Air is composed of 78% Nitrogen (N2) 21% Oxygen (O2) and .3% Carbon Dioxide (CO2). Well about that, at sea level, away from big trees and heavy breathers.
There can be major benefits in modifying gas levels to the range of 3-5% oxygen and 3-10% carbon dioxide. These gas levels slow respiration (calming effect) and thereby slow physiological ageing (at a fraction of the price of plastic surgery or those slimming lotions), inhibit enzymatic browning (whatever that is - something to do with tanning?) and slow microbiological growth (they must be nasty little things - always there but you can't see 'em).
Oh sorry, I thought we were talking about flying fruit...
Take me home, country roads, to the place, I belong, JetBlast beckons...