Radiological and Nuclear Terrorism Practice Questions

25 multiple-choice questions on Radiological and nuclear terrorism for paramedic and EMT students, from Chapter 51 (Terrorism Response). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A radiological dispersal device (dirty bomb) is best described as:

   1. A. A small nuclear weapon with a very low yield
   2. B. A hidden source that irradiates passersby
   3. C. A reactor sabotaged so that it melts down
   4. D. Explosives packed with radioactive material
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   Answer: D. Explosives packed with radioactive material

   A dirty bomb uses conventional explosives to scatter radioactive material; there is no nuclear explosion. A low-yield nuclear weapon is the tempting confusion, but that is an improvised nuclear device, with far greater destruction.

2. At a dirty bomb explosion, most deaths and serious injuries result from:

   1. A. Acute radiation syndrome within hours
   2. B. Thyroid cancer from radioactive iodine
   3. C. The blast itself, not the radiation
   4. D. Radiation burns to the exposed skin
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   Answer: C. The blast itself, not the radiation

   The radioactive material in a dirty bomb is usually too dispersed to give doses that cause acute illness, so the explosion causes the real injuries. Acute radiation syndrome is unlikely; the larger effects are fear, disruption, and costly cleanup.

3. Over 3 weeks, several workers who sit in the same row of desks develop painless red patches on their thighs and hips that later blister, and two have falling blood counts. None recalls a burn or chemical contact. You should suspect:

   1. A. Cutaneous anthrax from spores in the mail
   2. B. A radioactive source hidden near the desks
   3. C. Contact dermatitis from a desk cleaning spray
   4. D. Bedbug bites from the office chairs
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   Answer: B. A radioactive source hidden near the desks

   Painless redness that appears and blisters days to weeks later in people who spent time in the same spot, with falling blood counts, fits cutaneous radiation injury from a hidden radiation exposure device; there is no history of heat because radiation is not felt. Notify public health and law enforcement and have the area surveyed. Cutaneous anthrax causes a single painless ulcer with a black eschar, not patches over a shared body area, and does not lower blood counts. Contact dermatitis itches and does not affect the bone marrow. Bedbug bites are itchy clusters that do not turn into burns or lower blood counts.

4. A radioactive source is hidden under a bench at a busy transit station, exposing people who sit nearby without any explosion. This is a:

   1. A. Radiological dispersal device
   2. B. Improvised nuclear device
   3. C. Nuclear power plant leak
   4. D. Radiation exposure device
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   Answer: D. Radiation exposure device

   A radiation exposure device (RED) is a hidden source that irradiates people near it but does not spread contamination. A dispersal device uses an explosion or spray to scatter radioactive material.

5. An improvised nuclear device differs from a dirty bomb because it:

   1. A. Scatters material with ordinary explosives
   2. B. Produces a nuclear explosion
   3. C. Spreads less radioactive material
   4. D. Causes no blast or thermal injury
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   Answer: B. Produces a nuclear explosion

   An improvised nuclear device creates a nuclear yield with massive blast, heat, prompt radiation, and fallout. Using conventional explosives to spread radioactive material describes a dirty bomb.

6. After a nuclear detonation 15 km (10 miles) away, the public is told to 'get inside, stay inside, stay tuned.' The best shelter location is:

   1. A. A parked car with the windows rolled up
   2. B. A wood-frame house, close to a large window
   3. C. The basement or center of a large building
   4. D. The top floor of an office tower
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   Answer: C. The basement or center of a large building

   Thick walls, earth, and distance from the roof and outer walls give the most shielding from fallout. A car gives almost no protection, and the top floor is exposed to fallout settling on the roof.

7. Sheltering in place for at least the first 24 hours after a nuclear detonation is advised mainly because:

   1. A. Fallout radiation drops quickly over time
   2. B. The blast wave returns after a few hours
   3. C. Fallout does not reach the ground for a day
   4. D. The pulse disables radios for 24 hours
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   Answer: A. Fallout radiation drops quickly over time

   Fallout radiation decays rapidly, falling by about 90% within 7 hours and about 99% within 2 days, so early sheltering prevents most of the dose. Fallout starts to arrive within minutes to hours, not after a day.

8. After a dirty bomb downtown, hundreds of uninjured people who were nearby want to know whether they are contaminated. Public health will usually direct them to:

   1. A. A community reception center for screening
   2. B. The nearest ED for a full radiation workup
   3. C. Their own doctors within the next week
   4. D. The blast site to be checked by EMS crews
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   Answer: A. A community reception center for screening

   Community reception centers are set up by public health away from hospitals to screen uninjured people for contamination, help them decontaminate, register them, and decide who needs dose assessment or follow-up; people with serious injuries go to hospitals instead. Sending uninjured people to the nearest ED would overwhelm it when it is needed for the injured. Waiting a week to see a personal doctor delays decontamination and screening. Sending people back to the blast site exposes them again and interferes with the crime scene.

9. The correct order of the phases of acute radiation syndrome is:

   1. A. Latent, prodromal, recovery, manifest illness
   2. B. Prodromal, latent, manifest illness, recovery
   3. C. Manifest illness, latent, prodromal, recovery
   4. D. Prodromal, manifest illness, latent, recovery
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   Answer: B. Prodromal, latent, manifest illness, recovery

   Early nausea and vomiting (prodromal) are followed by a symptom-free latent period, then the manifest illness, then recovery or death. Placing the latent phase first is tempting because the person may feel well at first, but the prodrome comes within hours.

10. A worker had nausea and vomiting the day after a large radiation exposure, then felt well for 2 weeks before becoming ill again. The symptom-free period is the:

    1. A. Prodromal phase
    2. B. Recovery phase
    3. C. Latent phase
    4. D. Manifest phase
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    Answer: C. Latent phase

    The latent phase is a deceptive period of feeling well while the bone marrow and gut lining fail beneath the surface. It is not recovery, because the manifest illness follows.

11. Two to four weeks after a large radiation dose, a patient develops bleeding gums and repeated infections. These problems reflect damage to the:

    1. A. Thyroid gland
    2. B. Skin and hair
    3. C. Brain and spinal cord
    4. D. Bone marrow
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    Answer: D. Bone marrow

    The hematopoietic syndrome results from loss of blood-forming cells, causing low platelets (bleeding) and low white cells (infection). Thyroid injury from radioactive iodine appears much later as cancer or hypothyroidism.

12. The hospital lab test most useful early on to estimate a victim's radiation dose is:

    1. A. Serial hemoglobin levels
    2. B. A single platelet count on arrival
    3. C. Serial absolute lymphocyte counts
    4. D. Serial serum lactate levels over 24 hours
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    Answer: C. Serial absolute lymphocyte counts

    Lymphocytes are very sensitive to radiation, and how fast they fall over the first 48 hours helps estimate the dose. Lactate reflects perfusion and does not measure radiation dose. Hemoglobin and platelet counts fall days to weeks later, so they do not help estimate the dose early.

13. After a dirty bomb made with cesium-137, a frightened bystander asks you for potassium iodide. You should explain that potassium iodide:

    1. A. Will not help, as cesium is not radioiodine
    2. B. Should be taken by people near the blast
    3. C. Will flush the cesium out of his body
    4. D. Shields his bone marrow from the gamma rays
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    Answer: A. Will not help, as cesium is not radioiodine

    Potassium iodide protects the thyroid against radioactive iodine by filling it with stable iodine. A cesium-137 dirty bomb releases no radioiodine, so KI offers no benefit and still carries side effects, which is also why it should not be handed out to people near the blast. It does not remove cesium from the body; a different drug is used for internal cesium. It gives no shielding from gamma radiation to the bone marrow or any other organ.

14. The drug used to help remove internal contamination with cesium-137 is:

    1. A. Potassium iodide
    2. B. Prussian blue
    3. C. DTPA chelation
    4. D. Dimercaprol
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    Answer: B. Prussian blue

    Prussian blue binds cesium (and thallium) in the gut so it is passed in the stool. DTPA is a chelating drug used for plutonium, americium, and curium, not cesium.

15. Survivors of a nuclear detonation who have both radiation exposure and burns or trauma:

    1. A. Heal faster, since radiation kills the bacteria
    2. B. Have the same outcome as with trauma alone
    3. C. Need no surgery until the latent phase ends
    4. D. Have higher death rates than with either alone
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    Answer: D. Have higher death rates than with either alone

    Radiation weakens the immune system and slows healing, so combined injuries are far deadlier than either alone; surgery should be done early, before marrow failure. The idea that radiation helps by killing bacteria is wrong; infection is a leading cause of death.

16. Survivors who were looking toward a nuclear detonation may have:

    1. A. Acute glaucoma from the bright light
    2. B. Immediate radiation cataracts
    3. C. Bleeding inside the eye
    4. D. Temporary flash blindness
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    Answer: D. Temporary flash blindness

    The intense light of a nuclear flash can cause temporary blindness lasting seconds to minutes, and sometimes retinal burns. Radiation cataracts take months to years to develop, bright light does not trigger acute glaucoma, and bleeding inside the eye comes from blunt or penetrating trauma rather than from looking at the flash.

17. A nuclear detonation's electromagnetic pulse (EMP) can:

    1. A. Spread the fallout much faster
    2. B. Disable radios and electronics
    3. C. Cause cardiac arrest in people nearby
    4. D. Cause the flash burns seen on skin
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    Answer: B. Disable radios and electronics

    EMP is a burst of energy that can damage electronic devices and communications over a wide area, so responders must plan for radio failure. It does not injure people directly: flash burns come from the thermal pulse, and the EMP does not stop the heart.

18. Responders at a radiological incident set a turn-back dose on their dosimeters. This reading tells them when to:

    1. A. Leave the area and stop working there
    2. B. Report the reading and keep working
    3. C. Move to a lower-dose task in the zone
    4. D. Put on a lead apron and continue
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    Answer: A. Leave the area and stop working there

    A turn-back dose is a preset exposure limit; when a responder reaches it, he or she leaves the hazard area, applying the time principle to limit total dose. Staying in the zone on a lighter task, or reporting the reading and continuing, keeps adding dose, and lead aprons give little protection from high-energy gamma radiation.

19. A hospital is reluctant to accept a seriously injured patient who has radioactive dust on his clothes. The best response is to explain that:

    1. A. Radiation decays to zero within a few minutes
    2. B. Field decon removed every trace
    3. C. Contamination rarely puts staff at risk
    4. D. Lead aprons in the ED will block the gamma rays
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    Answer: C. Contamination rarely puts staff at risk

    With standard precautions and removal of clothing, the dose to staff from a contaminated patient is very low, and refusing care is never justified for this reason. Radiation does not decay to zero in minutes, so that reassurance would be false. Field decon reduces contamination but rarely removes every trace, and lead aprons do little against high-energy gamma rays; staff are protected by standard precautions, removing clothing, and monitoring.

20. For a contaminated but stable patient after a dirty bomb, the most effective field decontamination is to:

    1. A. Remove clothing, then wash gently with soap and water
    2. B. Scrub hard with a stiff brush and dilute bleach solution
    3. C. Leave the decon for the hospital to do
    4. D. Rub the skin with alcohol wipes until it is red
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    Answer: A. Remove clothing, then wash gently with soap and water

    Removing clothing takes off most contamination, and gentle washing removes the rest without damaging skin. Hard scrubbing is tempting but abrades the skin and lets radioactive material be absorbed.

21. A dirty bomb victim's wound contains small pieces of radioactive debris. This is a concern mainly because the material:

    1. A. Will make the wound bleed more
    2. B. Can be absorbed into the body
    3. C. Burns the tissue at once
    4. D. Makes the wound unsafe to irrigate
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    Answer: B. Can be absorbed into the body

    Radioactive material in a wound can enter the body and cause internal contamination, so wounds are covered and irrigated by hospital staff. Irrigation is safe and helps wash fragments out, and radiation injury to nearby tissue develops over days to weeks rather than at once.

22. After a dirty bomb in a downtown area, the largest group seeking care at local hospitals is likely to be:

    1. A. Patients with acute radiation sickness
    2. B. Patients with crush injuries
    3. C. Uninjured people fearing exposure
    4. D. Patients with thyroid cancer
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    Answer: C. Uninjured people fearing exposure

    Fear of radiation drives many uninjured people to seek care, which can overwhelm EDs and is why public messaging and community screening sites matter. Acute radiation sickness is unlikely after a dirty bomb.

23. Fallout from a ground-level nuclear detonation is most dangerous:

    1. A. Upwind in the first minutes
    2. B. At ground zero, days later
    3. C. Spread evenly around the site
    4. D. Downwind in the first hours
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    Answer: D. Downwind in the first hours

    Fallout is carried by the wind and settles downwind, with the highest radiation levels in the first hours. Upwind areas receive little fallout, which is why responders approach from upwind.

24. A man near a dirty bomb blast begins vomiting 30 minutes after the explosion. He has minor cuts and is very anxious. The most likely cause of his vomiting is:

    1. A. Stress or blast injury, not radiation
    2. B. A lethal radiation dose from the bomb
    3. C. Thyroid uptake of radioactive iodine
    4. D. Internal cesium from his small cuts
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    Answer: A. Stress or blast injury, not radiation

    Dirty bombs rarely deliver doses high enough to cause early vomiting, so anxiety, head injury, or other blast effects are more likely. Early vomiting suggests a high dose after a nuclear detonation or exposure device, which is why it is tempting here.

25. Rescuers must reach a casualty lying 3 m (10 ft) from a scattered piece of a radioactive source. The best plan to limit their dose is to:

    1. A. Treat him fully where he lies first
    2. B. Shield him with a lead apron as you work
    3. C. Move the source with gloved hands
    4. D. Work fast, then move him well away
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    Answer: D. Work fast, then move him well away

    Spending little time near the source and increasing distance quickly cut the dose sharply, so the patient is moved before full treatment. A lead apron is too thin to block much penetrating gamma radiation, and picking up the source, even with gloves, gives the hands a very high dose; trained teams move sources with tools.