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This course will expire or be updated on or before April 3, 2014.
ABOUT THIS COURSE
You must score 70% or better on the test and complete the course evaluation to earn a certificate of completion for this CE activity.
ACCREDITATION / APPROVAL
Wild Iris Medical Education is an approved provider for paramedic and EMT continuing education in California by the Coastal Valleys EMS Agency: CE Provider #49-0057.
This course is appropriate for EMTs, paramedics, and first responders.
Wild Iris Medical Education, Inc. provides educational activities that are free from bias. The information provided in this course is to be used for educational purposes only. It is not intended as a substitute for professional health care. See our disclosures for more information.
Copyright © 2011 Wild Iris Medical Education, Inc. All Rights Reserved.
This course is based on information from the Centers for Disease Control and Prevention, the U.S. Environmental Protection Agency, and the U.S. Department of Health and Human Services.
COURSE OBJECTIVE: The purpose of this course is to provide healthcare professionals with information on radiation emergencies and how to respond to them.
Upon completion of this course, you will be able to:
The term radiation in its most basic sense refers simply to a process in which energy moves through some medium as either waves or particles. Radiation exists naturally throughout the environment as well as being generated by human sources. Radiation falls into two major divisions: nonionizing and ionizing.
Nonionizing radiation is lower in energy; it can cause atoms in a molecule to vibrate. Common forms of nonionizing radiation energy include sound waves, visible light, and microwaves. Examples of human sources include power lines, radio and television broadcasting, and microwave ovens.
Ionizing radiation breaks the bonds in an atom by “stripping” electrons or even breaking up the nucleus, which releases energy in the form of radiation. This in turn can damage living cells and cause health affects. Ionizing radiation is the type generally thought of as “radiation.” Natural sources include radon, which is commonly found in soil, and cosmic (space) radiation, which enters the Earth’s atmosphere from space. Examples of human sources include medical X-rays, some industrial processes, nuclear power plants, and nuclear weapons (EPA, 2011).
Radiation across the electromagnetic spectum. (Source: Environmental Protection Agency.)
Ionizing radiation is emitted both as particles and waves. Alpha particles can travel only a few inches in air. They are not able to penetrate human skin or clothing but can be harmful if inhaled, swallowed, or absorbed through open wounds. Beta particles can travel only a few feet in air and are moderately penetrating, but clothing provides some protection. Gamma and X-ray radiation are emitted as waves and may travel many feet in air and many inches in human tissue. They readily penetrate most materials and are thus sometimes called “penetrating” radiation. (HPS, 2009)
Radiation is commonly measured in the following three ways:
The amount of radiation being emitted by a radioactive material is measured using the conventional unit curie (Ci) or the Système Internationale (SI) unit becquerel (Bq). One Ci is equal to 37 billion Bq. Ci or Bq may be used to refer to the amount of radioactive materials released into the environment. For example, during the Chernobyl power plant accident that took place in the former Soviet Union, an estimated total of 81 million Ci of radioactive cesium (a type of radioactive material) was released.
When a person is exposed to radiation, energy is deposited in the tissues of the body. The amount of energy deposited per unit of weight of human tissue is called the absorbed dose. Absorbed dose is measured using the conventional unit “radiation absorbed dose” (rad) or the SI unit gray (Gy). One Gy is equal to 100 rad.
A person’s biological risk (that is, the risk that a person will suffer health effects from an exposure to radiation) is measured using the conventional unit rem or the SI unit sievert (Sv). One Sv is equal to 100 rem. To determine a person’s biological risk, the absorbed dose is multiplied by a “quality factor” (Q), which depends on the type of radiation and its ability to transfer energy to the cells of the body. Thus, risk in rem = rad X Q.
Some common ways that people are exposed to radiation and the associated doses are shown in the table below.
|Source of Exposure||Dose
|Source: CDC, 2006b.|
|Exposure to cosmic rays during a roundtrip airplane flight from New York to Los Angeles||3||0.03|
|One dental X-ray||4–15||0.04–0.15|
|One chest X-ray||10||0.1|
|One year of exposure to natural radiation (from soil, cosmic rays, etc.)||300||3|
Radiation exposure occurs whenever radiation energy penetrates the body, for example, when receiving a medical X-ray. A person can also be exposed by being close to radioactive material or a contaminated person, place, or thing.
Radioactive contamination occurs when radioactive material is deposited on or in an object or a person. Radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated. A person exposed to radiation is not necessarily contaminated. For a person to be contaminated, radioactive material must be on or inside the body.
When radioactive materials—in the form of dust, powder, or liquid—come into contact with a person’s skin, hair, or clothing, he or she is considered externally contaminated. External contamination can be removed by shedding contaminated clothing and/or completely washing off the source of radioactivity. Internal contamination occurs when people swallow or breathe in radioactive materials, or when radioactive materials enter the body through an open wound or are absorbed through the skin.
Internal contamination continues until the radioactive material decays, is flushed from the body by natural processes, or is removed by medical countermeasures. Some types of radioactive materials stay in the body and are transported in the blood to cells, tissues, and organs. Other types are eliminated from the body in blood, sweat, urine, and feces. (CDC, 2006a)
Radioactive materials can be released into the environment as the result of an accident, an event in nature, or an act of terrorism. Examples of such releases might include:
Radiation reactor incidents occur almost exclusively at fixed facilities, like nuclear reactors or nuclear power plants. Typically, facility operators and local officials have formal response plans and practice response operations. In some cases, such as the accident at the Fukushima Daiichi nuclear power plant in Japan in 2011, such response plans may be insufficient to address the scope of the emergency.
For accidents at fixed facilities, there is likely to be a window of time before the release of radiation into the environment (as opposed to a nuclear bomb or sabotage, which will likely come without advanced warning).
Accidents at a nuclear reactor can lead to both exposure to radioactivity as well as to contamination. Workers close to the reactor could be contaminated due to external exposure to highly radioactive materials within the reactor or to radioactivity released and dispersed locally in a radioactive cloud, or plume. They may also suffer internal contamination due to ingestion or inhalation.
The general public could be similarly contaminated due to radioactivity released and dispersed widely in the plume. Some radioactive material may attach itself to dust particles in the air and can be carried long distances in the wind. When these particles are caught in precipitation (e.g., rain or snow), they are deposited directly onto the ground and may potentially contaminate drinking water sources and growing food supplies.
A nuclear bomb explosion results from the joining or splitting of atoms (called fusion or fission) to produce an intense pulse or wave of heat, light, air pressure, and radiation. When a nuclear device is exploded, it produces a huge fireball that vaporizes everything around, including soil and water, and carries it upward into a mushroom cloud. Radioactive materials in the mushroom cloud then cool, condense, and form into particles (known as “fallout”) that disperse back to the ground. Fallout can be carried long distances on wind currents and end up miles from the site of the explosion, causing the contamination of anything it lands on, including people, plants, and water. (CDC, 2006a)
A nuclear blast causes great destruction, death, and injury, and has a wide area of impact. People may experience skin burns, eye damage due to looking at the blast, and high levels of radiation exposure, including acute radiation syndrome (ARS) (see “Acute Radiation Syndrome” below). Effects may range from mild to severe. Exposure to very large doses of external radiation may cause death within a few days or months. External exposure to lower doses of radiation and internal exposure from breathing or eating food contaminated with radioactive fallout may lead to an increased risk of developing cancer and other health effects.
Radioactive material could be dispersed in an act of terrorism. This might include the detonation of a nuclear bomb, which could have the same effects as those described above.
Terrorists might also employ a “dirty bomb,” which is a mix of an explosive such as dynamite with radioactive material. Such a device is not the same as a nuclear bomb and will not create an atomic blast and the associated widespread impact. The main effect of a dirty bomb would likely be bodily injury and radiation exposure limited to those close to the blast site. Any radioactive dust and smoke spread farther away could also be dangerous if inhaled. (CDC, 2006a)
Another potential terrorist act would be to intentionally hide a radioactive device in a public location or release radioactive material into the food or water supply so as to expose people to its effects. Such exposure would likely not result in contamination, and the effects would depend on many factors, such as a person’s proximity to the source, length of exposure, and nature of the source.
Radioactive material may be released during an accidental spill. For instance, since many states do not permit the storage of radioactive waste and it must be shipped to distant locations, a spill could take place due to an accident during transport. A spill of radiaoactive material may also be caused by damage to a package containing radioactive material.
Strict packaging and labeling requirements are used when shipping radioactive materials to help prevent an accidental radiation release. The risk of exposure or contamination during a spill is dependent on whether any radioactive material is dispersed from the spill site. In all likelihood, healthcare providers along these routes do not ever expect to activate a response plan to such an emergency.
Any living tissue in the human body can be damaged by ionizing radiation. The severity and types of damage are based on the amount and duration of radiation exposure.
Short-term, high-level (or acute) exposure to radiation can cause burns and acute radiation syndrome (ARS, also called “radiation poisoning” or “radiation sickness”). It can also cause premature aging and death. (Medical patients receiving radiation treatments also often experience acute effects because they are receiving relatively high “bursts” of radiation during treatment.)
There is no firm basis for setting a “safe” level of exposure. However, there do appear to be threshold exposures for the various acute effects.
|Exposure (rem)||Health Effect||Time to Onset
|Source: EPA, 2011.|
|5–10||Changes in blood chemistry|
|75||Hair loss||2–3 weeks|
|400||Possible death||Within 2 months|
|1,000||Destruction of intestinal lining
|2,000||Damage to central nervous system
Loss of consciousness
Hours to days
|Acute effects are cumulative. For example, a dose that produces damage to bone marrow will have produced changes in blood chemistry and be accompanied by nausea.|
Acute Radiation Syndrome is caused when the entire body (or most of the body) is exposed to a high dose of penetrating radiation in a very short period of time. The survivors of the nuclear bombing of Hiroshima and Nagasaki as well as first responders to the reactor accident at Chernobyl in 1986 suffered ARS.
CONDITIONS CAUSING ARS
Source: CDC, 2006b.
The three classic acute radiation syndromes are bone marrow syndrome (sometimes referred to as hematopoietic syndrome), gastrointestinal syndrome, and cardiovascular/central nervous system syndrome (see table below).
|Bone Marrow (Hematopoietic)||Gastrointestinal||Cardiovascular/
Central Nervous System
|Source: CDC, 2006b.|
|Dose||> 0.7 Gy (70 rads)
(Mild symptoms may occur as low as 0.3 Gy or 30 rads.)
|> 10 Gy (1,000 rads)
(Some symptoms may occur as low as 6 Gy or 600 rads.)
|> 50 Gy (5,000 rads)
(Some symptoms may occur as low as 20 Gy or 2,000 rads.)
|Manifest Illness Stage||
Cutaneous radiation syndrome can result from acute radiation exposure to the skin, especially due to beta radiation or X-rays. This can also occur when radioactive materials contaminate a patient’s clothes.
Damage to the basal cell layer of the skin by radiation can cause inflammation, erythema (redness), and dry or moist desquamation. Hair follicles may also be damaged, causing epilation (hair loss). A transient and inconsistent erythema (associated with itching) can occur within the first few hours. Then, a latent phase may occur and last from a few days up to several weeks, characterized by intense reddening, blistering, and ulceration of the irradiated site.
In most cases, the skin will heal by regenerative means; however, very large radiation doses can cause permanent hair loss, damaged sebaceous and sweat glands, atrophy, fibrosis, decreased or increased skin pigmentation, and ulceration or necrosis of the exposed tissue.
Long-term, low-level (chronic) exposure to radiation can lead to cancer, often considered its primary health effect, due to radiation’s ability to disrupt cells and molecules. Because children are growing more rapidly, with more cells dividing, they stand a greater risk for such health effects. Radiation can also cause changes in DNA, leading to genetic mutations that are passed on to offspring.
Radioactive elements can accumulate in human organs as a result of internal contamination. For instance, ingested radioactive iodine (I-131) will concentrate in the thyroid and can lead to thyroid cancer (see figure below). Similarly, radioactive strontium and radium accumulate in calcium-rich areas, such as bones and teeth, and can lead to bone cancer.
Internal exposure to radioactive iodine-131 through ingestion.
(Source: HHS/National Cancer Institute/Division of Cancer Epidemiology and Genetics.)
Radioactive iodine (I-131) has a half-life of about 8 days and decays (loses its level of radioactivity) rapidly; it rarely exists at any meaningful level in the environment. In the case of a nuclear bomb or nuclear power plant accident, however, I-131 is produced and forced high into the atmosphere by the intense heat. It can then be carried by the wind and fall to the ground as particles or dissolved in rainwater.
The greatest risk to humans is due to consumption of contaminated milk and dairy products from cows or goats that ingested contaminated pasture grasses. Doses to humans from inhalation or ingestion of plants, animals, or water are usually small in comparison.
Major harmful releases of I-131 occurred between the 1940s and mid-1960s due to production and testing of nuclear weapons, however national security policies prevented their disclosure to the public. The estimated release from the Nevada Test Site between 1952–1970 was 150 million Ci; from the Chernobyl accident was 50 million Ci; and the Three Mile Island, Pennsylvania, accident was 15–21 Ci. (ATSDR, 2002)
Fetuses are highly sensitive to radiation, whether due to external exposure through the mother’s abdomen or to the mother’s internal contamination. Health effects depend on which systems are developing at the time of exposure.
In the first 2 weeks of pregnancy, when the fetus is made up of only a few cells, radiation damage to even one cell can cause the death of the embryo. During early development (weeks 2 to 15), the fetus may face severe consequences, including stunted growth, deformities, abnormal brain function, or cancer that may develop later in life. From week 16 to birth, health effects are unlikely unless the fetus is exposed to a large dose of radiation.
Scientists estimate only a small risk of health effects due to low doses of radiation. For instance, in a group of 10,000 people, 2,000 of them might die of cancer from all non-radiation causes. Accumulated exposure to 1 rem of ionizing radiation in small doses over a lifetime would increase that number by about 5 or 6 people. (Most people receive about 0.3 rem every year from natural sources of radiation.)
Among fetuses, scientists estimate that if 1,000 fetuses between 8 and 15 weeks old were exposed to 1 rem of radiation, 4 fetuses would become mentally retarded. For fetuses between 16 and 25 weeks, it is estimated that 1 of them would become mentally retarded.
Regarding genetic effects, scientists estimate about 50 severe hereditary effects in a group of 1 million live-born children whose parents were both exposed to 1 rem. In comparison, all other causes of genetic effects result in as many as 100,000 severe hereditary effects in 1 million live-born children. These genetic effects include those that occur spontaneously (“just happen”) as well as those that have non-radioactive causes. (EPA, 2011)
In the event of a radiation emergency, such as a nuclear power plant accident or the explosion of a dirty bomb, those nearby may be advised to evacuate the immediate area, “shelter in place,” or go to an emergency shelter. Local authorities will generally alert the public with radio and television messages. Utility companies operating nuclear plants are also required by law to have plans in place for contacting people in the community during an emergency and publicizing its evacuation plans and routes.
The safest initial response for those outside the immediate vicinity of the emergency may simply be to take shelter in place. The walls of a building may block any harmful radiation and reduce exposure. Thus, it is important to stay inside and protect against radioactive materials from entering the building. The CDC (2006a) advises the following:
It is also recommended to have on hand basic emergency supplies, whether for radiation, severe weather, or any other emergencies. These include food, water, clothing, bedding, radio, flashlights, batteries, etc.
Since each situation is different, it is important to wait for appropriate information before evacuating. For instance, the direction any radioactive plume is moving will dictate which areas should be evacuated and how people can best avoid the plume. Local authorities will advise the public when to go to an emergency shelter, where the shelter is located, and in which direction to travel when evacuating the area of the incident. Some people may be told not to evacuate, such as children in a school that is miles away and upwind from the incident.
For those evacuating to emergency shelters, they should bring any medicines and a change of clothes. Shelter will have most other supplies that people need. Most emergency shelters will not accept pets.
A release of radioactive material can expose people and contaminate their surroundings and personal property. However, it is difficult for people to know when they have contacted radioactive materials because radiation cannot be seen, smelled, felt, or tasted.
People who become externally contaminated may then contaminate other people or surfaces that they touch. Those who are internally contaminated can also expose others through their bodily fluids, which may contain radioactive materials.
For example, people who have radioactive dust on their clothing may spread the radioactive dust when they sit in chairs, hug other people, or even walk through a house. Contaminants can easily fall from clothing and contaminate other surfaces. Homes can also become contaminated with radioactive materials in bodily fluids from internally contaminated people. Making sure that others do not come in contact with bodily fluids from a contaminated person will help prevent contamination of other people in the household.
The CDC (2006a) provides the following recommendations. These steps depend on the nature of the emergency and a person’s location when the incident occurs.
HOW TO LIMIT EXPOSURE
In the event of a radiation emergency that involves the release of radioactive iodine (such as an accident at a nuclear power plant or a nuclear bomb explosion), non-radioactive potassium iodide (KI) may be recommended. Taking KI or other iodine substances will saturate the thyroid with iodine, thereby decreasing the amount of radioactive iodine that can be absorbed by it and minimizing or avoiding the subsequent risk of thyroid cancer. KI is most effective if given a few hours before exposure, but it is also effective if given within several hours after exposure. (KI does not provide protection from other types of radiation exposure.)
The need for prophylaxis and/or treatment with potassium iodide will be determined by officials managing the event, and instructions to the general public will be given based on the assessment of risk. Potassium iodide should be taken only on the advice of emergency management officials, public health officials, or a personal physician. There are health risks and side effects associated with taking KI, and it may be harmful to those with an allergy to iodine or certain skin disorders.
The U.S. Food and Drug Administration (FDA) has approved a tablet form and a liquid form of KI for use after a radiation emergency. They have established recommended dosages for all age groups; exceeding this dosage may cause adverse health effects. KI is sold without a prescription.
Following an accidental release of radiation from a nuclear power plant in California, healthcare providers across the country begin receiving phone calls from concerned parents worried about radiation dangers to themselves and their children. These parents have heard that milk can be contaminated by radioactive fallout that spreads thousands of miles from the damaged nuclear reactor and that they can protect themselves by taking potassium iodide pills.
Following local protocols, providers educate the callers about potassium iodide (KI) prophylaxis, stating that it should be taken only on the advice of emergency management officials, public health officials, or a personal physician. They notify the callers that milk and other food products can be contaminated by radioactive fallout and that public health officials will monitor the food supply for any dangerous levels of radiation and notify the public of any recommendations to limit their exposure.
Healthcare providers should always utilize appropriate personal protective equipment (PPE) when evaluating and treating patients known or suspected to be contaminated with radioactive material. Additionally, a personal radiation dosimeter should be worn by all providers, including first responders, to monitor radiation exposure.
Film badge (left) and ring badge (right) dosimeters. (Source: OSHA.)
Pregnant healthcare providers should not be permitted to work in pre-decontamination or decontamination areas, areas where internally contaminated patients are cared for or housed, or areas where there are elevated levels of environmental radiation.
Healthcare providers should be organized in order to minimize exposures to team members by frequently monitoring individual team member radiation doses and rotating teams and team members away from high radiation dose fields.
In radiation emergencies, first responders must consider certain specific issues, including the use of additional personal protective equipment and triaging, treating, and transporting potentially contaminated individuals (DHHS, 2011).
Dermal and respiratory PPE may
be worn by first responders.
(Source: Nebraska Department of
Health and Human Services.)
The choice of PPE is made by incident commanders and is proportional to the level of risk. In addition to a personal radiation dosimeter, PPE may include both respiratory and dermal protective equipment, which can guard against external and internal contamination via inhalation, ingestion, or absorption through open wounds. However, PPE cannot protect against exposure from high-energy penetrating forms of radiation associated with such emergencies. Responders should thus follow worker exposure guidelines to limit total exposure time. They can also reduce exposure by remaining in shielded areas.
After performing life-saving tasks, first responders manage radiation-related problems. Triage protocols may begin with evaluating people for contamination and be followed by decontamination (see “Decontamination” below). For those requiring further care, medical facilities should be notified of the number, type, and severity of casualties to be transported.
Transport of those who are exposed but not contaminated does not require protection of the vehicle or personnel. Transport of those who are contaminated does require protective measures, including covering any litter and gurney with sheets/blankets, removing the victim’s contaminated outer clothing, closing all open compartments within the vehicle, and using disposable equipment when possible. (The above are general recommendations; detailed local protocols should always be followed.)
First responders are called to the scene of a highway collision involving a truck that is carrying spent fuel from a nearby nuclear power plant. They arrive on the scene to find the truck overturned and on fire. The incident commander is already on scene and has identified contaminants in the air at a dangerous concentration. Responders don a full-face air-purifying respirator, protective clothing, and a personal radiation dosimeter. As they work to evaluate the truck’s driver for contamination, they monitor their dosimeters to ensure their exposure remains below safe limits.
Beyond the steps listed above for individual self-decontamination, decontamination of victims of radiation emergencies may be carried out by healthcare personnel. Decontaminating the skin and body will lower the risk of acute dermal injury, internal contamination, and contamination of medical personnel and the environment.
The U.S. Department of Health and Human Services (2011) provides detailed protocols for decontamination procedures. Following is a brief summary of general recommendations. In the case of mass casualty events and a large number of individuals seeking treatment, these recommendations may require major modification.
PERFORMING A SURVEY FOR RADIATION CONTAMINATION
In the event of suspected radiation contamination, healthcare personnel will use an instrument such as a GM meter (or Geiger-Mueller radiation instrument) to survey a patient.
Source: DHHS, 2011.
Images Source: Radiation Emergency Assistance Center/Training Site.
When treating shrapnel and open wounds, it is important to consider them contaminated until proven otherwise. It should also be assumed that embedded foreign bodies and wound contamination will produce uptake (internal contamination), and such patients should be assessed for internal contamination as well. When decontaminating open wounds, providers can limit the spread of radioactivity by carefully capturing water run-off during wound irrigation and by using waterproof dressings.
Since uptake of radioactive material may be faster through membranes than through intact skin, it is important to decontaminate body orifices before intact skin. Orifices should first be assessed to determine likelihood and extent of internal contamination. An ear syringe can be used to rinse the external auditory canal (only if the tympanic membrane is intact). Tooth brushing, frequent mount rinsing, and gargling with 3% hydrogen peroxide solution can be encouraged for oral decontamination. The eyes can be gently irrigated with copious amounts of saline or water if corneal contamination is present and the globe is intact.
To decontaminate localized areas of the skin, healthcare providers first mark (using a waterproof felt tip marker) any areas of high-level contamination found during the whole-body radiation survey. Decontamination should begin with areas of highest contamination by either gently brushing the skin surface or washing with tepid water and soap without damaging or abrading the skin. Recontamination can be avoided by directing contaminated waste water away from the patient and using serial washcloths, gauze pads, or surgical sponges. When removing all contamination from the skin is not feasible or desirable, residual contamination can be covered with waterproof dressings/drapes in order to limit its spread.
Following the explosion of a dirty bomb, contaminated bystanders are transported to the local hospital emergency room. ED staff have been notified in advance and are wearing appropriate PPE when the victims begin to arrive. Treatment is begun immediately for unstable patients. For those without life-threatening injuries, providers begin by removing contaminated clothing from the individuals and placing it in property bags that are then properly labeled. Using GM meters that they have already checked, they conduct whole-body scans of the patients and record the readings.
Some victims have been injured by shrapnel from the blast. ED staff remove the shrapnel to protect against possible internal contamination. They clean the wounds, carefully catching any water run-off. They also wash the patients’ bodies with soap and water to remove any external contamination. They then complete a second scan to determine the degree to which the decontamination process was successful.
For patients with acute radiation exposure, additional treatment recommendations include:
Certain drugs are also used to treat some instances of internal contamination. This includes the use of potassium iodide (see “Potassium Iodide (KI) Prophylaxis” above) as well as the following treatments. Since not all treatments are effective for all types of radiation contamination, it is important to follow the guidance of doctors and public health authorities.
Prussian blue, typically taken in capsule form, has been used since the 1960s to treat those who have been internally contaminated with radioactive cesium (and nonradioactive thallium). Originally produced as a dye, this substance traps these elements in the intestines and prevents their reabsorption into the body while they are being excreted in bowel movements. Prussian blue also reduces the biological half-life (the time required for one half of a substance to be expelled from the body by natural metabolic processes) from 110 to 30 days, thereby decreasing the body’s exposure time to radiation.
Prussian blue (or Radiogardase) is available only by prescription and should be taken only under a physician’s supervision. It is considered safe for most adults, including pregnant women, and children ages 2–12 years. Upset stomach and constipation are the most common side effects, and individuals suffering from constipation or other stomach or intestinal problems should notify their doctor of this before taking Prussian blue.
DPTA is a chelating agent used since the 1960s to treat internal contamination. It is currently approved for use in cases involving radioactive plutonium, americium, and curium. As a chelating agent, DPTA binds to these radioactive materials and is then excreted from the body in the urine. There are two forms: calcium (Ca-DPTA) and zinc (Zn-DPTA). Within the first 24 hours after contamination, Ca-DPTA is 10 times more effective, and after 24 hours, the two forms are equally effective.
DPTA is administered by direct injection, intravenous drip, or an inhaled mist or spray. It can be given to adults and children of all ages, with the dose based on size and weight. The length of treatment depends on the level of radioactive contamination. There are limited contraindications, and side effects may include nausea, vomiting, diarrhea, chills, fever, itching, muscle cramps, headache, lightheadedness, chest pain, and a metallic taste in the mouth.
Filgrastim (trade name Neupogen) was approved by the FDA in 1991 for cancer patients to help in the recovery of bone marrow damage due to chemotherapy or radiation therapy. Neupogen can be used in patients exposed to very high doses of radiation in order to stimulate the growth of white blood cells, thereby reducing the risk of infection.
Neupogen is administered by injection or intravenous infusion. It may be prescribed for most adults, however children, pregnant women, and breastfeeding women should take it with caution. There are limited contraindications, and side effects may include fever, diarrhea, skin rash, weakness, and mild to moderate bone pain.
The U.S. Environmental Protection Agency (EPA) monitors and tracks radiation across the nation, both at the time of any radiation emergency and on an ongoing basis.
The agency’s Radiological Emergency Response Team (RERT) can travel to the scene of an incident in order to detect localized radiation. Hand-held equipment is used to measure levels of radiation that may threaten the safety of responders or the public. Air samplers are placed away from the immediate incident to monitor the spread of radioactive materials. Mobile Environmental Radiation Laboratories (MERLs) are also deployed to sites in the United States in order to test samples taken from the environment.
The EPA’s RadNet system consists of a nationwide network of sampling stations that operates constantly to monitor samples of air, drinking water, precipitation, and other media where radiation may be present. By plotting sampling results, RadNet can detect the path of a contaminant plume due to large-scale radiation releases due to emergencies, such as that at the Fukushima nuclear plant in Japan in 2011.
The safety of food products is monitored by the U.S. Food and Drug Administration (FDA). This includes regulating, tracking, and radiation screening of food shipments into the country as well as inspecting and analyzing food and animal feed domestically. The FDA also works with other agencies as part of the Food Emergency Response Network (FERN).
Q:What is radiation exposure?
A:Radiation exposure occurs when one is in the presence of radioactive materials. People are naturally exposed to small amounts of radiation every day.
Q:What is radioactive contamination?
A:A person becomes contaminated when they have radioactive material on them or in them. External contamination is on the skin or clothing. Internal contamination is when people breathe in, swallow, or otherwise get radioactive materials inside the body.
Q:What is the difference between radiation exposure and radioactive contamination?
A:When a person is exposed to radiation, there is no transfer of radioactive material, for example, an X-ray. When a person is contaminated with radioactive material, they take that material with them wherever they go until they are decontaminated.
Q:What happens when people are exposed to radiation?
A:Radiation can affect the body in a number of ways, and the adverse health effects of exposure may not be apparent for many years. These adverse health effects can range from mild effects, such as skin reddening, to serious effects such as cancer and death, depending on the amount of radiation absorbed by the body (the dose), the type of radiation, the route of exposure, and the length of time a person was exposed. Exposure to very large doses of radiation may cause death within a few days or months. Exposure to lower doses of radiation may lead to an increased risk of developing cancer or other adverse health effects later in life.
Q:How is decontamination typically performed?
A:Removing outer clothing, washing the contaminated area with mild soap and water, or showering are typical methods for decontamination.
Q:What about contamination that’s inside the body?
A:Internal contamination is treated with medications specific to the materials to which a person is exposed. Potassium iodide (KI), Prussian blue, and DTPA are a few of the most common radiation treatment drugs.
Q:When do people need to be "treated" for radiation exposure or contamination?
A:If someone may have accidently been exposed to radiation, they should seek medical advice to determine what, if any, treatment is needed. Based on the type of radiation, the situation, the patient’s symptoms, how long the person was exposed, and whether he or she is contaminated, a physician, often assisted by a radiation expert known as a health physicist, will provide the patient with information about what treatment may be needed.
Q:If there is a radiation accident, when should someone take potassium iodide (KI)?
A:A nuclear power plant accident or nuclear bomb detonation releases radioactive iodine. KI is a medication that blocks the thyroid gland from absorbing this radioactive iodine. It works by providing all the iodine the gland needs so that it doesn’t absorb any radioactive iodine. KI should only be taken if a significant amount is released and only when advised by emergency management officials, public health officials, or a doctor. KI is available without a prescription, but people who are allergic to iodine or have some health conditions should not take it.
Q:What radiation doses are considered to be safe?
A:The average annual radiation dose per person in the United States from natural and manmade sources is 620 mrem (6.2 mSv) (EPA, 2011). The National Academy of Sciences (NAS) (2006) has found that, even at low doses, all ionizing radiation poses some risk. However, certain regulations and limits have been established to help protect people from receiving an amount of radiation that might cause adverse health effects. For instance, radiation dose limits have been set for U.S. radiation workers at 5,000 mrem (50 mSv) per year. The maximum contaminant level for beta particle and photo radioactivity from drinking water is 4 mrem per year.
CDC: General information
CDC: Radiation and Potassium Iodide Fact Sheet
Radiation Emergency Assistance Center/Training Site (REAC/TS)
U.S. Environmental Protection Agency
U.S. Food and Drug Administration
Agency for Toxic Substances and Disease Registry (ATSDR). (2002). Radiation exposure from iodine-131. Retrieved March 2011 from http://www.atsdr.cdc.gov/csem/iodine/exposure_pathways.html.
Centers for Disease Control and Prevention (CDC). (2006a). Radiation emergencies. Retrieved March 2011 from http://emergency.cdc.gov/radiation/
Centers for Disease Control and Prevention (CDC). (2006b). Acute radiation syndrome: A fact sheet for physicians. Retrieved March 2011 from http://emergency.cdc.gov/radiation/arsphysicianfactsheet.asp.
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