3. Let GPS Help

WHAT IS A 'DIRTY BOMB'?

TIME Pentagon correspondent Mark Thompson explains “Dirty nukes are what you may choose to build if you're unable to create a real nuclear bomb, i.e. one whose explosion is based on a nuclear reaction. A dirty bomb is a conventional explosive salted with radioactive isotopes in order to spew out that nuclear material and contaminate a wide area. The military usefulness of such devices have always been in dispute. In fact, the TNT in such a bomb may still be more dangerous than the nuclear material. Its destructive power would really depend on the size of the conventional bomb, and the volume and nature of the nuclear material.” The assumption has been that forces who would build a dirty nuke would do so because it's far, far easier than to build a nuclear bomb. It's unlikely to kill 10,000 people, but any bomb that killed people and set off Geiger counters would terrify a whole city. It's ultimately a pure terror weapon."

In addition, the Department of Defense and several other news organizations continue to expand the definition of a dirty bomb or radiological dispersion devices (RDD) is a simple con-ventional explosive, such as TNT (trinitrotoluene), packaged with radioactive material. It's a lot cruder and cheaper than a nuclear bomb, and it's also a lot less effective. But it does have the combination of explosive destruction and radiation damage. However, when people hear "bomb" and "radioactive" in the same sentence, their minds jump to nuclear war pretty quickly. But it turns out that a dirty bomb's primary destructive power would probably be panic, not radiation damage.

Dirty Bomb Possibilities

There is a huge range of possible dirty bomb designs. Different explosive materials, applied in different quantities, would generate explosions of varying sizes, and different types and quantities of radioactive material would contaminate an area to different degrees. Some designs include:

• A small bomb, consisting of one stick of dynamite and a very small amount of radioactive material
• A medium-size bomb, such as a backpack or small car filled with explosives and a greater amount of radioactive material
• A large bomb, such as a truck filled with explosives and a good amount of radioactive material

The builders of these bombs wouldn't have much trouble getting their hands on high explosives -- dynamite is readily available, and TNT isn't too hard to come by. The main limitation on the bomb would be the available radioactive material. It's not nearly as accessible as explosive material, but there are a number of sources for radioactive material around the world. For example:

• Hospitals use small quantities of radioactive material, such as cesium-137, in nuclear medicine.
• Universities use similar materials to conduct scientific research.
• Food irradiation plants use radiation from cobalt-60 to kill harmful bacteria on food.
• Natural radioactive uranium isotopes are mined for use in nuclear energy. Terrorists could conceivably acquire uranium from various mines in Africa.
• There are a number of abandoned "nuclear batteries" scattered around the former Soviet Union. These portable thermoelectric generators contain a sizable amount of strontium-90, a highly potent radioactive isotope.
• People could also collect spent radioactive fuel from Russian reactors, which have been abandoned in old nuclear submarines, among other places.

They could also put something together using various low-level radioactive materials available to anybody, such as the radioactive material in smoke alarms. Tale of the Radioactive Boy Scout is good evidence that this is a very real possibility. The big question, of course, is what would actually happen if someone set off a bomb containing any of this material. As it turns out, there isn't a clear answer. Ask 10 different experts and you'll probably get 10 slightly different answers.

The Federation of American Scientists (FAS) recently prepared a report detailing three representative scenarios of a dirty bomb attack. In all three scenarios, the FAS asserts that the risk of cancer in some contaminated areas would be so high that the government would desert or demolish the area. These predictions are based on the Environmental Protection Agency's current guidelines for safe radiation levels. There's no precedent for a dirty bomb attack, but we can learn from other incidents of radioactive contamination. Nagasaki and Hiroshima were both exposed to a much larger amount of radioactive material, from an actual nuclear blast, and today, they're both considered completely safe for habitation. On the other hand, there are still areas around Chernobyl that are considered unsafe because of high radioactivity.

No matter their opinion on the long-term health risks, most experts agree that a dirty bomb would be more of a disruptive weapon to the general population and a destructive weapon to first responders. Radiological dispersal devices are unlikely to contaminated victims in a way that will be harmful to responders and caregivers. It is important to remember that RDD’s are disperse radioactive materials and there is a great risk that finely divided material may and potentially will be ingested, inhaled or absorbed though the skin and that immediate care should focus primarily on preventing internal contamination. The reason to treat person is to reduce the radiation dose from the absorbed radionuclide and the risk of long term biological effects ( ie cancer) . Luckily, the risk of radioactive induced disease can be decreased by stating medical counter measures which include potassium iodide for potential radioiodine contaminants and calcium or zinc diethylenetriaminepentaacetate (DTPA) which will chelate the unknown elements of a radioactive contamination.