- Micronuclei
- Bad Assumptions
- Conditioning
- Decompression Tactics
- Putting it Togerther
MICRONUCLEI
The starting point is to understand
more about what causes DCS. Everyone understands that excessive bubbles
will cause DCS. But what a lot of divers don't realize is how these
bubbles start ... which will help a diver to understand how to decrease their
risk. When a diver goes underwater, the diver's tissues start taking in
inert gas due to the pressure. So when the diver surfaces, the tissues
have an excess of inert gas in them. But, contrary to what divers
believe, this is not the problem. A diver could take up a very large amount
of inert gas and never get DCS if it wasn't for one thing ... the presence of
micronuclei ... or bubble seeds. In other words, a diver could dive to
very deep depths for very long times without ever needing to decompress if it
wasn't for the micronuclei. These micronuclei act as a source for bubbles
to start occurring. They may be viewed as very tiny bubbles
themselves. What happens while ascending is that the gas built up in the
tissues from the dive are now in a supersaturated and high pressure state.
This gas wants to start leaving the tissue and escaping. This gas will go
wherever possible. One route is for it to enter the blood and exit that
way. Another possible route is that the gas leaving randomly bumps into
and enters a nuclei. This nuclei will continue to grow as more gas enters
it and/or the diver ascends towards the surface causing it to expand according
to Boyle's law. If this nuclei gets too big, a bubble results. So
why is this being mentioned? In addition to the obvious point of slowly
ascending/decompressing through the water column towards the surface, the
control of nuclei is a topic that should be discussed. It has been shown
that activity increases resulting bubbling from a decompression. Since
micronuclei can't be seen, they are postulated due to the known increase in
bubbling from activity. Most activity generates micronuclei, but the
activity performed by divers are especially bad for generating micronuclei such
as hauling gear to and from the water or climbing up the ladder onto a boat.
The greater the activity, the more nucleation that will occur. It doesn't
matter when the nucleation occurs. It can occur from pre-dive activity or
post-dive activity. As long as there is an excess of gas in the tissues
from the dive, nucleation will generate more places for gas to enter while
trying to leave the tissues ... and the more places gas has to enter, the
greater the number of resulting bubbles ... and the greater the risk of
decompression sickness. So the moral of the story is not to believe that
a model is responsible for your safety, but instead understand that your own
activity can be too and be aware that pre and post dive activity (as well as
that during the dive itself) can substantially increase the risk of getting
decompression sickness.
