There are two different types of nuclear terrorism threats. The first type is the use, or threatened detonation, of a nuclear bomb. The second type is the detonation, or threatened detonation, of conventional explosives incorporating nuclear materials. The number of nations with nuclear capability is small, and each places a high priority on the control of its nuclear weapons.

The Centers for Disease Control (CDC) is not able to assess the threat level of a terrorist nuclear attack. However, for many years CDC has participated regularly in emergency-response drills along with other federal, state and local agencies to develop, test and implement extensive national radiological emergency response plans.

In the event of a terrorist nuclear attack, one may experience two types of exposure from radioactive materials: external exposure and internal exposure. External exposure occurs when a person comes in contact with a radioactive material outside the body. Internal exposure occurs when people eat food or breathe air that is contaminated with radioactive material. Exposure to very large doses of external radiation may cause death within a few days or months. External exposure to lower doses of radiation and internal exposure from breathing or eating radioactive contaminated material may lead to an increased risk of developing cancer and other adverse health effects. These adverse effects range from mild, such as skin reddening, to severed effects such as cancer and death, depending on the amount of radiation absorbed by the body (the dose), the type of radiation, the route of exposure and the length of time of the exposure.

If there is a nuclear detonation, bodily injury or death may occur as a result of the blast itself or as a result of debris thrown from the blast. People may experience moderate to severe skin burns, depending on their distance from the blast site. Those who look directly at the blast could experience eye damage ranging from the temporary blindness to severe retinal burns.

In the event of a terrorist nuclear attack, a national emergency-response plan would be activated and would include federal, state and local agencies. You should seek shelter in a stable building and listen to local radio or television stations for national emergency-alert information. Your local emergency-response organizations, police agencies and public health facilities may be able to supply you with additional information. You should follow the protective-action recommendations that are made by your state or local health department in accordance with this plan. As a general rule, you can reduce the potential exposure and subsequent health consequences by limiting your time near the radiation source, increasing your distance from the source or keeping a physical barrier (such as the wall of a building) between you and the source. You can find out your state radiation control director by contacting The Conference of Radiation Control Program Directors (CRCPD) at (502) 227-4543.

A terrorist attack on a nuclear power plant will initiate a national emergency response that has been carefully planned and rehearsed by local, state and federal agencies for more than 20 years. If you live near a nuclear power plant and you have not received information that describes the emergency plan for that facility, you can contact the plant and ask for a copy of that information. Your local emergency response organizations, police agencies and public health facilities have been actively involved in this emergency plan and they may be able to supply you with additional information. You and your family should study these plans and be prepared to follow the instructions that local and state public health officials provide in the event of a terrorist incident involving the nuclear power plant near your home.

Centers for Disease Control and Prevention