(Updated 19/07/21)
Bruce, an engineer, who works with gases and trusts his instrument, sent this short video.
What is going on here is not so much a drop in oxygen levels but an increase in CO2 levels to the point where safety limits for a workspace are being exceeded.
When higher concentrations of exhaled CO2 displace oxygen in breathed air the following can occur: rapid breathing, rapid heart rate, clumsiness, emotional upsets and fatigue. As less oxygen becomes available, there may be nausea and vomiting, collapse, convulsions, coma and, finally, death.
If you suffer any of these and wearing a mask, my advice is to take it off immediately and see a doctor.
It is worth noting that some health professionals say there has been an increase in anxiety and depression since the Pandemic took hold. Things are stressful enough without adding to the problem by wearing a mask when it is not needed, or for long periods without a break.
Wearing a mask may increase a person's risk for serious respiratory infections, including pneumonia, due to continual rebreathing of stale and infected air.
If you must wear a mask, take it off the moment the need has passed.
However, just having elevated CO2 levels may only be the initial trigger for more, namely a drop in arterial CO2:
To explain why arterial CO2 may drop, Buteyko Breathing expert, Glenn White wrote this for me:
Can You breathe Through Your Nose When Wearing A Mask?
The main problem when wearing a mask is that many people have dysfunctional breathing. If these people wear a mask, they will struggle to breathe through their nose. The reason for this has less to do with oxygen and more to do with carbon dioxide (CO2).
Far from being a waste gas, CO2 is essential for optimal respiration. It is so vital that CO2 levels in the blood govern every breath. Wearing a mask can cause the following unintended negative consequences for people who have dysfunctional breathing and increased sensitivity to CO2:
CO2 in the airways and blood rises to uncomfortable levels, thereby excessively stimulating the urge to breathe.
An elevated urge to breathe is likely to lead to mouth breathing, bypassing nasal filtration, and the body’s immune defences.
Mouth breathing means a reduction in nitric oxide, a potent anti-viral, anti-bacterial and anti-fungal gas produced in the paranasal sinuses.
Breathing more may expose the mask wearer to more airborne germs.
A stimulated breathing pattern can also lead to a phenomenon known as respiratory alkalosis. Respiratory alkalosis is where an increase in breathing and drop in arterial CO2, known as hypocapnia, can reduce oxygen delivery to cells. The mechanism for this is vasoconstriction and the Bohr Effect, which reduce oxygen delivery to cells when arterial CO2 drops below an optimal level.
To understand how big volume breathing diminishes cellular oxygen, consider how blowing up a few balloons or an air mattress can leave you feeling light-headed or dizzy. So, with this in mind, some of the unpleasant symptoms reported by mask wearers, such as light-headedness, headaches, muscle spasms, visual disturbances, and anxiety, can be better explained due to breathing more than the physiological norm resulting in cellular hypoxia induced by CO2 deficit.
Glenn White is New Zealand’s only Buteyko Institute certified practitioner trainer and director of the Buteyko Breathing Clinics based in Auckland, New Zealand.
Glenn overcame a lifetime of asthma and allergies after completing a Buteyko breathing course in 2000. He has been asthma, allergy and medication-free since that time. Overcoming a lifetime illness was the inspiration to train as a Buteyko Institute practitioner in the UK, returning to open Buteyko Breathing Clinics in New Zealand in 2001.
The clinics specialise in stress, respiratory and sleep disorders. Since 2001, Glenn has been teaching clients and training practitioners in New Zealand, Australia, Singapore, Indonesia and Japan. His work was featured on TV3’s Modern Medicine in 2012 and on Campbell Live in 2006.
Glenn has spoken at conferences in New Zealand and internationally and is currently an asthma ambassador for Asthma New Zealand. His goal is to have breathing assessments and retraining incorporated into general practice to help reduce the burden of breathing disorders.
Glenn's website and clinic: https://www.buteykobreathing.nz/