The Basis For Radiation Protection

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The Basis For Radiation Protection

• Kyle Thornton
• RADL 70

2
What Is Radiation Protection?

• Applying the concepts of radiation physics and
  radiobiology in such a way that the maximum
  benefit is derived from obtaining a radiograph
  while the most minimal amount of radiation is
  used to produce it.
• ALARA

3
Who Is Responsible?

• The patients primary care physician ordering the
  examination
• You, the technologist
• The radiologist

4
Risk v. Benefit

• Radiographic examinations are on the increase
• This has an effect on the genetically significant
  dose
• Radiation protection guidelines assume that there
  is no threshold or level below which no effects
  are realized
• This means any amount of radiation holds a
  potential risk
• All human activities hold some amount of risk
• Potential benefits of an examination should
  always outweigh the risk

5
Ionizing Radiation

• Radiation
• A transfer of energy resulting from a change
  occurring within an atom
• Radioactive decay
• A process caused by interaction of a particle
  with an atom
• Ionizing Radiation
• Produces positively and negatively charged
  particles as it passes through matter

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How Is Radiation Harmful?

• Radiation damages body tissues by ejecting
  electrons from atoms within the tissues as it
  travels through
• This results in molecular change
• Which can cause cellular damage
• Abnormal cell function or loss of cell function
• Which can result in organic damage
• Mutations, cataracts, and leukemia

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Radiation Quantity Unit For Dose Equivalent

• International System - Sievert
• Traditional System - Rem
• Dose equivalent assists in calculation of the
  biological effects of different types of radiation

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Radiation Dose Equivalent And Biologic Effects
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Ionizing Radiation Sources

• Natural or background
• Part of the environment
• Cosmic
• Terrestrial
• Internal
• Man-made
• Created by humans
• Industrial
• Consumer Products
• Nuclear Fallout
• Medical

10
Natural Radiation

• Cosmic
• From sun and solar/galactic system
• Consists of photons and particulate radiation
• Exposure determined by altitude
• Sea level is half that of 1 mile high
• Affected by earths magnetic field
• Intensity increases at north pole
• Decreases at equator
• Approximate average annual US dose - 30 mrem

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Natural Radiation

• Terrestrial
• From the earth
• Depends on location and type of soil/rock
• Main sources
• Uranium
• Radium
• Thorium
• Radon

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About Radon

• Decay product of radium
• Radon is in the form of a gas
• Can enter buildings via
• Cracks
• Floor drains
• Porous cement
• Well water
• Decay products affect lungs
• Increases risk of lung cancer
• Thought to be the second leading cause of lung
  cancer in US

13
Internal Radiation

• Internal radionuclides found in the body from
  food, air, and water
• These include
• Carbon, Hydrogen, Potassium, Radium, Polonium,
  Lead, Uranium - just to name a few

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Man-Made Radiation

• Industrial
• Mining
• Nuclear power
• Refining
• Handling and transport of radionuclides
• Air travel
• Fallout from nuclear testing
• Nuclear plant explosions

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Man-Made Radiation

• Consumer Products
• Tobacco
• Smoke alarms
• Television
• Luminous products
• Building materials
• Airport inspection systems
• Combustible fuels
• Gas mantles

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Man-Made Radiation

• Medical Radiation
• Diagnostic
• Therapeutic
• Nuclear medicine procedures
• Largest source of man-made radiation dose to
  population

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Patient Dose

• Important indicators of patient dose
• Entrance skin exposure
• Skin dose
• Bone marrow dose
• Gonadal dose
• Fetal dose