Originally Posted by BEA 71
These days passengers have to wear a mask once they enter the terminal, which, as I know myself, reduces the intake of oxygen.

You might find reading this helpful: Face masks have negligible negative effect on CO2 and O2 levels

Negligible? Try to carry your luggage and run through an airport terminal with mask on versus without one. And then decide which variant is easier to breathe with? I'd clearly say without one. No smart studies needed.

Every morning I get on an exercise machine (NuStep) for a 20 minute session. Several times I have tried the my routine exercise protocol with and without a mask. With a mask is definitely more difficult.

BEA 71 I suspect experienced shortness of breath, even though he didn't say that directly. BEA 71 - Please correct me if I am wrong.

The link you posted David said this towards the end....

Dr. Campos explains, “Dyspnea, the feeling of shortness of breath felt with masks by some, is not synonymous [with] alterations in gas exchange. It likely occurs from restriction of air flow with the mask in particular when higher ventilation is needed on exertion.”

So your Vol O2/CO2 may not vary significantally but you can experience shortness of breath... And that can be distressing/frightening.

Interesting article which may well have some relevance to this event. https://wsvn.com/news/special-report...nts-on-planes/

Engine Maintenance question following a fume event.
 

Does anyone know the A/C maintenance decontamination procedure for an engine oil bleed air contamination event. Many thanks