1 - An estimated 90% of the lung is filled with air and only 10% is hard tissue.
2 - The lungs are the largest organ is the body.
3 - About 1 litre of air always stays in the lungs no matter how hard we breathe out.
4 - In an average lifetime a person takes around half a billion breaths.
5 - You breath out 23,000 times a day.
6 - You have two lungs, but you could live with just one!