Ch 4 Flashcards
Clarence daily
First person to die from radiation induced cancer
Wonder rays
Early term for x rays
1900-1930
Skin erthermya dose SED
When skin looked red dose limit reached
1930 - 1950 dose limit
Tolerance dose TD
Dose limit reached any visible damage
1950 - 1977 dose limit
MPD
(Maximum permissible dose)
Dose reached without any biological effects with the use of a PMD (personal monitor devices)
Measured in REM
( radiation equivalent to man )
1977-1991 dose limit
EQD
Equivalent dose equivalent
1991 - present dose limit
Effective dose limit
EFD
Equivalent dose limit takes in account for
Absorbed dose and type of radiation
Effective dose limit takes in account for
Absorbed dose Type or radiation received Organ radio sensitivity
Wt
Tissue weighing factor
Wr
Radiation weighing factor
Occupational exposure
Rad exposure recieved by worker In the course of exercising their professional responsibilities
Early tissue reactions (short term somatic effects)
Bio effects that occur minutes, hrs, days after exposure to ionizing radiation
Late tissue reactions (long term somatic effects)
Bio effects that occur months or years after exposure to ionizing radiation
Have potential of creating genetic or hereditary effects
Early tissue reactions examples
Loss of hair Fever Intestinal disorder Blood disorders
Late tissue reaction example
Fibrosis Organ atrophy Reduced fertility Cataracts
Stochastic effects
Don’t know when or what dose this happens
Cancers
Exposure X
When volume of air is radiated
Change intensity of primary beam before reaches patient
C/kg
Roentgen
Exposure is measured by
Cutie pie
Ionization chamber
Test output of imaging machines
Air KERMA
kinetic energy released in matter
Amount of radiation in air
Replacing exposure
Measured by cutie pie
Joule/kg
Gya
Absorbed dose D
Ammount of energy per unit unit of mass absorbed into radiated object
Gyt
Rad
Responsible for bio damage in pt tissue
Convert gray to milligray
Gy x 1000 = milligray
Convert milligray to gray
Milligray divided by 100 = gray
Dose area product DAP
Takes account for dose and field size ( pt thickness)
Expressed in mGycm2
Differential absorption
3 things effects ammount of absorption in tissue
A) anatomical structures
B) mass
C) kvp
Abosption pt dose and biological effects are ___ related
Directly
Wr for xray, gamma, beta , alpha, fast acting neutrons, thermal neutrons
Xray, beta & gamma = 1
Thermal neutrons = 5
Alpha & fast acting neutrons = 20
LET
Linear energy transfer
Amount of energy transfers on average by incident e to an object per unit length of track through the object
LET , bio damage , and QF / Wr are ___ relationship
Direct
Convert Msv to Sv
Msv / by 1000 = Sv
Convert Sv to Msv
Sv x 1000 = Msv
Convert Csv to Sv
Csv / 100 = Sv
Convert Sv to Csv
Sv x 100 = Csv
Equation for EQD
EQD = (d) x (Wr)
Sv = Gyt x Wr
Efd equation
Efd = D x Wr x Wt
Best measurement for biological risk
NRC ( nuclear regulatory commission) roles:
Controlled possession use & production of atomic energy
Enforces rad protection standards
-don’t inspect image facilities
-license users if radioactive material
-make unannounced inspections
-write standards
Agreement states
States that assume responsibility of enforcing radiation protection regulations through their health departments
Have agreements with NRC
States enforce own laws more stringent
EPA
Environmental protection agencies
Responsible for protections the health of human beings + for safeguarding the natural environment
Responsible for development + enforcement of radiation in environment
Main area is detection + control of radon
FDA
Food & Drug administration
Regulates the design & manufacturing of electronic products, including diagnostic equipment
Inspects x ray equipment
Complies with FDA standards
OSHA
Occupational safety & health administration
Functions as a monitory agency in places of employment predominantly in industry
Regulated right to know of work place hazards
Regulates training programs
Radiation safety program
