Ionizing Radiation in the Hospital Flashcards
What is radiation exposure measured in?
Roentgens (R) for physicists.
Dose is measured in rads.
equivalent and effective dose measured in rem
mR=mrad-mrem
rem = 1/100 sievert (Sv)
What is direct action of radiation? Indirect?
Direct - radiation directly attacks DNA and causes a chemical change.
Indirect- radiation ionizes a reactive agent, which then in turn reacts with DNA
What will high dose rate exposure do?
limits ability to repair damage
What is LET?
???
What does stochastic mean?
Non-deterministic. In part, the result of a random chance, not a specific cause.
When is the riskiest period of life to be exposed to radiation?
very young ages. Fetus, neonate, children. Risk drops as you age.
How do you get rid of radon?
exchange fresh air. Radon has about a 3 day half-life.
What is the most commonly used dose-response curve for regulations?
linear nonthreshold curve. It is the most conservative estimate
Which type of dose-response curve is frequently used for scientific studies?
linear-quadratic, non-threshold curve.
How much more radiation is given from a CT than a plane x-ray?
100-250x as much radiation
How does distance affect radiation dosage?
it is a squared relationship. If you double your distance from the source, your exposure is reduced to 1/4.
conversely, if you half your distance, you quadruple your exposure.
What sort of radiation dosage will cause sterility in women? in men?
250-600 rad.
men = 350 to 600 rad (3.5-6 Gy)
How does radiation cause cataracts?
it disrupts the normal cell differentiation and proliferation. A dose of 2 Gy