(d) What is the maximum OER for g- and x-rays?
(e) Is misonidazole a radiosensitizer or radioprotector for hypoxic
cells?
(f) What is the specific composition of radioprotectors and how do
they function?- (a) What is the doubling dose and what is its value for humans?
(b) What are the doses at which permanent sterility can be induced in
(a) males and (b) females?
(c) Define the genetically significant dose (GSD).
(d) What is the GSD for humans?
(e) Which one of all medical radiations contributes most to the GSD?
(f) What are the factors that influence the GSD? - (a) The mean latent period for radiation-induced leukemia is about (i)
5 to 10 years; (ii) 12 to 20 years; (iii) 21 to 30 years.
(b) The mean latent period for radiation-induced solid tumors is about
(i) 5 to 10 years; (ii) 12 to 20 years; (iii) 21 to 30 years.
(c) Cataract can be induced in humans with (i) 10 to 30 rad (10 to
30 cGy); (ii) 100 to 110 rad (100 to 110 cGy); (iii) 200 rad (200 cGy).
(d) What is the risk of cancer in the general population from small
doses of low-LET radiation exposure? - What are the two most common chromosome aberrations that are
responsible for carcinogenesis? - In the linear quadratic model of the cell survival, what is the value of
parameter bfor high-LET doses? - Elucidate the mechanisms of sublethal damage repair and potentially
lethal damage repair. Give an example of the latter. - What is the recent value of cancer death attributable to radiation
exposure in Japanese survivors of the atomic bomb? - What are the different dose-response models preferred for solid tumors
and leukemia? - What are the risk estimates of fatal cancer by the ICRP and the BEIR
VII for the general population? - What is a dirty bomb? How does it differ from an atomic bomb?
- What are the common radionuclides used in the radiological dispersal
device? What are the common sources of radioactive materials used in
dirty bombs? - Describe the types of effects caused by radiation.
- Describe the basic principles of decontamination of the contaminated
individuals. - What are the recommended steps one should take in the case of the
explosion of a dirty bomb? - The U.S. Homeland Security monitors radioactivity for dirty bombs at
strategic points of commuting. The patients undergoing nuclear studies
are given cards by the hospitals to provide proof of radioactive exam-
inations. How long should the patient normally carry the card for^18 F,
99mTc, (^123) I,IIIIn, (^67) Ga, (^201) Tl, and (^201) Tl?
266 15. Radiation Biology