Ch. 4 Radiation Quantities and Units Flashcards
X-rays were called what at one point?
“Wonder rays”. there was lots of experimentation with them, but No one knew the effects they had on tissues.
This led to visual, somatic effects.
Who is Clarence Dally?
The first person to die from radiation poisoning, at age 39. He was Thomas Edison’s assistant.
Skin Erythema Dose
A unit of measurement used for radiation dose, used from 1900-1930
Determine by “when the skin looked red, the dose limit was reached”
Tolerance Dose
Used from 1930-1950
Dose limit is reached when any visible damage is seen
Maximum Permissible Dose
Used from 1950-1977
The dose was thought to be acceptable without any biological effects.
Rad workers began monitoring dose with personal monitoring devices
This was measured/expressed in REM (Radiation Equivalent Man)
Effective Dose Equivalent (Equivalent Dose)
Used from 1977-1991
Uses radiation weighing factors (Wr)to adjust the value of the absorbed dose to reflect the different capacity for producing biological harm by various types of energies of ionizing radiation
Effective Dose Limit
Used rom 1991- present
Uses Tissue Weighing Factors (Wt) to adjust the quantity equivalent dose to reflect the difference in harm to the person as a whole depending on the tissues and organs that have been irradiated.
Takes into account both the type of radiation and the part of the body being radiated
What is an occupational exposure?
Radiation exposure received by a radiation worker in the course of exercising their professional responsibilities
What are Early Tissue Reactions?
Also known as short-term somatic effects and acute of early effects
Biological effects that occur within minutes, hours, days, or weeks after exposure to ionizing radiation
What are Late Tissue Reactions?
Also known as Long-term or late somatic effects
Biological effects that appear months or years after exposure to ionizing radiation
Can be genetic or inheritable effects
Examples of Early Tissue effects:
-Nausea
-fatigue
-Redness of skin
-Loss of hair (epilation)
-Intestinal disorders (vomiting)
-Fever
-Blood disorders
-Shedding outer layer of skin
Examples of Late tissue Effects
-Cataract Formation
-Fibosis
-Organ Atrophy
-Loss of Parenchymal cells
-Reduced fertility
-Sterility
Examples of Stochastic Effects
-Cancer
-Genetic (hereditary) effects
What is the SI unit for Exposure (X)?
This is when x-ray photons ionize air molecules, can and will change the intensity of the primary beam before it reaches the patients skin
SI Unit= Columb per kilogram (C/kg)
Traditional Unit= Roentgen (R)
What is used to measure Exposure (X) output?
An ionization chamber, aka cutie pie
