Q&A for education on nuclear terror

The Centers for Disease Control and Prevention (CDC) provides these answers to frequently asked questions about nuclear terrorism:

Question: What is a nuclear blast?

A nuclear blast, produced by explosion of a nuclear bomb (sometimes called a nuclear detonation), involves the joining or splitting of atoms (called fusion and fission) to produce an intense pulse or wave of heat, light, air pressure, and radiation. The bombs dropped on Hiroshima and Nagasaki, Japan, at the end of World War II, produced nuclear blasts. When a nuclear device is exploded, a large fireball is created. Everything inside of this fireball vaporizes, including soil and water, and is carried upward. This creates the mushroom cloud that we associate with a nuclear blast, detonation, or explosion. Radioactive material from the nuclear device mixes with the vaporized material in the mushroom cloud. As this vaporized radioactive material cools, it becomes condensed and forms particles, such as dust. The condensed radioactive material then falls back to the earth; this is what is known as fallout. Because fallout is in the form of particles, it can be carried long distances on wind currents and end up miles from the site of the explosion. Fallout is radioactive and can cause contamination of anything on which it lands, including food and water supplies.

Question: What are the effects of a blast?

The effects on a person from a nuclear blast will depend on the size of the bomb and the distance the person is from the explosion. However, a nuclear blast likely would cause great destruction, death, and injury, and have a wide area of impact. In a nuclear blast, 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 temporary blindness to severe burns on the retina. Individuals near the blast site would be exposed to high levels of radiation and could develop symptoms of radiation sickness (called acute radiation syndrome, or ARS). While severe burns would appear in minutes, other health effects might take days or weeks to appear. These effects range from mild, such as skin reddening, to severe 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.

People may experience two types of exposure from radioactive materials from a nuclear blast: external and internal. External exposure occurs when people are exposed to radiation outside of their bodies from the blast or its fallout. Internal exposure would occur when people eat food or breath air that is contaminated with radioactive fallout. Both internal and external exposure from fallout could occur miles away from the blast site. 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 food contaminated with radioactive fallout may lead to an increased risk of developing cancer and other health effects.

Question: How can I protect my family and myself from during a nuclear blast?

In the event of a nuclear blast, a national emergency response plan would be activated and would include federal, state, and local agencies. Here are some steps recommended by the World Health Organization if a nuclear blast occurs:

If you are near the blast when it occurs:

  • Turn away and close and cover your eyes to prevent damage to your sight.
  • Drop to the ground face down and place your hands under your body.
  • Remain flat until the heat and two shock waves have passed.

If you are outside when the blast occurs:

  • Find something to cover your mouth and nose, such as a scarf, handkerchief, or other cloth.
  • Remove any dust from your clothes by brushing, shaking, and wiping in a ventilated area — however, cover your mouth and nose while you do this.
  • Move to a shelter, basement, or other underground area, preferably located away from the direction that the wind is blowing.
  • Remove clothing since it may be contaminated; if possible, take a shower, wash your hair, and change clothes before you enter the shelter.

If you already are in a shelter or basement:

  • Cover your mouth and nose with a face mask or other material (such as a scarf or handkerchief) until the fallout cloud has passed.
  • Shut off ventilation systems and seal doors or windows until the fallout cloud has passed. However, after the fallout cloud has passed, unseal the doors and windows to allow some air circulation.
  • Stay inside until authorities say it is safe to come out.
  • Listen to the local radio or television for information and advice. Authorities may direct you to stay in your shelter or evacuate to a safer place away from the area.
  • If you must go out, cover your mouth and nose with a damp towel.
  • Use stored food and drinking water. Do not eat local fresh food or drink water from open water supplies.
  • Clean and cover any open wounds on your body.