Acute, Late, Dose Response Flashcards
(150 cards)
1
Q
damage to a living organism that was exposed
A
somatic damage
2
Q
what determines whether an effect is acute or late?
A
time lag from exposure to first symptom
3
Q
what does the amount of somatic damage done depend on?
A
quantity of radiation, type of radiation, LET, amount of body area exposed, and type of part exposed
4
Q
what time frame will acute symptoms occur?
A
within minutes, hours, or days
5
Q
common symptoms of acute radiation syndrome
A
nausea, vomiting, erythema, hair loss (epilation), blood and intestinal disorders
6
Q
how many rads to suppress sperm count
A
10 rads
7
Q
how many rads to delay or suppress menstruation
A
10 rads
8
Q
how long should you wait to procreate if you have received 10 rads?
A
several months
9
Q
how many rads cause genetic mutations
A
25 - 50 rads
10
Q
how many rads cause temporary sterility (2 months)
A
200 rads
11
Q
how many rads cause permanent sterility
A
500 rads
12
Q
10 rads to local tissue will cause what
A
gonad disfunction
13
Q
300 rads to a body part will cause what
A
skin erythema and / or epilation (hair loss)
14
Q
5 rad to the whole body will cause what
A
chromosome aberrations
15
Q
what dose rate will cause acute effects
A
protracted dose
16
Q
25 rads to the whole body will cause what
A
hematologic depression (lower blood count)
17
Q
100 rads to the whole body will cause what
A
ARS
18
Q
how many dies of ARS at Chernobyl in 1986
A
30 individuals
19
Q
how long does ARS take to kill?
A
days or weeks
20
Q
four stages of radiation sickness (ARS)
A
prodromal, latent, manifest illness, death or recovery
21
Q
how many rads until the prodromal stage will begin?
A
100 rads
22
Q
symptoms of the prodromal stage
A
nausea, vomiting, diarrhea, leukopenia (low white blood cell count)
23
Q
how long do prodromal stage symptoms last
A
hours or days
24
Q
at how many rads does the prodromal stage blend into manifest stage, skipping the latent period
A
over 1000 rads
25
definition of latent period
disappearance of symptoms
26
between 100-500 rads, how long does the latent period last?
days
27
over 1000+ rads, how long does the latent period last
hours or not at all (blends)
28
which ARS stage is characterized by the appearance of debilitating symptoms
manifest illness
29
hematologic manifest effects
changes in white cells, red cells, and platelets
30
GI manifest symptoms
nausea, vomiting, diarrhea, dehydration, weight loss
31
listlessness, apathy, sweating, fever, headache, high blood pressure are symptoms of what
neuromuscular or CNS manifest
32
when can repair and recovery occur with ARS?
when dose is small, allowing cells to reproduce and repair after exposure
33
how many rads causes hematological death
200-1000 rads
34
symptoms of hematologic death
infections, hemorrhage, dehydration
35
why is GI and CNS death not commonly seen?
death is more likely
36
how many rads causes GI death
1000 - 5000 rads
37
number 1 cause of damage and death with GI death
electrolyte imbalance, causing heart attack
38
how many rads cause CNS death
5000+ rads
39
survival time of hematological death
dose dependent ;)
40
how long until death if GI death is manifested?
within 4 - 10 days
41
how long until death if CNS death is manifested?
death within hours
42
symptoms of CNS death
lethargy, nervous and confused, loss of vision, loss of consciousness
43
possible latent period of CNS death
6-12 hours
44
causes of death from CNS death
fluid on brain and intracranial pressure, vasculitis, meningitis
45
whole body dose which will be lethal is known as
lethal dose (LD)
46
lethal dose at 350-450 rads to whole body
LD 50 / 30
47
lethal dose at 650 - 700 rads to whole body
LD 100 / 30
48
mean survival time is ____ proportional to dose
inversely
49
definition of mean survival time
as dose increases, the time between exposure and death decreases
50
mean survival time with hematologic syndrome
dose dependent
51
how long for recovery from hematologic syndrome if dose is not lethal?
2 - 4 weeks, up to 6 months recovery
52
mean survival time of GI syndrome
4 days
53
mean survival time of CNS death
0 - 3 days
54
dose response of epithelial tissue
non-linear, threshold
55
how many rads cause skin erythema in 1 - 2 days
300 - 1000 rads
56
meaning of SED50
50% of people get skin erythema dose at 600 rads
57
how are radiation sickness effects reduced in radiation therapy?
fractionated doses are given
58
dose of angiographic procedures
20 R/min
59
ovarian sensitivity at age 0 - 20
highly sensitive
60
ovarian sensitivity at age 20 - 30
decline in sensitivity
61
ovarian sensitivity at age 30+
sensitivity increased
62
concerning DNA, at what dose do multi hit aberrations increase
above 100 rads
63
dose response of DNA single hit
linear, non-threshold
64
dose response of DNA multi hit
non linear, non threshold
65
most significant type of latent human damage from radiation
multi-hits to DNA
66
DNA hits during G1 (pre - synthesis) are known as
chromatid deletion
67
how many rads causes a decrease in blood cell count
25 rads
68
how many rads cause chromosome aberration
5 rads
69
principal effect of radiation on hematologic tissue
decrease in number of cells in circulating blood
70
two types of late effects
genetic effects and radiation induced malignancies
71
what are radiation protection protocols based on?
late effects of low-dose radiation exposure
72
dose response relationship of late effects
linear, non threshold (deterministic)
73
study of effects on a large number of people
epidemiology
74
difficulties of epidemiological studies on irradiation
small number of people, dose may be unknown, frequency of response may be low
75
opacities of the lens of eyes causing loss of vision
cataracts
76
dose required to induce the formation of cataracts
100 rads (1 gray)
77
life span shortening time and dose
10 days shortened for every rad
78
percentage of live births in US that have spontaneous mutations
10%
79
populations that developed leukemia from radiation
atomic bomb survivors, radiologists, ankylosing spondylitis (fused bones) patients
80
type of bomb that hit hiroshima
hydrogen bomb
81
radiation type percentages produced by hydrogen bomb
50% gamma 50% neutron
82
type of bomb dropped on nagasaki
plutonium bomb
83
radiation type percentages produced by plutonium bomb
90% gamma 10% neutron
84
relative risk of radiation induced leukemia
100 times the non-radiated populations
85
threshold of radiation induced leukemia
50 rads
86
latent period of radiation induced leukemia
4 to 7 years
87
at risk period for radiation induced leukemia
20 years
88
1940s radiologists average yearly dose
100 rads per year (leukemia)
89
percentage of the population that dies from cancer
about 20%
90
populations that developed thyroid cancer from radiation exposure
young children who were radiated for thymic enlargement
91
dose and latent period of radiation induced thyroid cancer
doses up to 500 rads and latent period of 20 years
92
populations that developed bone cancer from radiation exposure
radium dial painters
93
half life of radium
1620 years
94
relative risk of being a radium dial painter to develop cancer
122:1
95
populations that developed skin cancer from radiation exposure
radiation therapy patients
96
latent period of skin cancer
5 - 10 years
97
dose amount and dose response relationship of skin cancer
500 - 2000 rads, linear threshold dose
98
populations that developed breast cancer from radiation exposure
early TB patients treated under fluoroscopy, atomic bomb survivors
99
doses received by early TB patients
anywhere between 75 - 1000 rads
100
dose to the breast of atomic bomb survivors
above 10 rads to the breast
101
populations that developed lung cancer as a result of radiation exposure
german / american uranium miners exposed to radon gas
102
half life of uranium
10 years
103
type of radiation uranium emits
alpha and beta
104
doses to workers exposed to radon
as high as 3000 rads
105
populations that developed liver cancer from radiation exposure
thorotrast patients
106
agents used on thorotrast patients
thorium dioxide contrast agents
107
latency period of liver cancer from radiation exposure
15 - 20 years (thorotrast patients)
108
where are thorium dioxide particles deposited
phagocytes, concentrated in the liver
109
3 types of risk estimates
relative risk, excess risk, absolute risk
110
risk that estimates late effects in large population without knowing dose
relative risk
111
formula for relative risk
observed cases (irradiated) divided by expected cases (not irradiated)
112
range of relative risk
1 to 10
113
what does 1.6 relative risk indicate?
an irradiated population has a 60% higher incident / responses
114
risk that measures the magnitude of effect
excess risk
115
formula for excess risk
observed cases minus expected cases
116
what is required to calculate absolute risk?
when at least 2 different dose levels are known
117
value of absolute risk equals
the slope of the line (linear relationship)
118
usual range of absolute risk
1 - 10 cases per 100,000 persons per year
119
result of local tissue damage from radiation to chromosomes
radiation induced leukemia and lymphoma
120
result of local tissue damage from radiation to the skin
malignant changes, erythema, scaly, calloused hands (radiologists)
121
threshold or start of ARS
100 rads
122
percentage of babies born that have birth defects without radiation
20%
123
visual representation of the relationships between the dose and the effect or response
dose response relationships
124
why are dose response relationships important?
design therapeutic treatment doses, determine effects of low dose radiation, identify radiation protection activities
125
point of radiation exposure that response begins
threshold
126
visual representation of responses from dose
curve
127
point on response curve that illustrates a level of stochastic effect PRIOR to irradiation
ambient
128
dose curve that is a straight line
linear curve
129
dose curve that is a curved line, not straight
non linear curve, curvylinear
130
dose curve that looks like an S
sigmoid curve
131
dose curve that represents complete data and overestimates risk
quadratic curve
132
dose curve with two inflexion points
sigmoid curve
133
point on curve that shows the speed where the rate of response changes
inflexion point
134
dose curve that is directly proportional to dose
linear
135
dose curve with a single inflexion where response changes during exposure
non linear
136
dose curve where as the dose increases, it becomes increasingly effective per increment of dose until it plateaus
sigmoid or S-curve
137
what type of exposure does quadratic curve represent
low dose, low LET exposure
138
dose response relationship of leukemia
linear, non threshold
139
dose response relationship of lung cancer
linear , non threshold
140
dose response relationship of skin cancer
linear, threshold (500 rads)
141
dose response relationship of bone cancer
linear, threshold
142
dose response relationship of genetic effects
linear, non threshold
143
dose response relationship of cataracts
linear, threshold
144
dose required for cataracts (both protracted and fractionated)
acute 200 rads, fractionated 1000 rads
145
what is CT dose to the eyes
about 5 rads per slice (total 50-100 rads)
146
dose response and dose required for acute radiation syndrome
linear, threshold (100 rads)
147
dose response relationship of sterility
linear, threshold
148
dose response relationship of life span shortening
linear, non threshold
149
dose response of DNA single hit
linear non threshold
150
dose response of DNA multi hit
non linear non threshold
