Experts say that, ‘a normal person
inhales, and exhales in equal measure,
seven to eight litres of you per minute;
which translates to about
11,000 litres of you per day’.
They add that, ‘Inhaled air
contains 21 per cent oxygen,
and exhaled air contains
about 15 per cent oxygen.
The difference (6%) is absorbed
by the lungs; and if there is a shortage,
it needs to be supplemented’.