Experiment starves professor of oxygen
21 Feb 2012
A London doctor has revealed how a TV presenter survived in an air-tight glass box for two days with only plants to keep him alive.
Professor Iain Stewart was locked in the chamber after the oxygen levels inside had been reduced to about 12 per cent – half of that in normal air.
Royal Free consultant Daniel Martin devised the experiment to prove human dependence on plants.
He was inspired by 18th-century chemist Joseph Priestley who used a mouse to prove the existence of photosynthesis.
If carbon dioxide levels in the box fell too low and the plants could not photosynthesise, Professor Stewart had to exercise to increase the amount of CO2, which the plants need to produce oxygen.
If the CO2 levels were too high, it would be damaging to Stewart and the plants.
Dr Martin said: “At the beginning, he had headaches and did not feel well at all but we could see him getting better and better over the 48 hours.” Oxygen levels were near-normal at the end.
The experiment was filmed at the Eden Project in Cornwall for the BBC2 series How To Grow a Planet.