Evening star., 1952-12-04

radiation and Dr. JACOBSON.
radio elements soon numbered
IN the thousands.
Today the knowledge resulting
from these efforts is used in the
treatment or diagnosis of a wide
range of disease. including leuke-
mia, goiter. cancer of the thyroid
heart disease, blood diseases and
in basic medical research. Clues
are even at hand for a solution OF
the problem of preventing deaths
and injuries caused by overex-
posure to radiation in an atomic
bomb explosion.
The story of the use of these
radioactive elements goes back
just over half a century when Will
liam Roentgen announced the dis
covery of a mysterious invisible
ray which was capable of penetrat-
ing solid material. including the
human body. He named these new
rays "X-rays."
This dramatic finding was soon
followed by the discovery by Henri
Becquerel that radioactive ele-
mentS existed. Before the dawn of
the goth Century, four separate
and distinct types of penetrating
rays were identified, including
X-rayS, gamma rays and alpha
and beta particles.
IN 1884. Ernest Lawrence de-
vetoped the cyclotron. new source
OF powerful rays known as neu-
irons and Enrico Fermi found that
radioactivity could be artificially
induced in elements which were
ordinarily stable or nonrad;oactive
Importance Realized Quickly.
Scientists soon became aware of
the practical Importance of these
discoveries. They saw the pos
sibility of utilizing these radio
active elements as tools to diagnose
and treat diseases more effectively
and to study how the cells and the
body as a whole worked.
What makes an element radio
active or stable? This can best be
explained by visualizing each ele-
ment as composed of a nucleus
shaped like ball or marble around
which are number of other balls
which are called electrons. It is
the electronS circulating around
the nucleus of an atom OF element
which determines the chemical
behavior of the element.
A radioactive element differs
only in that the nucleus or larger
central ball is in constant turmoil
and remains so until a ray is re-
leased from its interior. It might
be compared to the turbulent state
which would obtain if a cat and
dog were confined together IN
a small space. Turmoil and in
stability would exist until one or
the other was released. If the dog
got out. we would have one type
OF emission: if the cat got out,
another type of emission. So it
is with a radioactive element. Only
until ray of one variety or an
other is released from the nucleus
is stability resumed.
Some Of the more important
radioactive elements which a,e
used in the treatment of human
diseases are radiophosphorus,
radioiodine, radioarsenic, radio
gold and radiosodium.
Body Functions Aid Use.
Neutrality-suspicious. is made by
bombarding sulphur in the atomic
uranium pile. The sulphur atoms
change into phosphorus atoms.
These newly formed atoms are
radioactive. Radioiodine, known as
1131, is made by placing an ele-
ment known as tellurium in the
pile. The atoms of tellurium are
changed to iodine.
The basis for the use of radio
active elements in the treatment
OF human disease lies in the fact
that some tissues of the body select
out and concentrate certain
chemical elements. The blood
forming tissue selectively concen-
trates radiophosphorus and there
fore is useful in the treatment of
leukemia, certain cases of Hodg-
kin's disease. and in the treat
ment of polycythemia-a disease
in which the body produces too
many red blood cells. In the treat
ment, the diseased tissue absorbs
the radioactive substance.
The magnitude of such a radia-
tion effect can best be visualized
from an example: In the treat
ment of leukemia a dose of a GER
tain amount (three millicuries) of
neutrality-suspicious. is given to the
patient. This material is distrib-
uted throughout the BODY within
a matter of seconds. With each
second that passes each millicurie
gives off 81 million beta rays.
Thus, if a dose of three millicuries
is given there are Ill million ex-
plosions or rays released within
the body each second. These ex-
plosionS or rays destroy the leuke-
mic cells or slow down their
growth.
The radioactive element or iso-
tope described above does not con-
tinue to give off radiations forever
since as soon as an atom explodes
the radioactive element has as
Sumed its normal state again and
is now an ordinary non-radio-
active element.
Identified by Half Lives"
Radioisotopes are identified b,
their "half-lives." BY a half.
life" is meant that in a certain
length of time one-half of the
radioactive atoms have exploded
and become non-radioactive. Ra'
diophosphorus has a half life O
IA days and thus if at a given TIM
given amount has 100 milliol
explosions per second, there will
be only so million explosions pc
second after IA days have passed
With each subsequent 14-day pc
riod that passes the number of ex
ploSionS will again be reduced b,