Anotherthing
"Anotherthing" the argument is quite simple, really.The physiological needs at an altitude of 6000-8000 ft are far more stringent than at sea level. For instance whilst undertaking physically intensive duties (ie standing, bending, pushing,pulling) for a number of hours at 7000ft your body requires more O2 than at see level.
Unfortunately the current means of pressurisation of aircraft will dispense less 02 at a time when your body requires more 02.Notwithstanding the effects of jetlag, sleep deprivation and shift work on the immunity.
As to the credibility of the evidence produced...what can I say?That a team of aviation specialised doctors tasked by the European Aviation Safety Agency with the evaluation of professional flying and its associated physiological effects have gone completely mad?
I have included for your perusal a paragraph that you seem to have overlooked :
"It can be assumed that during onboard service periods, hypoxia is more severe in cabin
crew than in cockpit crew. Although the resting SaO2 is well preserved up to ~2400 m
(max. cabin altitude), the drop in PaO2 decreases the diffusion of oxygen from the lungs to
the blood and then from the blood to the cells. This decrease in oxygen diffusion rate
becomes apparent during physical activities as an arterial oxygen desaturation at altitudes
as low as 1000 m [Muza SR et al, 2004; Mollard P et al, 2006]. FAs’ duties include
considerably more physical activities than those of pilots. The high heart rate values that
are recorded from cabin crew are usually associated with hard physical workloads [Vejvoda
M et al, 2000]. This may be an additional cause of fatigue in cabin crew."