body exposure the radiation dose should not exceed 0.5 rems per year, and partial-
body radiation dose should not exceed 7.5 rems per year. The reason that medical and
dental x-rays are not included in these totals is that for medical procedures the risk of
the exam itself is outweighed by the medical significance of the exam results. (Without
the exam, an undiagnosed illness, disease, or injury could be life-threatening.).
d. Study groups that have spent many years in researching the safe amount of
radiation that a radiation worker may receive have taken into account the environmental
and other man-made radiation to which he is exposed. This includes everything from
cosmic rays to watch dials and TV screen emissions. Man's use of radiation in various
forms grows day by day. Consequently, the daily nonprofessional exposure can be
expected to rise. Three broad factors contribute to critical decisions concerning how
much radiation we can or should tolerate. They are:
Changing levels of environmental radiation.
Rapid progressions in technology.
(3) Increasing knowledge of the biological effects of radiation, particularly
those that may affect or modify the species.
The radiation protection guides discussed here are subject to constant modification and
revision. It is the professional responsibility of every radiologic specialist to remain alert
to these changing factors.
Section VII. RADIATION--BIOLOGICAL EFFECTS
Biological effects, also known as radiation injuries, are described as either
chronic or acute. Chronic injuries are those that appear after a large number of
repeated exposures to radiation. These injuries appear in 1, 5, or 30 years or perhaps
in succeeding generations. Acute injuries are those appearing relatively soon after
intense exposure (with 60 days or less). Such intense exposures, if survived, can lead
to chronic effects later. The acute effects of whole-body irradiation will probably never
be seen in an x-ray specialist, even with the most careless individual imaginable.
Therefore, the discussion of these effects will be brief and of academic interest only.
Chronic effects are, however, of vital concern to the x-ray specialist not only for his
personal interest, but also because of his responsibility to the patient in assuring an
absolute minimum of needless exposure. CHRONIC EFFECTS CAN BE BROUGHT
ABOUT BY THE CARELESS SPECIALIST through small overexposures that occur too