A nuclear explosion is followed by the production and release of radioactive particles. Signs of a nuclear explosion include a fireball shape, a shockwave from the explosion site, a cloud shaped like a mushroom that forms after impact, and an electromagnetic pulse (EMP) that will impact power in the surrounding area.

In the event of a nuclear attack, the impact area would have significant damage, and loss of life, and remain hazardous for up to two days. Health effects for those who survive the shockwave and heat may suffer serious health effects from radiation. The effects will depend on how much radiation is absorbed by the body, the type of radiation, and the length of exposure time.

The U.S. Department of Homeland Security has three key tips for reducing radiation exposure after an attack. These three keys include Time, Distance, and Shielding.

Time: Limit the amount of time spent in areas where there is radiation.

Distance: Increase your distance from a radiation source. If sheltered in a contaminated area, keep your distance from exterior walls and roofs.

Shielding: Create a barrier between yourself and the radiation source. Staying inside buildings or in your vehicle is highly recommended.

Listen for updates from local emergency officials in case of a nuclear attack. If you are advised to evacuate, pay close attention to evacuation route information, temporary shelters, and best practices. If there is time before leaving, close and lock all windows, doors, and points of entry to your property. Remember to turn off air conditioning, vents, fans, and furnaces to keep radioactive material from entering your home.

Resources: prep_nuclear_fact_sheet.pdf and nuclear-threat