Rem A unit of radiation dosage

Rem a unit of radiation dosage that accounts for both the energy of the dose and its effectiveness in causing biological damage (from roentgen equivalent for man). 

Rem a unit of radiation dosage used to relate various kinds of radiation in terms of biological destruction. It equals the rad times a factor for the type of radiation, called the relative biological effectiveness (RBE) rems = rads X RBE. (213)... 

Knowing how many disintegrations per unit time occur in a radioactive sample, or the number of ionizations in a volume of air, are not very helpful in characterizing the effects of radiation on human tissue and therefore the rad and the rem are commonly used to measure radiation dosage. Table 10-4 lists the types of radiation units, and the situations in which they are appropriately applied. A rad of a-rays will produce more damage than a rad of /3-rays. 

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