Late effects of radiation Flashcards
What are these outcomes called and what are they the result of?
Radiation-induced damage at the cellular level may lead to measurable somatic and genetic damage in the living organism as a whole later in life.
These outcomes are called late effects and are the long-term results of radiation exposure.
How long does it take for a late effect to show up?
Months to years after exposure
What might a late effect result from?
- Previous whole- or partial-body acute exposure
- Previous high radiation doses:
- Long-term low-level doses sustained over several years
T/F
Late effects come from cells that are damaged but live
True
T/F
Most stochastic effects and genetic effects at low dose levels from low-LET radiation, appear to follow a non-linear, threshold curve.
False; Most stochastic effects and genetic effects at low dose levels from low-LET radiation, appear to follow a linear non-threshold curve.
What relationship is this talking about?
Information obtained can be used to attempt to predict the risk of occurrence of malignancies in human populations that have been exposed to low levels of ionizing radiation.
Dose response relationship
What is a Non-stochastic Late Effect?
Late effects that can be directly related to dose received
What is a Stochastic late effect?
Late responses that do not have a threshold
What are 4 examples of Non-stochastic Late Effects?
1) cataracts
2) sterility
3) fibrosis
4) atrophy
What are 2 examples of stochastic late effects:
1) Cancer
2) embryologic effects
What dose in Gy can induce cataracts?
2 Gy will induce the formation of cataracts.
What is the DL for the lens of the eye?
150 mSv
What is the result of cataracts?
Partial or complete loss of vision
T/F
The formation of cataracts is a nonlinear dose-response relationship
True
What is the amount of radiation (low diagnostic amount) that could possibly cause cancer?
Could be caused by doses above .5mSv
What are Genetic Effects of radiation?
Stochastic effects from damaged genes
What is the most effective mutagen?
Ionzing radiation
T/F
Even a non-lethal dose to a germ cell can create genetic mutations which can be passed to successive generations
True
What are the natural mutations that frequency can be increased with ionzign radiation?
Huntingtons, Down syndrome, Duchenne muscular dystrophy, Cystic fibrosis
What are the two types of germ cell mutations?
1.Dominant mutation
2.Recessive mutations
T/F
Genetic mutations are threshold.
False; Genetic mutations are non-threshold
What do recessive mutations require in order to be expressed?
Requires a mutated gene from both parents
What do dominant mutations require in order to be expressed?
Only requires a mutated gene from one individual
T/F
GE’s or hereditary effects do not have a threshold
True
T/F
Ionizing radiation is thought to cause primarily dominant mutations
False; Ionizing radiation is thought to cause primarily recessive mutations
Damage from recessive mutation may appear as what?
Allergies, alteration on metabolism, decreased intelligence, predisposition to certain diseases
T/F
Currently there is evidence of radiation induced hereditary effects in diagnostic imaging workers and their patients
False; Currently there is no evidence of radiation induced hereditary effects in diagnostic imaging workers or their patients
What concept is this reffering to?
It is the radiation dose that causes the number of spontaneous mutations occurring in a given generation to increase to two times their original number.
Doubling dose concept
What is the radiation doubling equivalent dose for humans?
1.56 Sv
