The biggest source of man-made radiation is a CT scan, which produces views of your body as if they were in slices, layer by layer, to deliver a 3-D image--it can expose you to anywhere from 200 for a head scan to 11,000 mrem
for a full-body scan.
(11) The EPA states that there is no firm basis for setting a "safe" level of maximum radiation exposure, but we estimate it as the safe occupational dose threshold for workers at nuclear power plants: an additional 5000 mrem
of radiation a year above the 360 mrem
level, the equivalent of five CT scans a year.
For dose to the public resulting from the nuclear fuel cycle (e.g., nuclear power plants), the Environmental Protection Agency uses a standard of 25 mrem
per year of whole-body dose.
Flunitrazepam effects on human sleep EEG spectra: differences in MREM
, REM and individual responses.
The effective dose for the computed tomography (CT) procedures should have been listed in mSv, for example, the effective dose for a head CT is 2 mSv or 200 mrem
or 0.2 rem.
Estimates of the radiation exposure in the United Kingdom due to all these sources (in millirem per year) are 186 mrem
for natural radiations, including 50 mrem
for radon, and 53 mrem
for man-made irradiation, nearly all due to medical treatment and diagnosis.
A passenger on a polar-crossing airliner can experience the equivalent of a chest X-ray--about 10 mrem
--during an SEP event like the one in January 2005.
The monthly equivalent dose to the embryo or fetus should not exceed 0.5 mSv per month or 50 mrem