Today, it has become common sense to wear a mask when you come into contact with people, and we will consider how much the preventive effect of COVID-19 by actually wearing a mask is.
Route of infection of the virus
There are three main routes to infect virus:
- Contact infection: Contact infection is an infection caused by touching a “thing” with a virus attached
- Droplet infection: Infection caused by splashing from sneezing or coughing
- Air infection: Infection by inhaling viruses in the air
Currently, various studies and research are being conducted on COVID-19, but there is still no reliable information about exactly what kind of infection path is.
The size of the virus and the size of the mask mesh
The size of the mesh of a general mask is said to be approximately 10μm. On the other hand, the size of the virus is 0.1 μm. In other words, it is not possible to prevent viruses directly with a mask, which is ineffective as a preventive measure of air infection. However, it is effective when it comes to the fact that the throat is hard to dry.
When it comes to droplet infection, droplet that come out of the mouth due to human sneezing, coughing, and conversation are approximately 0.1 μm, so they cannot pass through the mesh of the mask. Therefore, it is thought that the possibility of droplet infection can be reduced by the mask.
There is a claim that contact infection can be reduced by not touching the mouth or nose too much by wearing a mask. It may be said that if you use the mask correctly, but if you use it frequently or put it on and off due to the heat, it may be counterproductive.
A study from the investigation case of droplet infection and air infection
The preventive effect of the mask varies greatly depending on whether droplet infection or air infection is the main. There is currently no clear information about COVID-19, but I will consider it based on some of the findings.
At first, many agencies, including who, had announced that COVID-19 was not afraid of air infection. However, when scientists began to make recommendations about the possibility of air infection about COVID-19, who began to admit air infection. A study analyzing the Diamond Princess cruise ship outbreak showed that 60% were infected by air infection (https://toyokeizai.net/articles/-/366956?page=3). If air infection becomes the main, it is thought that the effect of that much cannot be expected to the mask.
In addition, although it is influenza rather than COVID-19, a study examined about the effect of masks has shown no effect of wearing a mask to prevent infection (https://www.justa-pharma.com/2018/letter128/).
Personal opinion
I feel that the effect of the mask on COVID-19 is not as big as the public is making noise. I don’t want to wear a mask all the time, but now I have to worry about the public eye. However, if you wear a mask anyway, it may be an important factor to maximize the effect by believing in the mask thinking that “it is safe if you wear a mask” because there is also “disease is out of mind”.
Because I don’t like masks myself, I may have taken up only the bad side of masks here. It’s important to keep an eye on the information.