Radiation Quantities and Units

Chapter 3

Sherer

Somatic effects Long term somatic Genetic effects Box 3-1

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

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

– Not factoring in the effect on tissue Effective dose (EfD)

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

See Box 3-3 Absorbed Dose

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

Radiobiology and Cellular Biology (Bushong Chapter 33)

Pg 501 in Bushong

When an atom is ionized

Chemical binding properties change in large molecules: breakage or relocation

of molecules…become abnormal Abnormal means Function improperly cease to function -impairment or death of

cell

Damage is Reversible

Ionized atoms become neutral…How? Molecules are mended by repair enzymes Immediate response to radiation Latent response (Bushong) see Box 32-1

RADIATION INTERACTS AT ATOMIC LEVEL Atoms combine to form molecules The body is made of macromolecules What is the definition of macromolecules?

With this kind of potential damage….

The government tends to get involved

CHAPTER 9 SHERER

YOU ARE RESPONSIBLE FOR DIFFERENTIATING BETWEEN ICRP NCRP UNSCEAR NAS/NRC-BEIR NRC EPA FDA OSHA

DEFINE

RSC

RSO

NCRP REPORT NO 116