Originally Posted by
PDR1
CO poisoning produces permanent damage to red blood cells - it's a signature which remains and can be identified even in a long-deceased body and it gives fairly precise values of the scale. CO poisoning is not just a matter of lack of oxygen (as happens with CO2) - it is actually a poisonous gas. CO "locks" the haemoglobin in the blood such that it can't take oxygen even when it's present. If you suffer CO poisoning beyond a certain level even getting you away from the CO and giving you 100% oxygen via a mask won't save you - you will die unless you are given a rapid and massive transfusion of red blood cells (which is rarely possible).
So the detection of CO poisoning in "a body that had been under seawater for so many days" is not in any way remarkable or strange.
PDR
In fact it is worse than that; as well as haemoglobin in the blood the body's muscles contain myoglobin to which carbon monoxide binds in the same way as I outlined previously. However, I'm not aware of any research into the natural degradation of carboxyhaemoglobin over time and under high pressure in an anaerobic environment, so while the measurement can be made accurately I'd be uncomfortable with the statement that it was a precise representation of the level at impact.
Originally Posted by
Genghis the Engineer
There is evidence that sedentary smokers are less prone to hypoxia than fit non smokers.
I have no idea if that maps to CO poisoning, but I suppose it's at least hypothetically possible.
G
They are no less likely to be hypoxic on assay of blood gases but as they are used to permanent mild hypoxia (and of course low level carboxyhaemoglobinaemia) their nervous system tolerates it better.