Dirty Bomb — Immediate Actions

A dirty bomb — technically a Radiological Dispersal Device (RDD) — combines conventional explosives with radioactive material. When it detonates, the explosion scatters radioactive contamination over a localised area. It is not a nuclear weapon: there is no nuclear blast, no mushroom cloud, and the immediate explosive danger is from the conventional component, not a nuclear reaction.

Understanding what a dirty bomb actually does — and does not do — is critical to responding correctly in the first minutes.

What a Dirty Bomb Does

Effect	Scope
Conventional explosion	Immediate blast injuries within the explosion radius
Radioactive contamination	Particles spread over blocks to square kilometres depending on device
Fear and panic	Often greater impact than the radiation itself
Area denial	Contaminated zone requires professional cleanup

What a dirty bomb does NOT do:

• Create a nuclear explosion
• Cause immediate radiation sickness in most nearby people (except those very close to the radioactive source)
• Necessarily kill large numbers — the radiation dose from most dirty bombs is not immediately lethal to people beyond the explosion radius

⚠️ The greatest immediate danger from a dirty bomb is the explosion itself — blast, heat, and building collapse. After the explosion, the risk is ongoing contamination through inhalation and ingestion of radioactive particles.

Step 1: Survive the Explosion

If you are close to an explosion:

1. Get down and cover — the primary blast wave is the immediate threat.
2. Protect your head and torso from flying debris.
3. If inside a building, move away from windows — glass fragmentation is a major cause of blast injuries.
4. After the initial blast, check yourself for injuries before moving.

Step 2: Move Away From the Blast Site

Once you can safely move:

1. Leave the area immediately — move away from the explosion site.
2. Cover your nose and mouth — use an N95 mask, cloth, or any available covering. This reduces inhalation of contaminated particles (the primary internal exposure route).
3. Move upwind — contamination travels downwind; moving upwind reduces your exposure.
4. Do not return to retrieve belongings — exiting the contaminated zone takes priority.

Step 3: Decontaminate as Soon as Possible

Once clear of the immediate area:

1. Remove outer clothing — this removes approximately 80% of contamination. Use the roll-inward technique; bag and seal the clothing.
2. Cover your skin with any clean material until you can wash.
3. Wash exposed skin with soap and water — a thorough wash removes most surface radioactive particles.
4. Do not rub your skin — gentle washing is more effective than scrubbing.
5. Flush eyes if you think you had eye exposure.

Step 4: Seek Medical Assessment

After decontamination:

1. Go to a medical assessment point — authorities will establish these near but outside the contaminated zone.
2. You will be assessed with a radiation detector — this takes only seconds and confirms whether you have residual contamination.
3. Provide information about: your location during the explosion, how close you were, what direction you moved.
4. Receive a dosimetry badge if provided — this monitors your cumulative dose.

Do not go directly to a hospital emergency department without decontaminating first — you may contaminate the facility and other patients.

What Not to Do

Action	Why to Avoid
Returning to the scene	Ongoing exposure; potentially higher-concentration zone
Eating or drinking before decontaminating	Ingestion of contaminated particles
Touching face before washing hands	Ingestion and eye/nasal exposure
Driving through the contaminated zone	Contaminates your vehicle; spreads to new areas
Panic-driven decisions	Rational action within minutes reduces total dose significantly

If You Are Trapped or Cannot Move

If the explosion has trapped you in the contaminated zone:

1. Cover your mouth and nose with any available material.
2. Minimise movement — staying still reduces the particles you stir up.
3. Do not eat or drink anything in the area.
4. Signal for rescue — emergency teams will have appropriate PPE to enter.
5. Await decontamination by responders before being moved to a medical facility.

Radiation Dose Reality Check

The radiation dose from a dirty bomb at typical distances from the source is much lower than many people fear:

• A person 100 metres from the explosion who leaves the area promptly receives a small fraction of an annual dental X-ray dose from fallout particles
• Radiation sickness (acute radiation syndrome) requires very high doses — unlikely from brief exposure to a dirty bomb at distance
• The long-term cancer risk from a single dirty bomb exposure for most people is very small

This does not mean dismissing the event — it means that rational, prompt action dramatically limits exposure and that panic-induced decisions (like staying in the area to help without protection) create more harm than the radiation itself.

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Quick Reference

Step	Action
Explosion occurs	Get down; cover head; move from windows
After blast	Leave area immediately; upwind; cover nose/mouth
Once clear	Remove outer clothing (bag it); wash skin and eyes
Then	Medical assessment point (not hospital directly)
Avoid	Returning; eating before washing; touching face; driving through zone