This is my 100th post by the way, just thought I’d put that out there. Anyway. . .
This is a very interesting question that me and my friend was discussing one day. The question came to me because we were talking about why, we as humans, don’t live forever. Now, while I answered this question before in a previous blog, I never even entertained the fact that oxygen could be the cause, could oxygen be the 1# killer of all humans?
I mean, could the one thing that we need to survive also be our downfall? Interesting right?
I researched this all day so indulge me for a minute. . .
So many of you probably already know that too much oxygen can be toxic. After several days of breathing nothing but pure oxygen, you’d begin to experience nausea, dizziness, muscle twitches, and convulsions. You might even die. Scientists aren’t really sure why oxygen affects the body this way. Some think it has to do with a special form of the oxygen molecule which bonds with the proteins and membranes in the lining of the lungs, and ends up destroying them. In other words, with too much oxygen around, your insides begin to oxidize. But this is pure oxygen we’re talking about so this doesn’t exactly answer my question because oxygen only makes up about 21% of our atmosphere.
But then again, maybe that’s a good thing. Nitrogen, which makes up the majority of the atmosphere, is very stable, its also a fundamental element of plant life, so this alone probably accounts for a large amount of it in the atmosphere. From what I’ve read, I believe oxygen is a more unstable element, and often breaks down into isotopes of oxygen…, so its less likely to maintain high concentrations naturally.
It is theorized that our atmosphere had very little gaseous oxygen as the planet cooled. The first life forms were photosynthetic, and used the excess carbon dioxide in the atmosphere. They converted the carbon dioxide into oxygen over millions of years. Then lifeforms evolved that could use the oxygen.
So the oxygen content may have been more than 20% during the age of the dinosaurs, and may have changed during the same event that caused the dinosaur’s extinction.
So maybe its not necessarily killing us because we’re getting just the right amount of it?
People start to feel very uncomfortable when the air is as little as 18% oxygen, and even though we could adjust; drastically lowering the oxygen content of the air and some species would die off. Any more than 20% and it would be a lot easier for things to combust or catch on fire.