There are two kinds of radiation: non-ionizing radiation and ionizing radiation.
Non-ionizing radiation has enough energy to move atoms in a molecule around or cause them to vibrate, but not enough to remove electrons from atoms. Non-ionizing radiation can heat substances. Examples of non-ionizing radiation are radio waves, microwaves, infrared radiation, and the visible light spectrum.
We are exposed to low levels of non-ionizing radiation every day. Exposure to intense, direct amounts of non-ionizing radiation may result in damage to tissue due to heat.
Ionizing radiation has so much energy it can knock electrons out of atoms, a process known as ionization. Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. Ionizing radiation comes from x-ray machines, cosmic particles from outer space, and radioactive elements. Radioactive elements emit ionizing radiation as their atoms undergo radioactive decay.
Radioactive decay is the emission of energy in the form of ionizing radiation. Ionizing radiation can be emitted in the form of alpha particles, beta particles, or gamma rays.
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1. X-rays contain _____.
a. ionizing radiationAlpha particles are positively charged and made up of two protons and two neutrons from the atom's nucleus. Alpha particles come from the decay of the heaviest radioactive elements, such as uranium, radium, and polonium. Even though alpha particles are very energetic, they are so heavy that they use up their energy over short distances and cannot travel very far from the atom.
The health effect from exposure to alpha particles depends significantly on how a person is exposed. Alpha particles lack the energy to penetrate even the outer layer of skin. Hence, exposure to the outside of the body is not a significant concern. Inside the body, however, they can be very harmful. If alpha-emitters are inhaled, swallowed, or get into the body through a cut, the alpha particles can damage sensitive living tissue. The way these large, heavy particles cause damage makes them more dangerous than other types of radiation. The ionizations they cause are very close together - they can release all their energy in a few cells leading to more severe damage to cells and DNA.
Beta particles are small, fast-moving particles with a negative electrical charge emitted from an atom's nucleus during radioactive decay. These particles are emitted by unstable individual atoms such as hydrogen-3 (tritium), carbon-14, and strontium-90.
Beta particles are more penetrating than alpha particles. Still, they are less damaging to living tissue and DNA because the ionization they produce is more widely spaced. They also travel farther in the air than alpha particles. Still, they can be stopped by a layer of clothing or a thin layer of material, such as aluminum. Some beta particles can penetrate the skin and cause damage, such as skin burns. However, as with alpha-emitters, beta-emitters are most hazardous when they are inhaled or swallowed.
Gamma rays are weightless packets of energy called photons. Unlike alpha and beta particles, which have both energy and mass, gamma rays are pure energy. Gamma rays are like visible light but have much more energy. Gamma rays are often emitted along with alpha or beta particles during radioactive decay.
Gamma rays are a radiation hazard for the entire body. They can easily penetrate barriers that can stop alpha and beta particles, such as skin and clothing. Gamma rays have so much penetrating power that several inches of dense material, like lead, or a few feet of concrete, may be required to stop them. Gamma rays can pass entirely through the human body; as they pass through, they can cause ionizations that damage tissue and DNA.
2. _____ can be extremely harmful to only the inside of the body.
a. Beta particlesBecause of their use in medicine, almost everyone has heard of x-rays. X-rays are like gamma rays in that they are photons of pure energy. X-rays and gamma rays have the same basic properties but come from different parts of the atom. X-rays are emitted from processes outside the nucleus, but gamma rays originate inside the nucleus. They also are generally lower in energy and therefore less penetrating than gamma rays. X-rays can be produced naturally or by machines using electricity.
Thousands of x-ray machines are used daily in medical and dental procedures. Computerized tomography (CT or CAT scan) uses special x-ray equipment to make detailed bone and soft tissue images in the body. Medical x-rays are the single largest source of human-made radiation exposure.
Staff members can often be exposed to radiation from portable and fixed x-ray machines during diagnostic procedures. X-ray exposure can cause the following health issues:
Radiation exposure occurs when unprotected employees are near a machine in operation. The degree of exposure depends on the amount of radiation, duration of exposure, distance from the source, and the type of shielding in place.
Here are some possible solutions from OSHA when working with x-ray machines:
3. Which of the following is a chronic health effect of x-rays?
a. DermatitisOther x-ray exposure controls include:
4. Who should be the only person who has access to radioactive storage areas in a healthcare setting?
a. PatientsOSHA's Ionizing Radiation Standard [29 CFR 1910.1096] requires:
5. How often should employers advise employees of his or her personal radiation exposure?
a. Every yearHuman senses cannot detect radiation. A variety of handheld and laboratory instruments are available for detecting and measuring radiation. The most common handheld or portable instruments are:
6. When dealing with unknown sources of radiation, this tool tends to be the most useful.
a. Ionization (Ion) ChamberRadioactive contamination and radiation exposure could occur if radioactive materials are released into the environment due to an accident, an event in nature, or an act of terrorism. Such a release could expose people and contaminate their surroundings and personal property.
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. Some types of radioactive materials stay in the body and are deposited in different body organs. Other types are eliminated from the body in blood, sweat, urine, and feces.
External contamination occurs when radioactive material, in the form of dust, powder, or liquid, encounters a person's skin, hair, or clothing. In other words, the contact is external to a person's body. People who are externally contaminated can become internally contaminated if radioactive material gets into their bodies.
Radioactive materials give off a form of energy that travels in waves or particles. This energy is called radiation. When a person is exposed to radiation, the energy penetrates the body. For example, when a person has an x-ray, he or she is exposed to radiation.
7. _____ occurs when people swallow or breathe in radioactive materials.
a. Immediate deathEmergency services physicians and nurses will be among the first clinicians to see and treat radiation emergency victims. Clinicians of all specialties will be responsible for providing care and information to:
In a radiation emergency, the choice of appropriate personal protective equipment (PPE) depends on:
PPE can protect against the following:
PPE cannot protect against high energy exposure, highly penetrating forms of ionizing radiation associated with most radiation emergencies.
Lead aprons worn in diagnostic radiology do not provide sufficient shielding against these kinds of radiation.
PPE should include a personal radiation dosimeter whenever there is concern about exposure to penetrating ionizing radiation.
Recommended respiratory PPE includes a full-facepiece air-purifying respirator with a P-100 or High-Efficiency Particulate Air (HEPA) filter.
Other respiratory protective equipment (e.g., a simple surgical facemask, N-95 respirators), non-fit tested respirators, or ad hoc respiratory protection do not deliver appropriate or sufficient respiratory protection.
Environmental testing and hazard assessment by a safety professional can help identify hazards and risk levels and direct permissible PPE choices.
8. In a radiation emergency, the choice of appropriate personal protective equipment (PPE) depends on _____.
a. employer costIf you are injured after radiation exposure, seek medical attention right away. These injuries could be at high risk for infection and other long-lasting health effects.
Radioactive contamination and radiation exposure could occur if radioactive materials are released into the environment due to an accident, an event in nature, or an act of terrorism. Such a release could expose people and contaminate their surroundings and personal property.
People exposed to radiation will get ARS only if:
Symptoms of ARS may include nausea, vomiting, headache, and diarrhea. These symptoms start within minutes to days after the exposure, last for minutes up to several days, and may come and go. If you have these symptoms after a radiation emergency, seek medical attention as soon as emergency officials determine it is safe to do so. After the initial symptoms, a person usually looks and feels healthy for a while. He or she will become sick again with variable symptoms and severity that vary depending on the radiation dose that he or she received. This seriously ill stage may last from a few hours up to several months. Click the button to view these symptoms.
Treatment of ARS focuses on reducing and treating infections, maintaining hydration, and treating injuries and burns. Some patients may benefit from treatments that help the bone marrow recover its function. The lower the radiation dose, the more likely it is that the person will recover from ARS. In most cases, the cause of death is the destruction of the person's bone marrow, which results in infections and internal bleeding. For survivors of ARS, the recovery process may last from several weeks up to 2 years.
People with ARS typically also have some skin damage. There also can be hair loss. As with the other symptoms, the skin may heal for a short time, followed by the return of swelling, itching, and redness days or weeks later. Complete healing of the skin may take several weeks up to a few years, depending on the radiation dose the person's skin received.
9. What are the symptoms of acute radiation syndrome?
a. NumbnessCutaneous Radiation Injury (CRI) happens when exposure to a large dose of radiation causes injury to the skin. A doctor will suspect the presence of a CRI when a skin burn develops on a person who was not exposed to a source of heat, electrical current, or chemicals.
People may experience a Cutaneous Radiation Injury (CRI) when:
Symptoms of CRI can appear from a few hours to several days after exposure. The early signs and symptoms of CRI include:
Over time, other symptoms may develop depending on the injury's site and the level of radiation dose to which the skin was exposed.
After a radiation emergency, if you experience the above symptoms, seek medical attention as soon as emergency officials say it is safe to do so. If you cannot get medical attention quickly, gently rinse the area with water. Keep the site clean, dry, and covered until a doctor can provide additional treatment.
10. What is a symptom of Cutaneous Radiation Injury (CRI)?
a. DeathPeople who receive high doses of radiation could have a greater risk of developing cancer later in life, depending on the level of radiation exposure.
If employee exposures exceed either the PEL (Permissible Exposure Limits) or the excursion limit, employers must take the following actions:
Pregnant women must follow instructions from emergency officials and seek medical attention as soon as emergency officials say it is safe to do so after a radiation emergency.
Any emergency, including those involving radiation, can cause emotional and psychological distress.
11. What can be a long-term effect of receiving high doses of radiation?
a. Loss of tasteClick on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and recheck your answers.