Out of all the man-made radiation we are
exposed to every year, more than half comes from diagnostic x-rays.
Medical tests and treatments that make use of radiation have a huge
range: from simple dental procedures to aggressive radiation therapy for
cancer patients. Physicians use x-rays in more than half of all
medical diagnoses to determine the extent of disease or physical injury1.
The kind of radiation that medical professionals use is generally
strong at first, but has a short half-life (weakens quickly) and isn’t
readily absorbed into the body. This way the radiation is out of the
patient before it has time to do much damage.
Most
medical isotopes are used for imaging, whether they are ingested,
inhaled, or injected into the body. These materials are easily picked
up by x-ray machines and other types of detectors, allowing specialists
to track the flow of fluids in the body. The most common isotope used
for imaging is technetium-99m, which is used for nearly 80% of
diagnostic imaging procedures2.
Common isotopes for radiation therapy include yttrium-90 and
iodine-131.
The vast majority of all concentrated
radiation that a normal person runs across comes from medical sources.
In fact, we here at D-tect Systems recently ran across a mysterious
source. Even though medical isotopes are generally carefully controlled
and disposed of, many landfills get quite a steady influx of medical
radiation. We recently received permission to take a few samples of a
mysterious radiation source in the Trans-Jordan Landfill located at the
south end of the Salt Lake Valley. Like many landfills in the United
States, the Trans-Jordan Landfill has a set of huge portal monitors for
scanning all incoming loads for radiation. We were told that loads of
scrap metal almost invariably set off the detectors, as well as other
materials.
The object of our inquiry was a strong
radiation source in a black plastic bag that that landfill workers had
located and were observing. We brought in the D-tect Systems Rad-ID
system (a handheld isotope identifier) to see if we could figure out
what the mystery isotope was. It was definitely a strong source – it
set off the highest level on our MiniRad-D detector from several meters
away. After a few tests, we found it the source contained at least two
medical isotopes: Barium-133 and Radium-226. These isotopes are
commonly used in conjunction in medical treatments.
So
how can you make sure medical isotopes are worth the risk? Talk to a
doctor. Health care personnel take radiation very seriously and use it
on a case-by-case basis. Before receiving x-rays or other types of
medical treatments involving radiation, discuss the risks and benefits
of the procedure and make sure it’s worth it to you.
If
you’d like more information on radiation in medicine, we invite you to
visit World Nuclear Association’s page. It
contains lots of good basic information on radiation usage in medicine
as well as technical details on different isotopes.
1)
http://www.epa.gov/radiation/docs/402-k-07-006.pdf
2)
http://ie.lbl.gov/toi/
D-tect Systems is a
supplier of advanced radiation and chemical detection equipment sold
around the world. www.dtectsystems.com.
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