Rad Bio Ch 41
The Si unit for exposure is the _____ per kilogram (C/kg)
Coulomb
The Wr weighting factor is a ratio indicating the relative biological ______ of particular radiations compared to 250-kV x-rays.
harmfulness
DELS for specific organs of the body are generally much ______ than whole body dose limits, because radiation exposure limited to a small portion of the body is not as harmful to the whole organism as that delivered to the entire body.
higher
The emergency limit refers to _____ and _____ situations, in which a rescue worker may be exposed to large amounts of radiation while extracting or treating the victim.
life threatening?
The CLDEL is designed for _____-term control, but does not protect very young workers well.
long
The routine diagnostic exam making the greatest impact upon gonadal dose is the ________ _________ series, closely followed by the IVP(IVU).
lumbar spine
Through negligence and _____ laws, patients do have legal recousre for excessive and unnecessary exposure to radiation.
malpractice
In all cases, from the different types of Dels, the more______ limit must be applied.
stringent
Calculate the DAP; PT A, 3 mrad w/ 8" x 10" field= PT B, 3 mrad w/ 10" x 12" field=
240 mrad-in2 (millirad-square-inches) 360 mrad-in2
Precticing radiographers currently average ____-____ mrad per yr of actual occupational dose, less than 1/10 of the occupational limit. This is a very safe margin.
300-500 mrad
One curie is equal to ______ becquerels.
37 billion
The C/kg units is about _____ times larger than 1 R.
4,000
The embryo/fetus DEL refers to the occupational dose received by the fetus of pregnant radiation worker. The limit is ____ rem or _____ mSv per month.
0.05 rem or 0.5 mSv
How many grays are in 20 rads? How many sieverts in 200 rem? How many roentgens in 3 C/kg? How many Ci in 500 becquerels?
0.2 Gy 2 Sv 1.16 X 10^4 R 1.35 X 10^-8 Ci
The genral public DEL for people living near radiation industries or near radioactive waste sites is ____ rem or ____ mSv per year.
0.5rem or 5mSv
One R of exposure generates ______ rads of dose in human tissue, close enough that we generally round this number up to one.
0.96 rads
A dose of 1 rad of neutrons will generate 10 rems of dose equivalent, for alpha particles, 1 rad will cause 20 rems of damage, but not for x-rays, 1 rad of dose will cause only _____ rem of harm.
1
The current annual toatl body limit for radiographers equates to a weekly limit of ____mrem.
1
The current GSD is estimated to be approx ________ mrem per year, and is steadily rising.
20
The first known limit for occupational x-ray exposure made by dentist William Rollins in 1902 equated to about _____ rem/working day.
10
One gray is equal to ______ rads. The gray is the larger unit.
100
One sievert is equal to _____rems. The sievert is the larger unit.
100
Specifically one rad is defined as _________ ergs of energy absorbed in each gram of tissue.
100 ergs
The DEL for the lens of the eye is _____ rem per year.
15
The prospective DEL is set at _____ rem per year for occupational radiation workers.
5
The DELs for red bone marrow, the breast, lungs, gonads, skin, hand, and forearms are all set at ____ rem per yr.
50 rem
The rad unit is a unit that applies to __________ types of radiation.
All
The SI unit for radioactivity, named after the discoverer of radioactivitym is the _____, abbreviated Bq.
Becquerel
The conventional unit for radioactivity is the ______, a simple count of the number of decay events per second, or emissions of any wave or particle from a radioactive object.
Curie
Current occupational limits are called ___ ___ ___ or DELs.
Dose Equivalent Limits
Current limits are based on summing & weighing doses to essential organs to arrive at the total effective dose equivalent or TEDE. The 3 whole body dose limiting organs are:
Gonads Red bone marrow Lens of the eye
The SI unit for absorbed dose is the _____, abbreviated Gy.
Gray
The gray is defined as 1 _____ of energy deposited per kilogram of tissue.
Joule
The unit that takes into account the amount of radiant energy actually deposited within body tissues is the__________, abbreviated_______.
Rad, R
The term rad is an acronym for______ _____ ______.
Radiation Absorbed Dose
The unit for dose equivalent is the rem, which stands for ___ ___ ___.
Radiation Equivalent in Man(or mammals)
The SI unit for dose equivalent is the _____ (Sv).
Sievert
Radiation exposure is narrowly defined as the intensity of radiation incident upon the _________of an object or person.
Surface
Dose equivalent limits provide guidelines for corrective actions, but they do not constitute a statement of _________ levels of radiation. The ALARA concept supercedes DELs.
acceptable
The cumulative lifetime limit(CLDEL) for occupational radiation workers is 1 rem multiplied by the worker's ______.
age
The prospective DEL is a relative limit which can be subjected to ______ over time.
averaged
The rem is a true _______ unit, measuring actual harm done, whereas the roentgen and the rad are physics units.
biological
X-rays cause ionizations within air molecules near a detection surface. This process can generate an electric ______in a detection device.
charge
The dose are product(DAP) is an indication of the total effect on or harm to a patient, taking into account the ______ size as well as the technique set.
collimated field
A becquerel is a single ______ event.
decay
The correct use of the term dose is always in connection with internalized or absorbed energy, whereas exposure connotes only what we were _______ to from the outside.
exposed to
When the absorbed dose in rads is multiplied by these two weighting factors, we obtain ________ _________, a true measure of biological harm or biological effectiveness.
dose equivalent
The prospective limit is designed to restrict doses at __________ ages and allow flexibility at older ages.
early
Entrance Skin Exposure(ESE) is the intensity of radiation_____ through the skin surface into the body, not the amount absorbed by body.
entering
Occupational radiation exposure should be more or less _____ distributed over time.
evenly
The unit of dose, the rad, is independent of the collimated _____ size.
field
The genetically significant dose(GSD) is an averaged gonadal dose that gives us an indication of how much________ harm is being caused to the entire human population due to the use of medical radiation.
genetic
The roentgen unit is appropriate for measuring the _______ of the raw beam of x-rays, but not biological damage from radiation.
intensity
The emergency limit can only be applied _____ during a rescue worker's lifetime.
once
There is no DEL for medical _____. The amount of radiation a patient receives in the course of medical treatment is at the discretion the of the physician.
patients
The CLDEL is an absolute limit, meaning that if it is exceeded, corrective action is _______.
required
In nuclear power plants, a ______ limit of 3 rem per quarter ensures that all 5 rem of the annual limit is not received in a single quarter.
retrospective
The weighting factor, Wt, refers to the relative_______ of the type of tissue or organ being exposed.
sensitivity
Any amount of radiation less than the negligible individual dose(NID) is too low to be statistically _______.
significant
Pregnant radiographers should wear a second radiation monitor at their ______ level, from which fetal dose can be estimate.
waist
In 1931, US Advisory Committee on X-Ray and Radium Protection adopted Sievert's recommended limit of 50 rem per ____, ten time the current limit.
year
3 different types of whole body occupational DELs all interrelate with each other in such a way as to ensure that both short-term and long-term exposure levels are controlled for both the ____ and the ____ alike.
young and old
