Radiological Terrorism

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Radiological Terrorism

• Radiation Primer

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Radiation Overview

• Either ionizing or non-ionizing
• Risks of injury from exposure to ionizing
  radiation

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Radiation Overview

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

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Radiation Overview

• Four possible outcomes
• No damage
• Damage repaired
• Normal cell function
• Abnormal cell function
• Cell death

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Types of Ionizing Radiation

• Alpha particles
• Beta particles
• Gamma rays
• Neutron particles

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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

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Alpha particle decay U.S. Department of Energy
Image
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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

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Types of Ionizing Radiation

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

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Beta particle decay U.S. Department of Energy
Images
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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

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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
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Gamma decay U.S. Department of Energy Image
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Types of Ionizing Radiation

• Gamma rays
• Highly penetrating
• Can produce whole body exposure
• Equally dangerous with external or internal
  exposure

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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

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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

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Radioactive Isotopes

• Alpha emitters
• Americium-241
• Plutonium-239/238
• Radium-226

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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

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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

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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

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Radioactive Isotopes

• Beta emitters
• Iodine-131, 132, 134, 135
• Phosphorus-32
• Strontium-90

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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

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

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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

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Radioactive Isotopes

• Gamma emitters
• Cesium-137
• Cobalt-60
• Uranium-238, 234,235

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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

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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
• lt 5 absorption from the GI tract

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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

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Units of Radiation

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

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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

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Radiation Acute Exposure

• 10 rad or greater within a short period of time
  (lt 2-3 days)
• Acute Radiation Syndrome is apparent at doses gt
  100 rad
• Dose gt450 rad
• 50 of exposed population will die within 60 days
  without medical care

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Radiation Acute Exposure

• Blood-forming organs affected at gt100 rad
• Bone marrow, spleen, and lymphatic tissue
• Symptoms internal bleeding, fatigue, bacterial
  infection, fever

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Radiation Acute Exposure

• Gastrointestinal tract affected at gt1000 rad
• Stomach, intestines
• Symptoms
• nausea, vomiting, diarrhea, dehydration,
  electrolyte imbalance, bleeding ulcers

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Radiation Acute Exposure

• Central Nervous System affected at gt5000 rad
• Damage to brain and nerve cells
• Symptoms loss of coordination, confusion, coma,
  convulsion

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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

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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

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Radiation Prenatal Exposure

• Embryo/fetus highly sensitive
• First 20 weeks
• Potential effects
• Growth retardation
• Small head/brain size
• Mental retardation
• Childhood cancer

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Summary

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

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Summary

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

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Summary

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