Læknablaðið - 01.10.1968, Síða 52

214
LÆKNABLAÐIÐ
a result of the accidental radiation they received in obtaining
this amount and in treating patients (Fig. 1). In contrast, in the
atomic energy test at Bikini the equivalent ol' thousands of tons
of radioactive material was ])roduced, and with safety.
With the discovery of man-made radiation, the atomic age
has come to us with the great potential benel'its of tremendous
new sources of energy availal)le for an overcrowded world hut
also with the Pandora’s hox of radioactive contamination from
wastes or fallout and even with the horrendous risk of war
with atomic weapons. Probahly everyone in the world contains
a few atoms at least of 90strontium produced in atomic tests,
harmless in this very low concentration but, nonetheless, a
reminder that in this complex modern world action taken at one
place may eventually be noticeable everywhere.
Very soon after the life-saving use of X-rays and radium
l)ecame widespread, it was found that prolonged or repeated
exposure might lead to chronic injury of thc exposed skin. Many
of the early radiologists developed cancer ol' the hand because of
the practice of placing their left hand in the X-ray beam to see
whether or not the bones could he seen, evidence -that the X-ray
tuhe was fully operative and ready to he used for diagnostic
purposes. The repeated injuries thus sustained produced abnormal-
ities of the cells of the skin. This radiation dermatitis in turn
led to painful ulceration or to the development of cancer. In 1907
Wolbach5 and Porter0 made the first careful study of radiation-
induced skin cancer and stressed the importance of damage to
the vascular and supporting tissues as well as to the cells of
the epidermis itself.
Some forms of lil'e are much more susceptible to radiation
than others, as may be seen from tliis table (Table 1).
Also, cells and tissues within the same animal vary in
sensitivity to injury hy radiation. In general the follow the law
of Bergonié and Tribondeau that rapidly growing tissues made
up of short-lived cells are more easily injured. For example,
lymphocytes or intestinal lining cells which nmst be replaced
every few days, and hence are often in mitosis, are easily damaged
or killed.
Ionizing radiation exerts its effect on cells and whole
organisms hy their absorption of its energy witli local production
of charged ions and highly reactive chemical radicals. Several
sorts of ionizing radiation ean be distinguished: the poorly