An Etymological Dictionary of Astronomy and Astrophysics

A unit used for measuring the effective dose of radiation received by a living organism. It is the quantity of radiation whose biological effect is equal to that produced by one → roentgen of → X-rays.
1 rem = 0.01 sievert (Sv) or 10 → millisieverts.

See also: Rem, acronym for roentgen equivalent man. The unit was introduced in 1944 by Herbert M. Parker (1910-1984), a radiation physicist and co-inventor of the Paterson-Parker Radium Therapy System.