Radiation Quantities and Units

Chapter 3

Sherer

Review-Pages 53-56

Somatic effects Long term somatic Genetic effects Box 3-1

Page 56-58- specifically

Tolerance dose was replaced with Maximum Permissible dose (MPD)-dose limits-effective dose

Safe occupations (clerical) has a risk of 10 -4 per year- same as radiography

EfD – type of radiation and the sensitivity of the tissue being exposed. The Sievert is the unit of measurement

Focus on these terms and definitions-page. Begins on pg 58

Exposure (X) Absorbed dose (D) Equivalent dose (EqD) Effective dose (EfD)

– Overall risk based on absorbed dose, tissue and type of radiation

See Box 3-3 (see next slide) Absorbed Dose

Box 3-3(follow-up questions see assignment for this class)

Equivalent Dose EqD=D x Wr

Or

Sv=Gy x Wr

Effective dose EfD=D xWr x Wt

Quality Factor, pg 63 Sherer LET pg 63 Sherer "rate in which energy is

deposited in the form of a charged particle or ion pair as it travels through matter“

Rem = RAD x QF LETS of 3% or less have a QF of 1 = same

amount of damage of rad per rem QUALITY FACTOR and weighting factor OF

ALPHA IS 20 See box Table 3-2 Sherer 1 RAD = 20 REM FOR ALPHA PARTICLE

ABSORPTION

WHICH HAS A HIGHER LET NUMBER?

X-rays (HIGH OR LOW?) Alpha (HIGH OR LOW?) Beta (HIGH OR LOW?) Gamma (HIGH OR LOW?)

WR associated with Equivalent Dose- table 3-2

WT associated with Effective Dose- table 3-3