If you think about it like that anything can kill humans, even things like drinking too much water can kill you, it is called Water Intoxication, the human body is fragile.

Oxidation of human lungs (which is like the human equivalent to iron rusting or any other metal corroding) would also take longer than the quoted 75-100 years so it is unlikely to ever kill you.

Breathing pure oxygen on the other hand (which you can not get in natural cases on earth as the air we breath is only around 21% oxygen)can be toxic, I looked it up and it was confusing, so I am not going say anything.

SandSniffer wrote What if Oxygen is poisonous and just takes 75-100 years to kill us?

the rate that were heading i belive it or better there be charging us to breathe cleaner air

Oxygen is poisonous and water is acidic. Most life forms on Earth adapted to them in the early stages of life. Some micro-organisms only use nitrogen, because nitrogen is toxic to them; or the deep sea organisms that live near thermal vents.

No. From the air you breathe, the oxygen is transferred into your blood and used by your body to create energy to survive.

If that was the age they would know that it was poison

SandSniffer wrote What if Oxygen is poisonous and just takes 75-100 years to kill us?

What if this were true, and if we were able to counteract it we would become biologically immortal. Similar to a jellyfish.

MattDanner wrote

SandSniffer wrote What if Oxygen is poisonous and just takes 75-100 years to kill us?

What if this were true, and if we were able to counteract it we would become biologically immortal. Similar to a jellyfish.

No we wouldn't. the jellyfish you are talking about resets its biological clock if you will, repeating stages in its life. We would have to go through adolescence again.
Pure oxygen is harmful.

It is an interesting theory however we are all born to die ... stuff like pollution effects us too also

It would have been proven by now, because of all the ways the human body can just shut down. They would know oxygen is causing it.

I'm pretty sure that scientist would have find out about this now.