Nuclear Bomb Blast (Nuclear Explosion)

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What is a nuclear bomb blast?

A nuclear blast occurs when a nuclear bomb explodes. It causes destruction over a wide area within seconds to minutes. The blast creates a large fireball and a mushroom cloud of dust and particles. The fireball produces temperatures up to millions of degrees, shock waves similar to a large earthquake, flashes similar to lightning and intense radiation. The mushroom cloud carries radioactive materials from the bomb into the air. When the cloud settles down, dust and particles containing radioactive materials fall back to earth. This is called fallout. Fallout can be carried by the wind and can contaminate the air, soil, food and water.

How is a nuclear bomb blast different from a nuclear power plant accident?

An accident at a nuclear power plant would not produce a fireball or mushroom cloud like a nuclear blast. However, it could release radioactive materials into the air, though this would be at a much lower level than a nuclear bomb blast. More information on nuclear power plant accidents is available on a separate fact sheet.

What are the health effects of a nuclear bomb blast?

The health effects depend on the distance from the blast. Injury or death may result from the blast itself or from flying debris. Those who look directly at the blast could experience temporary blindness or severe eye damage. People near the blast site would be exposed to high levels of radiation causing severe skin burns, shock and death within minutes to days. People farther away may be exposed to lower doses of radiation from the blast or by breathing air, eating food or drinking water that is contaminated with fallout. Exposure to radiation increases the chance of developing cancer and other health problems years later.

How can I protect my family and myself?

If you are near the blast when it occurs: Turn away and close and cover your eyes. Drop to the ground face down and place your hands under your body. Remain flat until the heat and shock waves have passed.

If you are outside when the blast occurs: Cover your mouth and nose with a towel or other cloth. Remove any clothes that may be contaminated with fallout. If possible, take a shower, wash your hair and change clothes. Move to a basement or other underground area away from the path of the wind.

If you are already in a basement or underground area: Cover your mouth and nose with a towel or other cloth (damp if possible). Turn off heating/air conditioning systems, and seal doors and windows. Monitor the radio or TV for information and advice. Stay inside until officials say it is safe to come out. If you must go out, cover your mouth and nose with a damp towel or other cloth. Use stored food and drinking water. Clean and cover any open wounds.

If you are advised to evacuate: Monitor the radio or TV and follow the recommendations about evacuation routes, temporary shelters and other emergency procedures. Before you leave home, close windows, doors and fireplace dampers. Turn off heating/air conditioning systems, vents, fans and furnace. Take important items with you, such as prescription medicines, personal toiletry items, emergency food and water, first aid kit, flashlight, cash, credit cards and personal identification. If you are traveling in a vehicle, close all windows and vents to prevent radioactive material from entering the car.

Planning is the key to being prepared to protect yourself and your family during any emergency. Develop a family emergency plan, know how your community will respond, and consider whether relatives or neighbors with special needs may need assistance.

Can people take potassium iodine (KI) or other drugs to protect themselves from radiation?

Drugs are not available to protect a person from most radioactive materials. Potassium iodide, also called KI, only protects the thyroid gland from exposure to radioactive iodine, which could lead to thyroid cancer years after exposure. KI is not likely to be helpful after a nuclear bomb blast but may be recommended after a nuclear power plant accident.

Where can I find additional information about a nuclear bomb blast?

More information about nuclear blasts and radiation can be found through the Virginia Department of Health at or the U.S. Centers for Disease Control and Prevention