Section I. SOURCES OF IONIZING RADIATION
a. There are a number of radiation sources that can be found on a military
b. The medical facilities in the Army are among the largest users of radiation. In
order to get a good picture of this radiation use, we will consider the kinds of sources to
2-2. NATURAL BACKGROUND RADIATION
a. It is useful to begin any discussion of radiation sources with an understanding
of the exposure from natural sources of radiation. You must realize that you are
exposed to natural radiation all the time. That is the radiation that comes from space,
the radiation that comes from the crust of the earth, and some radioisotopes that we all
have inside our bodies. Actually, there is little we can do to reduce this exposure; it is
part of living.
b. On the average, we receive approximately 100 mrems/year from natural
background radiation. This dose varies depending on where you live. The point here is
that we are all exposed to this radiation naturally.
2-3. MAN-MADE RADIATION
a. Used extensively as a diagnostic tool, medical radiation is the single greatest
source of man-made radiation exposure to the general population.
(1) Diagnostic x-rays. This source accounts for greater than 90 percent of
man's exposure to man-made radiation.
(2) Therapeutic radiation. Therapy facilities are usually found at medical
centers only. Therapeutic radiation is produced by using radioisotopes such as Cobalt-
60 or by using medical accelerators.
(3) Nuclear medicine. Radioactive materials are used here to view organs of
the body for diagnostic information.