Poisoned by Oxygen
There was a good reason for the scientists’ interest in oxygen poisoning. The problem was how to facilitate the work of divers. A man can survive in an atmosphere of pure oxygen for about twenty-four hours. If he breathes oxygen for longer than that, pneumonia ensues and, strange as it may seem, death due to asphyxia, which is a shortage of oxygen in the most important organs and tissues. A man can endure a pressure of two to three atmospheres not longer than one and a half to two hours. Then he becomes intoxicated with oxygen, loses coordination of movement, and suffers from mental distraction and loss of memory. If the oxygen pressure exceeds three atmospheres, convulsions will soon follow causing death.
Oxygen proves even more poisonous for animals which live where there is a critical lack of oxygen. This is how ascarides living in human intestines are combated. Oxygen is fed into the intestines, causing no danger to the man himself, but surely killing the parasites.
An excess of oxygen is not only detrimental to animals, but also to plants. It is interesting that, although plants saturate the atmosphere of our planet with oxygen, the Earth’s atmosphere is not good for them. They are rather short of carbon dioxide and, strange as it may seem, there is too much oxygen for them. According to recent investigations not only the usual concentration of oxygen but even as little as two per cent, that is one-tenth of what is to be found in the atmosphere, considerably retards photosynthesis. This means that plants have created an atmosphere quite unsuitable for themselves. Had there been less oxygen they would have grown and developed more rapidly.
Filed under oxygen | Tags: breathing, carbon dioxide, excess of oxygen, lack of oxygen, oxygen, oxygen poisoning, oxygen shortage | Comment (0)Combatting Oxygen Shortages
Animal kingdom emerged on our planet when the atmosphere was still very poor in oxygen. It is no wonder that living organisms had to adapt themselves to an environment where oxygen was in short supply. However, we usually fail to notice another much more puzzling phenomenon, namely, that animals living in the presence of excessive oxygen have managed to restrain the intensity of the oxidation processes taking place in their bodies as if they were always ready to extinguish a constantly threatening fire.
The amount of environmental oxygen is constant, and, if it does alter, it decreases. This explains why animals have different means of combatting oxygen shortages, but no means of protection against excess oxygen.
Paul Bert was the first to discover that breathing pure oxygen can be poisonous around a hundred years ago. This was such an unexpected discovery that scientists did not believe him and a suspicion arose that the oxygen used by Bert contained various poisonous admixtures. The experiments were repeated many times, but no matter how thoroughly the oxygen was purified, the animals which breathed it for prolonged periods inevitably perished.
Filed under oxygen | Tags: animals, breathing, oxidation, oxygen, oxygen shortage | Comment (0)