Radiation tends to be a word that conjures up fear for some so I thought I would offer some basic considerations to keep in mind. The recent concern over North Korea testing a hydrogen bomb and the report the brothers behind the latest Brussels bombing hoped to build a so-called “dirty bomb,” offers a teaching moment for organizations.
Is a dirty bomb a nuclear weapon?
No. Nuclear weapons involve a complex nuclear-fission reaction and are thousands of times more devastating.
Is a dirty bomb a weapon of mass destruction?
Yes, but more because of its capacity to cause terror and disruption than its ability to inflict heavy casualties. Depending on the sophistication of the bomb, wind conditions, and the speed with which the area of the attack was evacuated, the number of deaths and injuries from a dirty bomb explosion might not be substantially greater than from a conventional bomb explosion. But panic over radioactivity and evacuation measures could create chaos. Moreover, the area struck would be off-limits during cleanup efforts, effectively paralyzing a local economy and reinforcing public fears.
Has a dirty bomb ever been detonated?
No. According to a UN report, Iraq tested a one-ton radiological bomb in 1987 but gave up on the idea because the radiation levels it generated were insufficient. In 1995 Chechen rebels planted, but failed to detonate a dirty bomb consisting of dynamite and cesium 137 in Moscow’s Ismailovsky Park. 
In 2002 the United States arrested an alleged al-Qaeda operative, Jose Padilla, for plotting to build and detonate a dirty bomb in an American city.
If we agree the threat of a dirty bomb is at least possible, let’s review some facts about radiation. The United States Department of Energy sets a maximum annual occupational limit at 5,000 mrem, maximum emergency dose for saving property at 10,000 mrem and the maximum emergency dose for saving a life at 25,000 mrem. We all get around 360 mrem per year from naturally occurring background radiation. A chest x-ray adds about 10-20 mrem. Flights add on 0.5 mrem for every hour in the air. Smoking 1.5 packs/day adds 16,000 mrem per year. Mild radiation sickness occurs at about 200,000 mrem and a lethal dose of radiation is 450,000 mrem.
In a dirty bomb the blast effects and shrapnel of the conventional explosive device cause the most physical harm to victims. The intent is to spread radioactive contamination over some area, potentially causing physical harm via exposure to radioactive material but even greater psychological impact due to the public’s fear of radiation. Exposure means a person may have been subject to radiation energy, but they are not contaminated and themselves pose no risk of spreading radioactive material to others. Contamination means a person has radioactive particulate material on them. This is most likely in a dirty bomb. Contamination itself is not an acute medical emergency and it’s presence should not preclude delivery of life-saving care.
Protection from radioactive damage is obtained through:
Time – limit the time you are near any source of radioactive material
Distance – The inverse square rule applies. When you double your distance from the source, the amount of radiation goes down by a factor of four. Conversely exercise caution about approaching a source of radiation since every time you halve the distance, your dose rate increases by four.
Shielding – As ionizing radiation passes through matter, the intensity of the radiation is diminished. Shielding is the placement of an “absorber” between you and the radiation source. An absorber is a material that reduces radiation from the radiation source to you. Alpha, beta, or gamma radiation can all be stopped by different thicknesses of absorbers. Shielding material can include barrels, boards, vehicles, buildings, gravel, water, lead or whatever else is immediately available.
ALPHA – can be stopped after traveling through about 1.2 inches of air, about 0.008 inches of water. A thin piece of paper, or even the dead cells in the outer layer of human skin provides adequate shielding because alpha particles can’t penetrate it. However, living tissue inside the body offers no protection against inhaled or ingested alpha emitters. Covering your nose and mouth with your shirt fabric to filter out airborne dust post blast would be wise.
BETA – can only be stopped after traveling through about 10 feet of air, less than 2 inches of water, or a thin layer of glass or metal. Additional covering, for example heavy clothing, is necessary to protect against beta- emitters. Some beta particles can penetrate and burn the skin. Had the Chechen device been detonated, BETA would have been the primary radioactive hazard. Quite manageable if thought is given to the correct response based on risk.
GAMMA: To reduce typical gamma rays by a factor of a billion, thicknesses of shielding need to be about 13.8 feet of water, about 6.6 feet of concrete, or about 1.3 feet of lead. Thick, dense shielding is necessary to protect against gamma rays. The higher the energy of the gamma ray, the thicker the shield must be. X-rays pose a similar challenge. This is why x-ray technicians often give patients receiving medical or dental X-rays a lead apron to cover other parts of their body.
Medical Response Considerations to a Dirty-bomb Event
- Enter obviously contaminated area only to save a life or provide necessary first-aid. Limit entry to shortest possible time. Remember – Time, Distance and Shielding
- Life-saving first-aid takes priority over dealing with radiation in most cases. Symptoms related to radiation exposure will be delayed. Treat other medical or trauma conditions by normal protocol.
- Wear respiratory protection, gloves and protective clothing, if available.
- Approach victims with radiation detection equipment, if available, and know how to use it.
- Move victim away from the radiation source, if possible, without endangering the patient.
- Contamination Control Procedures
- Wipe around the patient’s mouth before applying oxygen mask or respirator. Be cautious if intubating patients.
- For intravenous therapy, use uncontaminated area on patient if possible.
- Gently brush away dry particles and blot absorbent material and any excess liquids that are present.
- Field decontamination should normally be limited to removal of clothing, jewelry and shoes. Further field decontamination should only be attempted by trained personnel. Only in rare cases should decontamination delay other emergency response actions.
- Wrap patient using two blanket method. Rescue crews should pass patient over perimeter control line to ambulance crews.
- Notify hospital of contaminated patients as early as possible. Use entrance directed by hospital.
- If it is possible that you have been contaminated,notify the hospital and remain in the ambulance.Allow hospital personnel to unload the patient.
When I was a young twenty-something EMT I didn’t really appreciate the advice in the D.O.T. curriculum that said in the event of a radiation incident, use the oldest EMTs. Radiation’s greatest risk is as a cumulative dose agent. Makes perfect sense to let the older personnel on scene of a dirty bomb to do most of the work inside the perimeter. The bottom line is that you can deal with a dirty bomb without a great deal of added risk over a conventional bomb detonation.
Jan – All good points! Because of the reality you described, the most harmful element of an RDD is the explosion itself, rendering the radiological component as a weapon of mass panic. The quantity and quality of radioactive material needed to make an RDD ‘effective’ is likely to kill the bombmakers well before they have completed, much less delivered, the device to its intended location.
And thank you for NOT mentioning KI!
TR
Great article Jan! The one thing that I have always been taught, and there is varying guidance on for medical treatment, is that those in the immediate blast area, affected by shrapnel should have shrapnel, if believed to be radioactive, removed. Typically shrapnel isn’t removed in the field as it can be the main blood stopper. In a radiological incident, leaving shrapnel can lead to higher exposures, for the same reasons as mentioned for responders, time and distance. This will likely kill or damage more tissue, and lead to higher rates other other future issues.
Do you have any thoughts on this?
I can understand the logic but would leave it up to my physician advisor regarding preferred course of action. I can certainly kill someone much quicker through dislodging an object which has helped slow bleeding. My gut tells me to leave material in unless I have a life and/or limb saving issue.
Understood and that has long been the argument. Most EMS providers are against it, just as many are still against tourniquets. It isn’t intuitive as it is an unusual occurrance. But, there are numerous studies that point to removal due to damage and long term effects from ionization. Definitely something for EMS providers and other responders to discuss and figure out before it happens. Just as a “lesson learned” in Paris was to not push IVs to keep the blood pressure down. Is it a best practice, I don’t know but, it does have merit.
Removal also protects the responders, during a MCI as it reduces their exposures, if removed and then shielded or placed at a distance.
We used to teach removal to USAF Medics, Docs, etc.
At my age I’ll be dead from natural causes (or a car crash statistically) before the radiation exposure will kill me.