Glossary cont'd - hdbk110697

DOE-HDBK-1106-97

GLOSSARY (continued)

Uptake: Quantity of a radionuclide taken up by the systemic circulation, e.g., by injection into the blood,

by absorption from compartments in the respiratory or gastrointestinal tracts, or by absorption through the

skin or through wounds in the skin.

Weighting Factor: The fraction of the overall health risk, resulting from uniform, whole body irradiation,

attributable to specific tissue (T). The dose equivalent to tissue, T, is multiplied by the appropriate

weighting factor to obtain the effective dose equivalent to that tissue.

Whole-Body Counter: A device used to identify and measure the radiation in the body (body burden) of

human beings and animals; it uses heavy shielding to keep out background radiation and ultrasensitive

scintillation detectors and electronic equipment.

Whole-Body Counting: A technique to determine the internally deposited radionuclides within the body

by measuring with an external radiation detector the photons emitted. Results are generally expressed in

the form of percent of the ALI for the nuclides in question. This technique can identify and measure

accurately normal body radiations as well as those that are taken into the body due to such things as

injection, ingestion, and inhalation from atmospheric releases, medical diagnostic and therapeutic

techniques, etc.

Whole Body Dose Equivalent: The dose equivalent that results when the whole body is irradiated and

taken, when the irradiation is uniform, as equivalent to the effective dose equivalent.

X-rays: Penetrating electromagnetic radiation having wavelengths shorter than those of visible light,

usually produced by bombardment of a metallic target with fast electrons in a high vacuum. In nuclear

reactions, it is customary to refer to photons originating in the nucleus as gamma rays, and those

originating in the extra nuclear part of the atom as X-rays.