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FAMILY MEDICINE®
COLUMN
By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic
Medicine
3428-FM
01/19/11
RADIATION FROM X-RAYS IS GENERALLY
MINIMAL
Question: My
son is very athletic and has needed to have
three wrist or ankle x-rays in the last 10
months. I am beginning to worry that he is
having too many x-rays. How many can a
person have done and still be safe?
Answer: Here on
earth we are constantly bombarded by cosmic,
terrestrial, internal and environmental
radiation. As a group, these types of
radiation are referred to as background
radiation. Background radiation exposure
varies in amount depending on many factors.
People who live at high altitudes get more
background radiation exposure than people
who live at sea level. Radon gas, which is
found is many homes, is another major source
of terrestrial radiation. Traveling in
airplanes, living in a brick house, and many
other sources all contribute to background
radiation exposure. So even if you have
never had a medical x-ray, you are still
exposed to radiation on a regular basis.
Cigarette smoking also exposes the smoker to
increased amounts of internal radiation. A
cigarette smoker has an increased radiation
exposure that is equal to about 35 chest
x-rays per year — just from smoking
cigarettes!
Medical x-rays can be diagnostic — that is,
used to make a diagnosis such as a broken
arm or foot — or they can be therapeutic,
like the radiation therapy used to treat
some forms of cancer. You are asking about
diagnostic x-rays.
Diagnostic x-rays like those used to “see”
the bones in an extremity or in the chest
use very little radiation. The radiation
exposure from having a wrist x-rayed is the
equivalent of about three hours of
background radiation, while a chest x-ray is
about ten days’ worth. Other types of
x-rays, such as a gastrointestinal series,
can be equivalent to two years of background
radiation.
Computerized tomography scans — CT scans —
are a diagnostic x-ray that can expose a
person to comparatively high doses of
radiation. A CT of the head is comparable to
eight months of average background
radiation, and some CT scans use
considerably more radiation. However,
ultrasounds and magnetic resonance imaging (MRI)
exams do not expose the patient to radiation
at all.
X-rays are safe, but people should always be
concerned about cumulative lifetime exposure
to radiation since it adds to the risk for
developing cancer. Pregnant women,
particularly, should avoid x-rays and
contrast materials (dyes used in x-rays and
MRIs) whenever possible to avoid harm to
their unborn child.
Family Medicine® is a weekly column. General
medical questions can be sent to Martha A.
Simpson, D.O., M.B.A., Ohio University
College of Osteopathic Medicine,
Communication Office, Athens, Ohio 45701, or
familymedicine@oucom.ohiou.edu. Please
do not send letters asking Dr. Simpson to
diagnose a condition or suggest a treatment
plan. Medical information in Family
Medicine® is provided as an educational
service only and does not replace the
judgment of your personal physician, who
should be relied on to diagnose and
recommend treatment for your medical
conditions. Past columns are available
online at
www.familymedicinenews.org.
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