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R a d i u m 45
of aplastic pernicious anemia, it is reasonable to conclude that ex|Kisure
to radium was an important etiological factor.
From the available literature on this subject it appears that continued
exposure to radiation usually produces the following harmful
effects:
I. Pain, sensitiveness, or anesthesia of the skin of exposed lingers
or hand.
2. Burns or destruction of the skin and underlying tissues.
3. Effect upon the blood and blood-making organs—usually a profound
leucopenia affecting both the |tolymiclears and lymphocytes; a
decrease in blood platelets; also a milder anemia accompanied by a high
color index. The reduction of the lymphocytes seems to be definite and
regular; the effect upon the polynuclears is irregular.
4. Sterility.
5. The inhibition of the absorption of fat in the intestinal canal.
This has been demonstrated experimentally (13).
The extent of the effect of the exposure to radiation depends upon—
(a) Amount of radium to which the subject is exposed.
(b) Length of time of the exposures.
(c) Frequency of the exposures.
(rf) Proximity of the radium to which the subject is exposed.
(e) Amount and character of protection afforded against radiation.
(/) Character of the rays to which the subject is exposed.
The following is quoted from J. C. Mottram (11) regarding the
biological action of radium:
"Surveying the biological action of radiation, one of the first generalizations
which may be made is that the various tissues differ widely
in their susceptibility; some—for instance, nerve cells—show no changes
after relatively large exposures, whereas others—for instance, reproduction
cells—are altered by small amounts of radiation. The following
tissues arc especially sensitive: skin, blood vessels, connecting tissues.
hair follicles, reproduction cells, lymphoid tissues, and blood cells. Experimental
evidence goes to show that the last three are more susceptible
than the others, so much so that these tissues would be especially chosen
for examination in searching for the earliest effects of radiation. There
is no doubt about the sensitiveness of the reproduction cells. The sterility
of X-ray workers who have good health in other respects is very
clear evidence. As regards the blood changes, it may be mentioned
that experiments on rats have shown that, by their blood changes, X-
radiation could be detected where a photographic plate gives no record.
For this reason, and also because the blood changes have been the subject
of large investigation, it may be concluded that they will serve as
an excellent indicator for the biological effects of radiation. The present
state of our knowledge would lead to the conclusion that in the absence
of blood changes the worker had received no more than a harmless
amount of exposure to radiation."
Most of the articles appearing in the literature deal with the harmful
effects of continued exposure to radiation upon persons handling
radium for therapeutic purposes. As this study was made upon persons
who are engaged in measuring the gamma radiation of the radium s.dts