RADIATION PROTECTION - ILEA

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Preface
they gave quite similar numerical values for the equivalent uniform wholebody
dose. Their use has the advantage of simplicity and standardization
and is well suited to express dose for regulatory purposes, or whenever a
simple expression of the risk of radiation exposure is called for, as in consent
forms. However, their value as a measure of individual and population
exposure for scientific and epidemiological purposes is, at best, very tenuous.
Cancer statistics, on which the formula for their calculation is based,
have a high degree of variability; they change not only with better epidemiological
studies but with improvements in treatments for the different
types of cancer, necessitating changes in the constants in the formula.
Given the uncertainty of quantities based on biological effects, I have chosen
to present the actual absorbed doses to organs when these data are
available. I refrained from presenting effective doses except within a regulatory
or nontechnical context, or when they are the only data available for a
particular subject.
The risk of lung cancer from exposure to radon gas in the home was a
major concern in public health at the time of the third edition. However,
this concern has tapered off considerably, possibly because epidemiological
studies have not demonstrated a strong relationship between exposure in
the home and lung cancer, possibly because the public became accustomed
to living with radon, possibly because the homeowner must pay the costs
of remediation. Yet radon remains a major source of radiation exposure to
the world’s population, and its continued epidemiology and dosimetry
should shed much light on the risk of exposure to radiation. Accordingly, I
have expanded on the detailed discussions of radon presented in previous
editions.
The risk of harm from exposure to radiation is not generally considered
by physicians when they prescribe radiological examinations, except when
the patient is a pregnant woman or a young child. The benefit far outweighs
the risk in most studies that have been made. Malpractice litigation
and other legal considerations—and possibly economics, as well—are also
significant factors in decisions to use ionizing radiation for diagnostic purposes.
I have expanded considerably the sections dealing with doses accompanying
the use of radiation in medicine to help physicians make these
decisions.
I use Standard International (SI) units for dose and activity in this edition,
except when reproducing verbatim data in the published literature
given in traditional units. However, I have retained the traditional unit for
exposure, the roentgen. It is much easier to work with exposures expressed
in roentgens than in the SI unit of coulombs per kilogram.
Since publication of the last edition of Radiation Protection, the Internet
has become an invaluable resource. In this edition, therefore, I have in-