Back to Basics is a weekly feature that highlights important but possibly overlooked information that any EHS professional should know. This week, we examine how to prepare your workers for a radiation emergency.
A radiation emergency is a non-routine situation in which radiation is released or there is other risk of exposure to radiation, according to the Occupational Safety and Health Administration (OSHA). Radiation emergencies include nuclear and radiological events in which there is (or there is the perception of) a hazard from a nuclear explosion, release of radioactive material, or unintended exposure to another type of radioactive source.
Radiation emergencies can result from accidental or deliberate causes.
Accidental causes include:
- Releases from a fixed nuclear facility (e.g., a power plant or research or test nuclear reactor)
- Releases from non-nuclear facilities such as laboratories or hospitals using radioactive materials
- Lost, found, or orphan (i.e., no longer under proper control) sources of radioactive material (e.g., nuclear fuel sources, medical imaging devices)
- Transportation incidents
- Nuclear weapons accidents
Deliberate causes include:
- Improvised nuclear or radiological dispersal devices
- Sabotage or intentional releases at a fixed nuclear facility
- Nuclear attacks by other nations
OSHA’s Ionizing Radiation standards (including 29 CFR 1910.1096 in general industry and to the extent it applies, shipyard employment, marine terminals, and longshoring; and 29 CFR 1926.53 in construction) are based on limiting the radiation dose to the most critically exposed part of the body.
Protective actions
Employers should have plans in place to protect workers and themselves during and after a radiation emergency. First and foremost, always follow guidance and directions from local emergency response authorities.
The most likely types of potential radiation contamination events include laboratory spills or other accidents and leaking packages, according to OSHA. Bodily fluids such as urine from individuals who have undergone procedures involving radiopharmaceuticals (radioactive drugs) may also contain radioactive materials. In each of these instances, the radiation hazard may be contained to a particular part of a facility, such as a contaminated laboratory or restroom, or small geographic location.
Regardless of the emergency’s size, workers and employers can reduce their exposure to radiation by:
- Minimizing the amount of time spent near a radiation source. Get away from a radioactive spill as quickly as possible. Spend as little time as possible in exterior rooms of buildings if radioactive fallout from a nuclear detonation has contaminated the outside of the building. For every sevenfold increase in time after a nuclear detonation, there is a 10-fold decrease in radiation exposure rate.
- Increasing the distance between yourself and the radiation source. If emergency response authorities say it is safe to do so, move to an area farther away from where a radiation emergency occurred. In general, radiation intensity decreases rapidly with distance. But you should know the type of emergency you’re facing before increasing your distance. For example, after a nuclear detonation, the areas with radioactive fallout may have higher radiation levels than places closer to the detonation site.
- Increasing shielding between yourself and the radiation source. Appropriate shielding materials vary by the type of radiation. Lead or concrete shielding may be best in some scenarios, but not in others. Keep all or as much of your body as possible on the opposite side of a cinder block wall (or other appropriate shielding) from a radiation source.
During small, localized radiation emergencies, moving workers and visitors to shelter in a different part of the facility or closing off part of the facility may suffice to help you decrease time, increase distance, and increase shielding between people and a dangerous radiation source.
In more serious radiation emergencies, the radiation hazard may come from outside. Workers and employers who are not emergency responders should follow these basic actions:
- Get inside, away from radiation sources especially when there is airborne radioactive material or fallout from a nuclear detonation.
- Stay inside.
- Stay tuned to television, radio, and social media for updated instructions from emergency response official. Although it’s possible that those traditional methods of communication will be inoperable, so alternative communication methods may be required.
Training workers to remember the “Get inside, stay inside, stay tuned” slogan can be useful even if communication devices aren’t working. If possible, moving to a location away from outside walls, preferably underground, may offer added protection from radiation contamination or nuclear fallout from a radiation emergency.
Knowing the types of radiation against which shielding is meant to protect can help determine the type of shielding material, according to OSHA. Alpha particles can be stopped by a sheet of paper, beta particles are better shielded with low-density materials such as water and plastic, and heavier materials such as lead and concrete are common shielding materials for x-ray and gamma radiation.
Ensure that you select appropriate shielding materials because it can be more harmful for workers to use the wrong shielding for a particular type of radiation. For example, lead, which is used to shield against x-ray and gamma radiation, can result in secondary radiation if used to shield against beta particles. In some cases, secondary radiation can be more harmful than if there was no shielding at all.
To guard against radioactive particles, workers and employers in areas affected by a radiological release, nuclear detonation, or other radiation emergency should do the following:
- Stay away from any obvious plume or dust cloud.
- Quickly go inside a building with closed doors and windows.
- Set building ventilation systems to recirculate air and avoid drawing in outside air that may contain radioactive material, or if possible, turn off the systems.
- If outside or in a building with potentially contaminated air, cover mouth and nose with a tissue, filter, or damp cloth to avoid inhaling or ingesting radioactive material. If respiratory protection suitable for radioactive air contaminants is not available, avoid contact with other individuals until after decontamination of both (or all) parties.
- Carefully remove contaminated clothing as soon as possible. Avoid agitating or shaking out clothing to prevent exposure or further contamination. Place contaminated clothing in a sealed container such as a plastic bag. Store the bagged clothing in an area away from people and animals; the clothing could be used later to estimate a person’s dose.
- Gently wash skin and hair to remove possible contamination, ensuring that no radioactive material enters the mouth or transfers to areas of the face where it could be easily moved to the mouth and ingested.
- Provide first aid or facilitate medical care for ill and injured individuals, when possible.
- Avoid eating, drinking, or smoking, especially until skin (including hands and face) is decontaminated.
Workers may also be exposed other hazards, including:
- Hazardous substances, including releases of chemical and biological agents resulting from the initial explosion, subsequent structural damage/collapse, fires, and mismanagement of waste and debris.
- Heavy equipment and vehicular traffic, such as trucks, bulldozers, cranes, fork trucks, and other equipment that will be needed to clear roads and move rubble to enable rescue operations and control fires.
- Hazardous energy, including electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy that may be hazardous if it unexpectedly released or discharged, or if worker contact occurs.
- Slips, trips, and falls on uneven, unstable, weakened, broken, or collapsing/collapsed walking and working surfaces and falls from heights.
- Fires and explosions, resulting from a nuclear blast or secondary ignition of fuel source such as damaged containers, pipes, or utility lines.
- Noise exposure, including from a nuclear blast, heavy equipment, and other sources.
Visit OSHA’s Radiation Emergency Preparedness and Response page for more information.