Guten Tag zusammen,
Gene Hobbs, unter anderem für http://rubicon-foundation.org/ verantwortlich, rührt gerade auf vielen Listen (gavinscooters, divingaccidents) für folgenden Artikel die Werbetrommel - meiner Meinung nach eine sehr interessante Zusammenfassung zum Thema "komprimierte Atemluft" mit viele Aspekten, die sonst zu kurz kommen - aber lest selber, viel Spass damit! Gruss, tobi...
-------------------------------------
There have been many discussions on contaminated breathing gas over the
years. Last year, Drs. Millar and Mouldey published an extensive
review in *Diving
and Hyperbaric Medicine* on breathing gases and the potential problems
associated with breathing gas production and storage.
*Diving and Hyperbaric Medicine* is the journal of the South Pacific
Underwater Medicine Society (http://www.spums.org.au/) and European
Underwater and Baromedical Society (http://www.eubs.org/). Our agreement
with SPUMS includes a three year embargo on the journal for their members.
Yesterday, the journal granted a waiver for this article due to the impact
this information could have on divers worldwide. I HIGHLY encourage you to
download this article and pass the link along to other divers as this is an
often overlooked topic that impacts all of us. Instructors, please consider
adding this to your training materials for 'Gas Mixing and Blending' courses
as well as sending an email to your former students.
This is an exceptional review and I hope that you learn as much from it as I
did.
Millar and Mouldey abstract:
Human underwater activities rely on an adequate supply of breathable
compressed gas, usually air, free from contaminants that could cause
incapacitation underwater or post-dive or longer-term health effects.
Potentially fatal but well-known hazards are hypoxia secondary to steel
cylinder corrosion and carbon monoxide (CO) poisoning due to contaminated
intake air. Another phenomenon may be behind some previously unexplained
episodes of underwater incapacitation and perhaps death: low-level CO
poisoning and/or the effects of gaseous contaminants generated within the
compressor, including toluene and other volatile compounds. Many low
molecular weight volatile contaminants are anaesthetic and will be
potentiated by pressure and nitrogen narcosis. In sub-anaesthetic doses,
impaired judgement, lowered seizure threshold and sensitisation of the heart
to arrhythmias may occur. Toxic compounds can be volatilised from some
compressor oils, especially mineral oils, in overheated compressors, or be
created de novo under certain combinations of temperature, humidity and
pressure, perhaps catalysed by metal traces from compressor wear and tear.
Most volatiles can be removed by activated carbon filtration but many
filters are undersized and may overload in hot, moist conditions and with
short dwell times. A compressor that passes normal testing could contaminate
one or more cylinders after heating up and then return to producing clean
air as the filters dry and the systems cool. The scope of this problem is
very unclear as air quality is tested infrequently and often inadequately,
even after fatalities. More research is needed as well as better education
regarding the safe operation and limitations of high-pressure breathing air
compressors.
From:
Millar IL, Mouldey PG. Compressed breathing air - the potential for evil
from within. *Diving and Hyperbaric Medicine.* 2008; 38: 145-51. RRR ID:
http://archive.rubicon-foundation.org/7964
PLEASE NOTE: please use the link
http://archive.rubicon-foundation.org/7964and not a direct link to the
pdf to help us save our bandwidth.
Thanks,
G
Gene Hobbs
Rubicon Foundation, Inc.
http://rubicon-foundation.org/
