13 - 14 weeks // Stochastic Effect Flashcards
(42 cards)
The probability of the effect increases with increasing dose.
Stochastic Effect
It is the studies of large numbers of people exposed to a toxic substance require considerable statistical analysis.
Epidemiologic Studies
Epidemiologic studies of people exposed to radiation are difficult because:
The dose usually is ___ _____ but is presumed to be ___ and the frequency of response is ____ ___.
Epidemiologic studies of people exposed to radiation are difficult because:
The dose usually is not known but is presumed to be low and the frequency of response is very low.
The irradiation of blood forming organs can produce hematologic depression as a deterministic response or leukemia as a stochastic response.
Chromosomes
Chromosome damage in the circulating lymphocytes can be produced as both a _____ _____ and a _____ _____.
Chromosome damage in the circulating lymphocytes can be produced as both a deterministic effect and a stochastic effect.
Individuals accidentally exposed with ___ ____ doses continue to show chromosome abnormalities for __ ____ after the exposure.
Individuals accidentally exposed with high radiation doses continue to show chromosome abnormalities for 20 years after the exposure.
Year when cyclotron used to accelerate charged particle to very high energies.
1932
Year when every university physics department had one and was engaged in high energy experiments.
1940
First cataract report
1949
Year when several hundred cases of cataracts were reported
1960s
Radiation induced cataracts occur in the _____ ___ of the lens.
Radiation induced cataracts occur in the posterior pole of the lens.
Radiosensitivity of the eyes is ___ dependent.
Radiosensitivity of the eyes is age dependent.
___ let radiation have ___ rbe for the production of cataracts.
High let radiation have high rbe for the production of cataracts.
__gyt (____rad) where cataracts develop in nearly 100% of those who are irradiated.
10gyt (1000rad) where cataracts develop in nearly 100% of those who are irradiated.
Threshold after an acute x-ray exposure is approximately __gyt (___rad).
Threshold after an acute x-ray exposure is approximately 2gyt (200rad).
The threshold after fractionated exposure is probably in excess of __gyt (____rad).
The threshold after fractionated exposure is probably in excess of 10gyt (1000rad).
Occupational exposures to the lens of the eye are ___ ___ to require protective lens shields for radiologic technologists.
Occupational exposures to the lens of the eye are too low to require protective lens shields for radiologic technologists.
In computed tomography, the lens dose can be __mgyt (_rad).
In computed tomography, the lens dose can be 50mgyt (5rad).
At worst, humans can expect a reduced life span of approximately 10 days for every 10mgyt.
Whereas, the average life shortening caused by occupational accidents amounts to 74 days, for radiation workers, life is shortened by only 12 days.
Life Span Shortening
Nearly 100,000 died from the blast and early effects.
Another 100,000 received a high dose but survived.
The remainder received less than 10rad.
Atomic Bomb
Radiation induced leukemia follows a _____ ______ dose - relationship.
Radiation induced leukemia follows a linear nonthreshold dose - relationship.
Year when in Great Britain, patients with ankylosing spondylitis were treated with radiation to cure.
1940s to 1950s
Most radiologist received doses ___ rad/year.
Most radiologist received doses100rad/year.
20 years until patient cured started dying from ______.
20 years until patient cured started dying from leukemia.