Effective Dose Limit Recommendations
While reviewing for the Registry, I keep coming across questions on dose limits that I just can’t seem to keep straight in my mind. I hope this list will help me keep things straight in my mind:
The two units of measure associated with absorbed patient dose are the rem and the sievert. The rem (radiation equivalent man) is the traditional measure and the sievert is the SI unit of measure. To convert a rem measurement to a sievert measurement, you multiply the rem number times 10.
Effective dose measurements are divided into two categories: Occupational Exposure and Public Exposure.
Occupational Exposure:
Effective Dose Limit:
50 mSv / 5 rem (Annual) and 10 mSv x age / 1 rem x age (Lifetime)
Equivalent Dose Limits for Tissues and Organs:
Lens of Eyes: 150 mSv / 15 rem
Skin, Hands, Feet: 500 mSv / 50 rem
Public Exposure:
Effective Dose Limit:
Continuous/Frequent Exposure: 1 mSv / 0.1 rem
Infrequent Exposure: 5 mSv / .5 rem
Effective Dose Limit for Tissues and Organs:
Lens of Eyes: 15 mSv / 1.5 rem
Skin, Hands, Feet: 50 mSv / 5 rem
Embryo/Fetus Exposures (MONTHLY):
Equivalent Dose Limit: 0.5 mSv / .05 rem
Education and Training Exposures:
Effective Dose Limit: 1 mSv / 0.1 rem