Radiological Terrorism

1
Radiological Terrorism

• Nuclear Reaction

2
Nuclear Reaction Overview

• Two main scenarios exist
• Nuclear blast (warhead, suitcase nuke)

XX-01 The Stokes Test, conducted at the Nevada
Test Site on August 7, 1957 U.S. Department of
Energy image
3
Nuclear Reaction Overview

• Two main scenarios exist
• Power plant reactor meltdown

Three Mile Island Nuclear Power Plant near
Harrisburg, Pennsylvania U.S. Department of
Energy image
4
Nuclear Reaction Overview

• Nuclear blast produces
• 60-second pulse of extremely high dose gamma and
  neutron radiation
• Radioactive fission products within the fallout
  area close to ground zero

XX-12 GRABLE was fired on May 25, 1953 at the
Nevada Test Site. U.S. Department of Energy image
5
Nuclear Reaction Overview

• Reactor meltdown produces
• High-level nuclear reaction releasing large
  amounts of gamma and neutron radiation
• Without an explosion

Nuclear Power Plant Cooling Towers U.S.
Department of Energy image
6
Nuclear Reaction Overview

• Meltdown is the result of
• Complete loss of the cooling system
• High heat melts containment rods in the reactor
  core

Nuclear Power Plant Cooling Towers U.S.
Department of Energy image
7
Nuclear Reaction Overview

• Both forms of nuclear reaction result in
• Sudden high dose gamma and neutron radiation
  release
• Major challenge for medical response
• High-level nuclear reactions are the only source
  of neutron radiation
• Produced only during nuclear reaction
• Not a fallout hazard

8
Nuclear Reaction Radioisotopes

• Plutonium-239/238 is the primary fissionable
  material used in power plants and weapons
• Uranium-238/235/234 may also be encountered
• (See Radiation Primer for more on these
  isotopes)

9
Nuclear Reaction Radioisotopes

• A nuclear reaction may produce
• Americium-241, a decay daughter of plutonium
• Strontium-90, a fission product of uranium
• Radioactive iodine (iodine-131/132/134/135), a
  fission by-product
• (See Radiation Primer for more on these
  isotopes)

10
Nuclear Reaction Health Risks

• The intense, high dose-rate exposure caused by a
  nuclear reaction produces both direct and
  indirect biological damage
• Direct by ionization of cells
• Indirect by ionization of body water, producing
  unstable, toxic hyperoxide molecules that can
  damage subcellular structures

11
Nuclear Reaction Health Risks

• Actively dividing cells are most vulnerable
• Hematopoietic and gastrointestinal systems

12
Nuclear Reaction Health Risks

• Without appropriate medical care
• The LD50/60 is estimated to be 3.5 Gy (equals 350
  rem for gamma radiation)
• With modern medical care
• Nearly all radiation casualties are considered
  treatable if care is quickly made available

13
Nuclear Reaction Health Risks

• Acute Radiation Syndrome is likely and of
  greatest concern
• Tumor induction is the most important long-term
  health sequelae from high dose radiation
• Latency period for radiation-related cancers may
  be several years

14
Nuclear Reaction Health Risks

• Other sequelae of radiation exposure include
• Cataracts
• 200 rem threshold for acute gamma exposure
• 1500 rem for chronic exposure
• May develop 6 months to many years later

15
Nuclear Reaction Health Risks

• Other sequelae of radiation exposure include
• Infertility
• Whole body exposure of 12 rem causes transient
  azoospermia 600 rem, permanent sterility

16
Nuclear Reaction Health Risks

• Ionizing radiation has four main effects on
  fetus
• Growth retardation
• Severe congenital malformations
• Embryonic, fetal, or neonatal death
• Carcinogenesis

17
Nuclear Reaction Health Risks

• Peak incidence of teratogenesis occurs during
  period of fetal organogenesis
• CNS is most commonly involved
• Other organ malformations are less likely in
  humans

18
Nuclear Reaction Decontamination

• Primary contaminants will be alpha and beta
  emitters
• Simply removing clothing and shoes will reduce
  contamination by approximately 90

19
Nuclear Reaction Decontamination

• Other external contaminants are particulates that
  can be washed off the skin and hair
• Internal contaminants pose no secondary threat to
  healthcare workers

20
Acute Radiation Syndrome

• Acute Radiation Syndrome (ARS) is the result of a
  sudden, high dose-rate exposure to radiation
• Presents as a sequence of phased symptoms
• Symptoms vary with individuals radiation
  sensitivity, type of radiation, and the dose

21
Acute Radiation Syndrome

• Prodromal phase
• Early onset of nausea, vomiting, and malaise, as
  well as fatigue, fever, headache, and diarrhea
• Larger doses produce symptoms earlier
• Radiogenic vomiting can be confused with
  psychogenic vomiting from stress and fear

22
Acute Radiation Syndrome

• Latent phase
• Relatively symptom-free period following the
  prodromal phase
• Longer in lower dose exposures causing only bone
  marrow suppression

23
Acute Radiation Syndrome

• Latent phase
• Shorter (days to a week) with higher doses
  leading to marrow suppression and
  gastrointestinal syndrome
• Brief (hours) in extremely high doses that
  produce CNS syndrome

24
Acute Radiation Syndrome

• Manifest illness phase
• Clinical symptoms of the injured organ systems
  are displayed
• Primary syndromes
• Bone marrow suppression
• Gastrointestinal Syndrome
• CNS (Neurovascular) Syndrome

25
Acute Radiation Syndrome

• Bone marrow suppression
• Not just marrow, but also spleen and lymphatic
  system all blood-forming organs
• Injury occurs with exposures gt100 rem (1 4 Gy)
• Peripheral blood smear changes within 24 hours

26
Acute Radiation Syndrome

• Bone marrow suppression
• Lymphocytes decrease most rapidly but ultimately
  pancytopenia develops
• Immune system compromise and anemia develop
  between 10 45 days post-radiation

27
Acute Radiation Syndrome

• Gastrointestinal Syndrome
• Occurs with exposures gt 600 1000 rem (6 10
  Gy)
• Stomach and intestinal tract injured
• After a short latent period, nausea, vomiting,
  diarrhea, dehydration, electrolyte imbalances,
  and bleeding ulcers with hemorrhage develop

28
Acute Radiation Syndrome

• Gastrointestinal Syndrome
• Damage to the luminal epithelium and submucosal
  vasculature causes the loss of intestinal mucosa
• Since marrow suppression also occurs, radiation
  enteropathy produces no inflammatory response

29
Acute Radiation Syndrome

• CNS (Neurovascular) Syndrome
• At doses gt2000 4000 rem (20-40 Gy), the CNS and
  other nervous tissue are damaged
• Victim displays a steadily worsening state of
  consciousness leading to coma and death
• Convulsions may or may not occur

30
Acute Radiation Syndrome

• CNS (Neurovascular) Syndrome
• Signs of ? ICP may or may not be evident
• Individuals receiving such high doses are well in
  range of 100 lethality due to blast and thermal
  effects

31
Acute Radiation Syndrome

• Other organ injuries
• 50 rem thyroid damage
• 125-200 rem ovarian damage
• 200-300 rem skin erythema and hair follicle
  damage
• 600 rem gonadal damage with permanent sterility

32
Chronic Radiation Syndrome

• Syndrome defined by exposure of at least 100 rem
  to the marrow for at least 3 years

33
Chronic Radiation Syndrome

• Victim complaints include
• Sleep/appetite disturbances
• Generalized weakness/rapid fatigue
• Poor concentration or impaired memory
• Headaches / chills
• Bone pain and hot flashes

34
Chronic Radiation Syndrome

• Clinical findings
• Localized bone or muscle tenderness
• Mild hypotension, tachycardia, intention tremor
• Ataxia, asthenia, and hyperreflexia

35
Chronic Radiation Syndrome

• Reproductive effects in exposed children include
  
• Delayed menarche
• Underdeveloped secondary sexual characteristics

36
Chronic Radiation Syndrome

• Lab findings include mild to marked pancytopenia
  and bone dysplasia
• Gastric hypoacidity and dystrophic changes may be
  present
• Clinical findings slowly resolve when patient is
  removed from continued exposure
• Complete recovery possible with lower doses

37
Treatment ARS

• During prodromal phase, provide supportive care
  and oral antiemetics
• Granisetron or ondansetron
• Antiemetics are not radioprotectants

38
Treatment ARS

• With bone marrow suppression, the prevention and
  management of infection governs therapy
• Antibiotic prophylaxis in afebrile patients with
  profound neutropenia (lt 0.1 x 109 cells/l)
• With prolonged neutropenia, risk of secondary
  infections increases

39
Treatment ARS

• With bone marrow suppression, the prevention and
  management of infection governs therapy
• Consider using cytokine hematopoietic growth
  factors, such as filgrastim or sargramostim, to
  stimulate hematopoiesis -- must be started
  within 72 hours of exposure

40
Treatment ARS

• It must be assumed during the care of all
  patients that even those with a typical
  gastrointestinal syndrome may be salvageable
• Replacement of fluids and prevention of infection
  by bacterial transmigration is mandatory

41
Treatment General

• Inhalation exposures
• Particles lt5 microns move into the alveoli
• Soluble particles are absorbed into the blood
  stream and lymphatic system
• Residual particles produce inflammatory response
  with subsequent fibrosis and scarring

42
Treatment General

• Inhalation exposures
• Mucociliary apparatus will clear larger particles
• Consider sputum induction and pulmonary toilet
  to aid the clearance of these insoluble particles

43
Treatment General

• Ingestions
• Absorption depends on chemical state of the
  contaminant
• Radioiodine is quickly absorbed
• Plutonium and strontium are poorly absorbed, if
  at all
• Lower GI tract becomes target organ for residual
  radionuclides

44
Treatment General

• Ingestions
• If used promptly, gastric lavage and emetics can
  help clear the stomach
• Purgatives, laxatives, and enemas can be
  administered to reduce colon exposure

45
Treatment General

• Inhaled particles cleared by the mucociliary
  apparatus end up in the GI tract
• Consider ion exchange resins to reduce GI uptake

46
Treatment General

• Skin
• Impermeable to most radionuclides
• Wounds and burns may hide weak alpha and beta
  emissions from detection
• All wounds and burns must be meticulously cleaned
  and debrided

47
Treatment General

• Heavy metal poisoning
• Consider chelation therapy where appropriate
• Calcium edetate (EDTA)
• Used primarily to treat lead poisoning
• Use with extra caution with preexisting renal
  disease

48
Treatment General

• Heavy metal poisoning
• Diethylenetriaminepentaacetic acid (DTPA) is more
  effective in removing many of the heavy-metal,
  multivalent radionuclides
• Also consider dimercaprol and penicillamine

49
Treatment Specific

• Isotope specific treatments
• Americium-241 Use DTPA or EDTA chelation in
  first 24 to 48 hours following pulmonary
  exposure.
• Plutonium-239/238 Administer 1 g CaDTPA within
  24 hours of exposure followed by 1 g ZnDTPA qd
  while monitoring urine levels.
• Radioiodine Potassium Iodide (see later slides)

50
Treatment Specific

• Isotope specific treatments
• Strontium-90
• Aluminum phosphate decreases absorption by up to
  85
• Stable strontium inhibits metabolism and
  increases excretion
• Calcium and acidification of urine with ammonium
  chloride increases excretion

51
Treatment Specific

• Isotope specific treatments
• Uranium-238/235/234
• Sodium bicarbonate
• Uranyl ion less nephrotoxic
• Tubular diuretics beneficial.
• Thorough laboratory evaluation

52
Treatment Specific

• Potassium Iodide (KI)
• Blocks thyroid's uptake of RAI and reduces cancer
  risk
• Protective effect lasts 24 hours
• Must be dosed daily until exposure risk no longer
  exists
• Pregnant women should be given KI
• Iodine (stable or radioactive) readily crosses
  the placenta

53
Treatment Specific

• Potassium Iodide (KI)
• Dose of 130 mg
• Adults over 40 (exposure gt500 rem)
• Adults 18 through 40 (exposure gt10 rem)
• Pregnant or lactating women

54
Treatment Specific

• Potassium Iodide (KI)
• Dose of 65 mg
• Children and adolescents (ages 3 to 18)
• Dose of 32 mg
• Children ages 1 month to 3 years
• Dose of 16 mg
• Infants (lt1 mo, exposure gt 5 rem)

55
Treatment Specific

• Potassium Iodide (KI)
• Pregnancy
• Expectant mothers should receive KI to protect
  themselves and their baby
• Repeat dosing should be avoided to prevent fetal
  thyroid dysfunction

56
Treatment Specific

• Potassium Iodide (KI)
• Lactation
• Lactating mother and nursing infant should both
  receive KI directly
• Repeat dosing should be avoided if possible
• Monitor infant closely if repeat dosing is
  required

57
Nuclear Blast Summary

• Acute, high-dose rate radiation exposure can
  occur from a nuclear explosion or power plant
  meltdown
• Can lead to sudden, high-dose gamma and neutron
  radiation exposures, and exposure to fission
  by-products within fallout area

58
Nuclear Blast Summary

• Plutonium-239/238, uranium-238/235/234,
  americium-241, strontium-90 and radioactive
  iodine may be encountered
• The intense, high dose-rate exposure caused by a
  nuclear reaction produces both direct and
  indirect biological damage

59
Nuclear Blast Summary

• Without appropriate medical care the LD50/60 is
  estimated to be 3.5 Gy (350 rem)
• Nearly all radiation casualties are considered
  treatable if care is quickly made available

60
Nuclear Blast Summary

• Acute Radiation Syndrome (ARS) presents as a
  sequence of phased symptoms
• Prodromal phase
• Latent phase
• Manifest illness phase
• Bone marrow suppression
• Gastrointestinal Syndrome
• CNS (Neurovascular) Syndrome

61
Nuclear Blast Summary

• Chronic Radiation Syndrome (CRS) may be
  encountered in people living in surrounding area
• Treatment of ARS focuses on supportive care,
  antiemetics (early), fluid replacement, and
  prevention of infection

62
Nuclear Blast Summary

• General treatment is aimed at 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

63
Nuclear Blast Summary

• Chelation therapy should be used for potential
  heavy metal poisoning
• Specific treatment regimens are advised for each
  isotope encountered
• Potassium Iodide is a specific therapy against
  radioactive iodine