Dose trivia Flashcards
cumulative dose level to the lens of the eye for the development of cataracts
2 Gy
posterior pole
annual dose limit to a member of the general public
100 mrem (1mSv)
2 mrem/hr (0.02 mSv/hr)
background annual radiation dose
300 mrem (3 mSv)
total effective occupational dose limi for a radiation worker
5000 mrem
50 mSv
(roughly 15 x the average background radiation dose to a member of the general public)
dose limit to radiation worker’s extremity
500 mSv
50,000 mrem
Mettler Ch 13 pearl
Annual occupational dose limits:
effective dose: __________
the eye:_________
any organ or tissue: __________
Annual occupational dose limits:
effective dose: 5 rem (50mSv)
the eye: 15 rem (150mSv)
any organ or tissue: 50 rem (500 mSv, 0.5 Sv)
Mettler Pearl
public dose limits:
annually: _____________
per hour: ____________
public dose limits:
annually: 0.1 rem (1 mSv)
per hour: 2 mrem per hour (20 uSv per hour)
mettler ch 13 pearl
permitted variation for an administered dose from the prescribed dose
+/- 20%
Mettler Ch 13 pearl
definition of a medical event
A medical event must meet all these criteria:
- effective dose >5 rem (50mSv) OR an tissue/organ absorbed dose > 50 rem (500 mSv) - when you reached your occupational dose limit
- administed dose > 20% from prescribed
- wrong pharmaceutical, wrong route of administration, or wrong patient
rules for release of pt given therapeutic I-131
- PATIENT IS SELF SUFFICIENT:
- amount of administered activity or dose rate is < 33 mCi [1.2 GBq]…
- OR pt dose at 1m measured with an ionization chamber is < 7 mrem per hour
- PATIENT RELIES ON A CAREGIVER:
- caregiver will receive an effective dose < 0.5 rem
annual dose limit to a member of the general public
100 mrem (1mSv)
2 mrem/hr (0.02 mSv/hr)
background annual radiation dose
300 mrem (3 mSv)
total effective occupational dose limi for a radiation worker
5000 mrem
50 mSv
(roughly 15 x the average background radiation dose to a member of the general public)
dose limit to radiation worker’s extremity
500 mSv
50,000 mrem
occupational dose for people < 18 (minors)
10% of the adult values
At what exposures should you call the NRC within 24hrs?
- Total effective dose equivalent 5 rem
- Eye dose equivalent 15 rem
- Shallow dose equivalent 15 rem
At what dose exposure should you notify the NRC within 30 days?
annual limit dose excess of:
- occupational
- public
- embryo/fetal
who gets a film badge?
individuals who receive a radiation dose in excess of 10% of the allowable occupational limits in 1 year
what is the fetal dose limit if a worker does not declare her pregnancy?
there is no fetal dose limit if the pregnancy is not declared
when does a patient receive written radiation safety guidelines
if the total effective dose equivalent to any other individual exceeds 1 mSv
average American dose of radiation per year
6 mSv
3 mSv from background (Radon)
3 mSv from medical
BEIR 7 cancer prediction
1 in 100 will get a solid cancer or leukemia from a does of 100 mSv above background
17 year old receptionist in the nuclear medicine department. Dose limit?
1 mSv (public lmit)
“radiation area” dose limit
0.05 mSv in 1 hr at 30cm
“high radiation area”
any place you could get 0.1 rem (1mSv)in 1hr at 30 cm
“very high radiation area”
any place you could get 500 rads (5 Gy) in 1 hr at 1 meter
CFR stands fo
code of federal regulations
10 CFR part 19
“inspections”
notices, instructions, and reports to workers
10 CFR part 20
“radiation protection”
standards for protection against radiation
10 CFR part 35
“human use of radioisotopes”
medical use of by-product material
High LET radiation most likely to cause direct or indirect radiation?
DIRECT.
acts on DNA
Low LET more likely to cause indirect or direct radiation?
INDIRECT
acts on water in cytoplasm creating free radicals which in turn damage DNA
order of sensitivity of cells cycle
M > G2 > G1 > S
risk of radiation induced cancer per dose in adults
5% per Sv
risk of radiation induced cancer per dose in kids
15% per Sv per child
For a radiation worker, what is the annual maximal occupational dose exposure to the hands?
500 mSv
