Indirect or In Vitro Measurement

DOE-HDBK-1113-98

Module 104 Internal Dose Control

Lesson Plan

Instructor's Notes

therefore considered to be unacceptable. Improved

analytical and calculational techniques have now made it

possible to measure uranium concentrations resulting in

exposures of about 10 mrem with a reasonable degree of

accuracy. The estimation of low-level internal exposure to

uranium is no longer a matter for inordinate concern.

Indirect or In Vitro Measurement

Bodily processes will, to some degree, eliminate

uranium taken into the body. How effective the

body is at eliminating the uranium, and how long

the process takes, depends upon individual

metabolism and the chemical form of the uranium.

For example, uranium hexafluoride contains

uranium that is chemically bound to fluorine and is

more easily eliminated than uranium metal or

uranium dioxide.

Indirect measurements are made by sampling

material eliminated by the body for the presence of

uranium. It is possible to analyze both feces and

urine for the presence of uranium, but due to the

ease of collection and handling, the most common

method used is urinalysis.

Direct or In Vivo Measurement

Direct measurements are performed using whole

body counters or lung counters. These instruments