170 likes | 471 Views
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
E N D
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
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