Answer:
Im not sure about the "air from the Earth" part, but the longest people have gone without air and survived without serious brain damge is about 40 minutes - it was a case of a young boy that fell through ice and drowned. It was about 40 minutes before he was chopped out of the ice and revived. He had no long term effects from the experience. Most pople that drown or suffocate in warm weather don't make it after about 10 minutes, and even then - they are lucky not to have brain damage. Doctors believe that when the body is plunged into cold water (nearly freezing), we go into a sort of hybernation, stretching the time we can go without breathing.