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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is the conclusion of the BEIR V report on the incidence of cancer and radiation exposure?
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Based on linear model there would be 80 extra deaths among 20,000 people or .4% by being exposed to 1 rem of acute exposure
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What was the conclusion of the BEIR VI report?
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Inconclusive study on the effects of radon in private residences. estimated that 2100 to 2900 deaths out of 11,000 lung cancer deaths related to radon and also that smoking and radon exposure have synergistic effects
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What is an early effect of radiation and the threshold dosage?
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100 - 300 rads will cause skin erythema, desquamation with increased dosage
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What are some possible late tissue damage effects from radiation?
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atrophy, fibrosis, pigmentation change, ulceration, permanent depilation(hair loss), necrosis (worst case scenario)
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Apples Fall Primarily Under Dark Needles
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What is the minimum threshold dose for humans?
(3 effects) |
10 rads to see any measurable change in humans:
decrease in circulating WBC's then decrease in sperm cells in males and suppression and delay in menstruation in females |
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Why is sterility delayed in males?
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radioresistance increases with maturing sperm cells so when the stem cells are killed there are still mature sperm cells. when they are gone then there is sterility
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Exposure levels to cause temporary male sterility is _______
but as little as _______ may cause temporary sterility. |
250 rads, lasting 1-2 yrs, but as little as 15 rads may cause temporary sterility.
What level of acute exposure will cause permanent sterility? |
350 - 600 rads
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Exposure levels to cause temporary female sterility is _______?
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50 rads
What level can cause permanent sterilty? |
250 - 600 rads
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True or false: Mutations are proportional to dose
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True
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What is doubling dose mean in regards to mutations and radiation?
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The amount of radiation required to see twice the amount of mutations
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Name the 3 types of mutations?
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1. Mendelian diseases- single genetic mutation, simple predictiable pattern.
2. Chromosomal - gross abnormality in number of chromosomes (Down's syndrome) 3. Multifactorial diseases- genetic with mendelian pattern, influenced by genetics, environment and behavior( heart disease, diabetes, autism) |
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What is the doubling dose for mice?
for humans? |
30 rads for mice, 156 for humans, though some studies say 100, some 200
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Male mice are more radiosensitve than female mice, true or false?
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True
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What would indicate there is a repair process from radiation?
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Genetic consequences are reduced if there is time between irradiation and conception among mice
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Name the 4 guiding principles on the genetic effects of radiation?
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1. Most radiations are harmful
2. Any dose of radiation carries some genetic risk, but radiation is a relatively weak mutagen. 3. Number of mutations is proportional to dose, linear relationship. 4. Risk estimates for mice are close to those for humans |
Harmful Weak Linear Mice
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Because of the potential risk for hereditary effects what is the recommended waiting period between acute radiation exposure and conception for females?
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6 months
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What is the normal rate for congenital abnormalities?
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6% at birth, 12% when accessed later
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What are the 3 gestational periods when divided up into radiation risk?
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1. Pre-implantation 0-10 days
2. Organogenesis 10-41 days 3. Fetal stage 42 days - term |
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Describe the pre-implantation stage and its risk with radiation?
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period from fertilization to implantation of embryo in uterine wall. most sensitive to lethal effects of radiation. 5-15 rads will kill embryonic mice. But if embryo survives it grows normally. what is this called?
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All or nothing effect
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Describe Organogenesis stage and its radiation risk?
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10-41 days when major organs are formed, most cells are very sensitive to radiation. malformations and congenital anomalies are major effect of radiation exposure. also growth retardation from cell depletion, but is recoverable. what are dose rates?
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200 rads - 100% incidence of malformations in mice
100 rads - produces growth retardation in any animal 25 rads - no observable effects |
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Describe Fetal stage and effects of radiation?
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42 days to term where major organs grow. much larger dosages of radiation required to cause fetal death. growth retardation permanent at this stage
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What are the weeks where mental retardation is most likely to result from fetal radiation exposure?
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8 to 15 weeks as this is when brain cortex is being formed
when is there least risk of mental retardation? |
after 30 weeks. also from 2 to 8 weeks and from 16 to 30 weeks there is some risk but not as much as 8-15 weeks
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What is the National Council on Radiation Protection (NCRP) recommended dosage for pregnant mothers which has been adopted by NRC?
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500 mrem for entire gestation period or 50 mrem/month
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