Nuclear Blast - A nuclear blast is an explosion with intense light and heat, a damaging pressure wave and widespread radioactive material that can contaminate the air, water and ground surfaces for miles around. While experts may predict at this time that a nuclear attack is less likely than others, terrorism by its nature is unpredictable. If there is a flash or fireball, take cover immediately, below ground if possible, though any shield or shelter will help protect you from the immediate effects of the blast and the pressure wave. In order to limit the amount of radiation you are exposed to, think about shielding, distance and time. If you have a thick shield between yourself and the radioactive materials, it will absorb more of the radiation and you will be exposed to less. Similarly, the farther away you are from the blast and the fallout, the lower your exposure. Finally, minimizing time spent exposed will also reduce your risk.

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 upwards. 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.

What are the effects of a nuclear 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 would likely 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 exposure and internal exposure. External exposure would occur when people were exposed to radiation outside of their bodies from the blast or its fallout. Internal exposure would occur when people ate food or breathed air that was 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.

How can I protect my family and myself 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. Following 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 are already 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.

If you are advised to evacuate:

• Listen to the radio or television for information about evacuation routes, temporary shelters, and procedures to follow.
• Before you leave, close and lock windows and doors and turn off air conditioning, vents, fans, and furnace. Close fireplace dampers.
• Take disaster supplies with you (such as a flashlight and extra batteries, battery-operated radio, first aid kit and manual, emergency food and water, nonelectric can opener, essential medicines, cash and credit cards, and sturdy shoes).
• Remember your neighbors may require special assistance, especially infants, elderly people, and people with disabilities.

Is a nuclear bomb the same as a suitcase bomb?

The ?suitcase? bombs that have been described in new stories in recent years are small nuclear bombs. A suitcase bomb would produce a nuclear blast that is very destructive, but not as great as a nuclear weapon developed for strategic military purposes.

Is a nuclear bomb the same as a dirty bomb?

A nuclear blast is different than a dirty bomb. A dirty bomb, or radiological dispersion device, is a bomb that uses conventional explosives such as dynamite to spread radioactive materials in the form of powder or pellets. It does not involve the splitting of atoms to produce the tremendous force and destruction of a nuclear blast, but rather spreads smaller amounts radioactive material into the surrounding area. The main purpose of a dirty bomb is to frighten people and contaminate buildings or land with radioactive material.

Would an airplane crash in a nuclear power plant have the same effect as a nuclear blast?

While a serious event such as a plane crash into a nuclear power plant could result in a release of radioactive material into the air, a nuclear power plant would not explode like a nuclear weapon. There may be a radiation danger in the surrounding areas, depending on the type of incident, the amount of radiation released, and the current weather patterns. However, radiation would be monitored to determine the potential danger, and people in the local area would be evacuated or advised on how to protect themselves.

Do I need to take potassium iodide (KI) if there is a nuclear blast?

Local emergency management officials will tell people when to take KI. If a nuclear incident occurs, officials will have to find out which radioactive substances are present before recommending that people take KI. If radioactive iodine is not present, then taking KI will not protect people. If radioactive iodine is present, then taking KI will help protect a person's thyroid gland from the radioactive iodine. Taking KI will not protect people from other radioactive substances that may be present along with the radioactive iodine.

Radiation Threat or "Dirty Bomb" - A radiation threat or "Dirty Bomb" is the use of common explosives to spread radioactive materials over a targeted area. It is not a nuclear blast. The force of the explosion and radioactive contamination will be more localized. While the blast will be immediately obvious, the presence of radiation may not be clearly defined until trained personnel with specialized equipment are on the scene. As with any radiation, you want to try to limit your exposure. Think about shielding, distance and time. 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 people who are very close to the blast site. However, the radioactive dust and smoke spread farther away could be dangerous to health if it is inhaled. Because people cannot see, smell, feel, or taste radiation, you should take immediate steps to protect yourself and your loved ones.

If you are outside and close to the incident

• Cover your nose and mouth with a cloth to reduce the risk of breathing in radioactive dust or smoke.
• Don’t touch objects thrown off by an explosion—they might be radioactive.
• Quickly go into a building where the walls and windows have not been broken. This area will shield you from radiation that might be outside.
• Once you are inside, take off your outer layer of clothing and seal it in a plastic bag if available. Put the cloth you used to cover your mouth in the bag, too. Removing outer clothes may get rid of up to 90% of radioactive dust.
• Put the plastic bag where others will not touch it and keep it until authorities tell you what to do with it.
• Shower or wash with soap and water. Be sure to wash your hair. Washing will remove any remaining dust.
• Tune to the local radio or television news for more instructions.

If you are inside and close to the incident

• If the walls and windows of the building are not broken, stay in the building and do not leave.
• To keep radioactive dust or powder from getting inside, shut all windows, outside doors, and fireplace dampers. Turn off fans and heating and air-conditioning systems that bring in air from the outside. It is not necessary to put duct tape or plastic around doors or windows.
• If the walls and windows of the building are broken, go to an interior room and do not leave. If the building has been heavily damaged, quickly go into a building where the walls and windows have not been broken. If you must go outside, be sure to cover your nose and mouth with a cloth. Once you are inside, take off your outer layer of clothing and seal it in a plastic bag if available. Store the bag where others will not touch it.
• Shower or wash with soap and water, removing any remaining dust. Be sure to wash your hair.
• Tune to local radio or television news for more instructions.

If you are in a car when the incident happens

• Close the windows and turn off the air conditioner, heater, and vents.
• Cover your nose and mouth with a cloth to avoid breathing radioactive dust or smoke.
• If you are close to your home, office, or a public building, go there immediately and go inside quickly.
• If you cannot get to your home or another building safely, pull over to the side of the road and stop in the safest place possible. If it is a hot or sunny day, try to stop under a bridge or in a shady spot.
• Turn off the engine and listen to the radio for instructions.
• Stay in the car until you are told it is safe to get back on the road.

What should I do about my children and family?

• If your children or family are with you, stay together. Take the same actions to protect your whole family.
• If your children or family are in another home or building, they should stay there until you are told it is safe to travel.
• Schools have emergency plans and shelters. If your children are at school, they should stay there until it is safe to travel. Do not go to the school until public officials say it is safe to travel.

How do I protect my pets?

• If you have pets outside, bring them inside if it can be done safely.
• Wash your pets with soap and water to remove any radioactive dust.

Should I take potassium iodide?

• Potassium iodide, also called KI, only protects a person's thyroid gland from exposure to radioactive iodine. KI will not protect a person from other radioactive materials or protect other parts of the body from exposure to radiation.
• Since there is no way to know at the time of the explosion whether radioactive iodine was used in the explosive device, taking KI would probably not be beneficial. Also, KI can be dangerous to some people.

Will food and water supplies be safe?

• Food and water supplies most likely will remain safe. However, any unpackaged food or water that was out in the open and close to the incident may have radioactive dust on it. Therefore, do not consume water or food that was out in the open.
• The food inside of cans and other sealed containers will be safe to eat. Wash the outside of the container before opening it.
• Authorities will monitor food and water quality for safety and keep the public informed.

 How do I know if I’ve been exposed to radiation or contaminated by radioactive materials?

• People cannot see, smell, feel, or taste radiation; so you may not know whether you have been exposed. Police or firefighters will quickly check for radiation by using special equipment to determine how much radiation is present and whether it poses any danger in your area.
• Low levels of radiation exposure (like those expected from a dirty bomb situation) do not cause any symptoms. Higher levels of radiation exposure may produce symptoms, such as nausea, vomiting, diarrhea, and swelling and redness of the skin.
• If you develop any of these symptoms, you should contact your doctor, hospital, or other sites recommended by authorities.