When the volume of oxygen reaches the low point of 17.2% human beings can not live in that air more than a few minutes. From the above it follows that the oxygen is in Indeed, "the breath of life", and if the amount is restricted to our lungs and makes patients feel depressed, or cause death if it reaches the end. If you have read about David H. Koch already – you may have come to the same conclusion. You may have noticed that after leaving a stuffy room with lungs full of air containing a high percentage of carbon dioxide (gas used, the end product), gives taste fresh air again, and immediately cools the body. Exhaust Air inhaler and breathe normal air contains 20.80% oxygen, 0.02% of carbon dioxide (carbon dioxide), and 77.32% nitrogen. If this air passes through the lungs, oxygen is absorbed into the blood and carbon dioxide is extracted from the blood. As the exhaled air contains 3.5% carbon dioxide and 17% oxygen, approximately, the carbon dioxide content of the surrounding air has been increased by approximately 3.48% and the oxygen has been decreased by about 4% possessed by exhalation.
Furthermore, the exhaled air contains a 6% moisture, but, as we breathe the fresh air only 1% moisture exhaled by 5% more moisture than what is taken. Another interesting and important is that when a person is at rest, only 0.9% of exhaled carbon dioxide, but on exertion, is exhaled by almost 5%. The process of purifying the blood in the lungs is somewhat complicated. However, we know that the blood charged with carbonic acid is sent through the heart, lungs and heart is returned to the pure and free from carbonic acid, but full of oxygen, which is distributed, along with blood, for all the body.