The repeated epidemic has made masks a daily standard for everyone. There have been some strange and even outrageous rumors about masks. For example, recently, some people said that wearing masks could lead to hypoxia, poisoning and even “hypercapnia”.
Rumors are often well-founded and serious at first glance, but professionals sometimes judge them in just four words: nonsense.
The myth has been spreading for years, and has been refuted by experts in the field. Today we are going to talk about whether wearing masks has any impact on health, and how it works.
Do masks really affect breathing?
After wearing a mask, people do not feel used to it, even a little uncomfortable. But does this really mean that normal breathing will be affected to the extent that, as the myth goes, blood oxygen levels will drop and hypercapnia will develop?
Let’s start with a little experiment.
The health Office at the University of California, San Diego, filmed an experiment to see if masks can affect breathing. The experimenters first measured their blood oxygen saturation, which was 98 percent — low enough to indicate hypoxia. She then put on four layers of a mask and measured her oxygen saturation, which was still 98%; After adding three more masks, her oxygen saturation dropped to only 97 percent.
Does this level of change affect our breathing? The conclusion is clearly no. In fact, blood oxygen levels between 95% and 100% are normal, and the body may not react at all to such changes.
Now look at the carbon dioxide measurements. In the same video, another experimenter first measured the PCO2 in the body, which was 31.6mmHg; After wearing four layers of masks, it became 31.8mmHg; After three more layers of masks were added, the rise was only 0.7mmHg, to 32.5mmHg.
For the average person, the normal value of pco2 ranges from 30mmHg to 45mmHg. It can be seen that the mask has little effect on this figure. As for some people who insist that masks make it difficult to discharge carbon dioxide, leading to repeated inhalation and poisoning, this is certainly not true.
You have to breathe in up to 10 percent of the carbon dioxide that’s dangerous, and the amount of carbon dioxide in our daily air is only 0.04 percent, and even our breath is only 4 to 5 percent. Putting your head in a plastic bag and tightening the bag may cause the problem of high carbon dioxide concentration. Ordinary people wear medical masks daily because they are breathable. Although breathing requires a little more effort than usual, it is not difficult to suck in enough oxygen and expel carbon dioxide well.
Different people wearing different masks have different effects
We now know that wearing a regular surgical mask does not affect our oxygen supply. So the myth that masks cause hypoxia and high carbon dioxide levels cause disease has been dispelled. However, the above mentioned are healthy people wearing ordinary medical masks, some special circumstances still need to pay attention to:
Masks like the N95 or higher filter performance are actually better suited for professionals in high-risk situations. Ordinary people who wear N95 masks for a long time are indeed prone to discomfort.
In addition, people like smokers, emphysema patients and obese people, who are prone to poor breathing, will naturally suffer worse and even worsen their breathing problems if they wear N95 masks.
In addition, for patients with some pulmonary diseases such as pulmonary fibrosis, wearing masks may indeed affect blood oxygen. However, if such patients are infected with novel coronavirus, they are more likely to develop critical symptoms. Therefore, if they need to travel in closed public places, wearing masks for a short time may do more good than harm.
Can I wear a mask when I exercise? This question has also troubled many friends. Surprisingly, studies have shown that, at least for healthy young adults (participants were 28.2±8.7 years old), even when exercising while wearing a surgical mask, there is no need to worry about hypoxia, just that it may be a little unaccustomed. Of course, the study is only mentioned here to show that wearing masks is not dangerous, not to suggest that people exercise while wearing masks.
There are also these misconceptions about masks
Knowing that masks don’t interfere with normal breathing, let’s take a look at some other misconceptions about masks to help us use them better.
● “I don’t feel like I can’t breathe without wearing a mask?”
There’s nothing wrong with that, but if you feel that way, you’re probably not wearing your mask correctly.
If you feel that you can breathe smoothly after wearing the mask, check whether the metal nose clip on the bridge of the nose has been pressed to fit the bridge of the nose and whether there is air leakage at the chin. If the mask is worn correctly, breathing should actually be somewhat obstructed. If you wear a mask in winter and your glasses fog up when you breathe, that means the bridge of your nose is probably not properly adjusted.
● Graphene in face masks, cotton swabs is a health hazard?
In fact, most of the so-called “graphene masks” sold in the market are gimmicks. For example, a certain “biomass graphene” raw material was found to be processed from straw. However, it is worth noting that some mask materials use nanoscale activated carbon, and long-term wearing of activated carbon masks does pose a risk of inhaling particles. The public should choose masks that meet national standards for daily epidemic prevention.
As for the cotton swabs used to measure nucleic acids, adding graphene or activated carbon is nonsense.
● The higher the level of mask protection, the better?
This is not certain. As mentioned above, it is not necessary for ordinary people to wear masks of N95 level or higher in their daily life. However, if they go to places with large crowds, they should choose masks of N95 level as much as possible. In addition, when choosing N95, KN95 and above masks, be careful to avoid models with breathing valves. Most models with breathing valves are suitable for industrial user
● Must shake the mask before wearing, otherwise the residue on the mask will cause cancer?
Qualified surgical masks do not carry this risk. The mask adsorbs ethylene oxide used in disinfection. Although ethylene oxide belongs to a class of carcinogens, the toxicity also depends on the dose. According to the national standard, the residual amount of ethylene oxide in masks is not more than 10μg/g, which is safe. After sterilizing masks with ethylene oxide, manufacturers will wait for the residual amount to be qualified before leaving factory.