Lecture 7 - McMaster University

Acute Radiation Syndromes
Lecture 7
May 24, 2012

What is Acute Radiation Syndrome (ARS) ?
An acute illness caused by irradiation of the entire body by a high dose
of penetrating radiation in a very short period of time.
Conditions for Acute Radiation Syndrome:
• The radiation dose must be large
• The dose usually is external
• The radiation is penetrating
• The entire body
• The dose must have been delivered in a short time (acute)

Acute Radiation Syndrome
Lethal Dose (LD) 50 - the dose that will kill
50% of the population.
LD 50 (1) – means lethal dose to kill 50% of
population within 1 day.

3 Types of Acute Radiation Syndrome are:
• Hematologic (Bone Marrow) Syndrome
• Gastrointestinal (GI) Syndrome
• Central Nervous System (CNS) Syndrome

The 4 stages of Acute Radiation Syndrome are:
• Prodromal stage- 1 st set of symptoms occurs. (nausea, vomiting,
diarrhea)
• Latent stage- patient looks and feels generally healthy
• Manifest illness stage- prodromal stage symptoms reoccur along with
additional symptoms
• Recovery or death stage- Most patients who do not recover will die
within several months of exposure.

• Occurs between 1 Gy and 10 Gy
•
• Death occurs within 6-8 weeks at doses of 2 Gy for some individuals
• Death is caused by reduction of:
red blood cells
white blood cells
platelets
• Death results from anemia and infection

Prodromal Stage:
• Occurs 1 hour to 2 days after exposure
• Symptoms are anorexia, nausea and vomiting.
• Stage lasts for minutes to days
Latent Stage:
• Occurs from a few days up to 3 weeks after exposure
• Stem cells in bone marrow are dying, even though the patient may look
and feel well
Manifest Illness Stage:
• Reduction in blood cell count
• Occurs 3-5 weeks after exposure
• Symptoms are cytopenia, which causes anemia and infections

Recovery or death stage:
• 1.0 – 3.0 Gy bone marrow cells will begin to repopulate enough to
sustain an individuals life span.
• During the 3 rd week – 6 months a large percentage of these individuals
will fully recover.
• 4.0 – 6.0 Gy will have fewer survivors
• 10.0 Gy no survivors
• Survival decreases with increase in dose

• Occurs due to damage of the GI tract lining (bone marrow is done)
• Occurs with a dose of plus 10 Gy
• Symptoms appear at a threshold dose of about 6.0 Gy
• Survival time does not vary with dose
• Death happens at the same time regardless of the dose received

Prodromal Stage:
• Occurs within hours after exposure
• Symptoms are nausea, vomiting, cramps and diarrhea
Latent Stage:
• Occurs though the fifth day
• Stem cells in bone marrow and cells lining GI tract are dying, even
though patient may look and feel well.
Manifest Illness Stage:
• Reoccurrence of nausea, vomiting and diarrhea along with a fever
• Occurs from the fifth through the tenth days
Recovery or death stage:
• GI tract attempts regeneration after irradiation
• Death results from infection, dehydration and electrolyte imbalance
• Death occurs within 2 weeks of exposure

• Occurs at radiation doses of 50-100 Gy
• Death occurs in hours or sometimes 2-3 days after exposure
• CNS damage results from damage to the blood vessels that supply the
system, causing:
Edema- (swelling) in the cranial vault
Vasculitis- inflammation of blood vessels
Meningitis- inflammation of the spinal cord and brain
membranes
• Death is caused by increased pressure in the cranial vault as a result of
elevated fluid content

Prodromal Stage:
• lasts for minutes to a few hours
• Symptoms are nervousness, confusion, severe nausea, vomiting,
diarrhea, loss of consciousness, and burning sensations of the skin
Latent Stage:
• Last for several hours
• Patient may return to partially functional state
Manifest Illness Stage:
• Occurs 5-6 hours after exposure
• Symptoms are diarrhea, convulsions, coma and death
Recovery or death stage:
• No recovery is expected
• Death occurs within 3 days
Vasculitis �

Hematologic Syndrome is the destruction of bone marrow
caused by a reduction in production of red blood cells, white
blood cells and platelets resulting from radiation exposure.
Death may occur as a result of anemia and infection.
Gastrointestinal syndrome is exhibited by nausea , vomiting,
diarrhea as a result of damage to the villi in the small
intestine which leads to lack of absorption. Resulting in
dehydration and Infection.
Central Nervous System Syndrome is exhibited by
nervousness, confusion, nausea, vomiting, loss of
consciousness, and a burning sensation of skin which are the
result of damage to blood vessels and increased intracranial
pressure.

Acute Radiation Syndromes:
Radiation Accidents

• Since 1945 there have been at least 60 criticality accidents. These have caused at least 21 deaths: seven in the United States,
ten in the Soviet Union, two in Japan, one in Argentina, and one in Yugoslavia. Nine have been due to process accidents,
with the remaining from research reactor accidents.
• On 4 June 1945, Los Alamos scientist John Bistline was conducting an experiment to determine the effect of surrounding a
sub-critical mass of enriched uranium with a water reflector. The experiment unexpectedly became critical when water
leaked into the polyethylene box holding the metal. Three people received non-fatal doses of radiation.
• On 21 August 1945, Los Alamos scientist Harry K. Daghlian, Jr. suffered fatal radiation poisoning after dropping a tungsten
carbide brick onto a sphere of plutonium, which was later nicknamed the demon core. The brick acted as a neutron
reflector, bringing the mass to criticality. This was the first known criticality accident causing a fatality.

• Harry K. Daghlian
Video

Accidents And Emergencies
- Populations (Chernobyl)
- Individuals (Thailand)
Chernobyl
Bangkok, Thailand

• RBMK-1000 reactors
Chernobyl NPP
before the accident
• Units 1-4 online 1977-1983, producing ~10% of
Ukraine’s power
• Units 5-6 under construction
• Total of 12 units planned

• Occurred at 1:24 am
April 26, 1986
• Attempting test during
routine shutdown of
unit 4
• Massive steam explosion
followed by fuel vapour
explosion, and fires
• Design and operator
errors to blame
Chernobyl NPP
the accident
Courtesy of Viktor Krasnov

Chernobyl NPP
after the accident
• Approximately 5000t of material (boron,
dolomite, lead, sand and clay) dumped on core
• May 5, 1986 fire extinguished
• Oct-Nov 1986 units 1 and 2 back online
• Dec 1987 unit 3 operational
• Dec 1991 fire in unit 2, shutdown permanently
• 1996 unit 1 taken offline
• 2000 unit 3 taken offline

• 28 deaths within weeks
directly resulting from
acute radiation syndrome
– 20 received 6-16 Gy,7 4-6
Gy and 1 received 2-4 Gy
• 600,000 people classified
as ‘liquidators’
• 116,000 people
evacuated in 1986,
another 220,000
relocated after 1986
Chernobyl NPP
effects

Accident Biological Dosimetry
Bangkok, Thailand

Accident History
•Location : Samutprakarn Province (10 km south of Bangkok)
•10 people admitted to hospital for radiation sickness
•exposure Feb. 1, 2000 to Feb. 18, 2000
•Office of Atomic Energy for Peace (OAEP) notified Feb 18

Accident (Feb 1-18, 2000)
•3 people died
•9 people had clinical symptoms (ARS), 4 received
doses over 6 Gy
•1263 people examined
•824 blood samples were counted
•28 blood samples collected by McMaster
University for cytogenetics (May 2000 ~ 3 and 16
months later)
•12 samples sent to AFRRI (PCC)

The 60 Co Source
•Problem - 3 improperly stored teletherapy
units
•1 unit was dismantled (100kg
cylinder removed, 10” diameter x 20”
long)
•cylinder was cut open releasing
source
1”
2”

Building
7.05m
1.46m
3.35m
18.50m
Yard
Co-60
5.98m
425-450 Ci
7.0m
26.08 m
1 meter ~ 2 Sv/h

Radiation burn on both hands of P /LS ( taken on

Radiation burn on both hands of P /LS ( taken on

Epilation and skin lesion of P /NP

Acute radiation syndrome
Relation between the proportion of people with severe
epilation (loss of more than 2/3 of hair) and estimated
radiation dose.

Case Study: Nesvizh, Belarus
Irradiation Facility Accident

Case Study: Nesvizh (cont)
• 26 October 1991
• 1890 Ci Co-60 source used for steralization of
medical syringes & sponges
• 34 year old experienced operator
• 03:40 jam occurs in transport mechanism
(decoupling of linkage arms)
• Operator enters maze to fix coupling

Assumed position
of the operator
during exposure
(time ~ 1.5 minutes)

Dose
estimated
using ESR
(Gy)
Note: the
LD50 for
whole body
irradiation is
4.5 - 6 Gy.

Dry pit with movable floor
section at maze entrance.

Consequences
• Initial (0-7 days) - Latent period
– When operator sees source in upper position, he
noted a metallic taste in mouth and a feeling of
heat on his face.
– About 6 minutes post-exposure, experiences
nausea and vomiting, recurring over next 6 hours.
– Within 15 minutes, single case of diarrhea.
– Low psychological state

Consequences (cont)
• Clinical (8-39 days) - ARS
– Fever
– Blood changes
– Mucositis and oral herpes
– Intestinal bleeding
– Skin injuries appearing on day 11
• erythema, edema, wet desquimation
– Severe pain in feet
– Infection starts

Skin injury to buttocks (day 18)

Almost total body erythema (day 32)

Consequences (cont)
• Clinical (40-70 days) - Stable period
– Patient stabilizes
– Hepatitis indications begin
– Pneumonia indications begin
– Depilation (hair loss)
– Patient still on IV nutrition

Skin injury to legs
(day 53)

Consequences (cont)
• Clinical (102-113 days) - Terminal period
– Lung biopsy performed
– Sudden rise in body temperature
– Respiratory insufficiency
– Severe respiratory syndrome
– Intoxication
– Renal insufficiency
– Dies on day 113 caused by respiratory distress