The cabin atmosphere has 20% less oxygen than air at sea level
- once again, physics is cast aside in the interests of a 'good' story.
Air has one component that varies according to altitude, and that's water vapour. The percentage (partial pressure) of oxygen remains unchanged. There'd be a small % reduction in recycled air, but no worse than in an unventilated room.
Granted, there'd be fewer
molecules of air at a lower cabin pressure, but you'd have to be pretty ill for your respitory system to struggle, given you're at rest.
There was an age when newspapers would share this info, rather than conjure up rubbish.
