radiation protection Flashcards
(46 cards)
ionizing radiation
cosmic, gamma rays, x-rays, ultra voilet rays
non ionizing radiation
visible light, infrared, micro waves, radio waves
skin erythema dose
1900-1930 first unit used to measure radiation exposure
erythema
redness of the skin, irradiated area that had become inflamed
roengten / coulombs/kg
was accepted as the first unit of measure for exposure but was not adequately defined ; measures ionization occurring in the air ; coulombs/kg or air in SI units
rad / gray
radiation absorbed dose ; primarily used for patient dose 1 rad = .01 gray
rem / sivert
radiation equivalent man ; primarily used for radiation protection purposes ; film badges for radiation workers ; measure biological effects from radiation ; 1 rem = .01sv ; 1 rem = 10 mSv
occupational dose
5 rem or 50 msg of whole body effective dose per year
whole body dose
refers to the head, neck (thyroid), trunk, gonads
occupational cumulative dose
the lifetime effective dose limit for an occupationally exposed worker 1 rem or 10 msg times the years of age regardless of how many years that worker has been employed in field
occupational dose
dose received by any individual in the course of employment
pregnant technology exposure
0.05 rem, 50 mrem, or 0.5 msv, for any one month ; 0.5 rem, 500 rem or 5.0 msg for entire duration of pregnancy
general public exposure
0.1 rem ot 1 msv
personnel monitoring equipment
devices worn or carried by the individual for the purpose of measuring the dose equivalent received by that individual ; worn only on the job
personnel monitoring devices
film badges, TLD, OSL
film badges
a packaged film within a holder with a variety of filters ; sensitive to exposure equivalent doses as low as 10 milliards up to a high as 700 rads ; needs to be changed and read every month
TLD
thermoluminescent dosimeter ; common material used inside is lithium fluoride ; once the TLD has been read it cannot be read again ; can be changed and read every 3 months(may be changed every month)
OSL
optically stimulated luminescent dosimeter ; uses aluminum oxide crystals ; can bet read up to one year before reading
collimation
limiting the field size to the area of clinical interest only ; must be within +/- 2% of the SID used during an x-ray exposure
A.L.A.R.A.
as low as reasonably achievable ; close collimation, filtration of the primary beam, optimum kV techniques, high speed film/screen combinations, minimum repeat exams
entrance skin exposure (ESE)
patient dose in radiography is usually calculated according to the exposure level at the skin
law of bergonie and tribindeau
degree of sensitivity depends on - age of cell, differentiation or complexity of cell, metabolic rate or how much energy the cell uses, biotic rate or how quickly the cell produces
long term / latent
may not be observed for as long as 30 years ; greatest percentage occurs between 10 and 15 years ; effects are unpredictable ; severity of effects are unrelated to dose
somatic
occurring within the exposed individual
