21% oxygen, 78% Nitrogen, and 0.04% Carbon Dioxide
When we exhale:
16% oxygen, 78% Nitrogen, and 4% Carbon Dioxide.
What does this mean?
5% oxygen is used by our body for every breath we take. Humans have by far the least efficient lungs of any mammal. Compared to them, we already have a medical condition.
It get's worse though. Under OSHA, 29 CFR 1910.146 Paragraph (d)(2)(iii) of the Respiratory Protection Standard it states:
Extensively its rationale for requiring that employees breathe air consisting of at least 19.5 percent oxygen. In the OSHA Preamble, at 19.5% or below is considered oxygen deficiency (hypoxia).
That's a 1.5% drop in oxygen intake. That means your body is using 3.5% oxygen for every breath wearing a face mask.
It's gets even worse though.
Exhale contains 100 times the amount found in the air we breath. OSHA acknowledges that carbon dioxide is trapped in the 'dead space' of a face mask.
This is breathed in and replaces valuable oxygen from the air.
The OSHA Preamble states:
At oxygen levels of 10 to 14 percent, faulty judgment, intermittent respiration, and exhaustion can be expected even with minimal exertion (Exs. 25-4 and 150). Breathing air containing 6 to 10 percent oxygen results in nausea, vomiting, lethargic movements, and perhaps unconsciousness. Breathing air containing less than 6 percent oxygen produces convulsions, then apnea (cessation of breathing), followed by cardiac standstill. These symptoms occur immediately. Even if a worker survives the hypoxic insult, organs may show evidence of hypoxic damage, which may be irreversible (Exs. 25-4 and 150; also reported in Rom, W. [see reference in previous paragraph]).
https://www.osha.gov/laws-regs/federalregister/1998-01-08
These people wearing face masks are nuts. I'm a certified scuba diver and I can tell you breathing in your own exhale with that amount of carbon dioxide will kill or maim you underwater. Think of the long term damage and acidosis it causes.
In the OSHA Preamble, at 19.5% or below is considered oxygen deficiency (hypoxia).
How does this relate to high altitude? Humans are very sensitive to the total oxygen in air (partial pressure), not necessarily the percentage. Other gasses also have a significant effect, like CO2 and CO, on blood oxygenation.
It does relate to high altitude just as it relates to oxygen deprivation under water. Pressure is a factor that needs to be included though. Increased pressure amplifies and quickens the harmful affects. Take for example Nitrogen to which every one is familiar with in scuba diving for the 'bends'. Above surface, our bodies have no real use for Nitrogen. We inhale 78% and then exhale 78%. Underwater at depths of 30 feet or more, the water pressure causes it seep into our bloodstream. Without a proper timed ascension to decompress, it can be deadly. Excess carbon dioxide is even deadlier than nitrogen to the scuba diver.
At higher elevations, you are dealing with the inverse of higher pressure found at increasing water depths. 30 feet under water is 1 atm of pressure. I'm not an expert on altitude health, but I understand atmospheric pressure declines as one ascends. Add to this decreased oxygen and there's another set of problems, altitude sickness amongst them.
Air we breath in has:
21% oxygen, 78% Nitrogen, and 0.04% Carbon Dioxide
When we exhale:
16% oxygen, 78% Nitrogen, and 4% Carbon Dioxide.
What does this mean?
5% oxygen is used by our body for every breath we take. Humans have by far the least efficient lungs of any mammal. Compared to them, we already have a medical condition.
It get's worse though. Under OSHA, 29 CFR 1910.146 Paragraph (d)(2)(iii) of the Respiratory Protection Standard it states:
Extensively its rationale for requiring that employees breathe air consisting of at least 19.5 percent oxygen. In the OSHA Preamble, at 19.5% or below is considered oxygen deficiency (hypoxia).
That's a 1.5% drop in oxygen intake. That means your body is using 3.5% oxygen for every breath wearing a face mask.
It's gets even worse though.
Exhale contains 100 times the amount found in the air we breath. OSHA acknowledges that carbon dioxide is trapped in the 'dead space' of a face mask.
This is breathed in and replaces valuable oxygen from the air.
The OSHA Preamble states:
These people wearing face masks are nuts. I'm a certified scuba diver and I can tell you breathing in your own exhale with that amount of carbon dioxide will kill or maim you underwater. Think of the long term damage and acidosis it causes.
How does this relate to high altitude? Humans are very sensitive to the total oxygen in air (partial pressure), not necessarily the percentage. Other gasses also have a significant effect, like CO2 and CO, on blood oxygenation.
It does relate to high altitude just as it relates to oxygen deprivation under water. Pressure is a factor that needs to be included though. Increased pressure amplifies and quickens the harmful affects. Take for example Nitrogen to which every one is familiar with in scuba diving for the 'bends'. Above surface, our bodies have no real use for Nitrogen. We inhale 78% and then exhale 78%. Underwater at depths of 30 feet or more, the water pressure causes it seep into our bloodstream. Without a proper timed ascension to decompress, it can be deadly. Excess carbon dioxide is even deadlier than nitrogen to the scuba diver.
At higher elevations, you are dealing with the inverse of higher pressure found at increasing water depths. 30 feet under water is 1 atm of pressure. I'm not an expert on altitude health, but I understand atmospheric pressure declines as one ascends. Add to this decreased oxygen and there's another set of problems, altitude sickness amongst them.