82 terms

Chap 4&10 rad protection

STUDY
PLAY

Terms in this set (...)

x rays were discovered on what day
nov 8 1895
(date) initial cases of somatic damage caused by exposure are reported in Europe
1896
(date) Clarence dally becomes first radiation fatality - he was 39
1904
who was Clarence dally working with and on what
Edison - fluoroscope
(date) early radiologists and dentists develop radiodermatitis and erythema - cancer deaths due to xray are reported
1910
(date) british xray and radium protection committee is formed to investigate methods for reducing exposure
1921
(date) NCRP adopts SI units for use
1985
(date) ICRP replaces effective equivalent dose with the term effective dose
1991
SED
skin erythema dose
quantity of radiation that causes redness over an area of skin after exposure
SED
TD
threshold dose
dose that radiation workers could continuously be exposed to without any apparent effects
TD
MPD
maximum permissible dose
largest dose of ionizing radiation that an occupationally exposed person was permitted and was not anticipated to result in major adverses biologic effects due to ionizing radiation
MPD
(T/F) tolerance dose is no longer accepted
true
is any dose completely safe?
no
(date) what year were radiation units developed to account for the varied bio effects of different types of radiation and health effects on depend upon part irradiated
1970
(date) ICRP revised tissue weighting based on data from studies of atomic bomb survivors
1991
as intensity of the xray exposure of the air volume increases, the number of electron ion pairs ___________ (increase/decrease)
increases
what do you measure to find the amount of radiation responsible for the ionization of a well defined volume of air
electron ion pairs
radiation ionization in air
exposure
exposure is the total electrical charge per unit mass that _______ and ______ ray photons with energies up to__ MeV generated by air only
xray and gamma
3
measuring of exposure is done by a _______ _____ _______ _________
free air ionization chamber
what is the traditional unit of exposure in air
Roentgen
SI until of exposure in air
Coulombs per kilogram
what are fluoro entrance rates measured in
R/min
KERMA
kinetic energy released per mass of air
absorbed dose is _________ oriented
patient
the amount of energy per unit mass absorbed by the irradiated object
absorbed dose
absorbed dose energy is responsible for any _______ ________ resulting from the tissues being exposed to radiation
biologic damage
the amount of energy absorbed by a structure depends on what 3 things
1. atomic number
2. mass density of the tissue
3. energy of the incident photon
absorbed dose increases as the atomic number and the mass density __________
increases
absorbed dose increases and the photon energy _________
decreases
SI unit of absorbed dose
gray
traditional unit of absorbed dose
rad
absorbed dose indicates the amount of radiant energy transferred to an irradiated object by ____ ______ of ionizing radiation
any type
100 rads = ____ grays
1
the milliard = ______ rad
1/1000
centigray equals _______ rad
1/100
who uses the centigray to express doses delivered to patients
radiation oncology
equivalent dose is _______oriented
occupational
traditional unti for equivalent dose
rem
SI unit for equivalent dose
sievert
1 Sievert equals _______ rem
100 rem
_____ millisievert = 1 rem
10
EqD = _____ x ______
D x Wr
LET
linear energy transfer
amount of energy transferred on average by incident radiation to an object per unit length of track through an object
LET
measures the overall risk of radiation
effective dose
conceptual measure for the relative risk associated with irradiation of different body tissues
tissue weighting factor
EfD = ____ x____ x_____
DxWrxWt
tissue weighting factor for gonads
.20
tissue weighting factor for red bone marrow, colon, lung, stomach
.12
tissue weighting factor for bladder, breast, liver, esophagus and thyroid
.05
tissue weighting factor for skin and bone
0.01
ColEfD
collective effective dose
used to describe a radiation exposure of a population or a gray from low doses of different sources of ionizing radiation
collective effective dose
2 units for collective effective dose
1. person-sievert
2. man-rem
radioactivity is ________ _______ oriented
nuc med
the amount of radioactive material in a radiation source is designated by the _________ of the source
activity
traditional unit for radioactivity
curie (ci)
a curie is large, so what 2 subunits are typically used
millicurie and microcurie
SI unit of radioactivity
becquerel (Bq)
radiation therapy uses cobalt _____
60
cobalt 60 is about _______ Ci
6000
nuc med uses technetium ______
99
technetium 99 is about ______ to _____ Ci
3-20
the time it takes for a radioactive material to decrease its radioactivity to 1/2 of its original intensity
physical half life
half life for technetium 99
6 hours
half life for iodine 131
8 days
half life for cobalt 60
5 years
4 non govt non profit groups - make recommendations only
1. ICRP
2. NCRP
3. UNSCEAR
4. NAS/NRC/BEIR
ICRP
international commission on radiologic protection
NCRP
national council on radiation protection measurements
UNSCEAR
united nations scientific committee on the effects of atomic radiation
NAS
national academy of sciences
provides guidance through its recommendations on occupational and public dose limits
ICRP
(T/F) each nation enforces their own specific regulations
true
publish information in reports
NCRP
includes MMWR reports
UNSCEAR
MMWR
morbidity and mortality weekly reports
studies biologic effects of ionizing radiation - looks at groups of people
NAS