As I understand it 98-99% is the fraction “new air” that enters the body with a mask compared with to not wearing one.
The 1-2% is the amount of of “old” already breathed air that is not exchanged since is it is the small areas between the mask and the body.
So you see a small reduction in oxygen levels. This is much less than being in a stuffy room. The body can tolerate very low levels of oxygen.
CO2 is a bigger hazard, however just like with oxygen, the CO2 levels only increases by 1-2% which is negligible. You get much higher levels being in a room with a fireplace.

If someone has a better explanation please correct me.

The normal oxygen level reading by an oximeter is 96, I believe? Are you saying it is higher with a mask? Mine is usually low at 94 because I have some mild asthma. Wearing a mask is a little bit difficult for me but I do it when I have to.

@FrankZeleniuk Mine usually runs 98-99% saturation with or without a mask. Which surprises me because I often feel short of breath wearing them, particularly early in the day. Reminds me of being at high altitude.

@coalburned Seems odd. Maybe someone else here has a better understanding.

So much to unpack there.
Jumping first to the last sentence, let me compliment you on the point you’ve made (Not about masks, but about the where the focus should be). Reducing the viral load is part of a good strategy for combating true viral threats. The other part is increasing the body’s capacity to handle an increased load. If Covid-19 (SARS CoV2) were a severe threat, this would be a great idea. However, decreasing the body’s capacity to handle the load in the way you decrease the viral load defeats the purpose and cancels the gains that could have been realized. (It’s like trying to reduce spending in order to get out of debt by not going to work thereby reducing transportation costs, etc... when your current income won’t even cover the interest on your loans).

First sentence: not sure what your point is.

2nd sentence: maybe true in its basic elements, but incorrect in its implied conclusion. Science can tell us what will do more harm than good if we understand the details. We have plenty of scientific evidence (even proof) that tell us details about the various independent elements of the current strategy of handling the virus. These details should have been considered before taking the knee jerk reactionary tack that leads to more problems that they assumed would be avoided. The article gives only a tiny bit of the evidence of the harm caused by O2 deprivation (neurological studies showing brain before O2 deprivation vs after O2 deprivation as well as scientific studies showing the body inhales air (a little over 20% is oxygen) and it necessarily converts some of that oxygen into carbon dioxide leaving reducing oxygen concentrations of exhaled air at a little over 15% which mixes freely with the air in our atmosphere along with all the oxygen that was converted from carbon dioxide by plants, etc. There are also scientific studies showing that masks inhibit the mixing of fresh, oxygenated air in subsequent inhaled breaths. Over a period of time this depletion of oxygen will cause the neurological damage already discussed. The amount of time for “safe” wear of different masks has been established by PPE experts in scientific studies. There is a reason that surgeons are trained not to wear the specific masks for extended periods of time without a break. I won’t turn this post into a full study with all the references and the complete analysis, but if you really want to know it’s all still out there and hasn’t been censored by the left, because it requires a little thought and effort to connect all the pieces.

@Daveclark5

If your story about reduced oxygen levels causing neurological damage were true then 99% of people in cold countries before 1900 who lived in locked up rooms with almost no ventilation and indoor fires would be morons due to the brain damage they would suffer.
Similarly surgeons performing 8 hour surgeries would all be brain damaged.

Humans are able to deal with low oxygen levels over extended periods over a long time.

The studies you reference talk about extremely low oxygen levels. Below 5%. This does not happen wearing a surgical mask.

The amount of air you expel when you breath out is many times larger than the area available between the mask and your body. Hence almost all your breath is forced past the mask, and when you breath in almost all the air is pulled through the mask again. No mixing is needed since the already breathed air is almost completely replaced. There is simply no place inside the mask where old breathed air can be stored.

You are confusing surgical mask with full head masks used in hazardous environments where the air in the full mask is not forced out. There you need active reticulation of oxygen, and hence full face masks come with an oxygen bottle or a breather pipe.

@Daveclark5

Excellent reply.

My point was that masks are the best way to spread the virus in the absence of a vaccine. Speeding up the rapid spread of herd immunity while reducing the severity of disease.

On your second point I will offer some evidence.

"At 5 and 30 minutes, no major changes in end-tidal CO2 or oxygen saturation as measured by pulse oximetry of clinical significance were noted at any time point in either group at rest"

[atsjournals.org]

I'm not claiming this is either a well conceived nor conclusive test. It's just a data point.

Common sense says that people should take breaks from wearing a Mask. They should also be changed regularly. There are obvious logistical challenges in reaching that goal but they are not insurmountably.

Personally I'm not all wrapped up in the mask issue. I wear one when I'm out of the house because I have no need to wear one for long periods. I'm also pretty apolitical, which I believe makes me more objective. Politically however I do think the mask issue was a bad hill to die on. The vaccine issue even worse as it was Trump's vaccines that were developed. The pandemic clearly cost Trump reelection and his approach to dealing with it for whatever reasons didn't help.

@Hanno

We need both a better philosophy of science and to teach it more effectively. Those of us who have had to apply it practically understand both it's limitations and uses but I'm not sure that is enough.

@wolfhnd
Before responding, I just wanted to remind you the article clearly concluded, forcing children to wear masks in order to attend school was wrong.

Now, yours was a good study to quote and your observations about the study were outstanding. (The study was neither well-conceived nor conclusive, but certainly was a data point.)

The study of PO2 says after 5 and 30 minutes are well within the acceptable time frame for wear of surgical masks. PPE experts train medical professionals on the safe time periods for the various surgical masks. They never recommend them for use in infectious environments. They are used to prevent germs from being expelled by surgical professionals in water droplets (sneezing, coughing, spraying when talking, etc...) into the open wound of the patient being operated on.

There are masks that serve the purpose of protecting one from biological threats (like a killer virus). The masks I was trained to use in this type environment are far more sophisticated and require proper fitting and before donning them we use specially formulated disinfectant wipes on our entire face. We clear and check the mask (when possible) before entering the area of contamination (biological or chemical). These masks filter ALL air entering the mask and NONE of the air leaving the mask.

Neither of these types/classifications of masks serves the purpose you wisely proposed (reduce the viral load to increase the herd immunity gradually). The masks “suggested” by those in charge are nothing but a show of submission. They know this. Evidence: Fauci started off by saying masks don’t help; then he said they’re necessary and will save lives, now he’s saying you need two masks to provide that protection. Oh yeah, any kind of mask is fine: a surgical mask, a chem/bio mask, a painter’s mask, an open handkerchief, a knit scarf, a plastic bag over your head, a dirty diaper, whatever you want to use as long as you use 2 of them.... because science. That’s why there are so many different things being worn in so many different ways.

As for the statement, “ Common sense says that people should take breaks from wearing a Mask”: you know as well as I that common sense is far from common. Hence the assessment I referenced at the beginning of this reply.

I like that.