What are the most important actions to take to reduce radiation exposure?
Is evacuation or sheltering the better means of maintaining safety in the event of a radiological emergency?In the event of a dirty bomb explosion, people who live nearby, but not in the immediate area of the blast, may be asked to stay home and take shelter rather than evacuate. This is called “sheltering in place” by emergency response organizations. Staying in your home or office may be the best safety measure because many radioactive materials decay rapidly and dissipate. The thick walls of your home or office will block much of the harmful radiation.If you are outside when an alert of a dirty bomb is announced, try to remove clothing and shoes and place them in a plastic bag before entering your home or office. In severe weather, simply remove the outside layer of clothing.In the case of sheltering or evacuation, keep your radio tuned to an emergency response network at all times for updates on the situation.What happens when a person is exposed to radiation?All of us are continuously exposed to radiation in everyday life because radiation is a natural part of our environment—in the rocks and soil of the earth, in our air, water and food, and even in the cells of our own bodies. Many people also receive exposure to radiation when they receive X-rays or undergo medical tests or treatments for disease. With regard to dirty bombs, the question is whether there is a possibility of receiving radiation exposure far in excess of the amount that all of us receive every day. Excessive radiation can affect the body in a number of ways—ranging from mild effects such as skin reddening to fatal cancer—depending on the amount of radiation absorbed by the body, the type of radiation and the length of time a person is exposed. Although the detonation of a dirty bomb could cause serious injury from the explosion, it most likely would not have enough radioactive material in a form that would cause serious radiation sickness among a large number of people.What are the experts saying?U.S. Nuclear Regulatory Commission:“Most [dirty bombs] would not release enough radiation to kill people or cause severe illness—the conventional explosive itself would be more harmful to people than the radioactive material. However, depending on the scenario, [a dirty bomb] explosion could create fear and panic, contaminate property and require potentially costly cleanup. … A dirty bomb is not a ‘Weapon of Mass Destruction’ but a ‘Weapon of Mass Disruption,’ where contamination and anxiety are the terrorists’ major objectives.”Centers for Disease Control and Prevention:“A dirty bomb uses dynamite or other explosives to scatter radioactive dust, smoke or other material. … The main danger from a dirty bomb is from the explosion, which can cause serious injuries and property damage. The radioactive materials used in a dirty bomb would probably not create enough radiation exposure to cause immediate serious illness, except to those who are very close to the blast site.”Center for Nonproliferation Studies at the Monterey Institute of International Studies:“To cause a large amount of radioactive contamination, [terrorists] would be drawn toward very high-activity sources. However, in order to prepare the source for effective dispersal by removing the shielding, terrorists would risk exposing themselves to lethal doses. … If they tried to protect themselves by shielding the source, the weight of the radiological dispersal device could significantly increase, thereby increasing the difficulty of delivering the device and causing successful dispersion of the radioactive material” (Commercial Radioactive Sources: Surveying the Security Risk, January 2003).