soil. Radon cannot be seen and has no odor, but at elevated levels, radon in homes presents a serious health risks. Radiation emitted by radon in homes is an example of: A) Man-made radiation B) Naturally occurring radiation

  14. Minimizing Radiation Doses - ALARA • ALARA stands for As Low As is Reasonably Achievable • The purpose of ALARA is to minimize risk as a result of exposure to radiation or radioactive material to a level that is As Low As is Reasonably Achievable

  15. Mitigating External Radiation Doses Minimize Time Maximize Distance Maximize Shielding 15

  16. Dose Limits for Responders Performing Emergency Services ICRP (1991), NCRP Report No. 116 and NCRP Report No. 138, DHS (2007)

  17. Summary • Radiation is composed of subatomic particles or high-energy photons • Contamination results form the presence of radioactive material on or in the body, whereas radiation exposure results form being in the presence of a radiation source • R, rad and rem are units used to measure radiation exposure, absorbed dose and dose equivalent • ALARA is a radiation safety principle for minimizing radiation doses and releases of radioactive materials by employing all reasonable methods • Three basic rules of thumb for minimizing radiation exposure are time, distance and shielding

  18. State of Connecticut Radiation Professional Volunteer Program (CT-RPVP) Lesson 2 Radiation and Nuclear Threats and Vulnerabilities 18

  19. Objectives • Describe the radiological and nuclear threats faced by the U.S. • Understand the risks of contamination and exposure to volunteers when screening individuals involved in a radiological or nuclear incident

  20. Radiation Emission Device (RED) “Dirty” Conventional Bomb (RDD) Improvised Nuclear Device (IND) 1kT “Suitcase Nuke” Ballistic Missile Attack 250 kT Nuclear Weapon – “City Killer” Nuclear Weapon, IND More Impact/Damage Dirty Bomb RED Less Likelihood Less More Intentional Nuclear/Radiological Threats to the US 20

  21. Possible Terrorist-Related Scenario • Radiation Emission Device (RED) - concealed at high-traffic area: ~ 60 to 250 deaths and ~ 130 cases of radiation sickness requiring public health follow-up for 30 years; psychological trauma • Community recovery timeline: Months to years Source: Tofani A, Bartolozzi M. Ranking nuclear and radiological terrorism scenarios: The Italian case. Risk Analysis 2008;28(Oct):1431-44.

  22. Possible Terrorist-Related Scenario • Radiation Dispersal Device (RDD) - explodes at busy street corner: ~ 30 to 180 deaths • Few in any radiation-related injuries • Decontamination efforts for people and objects • Significant financial cost for decontamination of property in the affected area Source: Tofani A, Bartolozzi M. Ranking nuclear and radiological terrorism scenarios: The Italian case. Risk Analysis 2008;28(Oct):1431-44.

  23. Possible Terrorist-Related Scenario • Improvised nuclear device (IND) - explosion of 10 kilotons, in center of a city, such as Coleman Dock, Seattle, WA • Approximately 50,000 deaths • Infrastructure damage out to 1 mile • Contamination ~3,000 sq. miles • $100+ billion in costs • Community recovery time: Years Source: Tofani A, Bartolozzi M. Ranking nuclear and radiological terrorism scenarios: The Italian case. Risk Analysis 2008;28(Oct):1431-44.

  24. Risk to Volunteers from Screening Individuals of a Radiological or Nuclear Incident • What is the risk of exposure or contamination to volunteers performing radiological surveys of people involved in a radiological or nuclear event? • Depends on the nature of the event: • Contamination for RED: None • Exposure only (such as in an RED incident) • Acute radiation syndrome in exposed individuals • No risk of exposure or contamination to volunteers

  25. Risk to Volunteers from Screening Individuals of a Radiological or Nuclear Incident • Contamination (Radiation Dispersal Device ) • Individual’s person, articles of clothing, other belongings may be contaminated • Removing contaminated clothing will eliminate 80 - 90% of contamination • Individuals may be internally contaminated • Individuals with minor injuries may self-refer to screening centers • Relatively low risk for contamination to volunteers; very low level exposures possible (varies with degree of individuals’ levels of contamination)

  26. Risk to Volunteers from Screening Individuals of a Radiological or Nuclear Incident • Contamination (Nuclear Power Plant Incident) • Individual’s person, articles of clothing, other belongings may be contaminated • Individuals may be internally contaminated • Relatively low risk for contamination to volunteers; very low level exposures possible (varies with degree of individuals’ levels of contamination)

  27. Risk to Volunteers from Screening Individuals of a Radiological or Nuclear Incident • Contamination from Fall-Out, and High-Level Exposures (Nuclear detonation) • Individuals’ persons, articles of clothing, and other belongings may be contaminated • Individuals may be internally contaminated • Individuals may incur radiation doses up to several hundred rads are possible (acute radiation syndrome) • Individuals with minor injuries may self-refer • Relatively low risk for contamination to volunteers; very low level exposures possible (varies with degree of individuals’ levels of contamination) • Incident-related psychological stress/trauma among volunteers

  28. Test your knowledge Which of the following are the most likely terrorist-related threats to the U.S are: A) 250 kT nuclear weapon and an IND detonation B) Ballistic missile attack and an IND detonation C) Dirty bomb detonation and deployment of an RED D) Detonation of a RDD and IND E) No threat

  29. Test your knowledge Which of the following is true: A) The impact of an IND is greater than that of a 250 kT bomb B) With respect to a terrorist attack, the probability of an RDD detonation is greater than that of a IND detonation C) A dirty bomb detonation is likely to cause radiation injury, deaths and contamination of a small area D) The risk of radiation exposure and contamination to volunteers who may be called upon to screen victims of an RED is zero E) The risk of radiation exposure and contamination to volunteers who may be called upon to screen victims of an RDD is zero

  30. Summary • Threats to the U.S. involving the release of radiation and radioactive materials are the use of REDs, RDDs, INDs, and nuclear weapons with yields varying from 1 – 250 kT • Volunteers screening individuals impacted by an RDD have no risk of exposure or contamination • Volunteers screening individuals impacted by a dirty bomb or a nuclear weapon, including an IND, have a low risk of contamination, or radiation exposure

  31. State of Connecticut Radiation Professional Volunteer Program (CT-RPVP) Lesson 3 Biological and Clinical features of Radiation injuries

  32. Objectives • Distinguish between acute and chronic radiation exposure • State three types of DNA changes resulting from radiation exposure • Identify symptoms of acute radiation syndrome

  33. Acute Radiation Exposure • Acute radiation exposure is exposure to a large, single dose of radiation, over a short period of time (seconds) • A large acute exposure to radiation may result in immediate clinical effects (e.g., acute radiation syndrome) as well as long-term effects (e.g., cancer)

  34. Chronic Radiation Exposure • Chronic radiation exposure involves exposure to low levels of radiation over a long period of time (months – years) • Chronic radiation exposure may result in increased risk of developing cancer • Exposure to radiation emitted by radon gas present in many homes is an example of chronic radiation exposure

  35. Test your knowledge True or False: Unlike acute radiation exposure, chronic radiation exposure may result in the development of cancer A) True B) False

  36. Test your knowledge Of the following, which is a example of acute radiation exposure A) Radiation incurred on a round-trip flight from New York City to Los Angles B) Radiation incurred from a one-time chest x-ray C) Eating foods over one’s lifetime that contain high levels of potassium-40 (radioactive isotope) D) Living in high-altitude areas

  37. Radiation Targets All Cellular Components

  38. Janice Brock University RPO Types of DNA Damage Caused by Radiation Deoxyribonucleic Acid - • Radiation can damage DNA resulting in: • DNA mutations and DNA breaks • Gross structural rearrangements or chromosomal aberrations, • to the DNA can also occur

  39. Janice Brock University RPO DNA Damage Caused By Radiation Deoxyribonucleic Acid - • Radiation damages DNA may result in: • DNA mutations may not kill the cell; however over time, these mutations may transform the cell into a cancerous cell • This transformation is random (stochastic) and take place over several years • The higher the radiation dose, the greater the chance of developing cancer

  40. Janice Brock University RPO DNA is the most important Target of Radiation Deoxyribonucleic Acid - • Radiation damages DNA which result in: • Unrepaired DNA breaks and gross structural changes to the DNA almost always lead to cell death • High radiation doses, delivered quickly (seconds) and to a large area of the body, result in widespread cell death, causing: • Tissue and organ failure which manifest as acute radiation syndrome (ASR) • The occurrence of these biological events and clinical manifestations are predictable (or non-stochastic) and take place relatively quickly

  41. Effects of Acute Radiation Exposure (High Dose, High Dose Rate) 25 – 50 rads 100 rads 650 rads 1000 rads 250 rads Severe Vomiting (100%) Diarrhea Cramps Bleeding - mouth, kidneys Nausea Vomiting WBC WBC

  42. Test your knowledge Which is true of acute radiation syndrome: A. Affects more males than females B. Varies in severity according to the absorbed dose of radiation C. Can be treated with potassium iodide D. All of the above

  43. Summary • Acute radiation exposure is exposure to a large, single dose of radiation, over a short period of time • Chronic radiation exposure involves exposure to low levels of radiation over a long period of time • Both, acute and chronic radiation exposures can result in cancer • The most important cellular target of radiation is DNA. Radiation-induced damage to DNA include DNA mutations and chromosomal aberrations • The severity of ARS is directly proportional to dose

  44. State of Connecticut Radiation Professional Volunteer Program (CT-RPVP) Lesson 3 External Decontamination

  45. Objectives of this Section • Describe the purpose and goal of decontamination • List some key concepts of decontamination • Provide an overview of the decontamination process for removing radioactive contaminants present on body surfaces, including hair

  46. Decontamination Concepts • The purpose of the external decontamination is to remove or reduce radioactive contaminants from the surfaces of individuals and pets • Skin • Hair • Goal is < 2 times background or 2 decontamination attempts

  47. Decontamination Decontamination Concepts for Reception Centers • Decontamination, if required or advisable, follows immediately after the screening process • If survey readings are: • > 2 - 3x background, decontamination is advisable (EPA/NCRP) • > 20- 30x background, decontamination is required (EPA/NCRP)

  48. Test your knowledge • Decontamination of individuals should continue until survey readings indicate levels below 2 times background • True • False

  49. Decontamination Concepts for Reception Centers • Individuals (and pets) with contamination levels > 2x background, as per GM survey • Decontamination is repeated until survey readings are < 2x background or until additional rounds of decontamination do not reduce contamination levels by more than 10% (CDC) • After each round of decontamination, individuals are resurveyed

  50. Decontamination Process for Reception Centers • All contaminated clothing and valuables are placed in a plastic bag • Removing clothing will eliminate 80 – 90% of contamination • Items that cannot be decontaminated (e.g., porous materials) should be discarded in waste bins for contaminated items

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