Easy claim to make but where is the proof you have to back up this unsubstantiated claim? Real facts, figures and evidence not just an unverifiable comment made by one person on the internet.
Well the best place to look for reliable incontrovertible data is that from the accredited compressed breathing air laboratories such as TRI or Lawrence Factor in the USA although others exist. These labs receive thousands of air samples sent to them from all over the world, including the Red Sea, and so their pooled data is very representative of the current state of affairs with regard to breathing air contamination in the dive industry.
Unfortunately we are unable to look at pooled data from the UK, continental Europe, or Australia as these countries and regions have not moved from using the antiquated colorimetric devices (Drager tube technology) where testing is done on-site and the results typically remain on paper with the compressor operator. Here in Canada and the US the results are done by third-party bonafide analytical chemists typically using a gas chromatograph as you mention. It is this pooled data collected over the years which is most revealing.
The first indication that we might have a systemic but sporadic problem in the dive industry with regard to CO contamination came in an Alert Diver magazine article written by Robert Rossier in May/June 1998. As you probably know Bob Rossier continues to write for Alert Diver given his wealth of experience as a systems engineer involved with NASA and the US Navy over the years.
The article begins with the examination of a fatality caused by CO in 1997 (two were identified that year) and followed on by asking two of the accredited laboratories in the US what was the frequency of CO contamination in our dive air? In 1998 the laboratory Lawrence Factor in Florida which received 700 to 800 samples a
month stated that "5 to 8 percent of the air station samples tested monthly show CO in the 10 to 20 ppm range, and a few show levels in the 100 to 200 ppm range." Another test facility TRI Environmental Inc. which tests about 1000 samples a month reported that, "6 percent of their samples contain CO at more than 10 ppm."
That was over 12 years ago that we first had very good evidence our compressed breathing air was contaminated with a potentially lethal odorless, irritantless, and tasteless contaminant at a rate of 5 to 8 percent and yet nothing was done about it. Now if this was our blood supply with a potentially lethal virus or food supply with a bad strain of E. coli at these rates of contamination alarm bells would have gone off and something would have been done about it, but instead the self-regulating dive industry and DAN decided to ignore this elephant in the room and put their collective heads in the sand which remains the case to this day.
Seven years later in 2004 Bob Rossier wrote another article on CO contamination for Alert Diver magazine and asked the same question regarding the frequency of CO contamination in compressed dive air to the same laboratories. As you can see in the link below the frequency had improved somewhat but was still far too high for an activity where the toxicity of the contaminant increases at depth with increasing partial pressure. Clearly a failure rate for CO in dive air at 3 to 5 percent is unacceptable yet nothing to this day has been done by the dive industry nor DAN to rectify this situation.
Carbon Monoxide tester for scuba and firefighting
The US Navy looked at the rate of failures for CO and other contaminants from their land-based and shipboard compressors and even with a dedicated and trained compressor operator they had a failure rate of 2.5 percent for carbon monoxide at 10 ppm. These tests were done independently by TRI and the frequency of contamination results are from close to 3000 pooled samples. I'd post the link to the abstract at Rubicon Repository but the site seems to be down right now. The US Navy has been working on a real-time monitor for CO and other contaminants for some time now as they to recognize the problem of putting oil-lubricated compressors in tight spots with poor ventilation risks the production of carbon monoxide due to compressor oil pyrolysis.
http://archive.rubicon-foundation.org/dspace/handle/123456789/1636
Dr. Caruso, the US air force pathologist who reviews all DAN's dive fatality cases for the annual injury and fatality report, submitted an abstract to the UHMS meeting in 1998 which examined how many divers had their blood checked for carbon monoxide poisoning over a 5 year period from 1993 to 1997. Of the 451 fatalities reviewed only 15 percent had a carboxyhemoglobin (COHb) level done.
http://archive.rubicon-foundation.org/dspace/handle/123456789/734
Fast forward to 2010 where we continue to have hard data showing significant breathing air CO contamination in the dive industry at a rate of 3 to 5 percent, but in the event of a fatality only 15 percent of divers have a blood test done to rule out CO contamination as the possible antecedent event for the death. One suspects that the 15 percent of fatalities tested for carbon monoxide on a global basis is likely much lower since the fatalities in the Caruso abstract are those of US and Canadian citizens who where more likely to access the COHb test at the time of death. It would be almost impossible to get an COHb test at the time of death at most tropical dive destinations.
One would hope that is enough "facts" for you to examine and possibly reconsider your position regarding the risk of breathing air CO contamination within the dive industry. If we are not monitoring the compressors in real-time that we know can produce CO from within at a rate of at least 3 percent, and at the same time do not check
all fatalities for CO poisoning then this systemic but sporadic contamination problem will continue to remain under the radar.
Here is a recent incident which was confirmed to be carbon monoxide poisoning by the laboratory. Had the diver been deeper or spent more time at depth he likely would have had his cause of death recorded as a heart attack or drowning on the death certificate rather than CO poisoning. This example was a very close call as were the recent injuries in Cozumel, Mexico also due to CO.
August 2008 Volume 18 Number 8
Hopefully with Analox's new dedicated portable CO analyzer due to be released at DEMA this month we will get a much clearer idea, particularly in the tropics where the risk is greater due to the high ambient heat, as to the real rate of CO contamination in our compressed breathing air. Don't be surprised if the rate is at least 3 percent at the 10 ppm level.
With the conditions they have to fight in, they deserve clean air for sure.
