A radiation threat, commonly referred to as a “dirty bomb” or “radiological dispersion device (RDD),” is the use of common explosive devises to spread radioactive materials over a targeted area. In contrast to a nuclear blast, the force of the explosion and radioactive contamination will be more localized. While the initial explosion will be easily identified, the presence of radiation will not be clearly defined until trained personnel are able to use specialized equipment to monitor the explosion area. As with any radiation, the best policy is to try to limit exposure. It is also important to avoid inhaling the radioactive dust that may be released into the air.  

In the event of a radiation threat or “dirty bomb” 

As with all radiation, to limit your exposure think about shielding, distance, and time.

• Shielding: If you have a thick shield between yourself and the radioactive materials more of the harmful radiation will be absorbed and you will be exposed to less.

• Distance: The farther away you are from the blasts epicenter and the fallout the lower your exposure to harmful radiation.

• Time: Minimizing the time spent exposed to the radiation will also reduce your risk or serious side effects. 

• If you are outside and witness or are warned by authorities about a radiation-releasing explosion, cover your nose and mouth and quickly go inside an undamaged building. If you are already inside a building, ensure that it is free of damage and then remain where you are.
   
• Close windows and doors; turn off air conditioners, heaters and other ventilation systems
   
•  If you are inside and there is an explosion near where you are or you are warned of a radiation release inside, cover nose and mouth and go outside immediately. Look for a building or other shelter that has not been damaged and quickly get inside. Once inside, close all doors and windows; turn off air conditioners, heaters and other ventilation systems.
   
• If you think you have been exposed to radiation, take off your clothes and wash as soon as possible.
   
• Stay where you are, watch TV, listen to the radio, or check the Internet for official news as it becomes available.