Radiological Terrorism

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Radiological Terrorism

• The Dirty Bomb

2
Dirty Bomb Overview

• A radiation dispersion device, or RDD
• Conventional explosive device with radioactive
  material added
• Radioactive material spreads to surrounding area
  by physical dispersion and airborne diffusion

3
Dirty Bomb Overview
4
Dirty Bomb Overview

• Extent of contamination
• Size and sophistication of the bomb
• Type of radioactive material
• Weather conditions
• Extent of human exposure
• Speed of evacuation from contaminated area
• Example
• Bomb with a single cobalt-60 rod
• Acute dose of a few tenths of a rem to people
  within a half-mile radius

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Dirty Bomb The Threat

• Threat of fear and disruption
• Panic over radiation exposure
• Produce additional casualties
• Disrupt rescue and evacuation efforts
• Disruption arises from area remaining off-limits
  and unusable during clean-up work

Hazardous Materials Response Austin, TX Fire
Department Image
6
Dirty Bomb Materials

• Most likely to be used cobalt-60, strontium-90,
  cesium-137, and americium-241
• Less likely phosphorus-32 and radium-226
• Obtained from military, medical, industrial,
  academic or research sources
• Examples
• Cobalt-60 food and mail irradiation
• Americium-241 smoke detectors and oil
  exploration
• (See Radiation Primer for more on these
  isotopes)

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Dirty Bomb Health Risks

• Radionuclides cross capillary membranes through
  passive and active diffusion
• Rate of distribution
• Organ metabolism
• Ease of chemical transport
• Affinity of radionuclide for chemicals in organs
• Liver, kidney, adipose tissue, and bone
• Greatest capacity for binding radionuclides
• Higher protein and lipid makeup

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Dirty Bomb Health Risks

• Major health risks
• Acute trauma from the explosion itself
• Cancer
• Specific target organ damage
• Heavy metal poisoning

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Dirty Bomb Health Risks

• Cancer risk is not known
• Tumor induction statistics extrapolated from data
  on known exposures at doses gt100 rem
• Extrapolated data may be inaccurate for exposures
  lt 100 rem

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Dirty Bomb Health Risks

• Linear, no threshold model
• Endorsed by the EPA and American Federation of
  Scientists
• Non-linear, threshold model
• Endorsed by the Health Physics Society and
  International Council on Radiation Protection

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Dirty Bomb Health Risks

• Linear, no threshold model
• Biological damage follows a linear progression
  with exposure levels
• The higher the dose, the greater the damage
• Used to extrapolate data on exposures lt 100 rem
• Presents a worst-case scenario

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Dirty Bomb Health Risks

• Non-linear, threshold model
• Biological damage does not follow a linear
  progression with exposure levels
• Data supports a threshold in excess of 10 rem
• Delivered at high dose rates
• 0.8 increase in lifetime risk for cancer
• Allows for cellular repair at lower doses
• 10 rem at low dose rates may not increase the
  risk

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Dirty Bomb Health Risks

• Acute Radiation Syndrome unlikely
• Also unlikely
• Other known sequelae of radiation exposure
• Cataract formation
• Decreased fertility
• Fetal teratogenesis
• Chronic Radiation Syndrome
• Requires at least 100 rem to bone marrow over a
  several year time span

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Dirty Bomb Decontamination

• Primary contaminants alpha and gamma emitters
• Shoe and clothing removal will reduce
  contamination by 90
• Other external contaminants are particulates that
  can be washed off the skin and hair
• Internal contaminants pose no secondary threat to
  healthcare workers

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Dirty Bomb Signs and Symptoms

• The primary injuries, and their associated signs
  and symptoms, will be related to blast trauma
• Signs and symptoms of Acute or Chronic Radiation
  Syndromes will not be seen
• (See Nuclear Reaction for more on these
  syndromes)

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Dirty Bomb Treatment

• Inhalation exposures
• Particles lt5 microns move into the alveoli
• Soluble particles absorbed into blood stream and
  lymphatic system
• Mucociliary apparatus will clear larger particles
• Inflammatory response with subsequent fibrosis
  and scarring
• Clearance of these insoluble particles
• Sputum induction and pulmonary toilet

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Dirty Bomb Treatment

• Ingestions
• Absorption depends on chemical state of the
  contaminant
• Cesium salts are quickly absorbed
• Cobalt, radium, and strontium are not absorbed
• Lower GI tract becomes target organ for residual
  radionuclides

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Dirty Bomb Treatment

• Ingestions
• Gastric lavage and emetics help clear stomach
• Purgatives, laxatives, and enemas can be
  administered to reduce colon exposure
• Inhaled particles cleared by the mucociliary
  apparatus end up in the GI tract
• Consider ion exchange resins to reduce GI uptake
  of these and other ingested radionuclides

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Dirty Bomb Treatment

• Skin
• Impermeable to most radionuclides
• Wounds and burns allow radioactive particles to
  by-pass the epithelium
• Meticulously clean and debride all wounds and
  burns

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Dirty Bomb Treatment

• Heavy metal poisoning
• Consider chelation therapy where appropriate
• Calcium edetate (EDTA)
• Used primarily to treat lead poisoning
• Also consider dimercaprol and penicillamine
• DTPA more effective in removing many of the
  heavy-metal, multivalent radionuclides

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Dirty Bomb Treatment

• Isotope specific treatments
• Americium-241
• Use DTPA or EDTA chelation in the first 24 to 48
  hours following pulmonary exposure
• Cesium-137
• Early use of lavage and purgatives
• Prussian blue and ion exchange resins are useful

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Dirty Bomb Treatment

• Isotope specific treatments
• Cobalt-60
• Gastric lavage and purgatives for ingestions
• Penicillamine chelation in severe cases
• Phosphorus-32
• Lavage, aluminum hydroxide, and oral phosphates.

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Dirty Bomb Treatment

• Isotope specific treatments
• Radium-226
• Immediately lavage after ingestion
• Fecal elimination may be increased by ammonium
  chloride

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Dirty Bomb Treatment

• Isotope specific treatments
• Strontium-90
• Oral administration of aluminum phosphate
  immediately after ingestion
• Administration of stable strontium
• Calcium and acidification of the urine with
  ammonium chloride will increase excretion

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Dirty Bomb Summary

• Known as a radiation dispersal device (RDD)
• Conventional explosive device with radiological
  material added
• Main threat is one of fear and disruption
• Most likely radioisotopes to be used cobalt-60,
  strontium-90, cesium-137, and americium-241

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Dirty Bomb Summary

• Major health risks include
• Acute blast trauma
• Cancer
• Specific target organ damage
• Heavy metal poisoning
• A non-linear, threshold model of exposure is
  favored by health physicists

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Dirty Bomb Summary

• Primary injuries will be related to blast trauma
• Signs and symptoms of Acute or Chronic Radiation
  Syndromes will not be seen
• Treatment rapid elimination of the radionuclide
  from the body
• Pulmonary toilet for inhalation exposures
• Gastric lavage and purgatives for ingestions
• Debridement and cleansing for skin wounds

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Dirty Bomb Summary

• Chelation therapy for cases of potential heavy
  metal poisoning
• Specific treatment regimens advised for each
  isotope with potential for use in a RDD