Are COVID masks Poisoning Us?
There has been a number of cases reported in the media in recent months where people claim wearing a “Covid mask” has caused ill-health, accidents, or allege long-term health effects can arise.
In April last year a US driver claimed he crashed his SUV because he wore his N95 (P2) mask for too long and passed out at the wheel. At the time police recorded the cause of the accident as “insufficient oxygen intake or excessive carbon dioxide intake”, but police later amended the cause to “… didn’t know with 100% certainty that excessive wearing of N95 mask was a contributing factor …”.
Compulsory wearing of masks looks like it will continue for some time, particularly in shops, at major events and on public transport. So, what are the facts about wearing masks for long periods of time and their health and safety implications?
Mask-Associated Dry Eye
Optometrists report that exhaled air venting from the top of masks increases air flow across the surface of the eyes, causing the tear fluid to evaporate more quickly, leading to dry eyes and discomfort. However, adjusting the nose piece on the mask minimises this problem, and using eye drops, if necessary, will improve eye comfort. See also article P.8.
Oxygen Deficiency
Research confirms alleged oxygen deficiency from wearing a surgical mask, or P2/N95 respirator, or fabric face covering is not possible, as the filter/fabric is porous, and oxygen passes freely through it, but of course breathing may be more difficult.
Rebreathing Carbon Dioxide Poisoning
Carbon dioxide (CO2) rebreathing has long been recognised as a concern regarding respirator use and is related to symptoms of discomfort, fatigue, dizziness, headache, muscular weakness, and drowsiness.
These symptoms may be valid for certain individuals or particular circumstances, however, authoritative research* confirm whilst CO2 levels do increase inside a mask, particularly when exerting energy eg brisk walk or carrying groceries, the levels do not exceed safe exposure levels.
* Effect of CO2 in Breathing Zone by Geiss, EU Joint Research Centre, Italy, Feb. 2021.
For example, testing various masks found CO2 levels in the breathing zone between 2,000 to 3,000ppm, and baseline (fresh air) about 500ppm. Concentrations of less than 5,000ppm is typically an acceptable workplace exposure limit (8hr av.) in most jurisdictions.
Inhaled CO2 in concentrations below 10,000ppm has little or no toxicological effects, but levels above 50,000ppm is harmful.
Conclusions
Wearing masks for long periods of time, particularly if undertaking strenuous tasks, may cause things like headaches and increased fatigue, but they will not cause serious health effects.
Where employers require workers to wear masks for long periods and perform physical tasks, they should consider more comfortable and cooler air-supplied respirators, or seek alternatives to eliminate the need for masks.
