Common unit used to indicate an
absorbed dose of
radiation. A millirem is 1/1000 of a
rem. The
Three Mile Island incident exposed people to about 0.005 millirems, while
Chernobyl exposed people nearby to over 100 millirems. A
dental x-ray is about 0.15 millirems. The average person is exposed to about 170 millirems per
year, approximately half of which is
naturally occuring radiation (such as
cosmic rays).
A long list of radiation statistics (mostly in millirem) can be found under my node for radiation.