Page
created by
Heather C. Hopkins
Last updated 11/25/2009
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Scuba
Diving
Dangers:
Scuba diving is an experience of a lifetime. There
are quite a few hazards related to scuba diving, but these can usually
be avoided with basic understanding of physics. Many safety tips
are created on the basis of physics concepts, and being conscientious
of them can help prevent divers from harm. Some dangers to watch
out for include:
Photo
of coral and clown fish, courtesy of NOAA at
http://www.noaa.gov/features/economic_0309/medicines.html
Barotrauma:
Because of pressure, divers must be especially careful
when they come up to the surface. One of the most important
things a diver should know is to breathe normally, especially during
ascent. Since the volume of gas expands with decreasing pressure,
if a diver holds their breath while ascending, they can potentially
harm themselves. These unequal air pressures (barotrauma) can
cause extensive damage. Compression or decompression can destroy
tissues, cause swelling, and block blood supply.
DCS (Decompression Sickness):
During
a
dive,
nitrogen gas is compressed due to increased pressure underwater.
The compressed form then dissolves faster into a diver's bloodstream.
In addition, the deeper the dive,
the more nitrogen absorbed by a diver's body. A diver coming to
the
surface must be careful, because as
the
pressure
decreases (decompression), "off-gassing" happens. This is when
excess
nitrogen dissolves out of the diver's body, which results in small
nitrogen bubbles exhaled through the lungs. When there
is too
much nitrogen released too fast, the nitrogen can damage tissues in the
diver's body. These may result in symptoms of decompression
sickness
(DCS), which may potentially be fatal.
Divers must also be careful about flying after diving. Even
though an airplane cabin is pressurized, they are only pressurized to
approximately 8,000 feet. This is still a significant 25%
pressure decrease from sea level. During an airplane's ascent to
a lesser atmosphere of pressure (decompression), "off-gassing" can
happen. This can be dangerous at lower
pressures, and may cause symptoms of DCS. Therefore, divers must
take care to allow enough time for all the nitrogen to be released from
their bloodstream before flying on an airplane. Many researchers
suggest a 24 hour period between diving and flying.
A
dive table used to prevent divers from getting decompression sickness,
courtesy of Medscape at
http://www.medscape.com/content/1997/00/40/84/408472/408472_tab.html
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