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When you break down what I said it is misleading, my meaning is the same as yours. If I had said this: "Each person can have different levels of exposure they can handle... " one day they are OK and another they are not, just like you said one day a diver can handle 3.0 and then tox the next day at 1.4. When I said this : "You must take into account PO2 and duration of the exposure. Each >person can have different levels of exposure they can handle..." I also meant on any given day or dive, nothing is set with this stuff and I also said it is all debatable. But on any given day one diver is able to handle a higher PO2 than another, thus some Tox and some don't. The real key is not stay on 02 any longer than 20 mins, if you are new 10 mins. Once you have several hundred dives and have used 02 to deco at the short time, you should be aware of what your body tells you and can stay on it for 20 mins. If a diver starts to feel his muscles twitch at 14 mins on 02 and he is done with deco at 18min, does he stay on the 02 because he has not ever had a problem even at 20mins on 02 before........get real Mike. But none of this will prevent an oxtox with no symptoms. Only a buddy or support diver can help you then. That is why I did not like it when you guys left me alone in the water on 02 after a 300ft dive to the Vitric, when you came up here I had support divers in the water during your deco on the 300ft dive to the Washington. At 03:46 PM 9/10/02 -0400, Rodriguez wrote: >At 06:07 AM 9/10/2002 -0400, Capt JT wrote: > >"Oxygen poisoning is determined by interactions between the oxygen >dose and the relative susceptibilities of the exposed tissue" > >I'm not sure what you mean by "relative susceptibilities of the >exposed tissue" but it seems like you're suggesting that different >people (tissues?) have differing fixed susceptibilities to O2 tox. >This has been clearly shown not to be the case. There is no such >thing as a fixed susceptibility to O2 tox. All available evidence >suggests that whether or not you tox at a given PO2 on any given >exposure is random with the probability increasing with PO2. There >is no such thing as a diver who is better able to tolerate elevated >PO2 than another diver. > >"You must take into account PO2 and duration of the exposure. Each >person can have different levels of exposure they can handle..." > >Again, you appear to be suggesting that some divers can handle >a higher PO2 than other divers. This statement isn't supported >by the evidence; quite the opposite, actually. > >"and some will say they have the correct answers on this >subject, but the only answer they have is for themselves or the test >subject when pushing the limits." > >You're again suggesting that some people have some magic PO2 >beyond which they will tox. This is not so. I have dozens of >studies on this, and they all agree. Some divers have toxed after >a few minutes at 1.4 and others have sat around for 150 minutes >at 3.0 without a problem. There is, so far, no way to predict >tox. > >I feel compelled to jump in on this thread because I'm concerned >that, whether intentionally or not, you're giving people the idea >that if they've been diving high PO2 for a long time they are somehow >more "immune" to O2 than others. It's important for people to >understand that this is not so. All of us, those with 1000 dives >and those with 10, are rolling dice each time we dive a PO2 >approaching 1.6 even if we've done it and survived before; and >the only way to reduce the risk is to reduce the PO2, more so for >extreme dives. > >-Mike Rodriguez ><mikey@mi*.ne*> >http://www.mikey.net/scuba >Pn(x) = (1/(2^n)n!)[d/dx]^n(x^2 - 1)^n "You can't learn to dive on the net, sooner or later you have to get in the water" Your Guide to Great Wreck Diving along the East Coast & more Web Site http://www.capt-jt.com/ Email captjt@mi*.co* -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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