1what are late effects also known as?
stochastic effects
2what is the difference between stochastic effects and non-stochastic effects
stochastic effects ncreasing incidence of response, not severity, with increasing dose. non-stochastic is directly related to the dose received and the severity of the effect increases with increased dose
3what is late effects or stochastic effects defined as?
the result of low doses of radiation over a long period of time
4what dose response relationship does late effects follow?
linear, nonthreshold
5radiation protection is based on what?
non-linear threshold dose response (late effects)
6what are epidemiologic studies
study of occurrence and causes of disease in humans
7what does radiation hrmesis state?
doses below 10 rads (1dGy) are beneficial
8what is radiodermatitis
callused, discolored skin that severly cracks or flakes (threshold in nature)
9when can chromosome dmg in lymphocytes occur
as an early or late effect
10what is the latent period for cataracts
5-30 years
11what is the threshold after acute x-ray exposure for cataracts
200 rad (2 Gy)
12what is the threshold after fractionated x-ray exposure for cataracts
1000 rad (10 Gy)
13what is risks defined as
possibility of inducing a radiogenic cancer or genetic effect after irradiation
14what are the 3 risk estimates
Relative, excess, and absolute
15what is relative risk
the estimation of late radiation effects in a large population without having precise knowledge of the dose.
16what is excessive risk
the difference between observed and expected number of cases (ER = OC - EC)
17what is absolute risk
incidence of malignant disease in a population within 1 year for a given dose (Linear nonthreshold dose)
18why did radium watch dialers develop bone cancer
radium would deposit in their bones like calcium
19what were the late effects of. thymus irradiation
patients treated with radiation to the thymus later showed excessive risk for thyroid cancer
20what are the effects on fertility caused by low-dose long term irradiation
low doses of chronic radiation does not impair fertility, but can show genetic effects
21what are the effects of irradiation in utero
prenatal and neonatal death, congential abnormalities, malignancy induction, genetic effects, impairment of growth and cognitive delay.
22why is the first trimester of pregnancy the most radiosensitive period
the stem cells are young and multiply quickly
23what is doubling dose
dose necessary to double the amount of genetic effects
24what is major organogensis
The creation of the organs which happens from the 2nd through the 12th weeks. It’s the stage where organ abnormalities can be induced.
25what is ankylosing spondylitis
arthritic condition in the vertebrae
26who is HJ muller
did experiements on flies
27what is thorotrast
thorium dioxide that was used as contrast in 1925-1945 for angiography
28why is it difficult to link cancer to radiation exposure
occurs in high proportion naturally in the population
29how much rad will cause shrinking of the thymus gland
500 rad (5 Gy)
30what were radium salts used in?
arthritis and TB
31what is latent period for skin cancer
5-10 years
32what kind of dose respose relationship does skin cancer follow
threshold dose response relationship
33what is breast cancer relative risk
as high as 10;1
34What is radon gases
radionuclide that emanate through rock
35what dose response relationship does lung cancer follow
linear non threshold
36what is latent period for liver cancer
15-20 year latent period
37where was thorotrast deposited in and what does it produce
deposited in liver and spleen, produces alpha beta and gamma radiation
38what was the mrad at 100 mile radius of 3 mile island
1.5 mrad
39what was mrad at 50 mile radius of 3 mile island
8 mrad
40what is the beir committee
biologic effects of ionizing radiation
41how many cases of cancer in 100k people in 1 rad?
800 cases
42what is the relative risk of childhook leukemia after irradiation in utero
1.5