Scientists use three different ways of measuring the energy in radiation. Here they are:
 |
|
|
|
| CURIE |
Unit of Activity (A) |
A= # of decays
per second |
1 curie = 3.7 × 1010
Decays per second |
|
| RAD |
Unit of Absorbed
Dose (D) |
D = the energy
absorbed per gram
of tissue in the
body |
1 rad = 100 ergs per gram |
|
| REM |
Unit of Dose
Equivalent (H) |
H = the absorbed
dose multiplied
by a biological
effectiveness
factor (Q) |
1 rem = Q × D |
The best tool to measure an individual's risk from radiation exposure is the REM. In this formula, Q is really a weighting factor that represents the density of the ionization from various radiation types: alpha, beta, gamma particles, protons, neutrons that are emitted by a substance. Low level exposures are measured in millirems, or MREM, a thousandth of a rem.
EXAMPLE:
One chest X-Ray gives you about 10 mrem of radiation, or .01 rem.
A dental X-Ray emits 1 mrem, or .001 rem.
