DPT 7.0
Terminal Objective
Recognize the various types of radiological hazards, understand the acute health effects from radiation
exposure, hospital procedures for managing exposed and/or contaminated patients, and know
how to use radiation protection.
DPT 7.0
Terrorist Use of Nuclear Material
• Terrorist use of nuclear materials– Simple radiological
device
– Radiological dispersal device
– Reactor
– Improvised nuclear device
– Nuclear weapon
DPT 7.0
The Basics of Radiation
Ionizing radiation is electromagnetic energy or energetic particle emitted from a source.
Ionizing radiation is able to strip electrons from atoms causing chemical changes in molecules.
DPT 7.0
The Basics of Radiation
Chemical Damage
Free Radicals
10-10 Seconds
1. Proteins2. Membrane3. DNA
BiologicalMolecularDamage
Cells, tissues,whole animals
Hours to years
BiologicalDamage
Seconds to hours
DPT 7.0
Ionizing Radiation - Alpha
• 2 neutrons and 2 protons
• Highly ionizing
• Travels several centimeters in air and a few microns in tissue
• Component of nuclear fallout
• Stopped by a thin paper or clothing
• Threat is inhalation or absorption of alpha emitter in wounds
DPT 7.0
Ionizing Radiation - Beta
• High energy “electron” emitted from nucleus
• Can have wide range of energies depending upon the particular radionuclide
• Moderately penetrating
– Up to a few meters in air
– Millimeters in tissue
• Some protection by PPE
DPT 7.0
Gamma or X-Ray (Photons)
• High energy rays
• Very penetrating
• Difficult to shield
• Can be produced from radioactive decay and a nuclear weapon explosion or reactor accident
• PPE will not protect against photon radiation
DPT 7.0
Ionizing Radiation - Neutrons
• Neutral particle emitted from the nucleus
• Can be very penetrating
• Requires special consideration for shielding
DPT 7.0
Radiation Detection
• Instrumentation– G.M. Survey Meter– Dose Rate Meter - Ionization Chamber– Alpha Meter– Neutron Meter
• Personal Dosimeters– Film Badge– Thermoluminescent Dosimeter– Quarts Fiber Dosimeter– Electronic Instantaneous Read Out Dosimeter
DPT 7.0
Radiation - Units of Measure
• rad - basic unit for measuring radiation
• rem - quantifies the amount of damage that is suspected from a particular type of radiation dose
DPT 7.0
X-RAY 100 rads = 100 rem
BETA 100 rads = 100 rem
GAMMA 100 rads = 100 rem
NEUTRONS 10 rads x QF10 = 100 rem
ALPHA 5 rads x QF20 = 100 rem
Radiation - Units of Measure
DPT 7.0
Substance Half Life Emit Use
Americium 241 458 years , Smoke Detectors
Cobalt 60 5.3 years , Medical Therapy
Plutonium 238 87 years Thermoelectric Gen.
Plutonium 239 24,400 yrs Reactors and Weapons
Radium 226 1,620 yrs Medical Therapy
Uranium (natural) millions yrs , Reactors and Weapons
Iridium 192 74 days , Industrial Radiography
Examples of Radioactive Materials
DPT 7.0
Radiation Half-Life
• Time required for a radioactive substance to lose half of its radioactivity
• Each radionuclide has a unique half-life
• Half-lives range from extremely short (fraction of a second) to millions of years
Examples:Tc-99m 6.0 hrsI-131 8.05 daysCo-60 5.26 yrsSr-90 28.1 yrsPu-239 24,400 yrsU-238 4,150,000,000 yrs
DPT 7.0
Natural Background Radiation
Natural background and manmade radiation 360 mrem
Diagnostic chest x-ray 10 mrem
Flight from LA to Paris 4.8 mrem
Barium enema 800 mrem
Smoking 1.5 ppd - 1 year dose 16,000 mrem
Heart catheterization 45,000 mrem
Mild acute radiation sickness 200,000 mrem
LD50 for irradiation 450,000 mrem
mrem = millirem = 1/1000 of a rem
DPT 7.0
Types of Radiation Injury
• External irradiation - whole-body or partial-body
• Contamination by radioactive materials - external (deposited on the skin) or internal (inhaled, swallowed, absorbed through skin, or introduced through wounds)
• Incorporation of radioactive materials - uptake by body cells, tissues, or organs (bone, liver, kidney, etc)
• Combined radiation injury - combination of the above complicated by trauma.
DPT 7.0
Radiation - LD50
• We know what radiations are produced
• We know how to measure them
• But the body senses cannot detect radiation. Therefore, how can we measure the biological damage?
– LD50/30 Animals
– LD50/60 Man
DPT 7.0
Examples of LD50 for Given Species
Species Dose (rads)
• Guinea Pigs 250 LD 50/30
• Goat 350 LD 50/30
• Man 250-450 (LD 50/60)
• Mouse 570 LD 50/30
• Rat 550-800 LD 50/30
• Frog 700 LD 50/30
• Snail 8,000-20,000 LD 50/30
DPT 7.0
Severity of Injury
The higher the dose, the more severe the early effects and the
greater the possibility of delayed effects
DPT 7.0
Survival Time
200 Rads2 Gy
1000 Rads10 Gy
100,000 Rads100 Gy
Hematopoietic
Gastrointestinal
CNS/ CVS
SurvivalTime
DPT 7.0
Acute Radiation Syndrome (ARS)
• Group of symptoms that develop after total body irradiation (> 100 rads)
• May occur from either internal or external radiation
• Four important factors are:– High Dose
– High Dose Rate
– Whole Body Exposure
– Penetrating Radiation
DPT 7.0
ARS - Phases
1. Prodromal Phase - occurs in the first 48 to 72 fours post-exposure and is characterized by nausea, vomiting, and anorexia. At doses below about 500 rads last 2 to 4 days.
2. Latent Phase - follows the prodromal phase and lasts for approximately 2 to 2 1/2 weeks. During this time, critical cell populations (leukocytes, platelets) are decreasing as a result of bone marrow insult. The time interval decreases as the dose increases.
3. Illness Phase - period when overt illness develops
4. Recovery or Death Phase - may take weeks or months
DPT 7.0
ARS - Hematopoietic Syndrome
3.0
2.5
2.0
1.5
1.0
0.5
0.10 3 6 17 24 48 hrs
Normal Range
Moderate
Severe
Very SevereLethal
Injury
Abs
olut
e Ly
mph
ocyt
es (
109/L
)
Patient
DPT 7.0
ARS - Blood Count
24-hr 1 week 2 weeks 3 weeks
Lymphocytes
Neutrophils
Platelets
RBC
Cell Reduction
DPT 7.0
ARS - Gastrointestinal Syndrome
• Radiation > 600 rads
• Damages intestinal lining
• Nausea and vomiting within the first 2 - 4 hours
• May develop diarrhea
• Associated with sepsis and opportunistic infections
• At 10 days could develop bloody diarrhea resulting in death
DPT 7.0
ARS - Central Nervous System
• Seen with radiation dose > 1,000 rads
• Microvascular leaks edema
• Elevated intracranial pressure
• Death within hours
DPT 7.0
ARS - Skin
ResponseE
pila
tion
Ery
them
a
Dry
Des
quam
atio
n
Moi
stD
esqu
amat
ion
Nec
rosi
s
300 600 1000 >1500 >5000
Dose
DPT 7.0
ARS & Trauma
• Radiation and Trauma = Mortality
• Wound and burn care, surgery, and orthopedic repair should be done in the first 48 hours or delayed for 2 to 3 months
24 - 48 Hours 3 Months
EmergencySurgery
Hemopoietic RecoveryNo Surgery
After 3 Months
SurgeryPermitted
DPT 7.0
Triage
• Triage:
– Use your own triage method
– Ensure ABC’s
– Stabilize the patient first and only when this is done does one consider irradiation and contamination.
DPT 7.0
Classification, Treatment & Disposition
• Patients are classified in three categories based on signs and symptoms:
– Survival probable < 100 rads
– Survival possible 200 - 800 rads
– Survival improbable > 800 rads
DPT 7.0
Evaluation & Treatment - Hospital Care
• Activate hospital plan
• Establish triage area
• Plan to control contamination– Prepare area by cover/marking floor, control ventilation
– Prepare staff by issuing protective clothing
– Prepare for surveying
– Establish area for storage of waste
– Plan for decontamination of non-traumatized patients
DPT 7.0
Hospital Care - Patient Arrival
• Carefully remove and bag victim’s clothing and personal belongings
• Survey patient and conduct biological sampling
• Contaminated patients require decontamination
• If patient has a wound, decontaminate it first, then decontaminate skin
DPT 7.0
Decontamination
• Irrigate open wounds and cover with sterile dressing
• Soap and water showering (including hair)
• Effective for mixed radiation/chemical contamination
• Refer for any surgery
DPT 7.0
Internal Contamination/Incorporation
• Various medications can be used to limit uptake or facilitate removal of radioactive material
• Numerous medications are approved by the FDA. Certain drugs are investigational and can be used in an emergency (i.e. Radiogardase [Prussian Blue] and DTPA)
• NCRP 65
DPT 7.0
Psychological Casualties
• Mass Casualty Incident (MCI) caused by nuclear terrorism will create large numbers of concerned casualties who may not actually be injured or contaminated
• Establishing counseling centers will prevent psychological casualties from overwhelming health care facilities
DPT 7.0
Key Points
• Pre-planning to ensure adequate supplies of PPE and survey instruments
• Training to ensure competence at all levels
• Rescue and treatment protocols vary little for radiation contamination
• Donning PPE and decontaminating patients minimizes exposure risk
• Early symptoms are an indication of the severity of the radiation dose
• Treatment requires a unified effort