click below
click below
Normal Size Small Size show me how
Bushong ch 36 Late R
Late Radiation Effects
Question | Answer |
---|---|
what are late effects of radiation based on | low doses deliverd over a long period |
what are radiation protection guidelines based on | based on linear, nonthreshold dose-repones relationship |
what effect was was caused by high doses in the early practices of radiology that caused callused, cracked and discolored skin on hands and forearms of radiologists | radiodermatitis |
what type of stem cells are damaged by radiation | lymphocytic stem cells |
how long can effects be delayed in peripheral lymphocytes | for has long has 20 years |
what responses are damage to circulating lymphocytes early or late | Chromosome damage in the circulating lymphocytes can be produced as both an early and late respone. |
low doses of radiation have been proven to cause what? | malignancy and genetic effects |
what can be caused as a late effect of irradiation of blood forming organs | produce hematologic depession |
what is used principally to produce radionuclides for used in nuclear medicine | modern cyclotron is used |
what type of dose response are cataracts | a no dose threshold nonlinear |
What is the life shortening span for every rad | 10 days for every rad |
what is the life shortening span for radiation workers | 12 days |
formula for relative risk observed cases/expected cases | relative risk= observed cases/ Expected cases |
what is the theory of radiation hormesis | suggest that very low radiation doses are beneficial |
What is the only theory we practice | ARLA |
relative risk factor of 1 indicates what | no risk at all |
relative risk factor of 1.5 indicates what frequency of late response is 50% higher in the irradiated population | 50 or higher |
who/what determines the absolute risk of radiation-induced malignant disease | National Academy of Science (NAS) and Committee on the biological Effects of Ionizing Radiation (BEIR) |
what is stochastic | has no dose threshold |
what type of responses are all radiation induced malignancy | all the late effects |
how have radiation induced malignancy been observed | experimental animals and at the human level late effects have been observed |
what type of dose response is leukemia | linear and nonthreshold (stochastic) |
what groups have exhibited an elevated incidence of leukemia after radiation exposure | atomic bomb survivors |
where have we accumulated the most info for radiation induced leukemia | observations of survivors of the atomic bombings of Hiroshima and Nagasaki |
How much greater was the leukemia incidences for Hiroshima and Nagasaki survivors | 100 times that in the nonirridiated population |
what is the latent period for radiation induced leukemia | 4 to 7 years |
what is the risk period for radiation induced leukemia 20 years | 20 years |
What year was the incidence of leukemia high in radiologist and why 1940; no protection and received doses over 100 rad per year | 1940; no protection and received doses over 100 rad per year |
Skin cancer has what type of dose response threshold | threshold |
What is the BEIR Biological effects of Ionizing Radiation | Biological Effects of Ionizing Radiation |
What effect does chronic low doses have on fertility | low-dose, chronic irridiation does not impair fertility |
the most radiosensitive period in pregnancy | during the first trimester |
what period is of the least concern in pregnancy first 2 weeks | first 2 weeks |
cancer is what type of effect of radiation exposure | late effect |
what is the risk for skin cancer | 500 to 2000 rad risk 4:1 ; 4000 to 6000 rad or 6000 to 10000 rad risk 14:1 and 27:1 respectively |
what is the latent period for skin cancer | approximately 5 to 10 years |
how must epidemiologic studies be conducted to study effects of low dose radiation? | Studies of large number of people exposed to a toxic substnace |