[Illustration: IN MEDICINE: _Iodine-131 reveals spread of thyroid
cancer in patient’s body._]
[Illustration: IN SPACE: _Plutonium-238 is the fuel for the atomic
generator powering this TRANSIT satellite._
Courtesy The Martin Company]
[Illustration: IN FOOD PRESERVATION: _Potatoes stored for 18 months
at 47°F. Potato at right had been irradiated, that on left had
not._]
[Illustration: IN INDUSTRY: _Radioactive iridium was used to inspect
the hull of the carrier_ Independence.
Courtesy Technical Operations, Inc.]
As sources of radiation, radioactive isotopes are frequently replacing
more expensive and less convenient sources such as radium and X-ray
machines. The medical treatment of diseased tissue has been greatly
expedited by the new sources. In industry many applications of radiation
sources have been made. They are used, for example, in thickness gauging
and in making radiographs to check the quality of large castings. The
sterilization and preservation of food is another promising use for
inexpensive radioactive sources.
As a controllable means for inducing genetic mutations, radioactive
isotopes are speeding up the process of selecting and developing
superior agricultural products. Practically every agricultural research
center in the world has one or more projects under way which involve the
use of isotopes.
Small devices have also been constructed which produce electricity from
heat generated by decay of radioisotopes. Such devices have been used to
power instruments in a remotely located unmanned weather station, a
navigational buoy, a lighthouse, an underwater navigational beacon, and
space satellites. Many additional uses are foreseen for these isotopic
power generators.