Protection CH 9

Question 1

The long term results of radiation exposure

Answer 1

late effects

Question 2

The science that deals with the incidence, distribution, and control of disease in a population

Answer 2

epidemiology

Question 3

Demonstrated graphically through a curve that maps as observed effects of radiation exposure in relation to dose received. As dose increases so does effects.

Answer 3

radiation dose-response relationship

Question 4

a point at which a response or reaction to an increasing stimulation first occurs. means that below a certain radiation dose, no biologic effects are observed

Answer 4

threshold

Question 5

relationship meaning that any radiation dose will reproduce a biologic effect-No radiation dose is absolutely safe

Answer 5

nonthreshold

Question 6

estimates the risk associated with low level radiation

Answer 6

linear quadratic nonthreshold curve

Question 7

this model accurately reflects the effects of high LET radiation (neurons and alpha rays) at higher doses

Answer 7

linear dose response curve

Question 8

when living organisms that have been exposed o radiation sustain biologic damage, the effects are classified as somatic effects when late effects are mutational or randomly occurring biologic somatic change, independent of dose

Answer 8

stochastic (probabilistic) somatic effects

Question 9

effects that appear months or years after exposure to ionizing radiation–could result from previous whole or partial-body acute, high radiation doses or they may be the product of individual low level doses sustained over several years

Answer 9

late somatic effects

Question 10

late effects that can be directly related to dose received and occur months or years after a high level radiation exposure.. Ex. cataract formation, reduced fertility, organ atrophy

Answer 10

late nonstochastic (deterministic) somatic effects

Question 11

late effects that do not have a threshold, occur in an arbitrary or probabilistic manner, have a severity that does not depend on dose and occurs months or years after high level radiation exposure.. Examples: cancer and birth defects

Answer 11

late stochastic (probabilistic) somatic effects

Question 12

randomly occurring effects that are nonthreshold. this means the greater the dose an individual receives the greater the chance that a specific late effect will be seen. ex. cancer and genetic disorders

Answer 12

stochastic events

Question 13

when the biologic effects demonstrate the existence of a threshold, a dose below which a person has a negligible chance of sustaining specific biologic damage, and the severity of that biologic damage increases as a consequence or increases absorbed dose

Answer 13

nonstochasctic events

Question 14

Cancer is the most important late stochastic somatic effects caused by exposure to ionizing radiation. Cancer effect is a random occurrence that does not seem to have a threshold and for which the severity of the disease is not dose related

Answer 14

carcinogenesis

Question 15

biologic effects of ionizing radiation to future generations

Answer 15

genetic effects

Question 16

the radiation dose that causes the number of spontaneous mutations occurring in a given generation to increase to two times their original number

Answer 16

doubling dose

Question 17

know the difference between stochastic effects and deterministiec effects

Answer 17

Stochastic is the probability that the effect happens depends upon the received dose, but the severity of the effect does not. deterministic effects-both the probability and the severity of the effect depend on the dose

Question 18

For a dose response curve, what numbers variable are plotted along the axes of the graph to demonstrates

Answer 18

horizontal=dose received
vertical=biologic effects observed
curve=either be linear of non linear and will depict either a threshold or nonthreshold

Question 19

in reference to the linear quadratic nonthreshold curve what do the following terms mean:
linear-
quadratic-

Answer 19

linear-dose

quadratic-dose squared

Question 20

how are nonstochastic effects (ie skin erythema) demonstrated graphically>

Answer 20

linear threshold curve of radiation dose response

Question 21

what is the actual meaning of stochastic events

Answer 21

randomly occurring effects that are nonthreshold. meaning the greater the dose an individual receives the greater the chance that a specific late effect will be seen

Question 22

what are examples of late deterministic somatic effects

Answer 22

cataract formation
fibrosis
organ atrophy
loss of parenchymal cells
reduced fertility
sterility

Question 23

be able to list the 3 major types of late somatic effects

Answer 23

carcinogenesis
cataractogenesis
embryologic effects(birth defects)

Question 24

what single dose will likely cause the formation of cataracts

Answer 24

2 gy or 200 rad

Question 25

what procedures produces the highest radiation exposure to the lens of the eyes

Answer 25

fluoroscopic procedures

Question 26

when are all life forms more vulnerable to radiation

Answer 26

embryonic stage

Question 27

when Is the embryo-fetus most susceptible to death from radiation

Answer 27

during first 8 weeks of development at a dose in excess of 200 mSv (20 rem)

Question 28

what could happen to an embryo fetus if it is exposed to radiation during organogenesis

Answer 28

growth inhibition, mental retardation, microcephaly, genital deformities, and sense organ damage have a chance of occurrence

Question 29

at what dose does death occur to the fetus

Answer 29

excess of 200 mSv (@) rem)

Question 30

Genetic effects occur as result of

Answer 30

radiation induced damage to the DNA molecule in the sperm and ova of an adult

Question 31

what happens when radiation interacts with DNA molecules

Answer 31

it can modify the structure of the molecule by causing breaks in the chromosomes or change the amount of DNA belonging to a cell by causing a deletion or an alteration in the sequence of the nitrogen bases

Question 32

what does the information obtained from the fruit flies experiments indicate

Answer 32

that genetic effects does not have a threshold-- a dose at which radiation causes genetic effects begin to occur and below which they cannot occur. this implies that even the smallest dose could cause some genetic damage

Question 33

what must be done to minimize the possibility of genetic effects for those in medical imaging

Answer 33

You must use gonadal shielding effectively and with all exposures you must use and maintain ALARA