The FDA and other agencies work hard every day to help prepare the nation for potential threats.
Everyone can be involved in disaster readiness by learning more about different types of emergencies, and creating an emergency supply kit and family emergency plan.
What’s new
- October 22, 2024: The FDA approved Zarxio (filgrastim-sndz) with an indication to increase survival of patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. Zarxio is the ninth FDA-approved medical countermeasure and fifth biosimilar that is indicated to increase survival in patients exposed to myelosuppressive doses of radiation.
Fast facts about radiation emergencies
From the Centers for Disease Control and Prevention (CDC)
- During a radiation emergency, the most important steps you can take are to get inside or take shelter, stay inside to reduce your exposure to radiation, and stay tuned for further instructions on what to do.
- Potassium iodide (KI) specifically blocks the uptake of radioactive iodine into the thyroid gland. Only take KI on the advice of a medical doctor, public health, or emergency management officials. Taking too much KI or taking KI when it is not recommended can have serious health risks.
FDA’s role
The FDA plays a critical role in protecting the United States from chemical, biological, radiological, nuclear, and emerging infectious disease threats.
The FDA’s roles in radiological and nuclear emergency preparedness and response include:
- Facilitating the development and availability of medical countermeasures (MCMs) that can be used to diagnose, prevent, protect from, or treat conditions including those that result from radiation exposure. Also see Medical countermeasures below, and What are medical countermeasures?
- Ensuring the safety and security of FDA-regulated products that may be impacted, or used to respond to public health emergencies. This includes ensuring food safety and medical product safety when manufacturing facilities are in an area impacted by a disaster.
- Working with medical product sponsors to clarify regulatory and data requirements necessary to rapidly advance development of products essential to supporting response efforts. Also see Guidance for industry below
- Protecting consumers against fraudulent products – Unfortunately, during emergency situations, fraudulent products claiming to prevent, treat or cure conditions associated with the emergency almost always appear for sale. The FDA monitors for fraudulent products and false product claims related to radiation and nuclear protection and takes appropriate action to protect consumers.
- Conducting research to develop the tools, standards, and approaches to assess MCM safety, efficacy, quality, and performance and to help translate new technologies into innovative, safe, and effective MCMs. For example, FDA research includes an ongoing project to develop models of radiation damage in lung, gut, and bone marrow organs-on-chips and use these models to test candidate MCMs to treat such damage.
- Leading the Advisory Team for the Environment, Food and Health, a federal interagency group of subject matter experts in radiological health and related matters. Also see Advisory Team below
Overview
Exposure to radiation can affect the body in several ways. The adverse health effects from exposure to radiation range from mild, such as skin reddening, to serious, such as Acute Radiation Syndrome (ARS), cancer, and death. The adverse health effects of radiation exposure depend on the amount and type of radiation absorbed by the body. The duration of exposure (short vs. continuous) causes different adverse effects.
Exposure to radiation during a radiological or nuclear emergency can result from exposure to an external radiation source without any direct contact with radioactive materials, from direct contamination with radioactive materials, or from a combination of both. The type of exposure that would occur depends on the type of emergency.
- External Radiation Source: Exposure can occur when all or part of the body absorbs radiation from an external radiation source without any direct contact with radiological materials. Exposure to an external source of radiation stops when a person leaves the area of the radiation source, the source is shielded, or the process causing exposure is halted.
- Direct Contamination: Exposure also can occur when a person is contaminated with radioactive particles, which can be external and/or internal.
- External contamination occurs when radioactive materials are deposited on external body parts such as skin, hair, and eyes, and clothes. External contamination stops when the radioactive material is removed by taking off contaminated clothing and completely washing off the contamination.
- Internal contamination occurs when radioactive materials are taken into the body by inhalation or ingestion, or through open wounds. The deposition of radioisotopes in organs results in local exposure. Internal contamination stops when the radioactive material decays, is eliminated from the body via natural processes, or is removed by medical countermeasures.
Some medical countermeasures are available for treating the adverse health effects from exposure to radiation as well as for limiting or removing internal contamination to help prevent or minimize adverse health effects. In the event of a radiological or nuclear emergency, medical professionals will determine if MCMs are needed.
About Acute Radiation Syndrome (ARS)
Acute Radiation Syndrome is an acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a short period of time, usually a matter of minutes.
Patients exposed to high doses of radiation will not be able to produce sufficient numbers of new white blood cells, red blood cells, and platelets, a condition called myelosuppression.
Two major clinical manifestations of radiation bone marrow injury are neutropenia (abnormally low level of neutrophils, a type of white blood cell) and thrombocytopenia (abnormally low level of platelets) that directly impact the survival of victims exposed to radiation. Severe neutropenia increases the risk of sepsis and death due to infections, while thrombocytopenia increases the risk of hemorrhage and death due to bleeding.
MCMs to treat patients with radiation-induced myelosuppression following a radiological/nuclear incident (H-ARS)
Myelosuppression occurs when radiation damages the bone marrow. Suppression of the bone marrow blocks the production of blood cells. There are FDA-approved products that can help patients with H-ARS by facilitating recovery of bone marrow cells that develop into white blood cells, including neutrophils, which help fight off infections.
FDA-approved products that may be used to treat adult and pediatric patients acutely exposed to myelosuppressive doses of radiation, a condition known as Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS:
Internal contamination
Internal contamination with radioisotopes occurs when radioactive materials are taken into the body by inhalation or ingestion, or through open wounds, and are transported into cells, tissues, and organs specific for the radioisotope, (e.g. lungs, kidneys, bone marrow) resulting in local exposure at that site of incorporation. Internal contamination stops when the radioactive material decays, is flushed from the body via natural processes, or is removed by MCMs called decorporation agents.
