rad bio ch 34

Question 1

Radiation exposure we experience is ____ and ___ LET

Answer 1

low:low

Question 2

Our radiation protection guides are based on the ____ effects of radiation and are ____, ____ dose response

Answer 2

stochastic

linear, nonthreshold

Question 3

epidemiologic studies

- studies of large numbers of people exposed to a ___substance

Answer 3

toxic

Question 4

Epidemiologic studies of people exposed to radiation are hard because: 2

Answer 4

• dose is not known, or is low

- frequency response is low

Question 5

chronic irradiation of the skin can result in severe ___ canges

Answer 5

nonmalignant

Question 6

radiodermitis

- calloused, ___ hands that is stochastic effect

Answer 6

discolored

Question 7

irradiation of blood forming organs can produce hematologic depression as a deterministic response or ___ is a stochastic response

Answer 7

leukemia

Question 8

chromosome damage in the circulating lymphocytes can be produced as both a ____ and ___ response

Answer 8

deterministic

stochastic

Question 9

high radiation doses continue to show chromosome abnormalties in their peripheral lymphocytes for as long as ___ years

Answer 9

20

Question 10

radiation induced cataracts occur on the ___ ___ of the lens, which is age dependent

Answer 10

posterior pole

Question 11

dose response relationship for radiation induced is ___,___ response

Answer 11

nonlinear, threshold

Question 12

relationship between life span shortening and dose is ___,____

Answer 12

linear, nonthreshold

Question 13

at worst, a human can expect a reduced life span of appox ___ days for every ____ mGyt

Answer 13

10:10

Question 14

one pack cigarette a day reduces life expectancy by

Answer 14

1600 days

Question 15

radiation worker reduces life span

Answer 15

12 days

Question 16

three risk estimates

Answer 16

relative
excess
absolute risk

Question 17

relative risk
- number of persons in ____ population showing a given stochastic effect with the number in an ____ population who show the same stochastic effect

Answer 17

exposed:unexposed

Question 18

relative risk formula

Answer 18

observed cases
________________
expected cases

Question 19

relative risk of ___ is no risk

Answer 19

1.0

Question 20

relative risk of ____ indicates the frequency of late response is 50% higher in the irradiated population than in the non irradiated population

Answer 20

1.5

Question 21

theory of radiation hormesis suggest very low radiation doses are ___

Answer 21

beneficial

Question 22

excess risk

- difference between the _____ and ____

Answer 22

observed number cases

expected number would be excess risk

Question 23

excess risk formula

Answer 23

observed cases- expected cases

Question 24

excess cases is assumed to be ___ induced

Answer 24

radiation

Question 25

need __ different dose levels for absolute risk factor

Answer 25

two

Question 26

to determine absolute radiation risk, one must assume ____, if the dose response relationship is assumed be nonthreshold then its ___ response

Answer 26

linear dose response relationship

one

Question 27

largest man made radiation dose is ___

Answer 27

CT

Question 28

radiation induced leukemia follows a ____,____ dose response

Answer 28

linear

nonthreshold

Question 29

radiation leukemia has a latent period of __ to ___ years and at risk factor of __ years

Answer 29

4-7

20 years

Question 30

at risk period

- time after ___ during which one might expect radiation to effect to occur

Answer 30

irradiation

Question 31

chronic lymphocyte leukemia is rare and therefore not considered to be a form of ___ induced leukemia

Answer 31

radiation

Question 32

radiation induced skin cancer follows a __ dose response

Answer 32

threshold

Question 33

skin cancer beings as ___ at dose of ___-___ KVP

Answer 33

radiodermititis: 200-300

Question 34

relative risk of developing skin cancer is ___

Answer 34

4:1

Question 35

risk of death from radiation induced malignancy is ___

Answer 35

5/100

Question 36

_____ cancer is only radiation response know

Answer 36

thyroid

Question 37

low dose, chronic irradiation does not impair ___

Answer 37

fertility

Question 38

irradiation in utero concerns two groups:

Answer 38

rad worker

patient

Question 39

___ particulary sensitive to radiation

Answer 39

embyo

Question 40

___ trimester is most radiosensitive

Answer 40

first

Question 41

most pronounced effects of radiation is prenatal death which occurs in ___ weeks of fertilization, which is an all or nothing response

Answer 41

2

Question 42

relative risk of childhood leukemia after irradiation in utero is ____

Answer 42

1.5

Question 43

four effects in utero occur

Answer 43

spontaneous, abortion, congential abnormalties, ,mental retardation, childhood malignancy

Question 44

doubling dose is that dose radiation that produces ___ the frequency of gentic mutation as wold have been observed without radiation

Answer 44

twice

Question 45

conclusions of radiation genetics

• radiation mutation are usually harmful
• any dose of radiation , however small, to a germ cell results in some genetic risk
• frequency of radation induced mutation is directly proportionate to dose, so that linear extrapolation of data obtained at high doses provides a valid estimate of low dose effects
• effect depends on radiation protraction and fractionalism
• most pre- reproductive life, the woman is less sensitive than men
• most radiation induced mutations are recessive. these require that the mutant genes must be present in both male and female to produce trait, which may be expressed in future generations.
• frequency of radiation induced genetic mutation is extremely low .

Answer 45

radiation mutation are usually harmful

• any dose of radiation , however small, to a germ cell results in some genetic risk
• frequency of radation induced mutation is directly proportionate to dose, so that linear extrapolation of data obtained at high doses provides a valid estimate of low dose effects
• effect depends on radiation protraction and fractionalism
• most pre- reproductive life, the woman is less sensitive than men
• most radiation induced mutations are recessive. these require that the mutant genes must be present in both male and female to produce trait, which may be expressed in future generations.
• frequency of radiation induced genetic mutation is extremely low .

Question 46

Know chart

Answer 46

Pg 535