Radiological Dispersal Device (Dirty Bomb)

A dirty bomb is a type of weapon that combines chemical explosives, such as dynamite (also called TNT), with radioactive materials. When detonated it can spread radioactive materials through the air. These radioactive materials can then fall on people, streets, buildings, parks and any surfaces within a certain range. A dirty bomb is also called a “Radiological Dispersal Device” or RDD.

Dirty Bomb

Although a dirty bomb can pose a serious threat to people near the bomb when it explodes, it is much less destructive than a nuclear bomb. For more information about what to do if there is a nuclear bomb denotation, visit the Nuclear Incident: Improvised Nuclear Device (IND) page.

A dirty bomb cannot create a nuclear explosion. Instead, it uses dynamite or other chemical explosives to injure people and spread radioactive materials that threaten the health of more people in a larger area than the explosive blast. However, compared to nuclear weapons, dirty bombs spread radioactive materials across a much smaller area.

Health Risks and Hazards

One danger of a dirty bomb is from the explosion. People close to the bomb could suffer injuries such as broken bones, burns, cuts, head injuries, eye injuries, hearing damage or other trauma including death. If the bomb is large enough, it may break glass and cause more damage to nearby buildings.

The other danger is exposure to radiation caused by the radioactive materials used in a dirty bomb. Small particles of radioactive material could travel with the wind for a mile or more. Breathing in large amounts of these radioactive materials may increase your chances of health problems in the future. Being near contaminated items from the explosion could also cause future health problems.

Health Risks of Radiation Exposure

A dirty bomb can produce unsafe levels of radiation. You can get acute radiation sickness if you are exposed to a large enough amount of radiation. This painful condition can be fatal. Symptoms of radiation sickness include vomiting and diarrhea. Exposure to radiation can also increase your chances of getting cancer.

Breathing in radioactive materials could increase your exposure to radiation. An open wound is another way that radioactive materials on your skin can enter your body and result in longer exposure to radiation.

Radiation and Pregnancy

The effects of radiation depend on the radiation dose received and the trimester of the pregnancy. A fetus in the early stages of development (two to 18 weeks) is more vulnerable to a high level of radiation dose than later in the pregnancy.

Pregnant people who were close to the dirty bomb explosion and contaminated with radioactive dust and dirt, particularly on the face and head, may have breathed in or eaten radioactive material and should get medical help.

Protect Yourself and Others

During the Incident

If You Are Outdoors

If you are outdoors and witnessed the explosion or can smell the smoke of the explosion:

  • Cover your nose and mouth with a cloth or mask (like you wear to protect against COVID-19) to reduce the risk of inhaling radioactive dust or smoke.
  • Don't touch objects ejected from or damaged by the explosion, as they might be radioactive. Move as far away as possible from these suspected radioactive objects.
  • Seek treatment at the scene by first responders if you are injured.

If you are told to seek nearby shelter:

  • Go into the building designated as a shelter.
  • Enter an undamaged building if a shelter is not identified.
  • Wait for further instructions from authorities.

If You Are Inside

If you are inside a building near the incident and the walls and windows of the building are not damaged, stay inside and do not leave. To prevent radioactive dust from getting inside, shut all windows and doors leading outside, as well as at-home fireplace dampers. Turn off fans and heating and air-conditioning systems that bring in air from the outside. The radioactive debris from the explosion will disperse in about 15 minutes. You do not need to put duct tape or plastic around doors or windows.

If the walls and windows of the building are damaged, go into a room located in the center of the building and away from damaged windows and walls. Do not leave this location unless otherwise instructed. Once you are inside, remove potential radioactive contamination from your body by following the cleaning procedures detailed in the section below.

If You Are in a Vehicle

If you are in public transportation near the incident, follow instructions from the transit authorities and first responders.

If you are in a car and near the incident:

  • Close windows and vents and turn off the air conditioner and heater. If the interior of the car becomes too warm, only open a window after covering your nose and mouth with a cloth to avoid breathing airborne radioactive dust.
  • Use your radio or phone to tune in to official announcements for more information.
  • If permitted by the authorities, drive home and immediately go inside.

Protect Children and Other Family Members

If your family members are in another building such as at school or work, they should stay there until authorities say it is safe to leave. Schools have emergency plans and can act as shelters during emergencies. Do not travel to be with family members until authorities say it is safe to travel, otherwise you may increase the health risks to you and your family.

Protect Your Pets

If you have a pet outside near the dirty bomb explosion, bring it inside if you can do so safely. Wash your pet with soap and water to remove any radioactive materials.

To prevent contaminated hair from spreading radioactivity, do not brush or shave your pet’s fur. If your pet was inside your home, you do not need to wash them unless authorities tell you to do so.

Food and Water Safety

Food and water, especially those packaged and stored inside, will likely be safe to eat and drink. If a dirty bomb explodes in NYC, it will not affect the sources of the city’s water supply.

Avoid food located outdoors because radioactive contamination can settle anywhere that is open to the air. Food stored in your home will not be contaminated. You can eat food such as canned goods, food stored in the refrigerator or freezer, boxed foods and food in bottles or jars. If you’re unsure, rinse food containers before opening them. You can also rinse plates, glasses, and silverware before use.

It is safe to eat peeled fruits such as bananas and oranges. You should rinse fruits and vegetables that are not peeled before eating.

Remove, Detect and Treat Radioactive Contamination

Once inside, take off your outer layers of clothing and seal them in a plastic bag. Put the cloth or mask that you used to cover your mouth in the bag too. Removing the outer layers of clothing can eliminate up to 90 percent of radioactive contamination.

Put the sealed plastic bag in a place where no one will touch it. Keep the bag in that location until the authorities tell you what to do with it. Keeping it just a few feet away or more will greatly reduce any exposure from the contamination.

Shower or wash your body with soap and water. Washing will remove any remaining contamination on your skin and hair. Wash your hair with shampoo, but do not use hair conditioner, including 2-in-1 shampoo and conditioner products, because conditioner will make it more difficult to remove radioactivity from your hair.

Tune into official announcements for more information and instructions.

Detecting Radiation Contamination

The only way to accurately detect radiation is for a trained person to use a radiation detector. The Fire Department will respond to the explosion and determine if radioactive materials are present.

After the explosion, NYC will open Community Reception Centers to quickly examine people for radioactive contamination. If you are not injured but concerned that you might be contaminated by radioactive material, wait for instructions from authorities about going to a Community Reception Center.

Treatment for Radiation Exposure

There is no over-the-counter treatment for radiation exposure. If you think you were exposed to radiation after a dirty bomb incident, seek assistance at a Community Reception Center.

When to Seek Care at a Hospital

Only go to the hospital if you were injured but not treated on-scene by Emergency Medical Services. If you were not injured, do not go the hospital to be examined for radioactive contamination because hospitals are not equipped to screen members of the public.

Evacuation and Returning Home

Only evacuate if instructed to by first responders who are on the scene or by other authorities, including the Mayor or NYC Emergency Management. Follow the instructions from these authorities about what action you should take. If you do not immediately receive instructions, the safest place to be is indoors. Once you are inside, do not evacuate until instructed to by authorities.

Returning to a Contaminated Building

You can return to your home, school or office if it has been cleaned, or decontaminated, to a safe level of radiation. The U.S. Environmental Protection Agency has rules about how to safely clean buildings so people can return to them. These rules are regularly used for buildings that store radioactive materials.

Preparing for a Dirty Bomb Explosion

A dirty bomb explosion in NYC would be very stressful. It is normal to be afraid or confused, especially about a hazard that you may not know a lot about. Learning how to manage stress can help you cope. You can also find help by calling (888) NYC-Well (888-692-9355). NYC Well is a free, confidential helpline for New York City residents, available 24/7, with trained staff ready to take your calls and offer advice.

Sign up for emergency alerts at Notify NYC.

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