Exhaled Air is 78% Nitro

[Dibbons]

Nitrogen that is:
Exhaled air consists of 78 percent nitrogen, 16 percent oxygen, 4 percent carbon dioxide and potentially thousands of other compounds.

https://sciencing.com/chemical-composition-exhaled-air-human-lungs-11795.html

 

[Photon440]

They should proofread their numbers. If we breath in 21% oxygen and exhale 16% then we're using almost 25% of the oxygen that we take in, not the 4% that they claim. Also, argon is nearly 1% of our air(.934%), much more than the 0.09% mentioned in that article.

 

[69a100]

Your body take in more nitrogen than O2 when you breath as there's more nitrogen than O2 naturally!