The article is factually inaccurate in various aspects

(1) "We found cabin altitude pressure was significantly higher on shorter flights," researcher Leigh Seccombe said."

If the cabin altitude was set to a higher level, then the pressure would obviously be lower

(2) Ms Seccombe said that at sea level, air breathed in contained about 21 per cent oxygen. At the maximum pressure allowed in an aircraft cabin - equivalent to 2438 metres above sea level - air entering the lungs typically contained only about 15 per cent.

This is stupid. The air contains 21% Oxygen regardless of the altitude... unless, unbeknown to me they have introduced a scrubber to remove oxygen from the air. The partial pressure of inspired O2 may be lower, but that is totally different

Also, the maximum pressurisation would surely be 1 Atmosphere / 760 mm/hg when on the ground. The minimum pressure might be that of an altitude of 2438m

Anyway, with a surface pressure of approximately 1ATA then at 2500m the pressure would be approximately 0.748ATA. At this pressure, the Partial Pressure of Oxygen would be 15.7% rather than the 15% suggested.

Given the obvious lack of understanding of beginner grade physics, I find it hard to treat the article with any level of seriousness

Dave