Module 5 of 10 ~30 minutes

Radiation & Nuclear Emergencies

RDD, Nuclear Detonation, Acute Radiation Syndrome, and Medical Countermeasures

Radiation Types RDD vs Nuclear Countermeasures

Learning Objectives

1

Differentiate between alpha, beta, and gamma radiation and their clinical significance

2

Apply time, distance, and shielding principles for radiation protection

3

Differentiate RDD (dirty bomb) from nuclear detonation scenarios

4

Recognize all four phases of Acute Radiation Syndrome (ARS)

5

Implement the correct radiological decontamination sequence

6

Select appropriate radiation countermeasures based on specific radionuclides

Radiation Basics

Understanding radiation types is essential for selecting appropriate protective measures and assessing patient risk.

Video: Understanding Radiation Emergencies

Type Symbol Penetration Shielding Clinical Concern
Alpha (α) α LOW - stopped by paper, skin Paper, clothing, intact skin INTERNAL hazard - dangerous if inhaled/ingested
Beta (β) β MEDIUM - penetrates skin Plastic, glass, aluminum Skin burns, internal hazard
Gamma (γ) γ HIGH - penetrates body Lead, concrete, thick steel EXTERNAL hazard - whole-body exposure
Neutron n VERY HIGH Water, concrete, polyethylene Nuclear detonation; activates tissues

Key Concept: External vs Internal Contamination

External Contamination

Radioactive particles ON the skin/clothing. Easily removed by decontamination. Once removed, patient is NOT radioactive.

Internal Contamination

Radioactive material INSIDE the body (inhaled, ingested, wound). Requires specific countermeasures. Delivers continuous dose.

Radiation Protection: Time, Distance, Shielding

TIME

Minimize time spent near radioactive source

Application: Work quickly but efficiently. Rotate staff to limit individual exposure time.

DISTANCE

Dose decreases rapidly with distance (inverse square law)

Inverse Square Law: Double the distance = 1/4 the dose. Triple = 1/9 the dose.

SHIELDING

Place material between you and the source

Materials: Lead aprons, concrete walls, closed doors. Even distance from a wall helps.

Practical Example

If you're receiving 100 mR/hr at 1 meter from a source:

  • • At 2 meters: 100 ÷ 4 = 25 mR/hr
  • • At 3 meters: 100 ÷ 9 = 11 mR/hr
  • • At 10 meters: 100 ÷ 100 = 1 mR/hr

Radiological Dispersal Device (RDD) - "Dirty Bomb"

What is an RDD?

A conventional explosive combined with radioactive material. The explosion disperses radioactive contamination over an area.

Primary Goal

PANIC and economic disruption

Primary Injuries

BLAST trauma, NOT radiation

Radiation Level

Usually LOW-level exposure

Contagious?

NO - not transmissible

CRITICAL: RDD Management Priorities

  1. 1
    TREAT LIFE-THREATENING TRAUMA FIRST

    Radiation injuries are NOT immediately life-threatening. Blast injuries kill quickly. Control hemorrhage, manage airway, treat shock.

  2. 2
    DECONTAMINATE

    Remove ALL clothing (eliminates 80-90% of contamination). Wash with soap and water.

  3. 3
    COUNTERMEASURES (if indicated)

    Administer specific agents only if internal contamination is confirmed and radionuclide is identified.

Healthcare Worker Safety

Standard PPE (gown, gloves, surgical mask) provides adequate protection for treating contaminated patients.

  • • External contamination does NOT penetrate intact skin
  • • N95/PAPR recommended if patient has not been decontaminated (inhalation risk)
  • • Once decontaminated, patient poses NO radiation risk to staff

Nuclear Detonation vs. RDD Comparison

Characteristic RDD ("Dirty Bomb") Nuclear Detonation
Mechanism Conventional explosive + radioactive material Nuclear fission/fusion chain reaction
Radiation Dose Low - dispersed over wide area Very High - concentrated exposure
Primary Casualties Blast/trauma injuries Blast, thermal burns, radiation
ARS Expected? Unlikely Yes - mass casualties
Fallout Limited local contamination Widespread radioactive fallout
Infrastructure Local damage Massive destruction, EMP effects

Acute Radiation Syndrome (ARS)

ARS occurs after large whole-body doses of penetrating radiation (typically >0.7 Gy or 70 rad) delivered in a short time period. This is characteristic of nuclear detonation, NOT typical dirty bombs.

Four Phases of ARS

Remember: P-L-M-R (Prodromal, Latent, Manifest, Recovery)

1

PRODROMAL PHASE (Hours to Days)

Symptoms: Nausea, vomiting, diarrhea, fatigue, fever

Key Point: Onset time and severity of vomiting PREDICTS radiation dose:

  • • Vomiting within 1 hour = HIGH dose (likely fatal)
  • • Vomiting at 2-4 hours = Moderate dose
  • • Vomiting after 4+ hours = Lower dose
2

LATENT PHASE (Days to Weeks)

Symptoms: Patient appears to RECOVER - feels better, symptoms resolve

Key Point: This is the "WALKING GHOST" phase. Patient looks fine but cellular damage is occurring.

Duration: Higher dose = shorter latent period (may be hours with massive exposure)

3

MANIFEST ILLNESS PHASE (Weeks)

Symptoms: Clinical syndrome emerges based on dose received

Severity depends on which organ system fails first:

4

RECOVERY OR DEATH (Weeks to Months)

Outcome: Depends on dose, treatment, and supportive care

Survivors may have long-term complications including increased cancer risk

ARS Syndromes by Dose

Syndrome Dose (Gy) Primary Effects Prognosis
Hematopoietic 0.7 - 10 Gy Bone marrow suppression, pancytopenia, infection, bleeding Survivable with aggressive supportive care
Gastrointestinal >10 Gy GI mucosal destruction, severe diarrhea, sepsis, fluid loss Poor prognosis even with treatment
Cardiovascular/CNS >20-50 Gy Cardiovascular collapse, cerebral edema, death within hours-days Uniformly fatal

CRITICAL POINT

Once externally decontaminated, the patient is NOT radioactive and NOT contagious. They can be safely treated with standard precautions.

Radiological Decontamination

Correct Decontamination Sequence

1
REMOVE ALL CLOTHING

Eliminates 80-90% of external contamination. Bag and label for disposal.

2
SURVEY WITH GEIGER COUNTER

Identify remaining "hot spots" of contamination on skin.

3
WASH WITH SOAP AND WATER

Gently wash contaminated areas. Avoid abrasion (damages skin, drives contamination deeper).

4
RE-SURVEY

Repeat washing and surveying until clean or readings plateau.

DO

  • • Flush contaminated wounds FIRST
  • • Use lukewarm water
  • • Wash from head to toe
  • • Pay attention to hair, nails, skin folds
  • • Collect runoff if possible

DON'T

  • • Use hot water (opens pores)
  • • Scrub aggressively (damages skin)
  • • Use abrasive brushes
  • • Delay life-saving trauma care for decon
  • • Contaminate wounds during washing

Radiation Countermeasures

Different radionuclides require different countermeasures. There is NO universal "radiation antidote."

Radionuclide Countermeasure Mechanism Notes
Iodine-131 Potassium Iodide (KI) Saturates thyroid, blocks uptake of radioactive iodine ONLY protects thyroid; ONLY works for iodine
Cesium-137 Prussian Blue Binds cesium in GI tract, prevents reabsorption Oral medication; expect blue stool
Plutonium, Americium, Curium Ca-DTPA / Zn-DTPA Chelating agent; enhances urinary excretion IV or nebulized; start with Ca-DTPA
Uranium Sodium Bicarbonate Alkalinizes urine, enhances excretion IV infusion; target urine pH 8-9
Tritium (H-3) Increased Fluids Dilution and enhanced excretion >3-4 liters/day for 3 weeks

CRITICAL: KI Limitations

Potassium Iodide (KI) is often misunderstood. It is NOT a universal radiation protector!

  • • ONLY protects the THYROID gland
  • • ONLY works against radioactive IODINE (I-131)
  • • Does NOT protect against cesium, plutonium, or other radionuclides
  • • Does NOT treat radiation sickness
  • • Must be given BEFORE or shortly AFTER exposure

Expert Consultation

For radiation emergencies, contact:

REAC/TS (Radiation Emergency Assistance Center/Training Site)

Oak Ridge, Tennessee

865-576-1005 (24/7)

Nursing Interventions for ARS

Hematopoietic Syndrome

  • • Strict neutropenic precautions
  • • Monitor CBC daily
  • • Administer G-CSF (Neupogen/Filgrastim)
  • • Blood product transfusions PRN
  • • Broad-spectrum antibiotics for fever
  • • Bleeding precautions

GI Syndrome

  • • Aggressive fluid resuscitation
  • • Electrolyte replacement
  • • Anti-emetics, anti-diarrheals
  • • TPN if severe GI damage
  • • Pain management
  • • Infection prevention

Psychosocial Considerations

Radiation events cause significant psychological distress, often disproportionate to actual medical risk:

  • • Provide accurate, reassuring information
  • • Address fears directly - don't dismiss concerns
  • • Document all exposures for medical-legal purposes
  • • Refer for mental health support as needed
  • • Connect with health department for registry and follow-up

Key Takeaways

Alpha radiation = internal hazard; Gamma = external hazard (penetrates body)

Time, Distance, Shielding - inverse square law for distance

Dirty bombs cause BLAST injuries primarily; radiation is usually low-level

TREAT TRAUMA FIRST - radiation injuries are not immediately fatal

ARS phases: Prodromal → Latent ("walking ghost") → Manifest → Recovery/Death

Decontamination sequence: Remove clothing → Survey → Wash → Re-survey

KI ONLY protects thyroid from radioactive iodine - NOT a universal antidote

Decontaminated patients are NOT radioactive and NOT contagious

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