Radiological emergencies occur when there is, or is perceived to be, a hazard due to radiation exposure from radioactive sources. Such sources are most commonly used in research, medicine, industry and agriculture. In the past most emergencies have happened when sources have strayed or been stolen without those possessing them understanding what they are and the dangers associated with them.
Nuclear emergencies occur when there is, or is perceived to be, a hazard due to radiation exposure from nuclear reactor cores. Such cores are primarily used in nuclear power plants, research institutions and military installations, and in the past most emergencies have been the result of accidents at nuclear power plants. The gravest emergencies arose from the power spike and subsequent explosions during a stress test at the Chernobyl Nuclear Power Plant in 1986 and the failure of cooling systems and meltdown of several nuclear reactors in Fukushima Daiichi Nuclear Power Plant in 2011, after a tsunami flooded the plant.
Although nuclear and radiological emergencies are quite rare occurrences, the impact of these emergencies can potentially be very high, and the response and recovery can be lengthy. It is therefore vital that communities and emergency responders are prepared for such characteristic situations. Nuclear and radiological events differ from most other emergencies in several ways:
- It is difficult to identify radioactive material and determine radiation levels without specialized equipment, which may cause delays in the wariness of the public.
- Symptoms of exposure may not immediately be noticeable. Victims may therefore not seek treatment right away, and this can deteriorate their chances of recovery.
- The psychosocial effects of nuclear and radiological events can be substantial, with possible intense fear in the population and stigma surrounding the victims.
How do I prepare?
Radioactive material can be hazardous because it emits ionizing radiation that can penetrate and damage the body by killing cells or causing mutations to DNA. In situations where there is risk of exposure to such radiation, it is important to remain calm, pay attention to public information channels such as internet, radio and TV, and follow advice from the authorities with regards to safe shelter. Depending on contamination levels, size of affected area and available emergency shelter, it may be safer to shelter in place for shorter or longer time than to evacuate.
If this is the case, you should proceed in the following manner:
- Close and lock windows and doors, and if possible seal with duct tape.
- Turn off air condition and heating systems, and close ventilation shafts etc.
- Go to an interior room without windows or doors if possible. It is recommended to shield below ground level as a first choice. In larger buildings, you should opt for the middle floors if it is not possible to shield below ground level, as portrayed in the graphic below.
Source: Federal Emergency Management Agency (FEMA).
- Ensure you have access to news via internet or radio/TV in the room where you are sheltering, as well as a hard-wired telephone or mobile phone and charger.
- Bring everyone in the building into the room, including any pets you may have. Bring bottled water and packaged foods with you into the room, including baby food, pet food etc. in accordance with the needs of your family. Bring enough for at least three days, including minimum three litres of water per person per day.
- Bring medications that family members may be dependent on, as well as a first aid kit. Follow the advice of the authorities with regards to taking potassium iodide pills. In some countries this is distributed for households to stash before a nuclear emergency, and in others it is distributed at the onset of an emergency. Familiarize yourself with the procedures in your country before an emergency happens.
- Seal vents and door cracks inside the room with duct tape, heavy plastic sheeting or clothes etc. and keep listening to radio/TV until you are told either that the situation is safe or that you should evacuate.
If you are outside and believe you have already been exposed or contaminated, it is important to get away from the source(s) of ionizing radiation while shielding your mouth and nose (for instance with a cloth). You should look for a safe location to take shelter. This should be the largest concrete building easily accessible to you, but any building will be better than staying outside for a longer period. Once inside, it will be necessary to decontaminate, even if you are not sure whether you have been in contact with radioactive particles. You should:
- Remove clothing, preferably without touching the outside of the items, seal in plastic bags and remove yourself from the bags if possible.
- Remove contamination from your body by washing skin and hair thoroughly with soap if possible, rinsing eyes and ears with water (preferably bottled water) and blowing your nose. If you do not have access to water, scraping or wiping contamination off your skin is the next best option. Extra care should be made to clean around the mouth, nose, eyes and ears.
- Make sure to help people that are without shelter. If others join you in the building after you have arrived, ensure they decontaminate following the same procedure you did, leaving any outer layers of clothes by the entrance or in sealed bags out of site. It will then be safe to share the shelter.
- Take care of each other. Once someone has successfully decontaminated following the procedures described, the radiation dose they have received cannot be transmitted to others. It is therefore not dangerous to touch them, provide first aid etc.
- Seek medical attention as soon as you can, even if you do not initially show symptoms of contamination. Common symptoms in the weeks after exposure include nausea, vomiting, diarrhoea, gastrointestinal pain, flu-like sensation, radiation burns and hair loss.
What do I need to know?
Nuclear and radiological emergencies can pose a threat to life and health as the result of spread of radionuclides, or radioisotopes as they are sometimes called. These are atoms that spontaneously emit ionizing radiation. There are thousands of different radionuclides known to us, and exposure or contamination calls for targeted medical countermeasures to the specific radionuclides where possible, and treatment according to the radiation dosage received and symptoms showed.
Ionizing radiation can travel in the form of particles or electromagnetic waves, with ability to penetrate human skin and tissue and other materials to variable degree. One distinguishes between alpha particles, beta particles, gamma rays and neutrons. Alpha particles can penetrate and burn only the outer layer of skin, whereas beta particles can penetrate further into the skin and also affect tissue if ingested. Gamma rays are able to penetrate a whole person. Neutron radiation can result in a combination of gamma rays and beta radiation, alongside emission of protons and more neutrons, and can penetrate even deeper than gamma rays. The illustration below shows what is needed to protect against these different types of ionizing radiation.
Source: Foro de la Industria Nuclear Española.
In nuclear and radiological emergencies, a combination of several of these types of ionizing radiation may be spread, and the recommendations for safe shelter are therefore based on the assumption that gamma and neutron radiation may be part of the mix.
There are several ways one can be exposed to or contaminated by ionizing radiation.
- External contamination happens when airborne radioactive materials such as dust and aerosols land on skin or clothes. This type of contamination can be countered by finding shelter, removing clothes and washing skin and hair.
- Internal exposure to ionizing radiation happens when a radionuclide is inhaled, ingested or otherwise enters into the bloodstream, for instance through tears in the skin. If ingested, the radionuclides will naturally pass through the body’s digestive system and eventually leave the body. Internal exposure can to some extent be countered with medical treatment.
- External irradiation happens when the body is exposed to penetrating rays from an external source, such as those used in medical radiation therapy and x-ray machines. The only way to counter this is to block the rays with strong materials, as portrayed in the graphic above.
Following a nuclear or radiological emergency, a combination of somatic and psychological effects may be seen, calling for immediate decontamination, diagnostics and treatment, but also longer term follow-up with cancer screenings and psycho-social support.
In some cases, there are measures that can be taken at the onset of a nuclear or radiological emergency to limit contamination by certain radionuclides. One example of this is administering potassium iodide pills. Radioactive iodine (Iodine-131) is known to be a carcinogen, and was released in power plant accidents such as in Chernobyl in 1986 and Fukushima in 2011. Iodine is stored in the thyroid of the body, and if this gland is not already filled with non-radioactive iodine before being exposed to Iodine-131, it will absorb the radionuclide. A precautionary measure is therefore to ingest potassium iodide pills prior to exposure to avoid such absorption. The distribution of these pills, either before or during the emergency, is coordinated by the authorities in most countries. It should be taken only when advised specifically to do so by the authorities at the onset of a nuclear or radiological emergency.
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