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Radiological Terrorism

Radiological Terrorism. Radiation Primer. Radiation: Overview. Either ionizing or non-ionizing Risks of injury from exposure to ionizing radiation . Radiation: Overview. Biological injury Ionization of atoms within the cell Ionization breaks molecular bonds

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Radiological Terrorism

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  1. Radiological Terrorism Radiation Primer

  2. Radiation: Overview • Either ionizing or non-ionizing • Risks of injury from exposure to ionizing radiation

  3. Radiation: Overview • Biological injury • Ionization of atoms within the cell • Ionization breaks molecular bonds • Cell damage occurs when critical cell structures are affected

  4. Radiation: Overview • Four possible outcomes • No damage • Damage repaired • Normal cell function • Abnormal cell function • Cell death

  5. Types of Ionizing Radiation • Alpha particles • Beta particles • Gamma rays • Neutron particles

  6. Types of Ionizing Radiation • Alpha particles • Relatively large mass • Consists of two protons and two neutrons • Possesses +2 positive charge striping electrons from atoms it passes through

  7. Alpha particle decay U.S. Department of Energy Image

  8. Types of Ionizing Radiation • Alpha particles • Do not travel far • Range in air is 1-2 inches • Completely stopped by the dead layers of the skin or by clothing • Offer minimal external hazard • Can cause significant regional cellular damage when internalized

  9. The penetrating power of three types of radiation U.S. Environmental Protection Agency Illustration

  10. Types of Ionizing Radiation • Beta particles • Electrons emitted during decay • Found in fallout • Half the charge of alpha particles • Electrically interacts with passing atoms

  11. Beta particle decay U.S. Department of Energy Images

  12. Types of Ionizing Radiation • Beta particles • Travel further than alpha particles • Easily shielded by thin plastic, glass, aluminum or wood • External hazard to skin and eyes • Less dangerous internally but still can cause significant regional injury

  13. The penetrating power of three types of radiation U.S. Environmental Protection Agency Illustration

  14. Types of Ionizing Radiation • Gamma rays / X-rays • Electromagnetic wave / no charge • Ionize matter by direct interaction with orbital electrons • Difference between radiation is only their source • Best shielded by dense materials Gamma decay U.S. Department of Energy Image

  15. Gamma decay U.S. Department of Energy Image

  16. Types of Ionizing Radiation • Gamma rays • Highly penetrating • Can produce whole body exposure • Equally dangerous with external or internal exposure

  17. The penetrating power of three types of radiation U.S. Environmental Protection Agency Illustration

  18. Types of Ionizing Radiation • Neutron particles • Emitted from unstable atoms during a nuclear reaction • No electrical charge • Causes damage by direct collision with the nucleus of another atom • May produce indirect ionization

  19. Types of Ionizing Radiation • Neutron particles • Highly penetrating; difficult to stop • Best shielded by materials with high hydrogen content • Cause whole body injury like gamma rays, but 20 times more damaging

  20. Radioactive Isotopes • Alpha emitters • Americium-241 • Plutonium-239/238 • Radium-226

  21. Radioactive Isotopes • Americium-241 • Decay daughter of plutonium • Main threat is heavy metal poisoning • Large quantities : cause whole-body irradiation • 75% of the lung burden is absorbed • Absorbed rapidly from skin wounds • Urinary and hepatic excretion

  22. Radioactive Isotopes • Plutonium-238/239 • Produced from uranium in reactors • Primary fissionable material in nuclear plants and weapons • Always contaminated with americium • Primary toxicity is from inhalation • GI absorption depends on chemical state • May be washed from intact skin

  23. Radioactive Isotopes • Radium-226 • Primary alpha emitter, but daughter products emit beta and gamma rays • Most common exposure is ingestion • Follows calcium to bone deposition • Associated with leukemia, aplastic anemia, and sarcomas

  24. Radioactive Isotopes • Beta emitters • Iodine-131, 132, 134, 135 • Phosphorus-32 • Strontium-90

  25. Radioactive Isotopes • Iodine-131, 132, 134, 135 • Created during nuclear fission • Found in reactor fuel rods or after a nuclear explosion • Primary toxicity is to the thyroid gland

  26. Thyroid Glands National Institute of Diabetes and Digestive and Kidney Diseases Image

  27. Radioactive Isotopes • Phosphorus-32 • Found in research labs and medical facilities • Completely absorbed from all sites • Deposited in the bone marrow and other rapidly replicating cells • Local irradiation causes cell damage

  28. Radioactive Isotopes • Strontium-90 • Direct fission product of uranium • Daughters emit beta and gamma rays • Readily absorbed via respiratory and GI routes • ~ 50% of dose deposited in bone

  29. Radioactive Isotopes • Gamma emitters • Cesium-137 • Cobalt-60 • Uranium-238, 234,235

  30. Radioactive Isotopes • Cesium-137 • By-product of the manufacture of weapons-grade radioactive material • Half-life of 31 years • Salt that dissolves easily in water • Emits both gamma and beta radiation • Completely absorbed through the lungs, GI tract, and wounds

  31. Radioactive Isotopes • Cobalt-60 • Produced by non-radioactive cobalt to intense radiation in the reactor core • Emits both gamma and beta radiation • Half-life of 5 years • Rapidly absorbed from the lung • < 5% absorption from the GI tract

  32. Radioactive Isotopes • Uranium-238,235,234 • Natural mix of all three isotopes • Half-lives of 4.5x109, 7x108, and 2.5x105 years • Inhaled compounds metabolized and excreted in urine • Urinary levels of 100 µg per deciliter may cause renal failure • Absorption is determined by its chemical state

  33. Units of Radiation • Rad still used widely • International unit called gray (Gy) • Quality factor used to adjust for differences in tissue absorption

  34. Units of Radiation • (Dose in rads) x QF = rem • roentgen equivalent, man • (Dose in Gy) x QF = sievert (Sv) • Pure gamma radiation • 100 rad = 100 cGy = 1000 mGy = 1 Gy = 1 Sv = 100 rem

  35. Radiation: Acute Exposure • 10 rad or greater within a short period of time (< 2-3 days) • Acute Radiation Syndrome is apparent at doses > 100 rad • Dose >450 rad • 50% of exposed population will die within 60 days without medical care

  36. Radiation: Acute Exposure • Blood-forming organs affected at >100 rad • Bone marrow, spleen, and lymphatic tissue • Symptoms: internal bleeding, fatigue, bacterial infection, fever

  37. Radiation: Acute Exposure • Gastrointestinal tract affected at >1000 rad • Stomach, intestines • Symptoms • nausea, vomiting, diarrhea, dehydration, electrolyte imbalance, bleeding ulcers

  38. Radiation: Acute Exposure • Central Nervous System affected at >5000 rad • Damage to brain and nerve cells • Symptoms: loss of coordination, confusion, coma, convulsion

  39. Radiation: Acute Exposure • Other symptoms • Thyroid damage: 50 rad • Ovarian damage: 125-200 rad • Gonadal damage with permanent sterility: 600 rad • Skin erythema and hair follicle damage: 200-300 rad

  40. Radiation: Chronic Exposure • Small amounts over a long period • Type of exposure typically seen in occupational exposures • Body usually able to repair itself • Increased risk of some cancers

  41. Radiation: Prenatal Exposure • Embryo/fetus highly sensitive • First 20 weeks • Potential effects • Growth retardation • Small head/brain size • Mental retardation • Childhood cancer

  42. Summary • Alpha, beta, gamma, and neutron radiation • Alpha particles • No external risk • Produce regional internal injury • Beta particles • Significant external risk to skin & eyes

  43. Summary • Gamma radiation and neutrons • Highly penetrating • Produce whole body exposure • Units of radiation • Rad and rem • Gray (Gy) and sievert (Sv)

  44. Summary • Ionizing radiation • Cells interact on a molecular level • Potential cell damage • Acute radiation exposure • Blood-forming organs • GI tract • CNS

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