Dirty Bomb and Potassium Iodide Information - Radiation Control Program

Dirty Bomb Information

Potassium Iodide (KI) Information

Dirty Bomb Information

What is a Dirty Bomb?

A "dirty bomb" as it has been referred to by the media is a terrorist weapon. It is not an "atomic" bomb. The dirty bomb is a conventional weapon using conventional explosives (such as dynamite or TNT) to disperse or spread radioactive material. The dangerous part of the weapon is the explosive itself, not the radioactivity that would be spread. The intent of the weapon is to cause damage by the explosion and spread fear and panic by the presence of radioactivity.


Should we be afraid of Dirty Bombs?


Yes. If a terrorist uses a dirty bomb, the resulting explosion will most likely kill or injure people and damage property. We should not be afraid of the radioactivity that might be spread as a result of the explosion. Any deaths caused by the bomb will be a direct result of the explosion and will not be caused by the radioactive material involved.


Why shouldn't we be afraid of radioactive material in the bomb?


The terrorist is faced with a technological dilemma when constructing the bomb. If they use a large high energy source that is capable of creating lethal doses of radiation, they would also have to include a large amount of high density shielding material (such as lead or steel) with the weapon. The addition of this shielding will not only make the bomb much harder to handle, it will also make it much harder to hide and would require the use of heavy equipment and remote handling tools.

If they did not incorporate this shielding into the design of the bomb, they would die from the resulting radiation exposure before they could complete construction of the bomb. Increasing the amount of shielding for this type of high energy source would also help to contain the radioactive material and prevent a spread of radioactivity in an explosion. Because of this, the terrorist is limited to using a smaller high energy source or a large amount of lower energy material.


Why does spreading the material reduce its effectiveness?


It is like breaking up a rock. If someone was to throw a large rock at you it would probably hurt and it may cause you physical damage. If they take the same rock and break it up into grains of sand and then they throw the sand at you, the chances of it causing you any real damage are significantly lower. This same principal would apply to radioactive material dispersed in an explosion. This dispersion will lower radiation levels to a level like what you encounter in routine x-rays at your dentist's office.


What should I do if I am in an area where a bomb goes off?


If you have survived the blast from the explosion, do not panic. Keep calm and render assistance to others if you are able. Follow the instructions of the emergency workers when they arrive. You will not know if the bomb contained any radioactive material until emergency workers arrive with radiation detection instruments. If it is determined that you were exposed to radioactive material you will receive further instructions by experts on radiation protection about how to further lower your exposure from the radioactivity.


Can I take a pill to protect myself from radiation?


Not really. Potassium iodide (KI) is a pill that is commercially available and is being marketed as an "antidote" to radiation. This is not true. There is no single drug that will protect a person from radiation exposure. Potassium iodide is effective in providing protection for one specific type of radioactive material that is swallowed or inhaled. Potassium iodide specifically protects the thyroid against inhalation or ingestion of radioiodines if taken just before or within four hours after exposure. It doesn't protect other organs or the whole body from the effects of exposure to radioiodines or to any other radionuclides. Because of their relatively short half lives, radioiodines are not likely to be used in a dirty bomb. The effectiveness of the drug is further reduced if you take it after your exposure to the radioactivity.

Potassium Iodide (Also known as KI)

What is potassium iodide?

Potassium iodide is a salt, similar to table salt. Its chemical symbol is KI. Potassium iodide is the ingredient that is routinely added to table salt to make it "iodized."


How is potassium iodide used in a radiological emergency?


The purpose of radiological emergency preparedness is to protect people from the effects of radiation exposure after an accident involving radioactive materials. Evacuation from the area affected by the accident is the most effective protective measure because it protects the whole body (including the thyroid gland and other organs) from all types of radioactivity, regardless of how you are exposed. If an accident were to occur involving radioactive iodine and evacuation was not possible, potassium iodide could be taken to prevent internal exposure to the thyroid by the radioactive iodine that might be inhaled or ingested following the accident. Potassium iodide would be useless in a radiological emergency unless radioactive iodine was involved.


Will potassium iodide protect against all types of radiation?


No. Potassium iodide is not a magic pill or "antidote." Potassium iodide will only protect against exposure to inhaled or ingested radioactive isotopes of iodine. It will not protect against external exposure to radiation and it will not protect against any other radioactive isotope such as plutonium, uranium, cesium or cobalt 60.


What should I do in an emergency involving radioactive materials?


Do not panic. Follow the instructions of the emergency response personnel. Do not delay evacuation to take potassium iodide pills. Remember - the best way to prevent exposure to radiation is to leave the immediate area where the radioactivity is present.