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BASIC CONCEPTS
How much do you already know?
????QUESTIONS???
MATTER Occupies_____________ is a material substance Has________and shape Building blocks of matter are_______and
__________.
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MATTER The primary characteristic of matter is
_____________ Mass is the quantity or quality of an object? ANSWER…QUANTITY Does mass change when matter changes? Give an example of a change of matter.
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WEIGHT is the mass of matter in an object in ?
Why do we weigh less on the moon
than on earth?
Types of energy (joules or eV)
Potential Kinetic Chemical Electrical Thermal Nuclear Electromagnetic
RADIATION
ENERGY EMITTED AND TRANSFERRED THROUGH SPACE
PIANO STRING=RADIATE SOUND RIPPLES OR WAVES=WAVES
RADIATE
IONIZING RADIATION(AGAIN!!!)
Removes orbital electron from atom this electron can disrupt surrounding atoms
by transferring energy to them. This renegade(free) electron- negative ion The atom that lost the electron- positive ion negative ion & positive ion = ion pair
What two forms of electromagnetic radiation ionize matter?
X-rays
Gamma rays
What two particulate forms of radiation ionize matter?
alpha
beta
SOURCES OF RADIATION HARMFUL TO HUMANS Natural
– Cosmic
– Terrestrial
– Naturally occurring radionucleides in the human body
Manmade– medical x-rays– nuclear power plants– industrial sources– watch dials*– smoke detectors*– TV*– Airport surveillance
systems*
DID YOU KNOW?
Naturally + man-made radiation occurring radiation contributes 360 mrads to the average absorbed dose to humans.
Diagnostic x-rays make up the largest source of man-made radiation (39 mrem per year-50 mrem per year)
IN THE EARLY YEARS OF USING X-RAYS Skin damage (erythema) loss of hair (alopecia) low red blood cell counts(anemia)
INJURIES DUE TO low energy radiation looooonnnngggg exposure times
(30 minutes!!!!!!!!!!!!!!!)
REDUCTION TO RADIATION EXPOSURE
Coolidge tube (Hot-cathode x-ray tube)–vacuum tube–intensity and energy to be selected (1913)
Snook transformer
High voltage power, induction coils (1910)
Potter-bucky grid (1921)
PROTECTIVE APPAREL WAS DEVELOPED WHEN IT WAS NOTED THAT RADIOLOGISTS WERE DEVELOPING AT A HIGH RATE OF LEUKEMIA AND APLASTIC ANEMIA
Effects of radiation
Early
blood changes
decreased sperm count
Latent
cancer changes
possible genetic effects
REGULATION HISTORY
1966- ICRP developed
ALARA
Radiation must have a benefit
Dose should not exceed limits for specific circumstances
REGULATION HISTORY
1987- NCRP established
limits for radiation exposures for radiation workers and non-radiation workers
limits were to minimize potential harm
CARDINAL PRINCIPLES OF RADIATION PROTECTION
TDS
DEVICES FOR MINIMIZING RADIATION TO PT/WORKER
Filtration collimation Intensifying screen Protective barriers Protective apparel Technical factors (Highest optimal kVp,
shortest time)
“The risk of radiation exposure in diagnostic imaging departments is minimal. Radiography is now considered a radiation safe occupation.”RADIOLOGIC SCIENCE FOR TECHNOLOGISTS,Stewart Bushong, 1997Page 7