Chapter 2 Radiation: Types, Sources, and Doses Received Flashcards
(101 cards)
1
Q
is the emission of energy in the form of electromagnetic waves or as moving subatomic particles (protons, neutrons, beta particles, etc.) passing through space from one location to another.
A
Radiation
2
Q
Some types of radiation produce what
A
damage in biologic tissue, whereas others do not.
3
Q
Some sources of radiation are considered what
A
natural
3
Q
They are always present in the environment
A
natural
4
Q
what else is considered sources of radiation
A
human-made
5
Q
sources are created by humans for specific purposes
A
human-made or artificial
6
Q
what contributes a percentage of the total amount of radiation that humans receive during their lifetime
A
both sources
- natural
- human made
6
Q
the ability to do work—that is, to move an object against resistance
A
energy
7
Q
How does radiation relates to energy
A
Radiation refers to energy that passes from one location to another and can have many manifestations. This means that many types of radiation exist.
8
Q
Mechanical vibration of materials
A
ultrasound
8
Q
waves, electric and magnetic fields fluctuate rapidly as they travel through space.
A
electromagnetic wave.
9
Q
What are some examples of electromagnetic wave
A
- Radio waves
- Microwaves
- Infrared
- Visible light
10
Q
Examples of ultraviolet
A
- xrays
- gamma rays
11
Q
The full range of frequencies and wavelengths of electromagnetic waves
A
Electromagnetic spectrum
12
Q
Electromagnetic waves are characterized by their
A
- frequency
- wavelength
12
Q
This form of radiation can travel through space in the form of a wave but can interact with matter as a particle of energy called a photon
A
Dual nature of electromagnetic radiation (wave-particle duality)
13
Q
number of cycles per second
A
frequency
13
Q
have no mass but have energy
A
photons
14
Q
removal of an electron
A
ionizations
15
Q
what travel at the speed of light in a vacuum
A
electrons
16
Q
To study radiation protection, the electromagnetic spectrum can be divided into two part
A
- Ionizing radiation
- Nonionizing radiation
16
Q
x-rays, gamma rays, and high-energy ultraviolet radiation [energy higher than 10 ev)
A
Ionizing radiation
17
Q
can transfer sufficient energy to some orbital electrons to remove them from the atoms to which they were attached
- the foundation of the interaction of x-rays with human tissue
A
Ionizing radiation
18
Q
ultraviolet radiation [energy less than 10 eV ], visible light, infrared rays, microwaves, and radio waves) and MRI
A
Nonionizing radiation
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does not have sufficient kinetic energy to eject electrons from atoms
Nonionizing radiation
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removal of electrons
ionizing radiation
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biological tissue damage
ionizing radiation
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- Conversion of atoms to ions
- Makes tissues valuable for creating images
- Has the undesirable result of potentially producing some damage in the biologic material
ionization
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The amount of energy transferred to electrons by ionizing radiation is the basis of the concept of
radiation dose
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Form of radiation that includes alpha particles, beta particles, neutrons, and protons
Particulate Radiation
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- heavy form
- most damaging
- ejected from atoms at high speed
Particulate Radiation
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- All these are subatomic particles that are ejected from atoms at very high speeds.
- They possess sufficient kinetic energy to be capable of causing ionization by direct atomic collision
- No ionization occurs when the subatomic particles are at rest.
Particulate Radiation
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is a naturally occurring process in which unstable nuclei relieve that instability by various types of spontaneous nuclear emissions, one of which is the emission of charged particles.
- changes the chemical makeup
radioactive decay
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are emitted from nuclei of very heavy elements, such as uranium and plutonium, during their radioactive decay.
Alpha particles,
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- Each contains two protons and two neutrons.
- Are simply helium nuclei (i.e., helium atoms minus their electrons)
- Have a large mass (approximately four times the mass of a hydrogen atom) and a positive charge twice that of an electron
Alpha Particles
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are less penetrating than beta particles
- They lose energy quickly as they travel a short distance in biologic matter
- Considered virtually harmless
- As an internal source of radiation, they can be very damaging
- If emitted from a radioisotope deposited in the body, such as in the lungs, alpha particles can be absorbed in the relatively radiosensitive epithelial tissue and are very damaging to that tissue
- superficial of skin
- more biological damage
Alpha particles
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emitted from nuclei/ nucleus
- if you ingest it is very damaging to your internal organs
Alpha particles
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- Identical to high-speed electrons except for their origin
- 8000 times lighter than alpha particles and have only one unit of electric charge (−1)
beta particles
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two units of electric charge (+2)
alpha particles
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- Will not interact as strongly with their surroundings as alpha particles do.
- Capable of penetrating biologic matter to a greater depth than alpha particles with less ionization along their paths
beta particles
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occurrs when a nucleus relieves instability by a neutron transforming itself into a combination of a proton and an energetic electron
beta particle
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Alternative sources of high-speed (high energy) electrons are commonly produced in a radiation oncology treatment machine called
linear accelerator
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will penetrate more deeply and therefore cannot be stopped by ordinary pieces of paper.
beta particles
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can be stopped by paper
alpha particles
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can be stopped by lead
gamma and x-rays
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To treat superficial skin lesions in small areas
- To deliver radiation boost treatments to breast tumors at tissue depths typically not exceeding 7 to 8 cm
Require either millimeters of lead or multicentimeter thick slabs of wood to absorb them
For energies of less than 2 meV, either a 1-cm thick block of wood or a 1-mm thick lead shield would be sufficient for absorption
linear accelerator
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- Positively charged components of an atom
- Have a relatively small mass that, however, exceeds the mass of an electron by a factor of 1800
- Number of protons in the nucleus of an atom constitutes its atomic number, or Z number
Protons
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- Electrically neutral components of an atom
- Have approximately the same mass as a proton
neutrons
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If two atoms have the same number of protons but a different number of neutrons in their nuclei, they are referred to as
isotopes
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If one of these combinations of Z protons and some neutrons leads to an unstable nucleus, then that combination is called
- nuclear medicine
radioisotope
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the amount of kinetic energy per unit mass that has been absorbed in a material due to its interaction with ionizing radiation
- measured in units of milligray (mGy)
- tissue or matter
Absorbed dose
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- Takes into account the type of ionizing radiation that was absorbed
- Provides an overall dose value that includes the different degrees of tissue interactions that could be caused by different types of ionizing radiation
- Measured in units of the millisievert (mSv)
- 1/1000th of a sievert
Equivalent dose (EqD)
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- Takes into account the dose for all types of ionizing radiation (e.g., alpha, beta, gamma, x-ray) to various irradiated organs or tissues in the human body (e.g., skin, gonadal tissue, thyroid
- Intended to be the best estimate of overall harm that might be produced by a given absorbed dose of radiation in human tissue
- Measured in units of the millisievert (mSv)
- It takes into account both the type of radiation and the part of the body irradiated.
Effective Dose (EfD)
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Ionizing radiation primarily causes
biologic damage
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Produced by ionizing radiation while penetrating body tissues primarily by ejecting electrons from atoms composing the tissues
Biologic Damage Potential
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Result of destructive radiation interaction at the atomic level start where and end where
- Molecular change
- Cellular damage
- Organic damage
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leading to abnormal cell function or even complete loss of cell function
cellular damage
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Changes in blood count
- nonnegligible exposure to ionizing radiation
organic damage
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Sources of ionizing radiation
- Natural
* Human-made (artificial)
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Dose from natural background radiation is approximately
3.1 mSv annually
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Annual dose from medical radiation is approximately
2.3 mS
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Annual dose from human-made radiation is approximately
0.1 mSv annually
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Annual dose from natural background radiation is approximately
3.1 mSv
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Annual dose from all-natural, medical and human-made radiation is approximately
5.5 mSv
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remains constant unless an accident happens
natural radiation
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components of natural radiation:
- Terrestrial radiation
- Cosmic radiation
- Internal radiation from radioactive atoms
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examples radon and thoron
terrestrial radiation
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examples solar and genetic
cosmic radiation
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radioactive atoms also called radionuclides
internal radiation
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gases emit alpha particle radiation
radon
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- It behaves as a free agent that floats around in the soil
- gas into the lower levels of homes through cracks or holes in the foundation, and then the gas may permeate upward as it decays and becomes solid particles
- that 2.3 mSv of natural background radiation exposure comes primarily from the gaseous radionuclide,
- over 4 have to get ligation system
- 33% of background
radon
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grows more substantial because of accidental or deliberate human actions such as mining radioactive elements
enhanced natural sources
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Ionizing radiation created by humans for various uses is classified as
Human-made (artificial) radiation
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* Consumer products containing radioactive material
* Nuclear fuel for the generation of power
* Atmospheric fallout from nuclear weapons testing
* Nuclear power plant accidents
* Nuclear power plant accidents as a consequence of natural disasters
* Medical radiation
human-made, or artificial, radiation
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Consumer products and devices containing radioactive materia
Airport surveillance scanning systems
* Electron microscopes
* Ionization-type smoke detector alarms
* Industrial static eliminators
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results from the use of diagnostic x-ray machines and radiopharmaceuticals in medicine
Medical radiation
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The two largest sources of artificial radiation are
- Radiography and Fluoroscopy
- Computed Tomography (CT) procedures
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Accounts for approximately 2.3 mSv of the average annual individual EfD.
- Exposure to human-made radiation in medical applications continues to increase rapidly
Medical radiation
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Because of the large variety of radiologic equipment and differences in imaging procedures and in individual radiologist and radiographer technical skills, patient dose for each examination varies according to the facility providing imaging services.
medical radiation
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The amount of radiation received by a patient from diagnostic x-ray procedures may be indicated in terms of the following
- Entrance skin exposure (ESE), which includes skin and glandular dose
- Bone marrow dose
- Gonadal dose
65
blood changes is how many SV
0.25 sv
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nausea, and diarrhea, how much sv
1.5 sv
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erythema (redness)
2.0 sv
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if dose to to gonalds, temporary sterility
2.5 sv
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50? chance of death lethal dose of 50%
3.0 sv
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what is death sv
6.0 sv
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have higher energy
higher frequency
- shorter wavelenth (packed together)
gamma rays and x-rays ultraviolet
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lower enegry
lower frequency
higher longer wavelength
radio microwaves
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The atomic number of an element is determined by
the number of protons in the nucleus of an atom of that element;
69
what charge are electrons
negative charge
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what charge are protons
positive charge
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wha charge are neutrons?
neutral
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atomic number is represented by what letter
Z
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examples of particulate radiations
- alpha particles
- beta particles
- nuetrons
- protons
74
The recommended action limit for radon in homes is
4 pCi/L of air.
75
alpha particle is stopped by what
paper
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beta particle is stopped by what
plastic
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gamma and x-rays are stopped by what
lead
78
electrons origin is
outside the nucleus
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alpha and beta origin is from
the nucleus
80
x-rays have in reference to energy and wavelength and frequency
^ energy ^ frequency decreaase wavelengh(short)
