Wearing masks (including cloth masks, medical masks or anti-poison masks) is currently mandatory for people around the world when going to public places. The reason why? Find out with Jio Health through the following article!
1. Should I buy an anti-poison mask or a medical mask to use?
According to official recommendations in the United States (and Western countries), people do not necessarily wear anti-poison mask, the reason is because it is necessary to save anti-poison masks for medical staff. In addition, there are currently no scientific studies showing that medical masks or the masks that people wear every day are not effective.
In Vietnam, according to the latest recommendation from the Ministry of Health, only in cases such as: being a health worker directly treating a patient or suspected of having the disease or having contact with specimens of a respiratory patient. ; people who have or are suspected of having a disease; caregiver of a person with suspected or active illness; people visiting a medical facility. Thus, people do not necessarily need to wear medical masks in all cases. And for casual contact, the most important thing is to keep a distance of at least 2m from others and wear a mask.
In terms of quality, anti-poison masks have better protection than medical masks. However, the number of respirators may be in short supply, so priority should be given to medical staff. The Centers for Disease Control (CDC) pointed out that N95 respirators should be fully equipped, and priority should be given to experts and medical teams to perform the task. Therefore, the CDC recommends that healthy people only need to wear medical or cloth masks, and sick people can wear anti-toxic masks to ensure they do not become infected or spread the virus outside.
These guidelines show the urgency when it comes to saving specialized anti-pollution masks for medical professionals in the context of shortages of medical supplies and equipment in the midst of the battle with the Covid-19 epidemic (Coronavirus disease). ).
2. When should medical masks be used?
- If you are healthy, just wear a medical mask if you are caring for someone who has or is suspected of being infected with the SARS-CoV-2 virus (Coronavirus).
- Wear a surgical mask if you are coughing or sneezing – infected or suspected.
- Medical masks are only effective when used in conjunction with frequent hand washing with alcohol or soap and water.
- If you wear a medical mask, you need to know how to use and dispose of it properly.
3. Wearing a medical mask properly limits the spread of Corona virus
4. New research on medical masks and N95 respirators
It should be noted that medical masks and N95 respirators, if worn incorrectly, will not provide good protection. Then what is the risk? That you can still be infected even if you stand 2m away from others (recommended distance is safe) and keep your hands away from your eyes, nose and mouth.
Doctor, Dr. Sui Huang of the Institute of Biological Systems (Seattle, USA), an expert in molecular and cellular biology, shared a result of an individual study based on mechanical physics to examine and evaluate the protection of medical masks against Corona virus. Research posted on Medium shows that any physical barrier, like a surgical mask, can significantly reduce the spread of the Corona virus.
Analysis of the mechanism of disease transmission
According to published studies, the Corona virus is transmitted through the main mechanism of droplets from the sneeze and cough of an infected person. Analyzing the transmission mechanism, scientists have divided the droplets into 2 types based on their size. Consists of:
- The group of aerosols (<10 micrometers in size, i.e. less than half the diameter of a human hair) are small droplets that are wind-movable and can pass through gaps. N95 respirators differ from medical masks in that the front is designed to block gases: filtering 95% droplets less than 0.3 um.
- Droplets larger than 10um (micrometers) to 100um are called "spray droplets". These droplets can be larger, up to the size visible to the naked eye when coughing or sneezing.
The calculation presented in the report by Dr. Yuguo Li (University of Hong Kong) shows that droplets >0.1um can evaporate or fall to the surface within 2m, depending on the size, the humidity is not gas and temperature.
The droplets will be like "bullets" flying out at speeds of 50m/s (for sneezing) and 10m/s (for coughs), making them possible to reach distances of up to 6m. So, the 2m distance that we often think of as "absolutely safe" may still not be enough to protect us from infection with SARS-CoV-2.
Normally, dust particles or droplets want to go deep down to the alveoli where gas exchange occurs, they must be less than 10 micrometers in diameter. In contrast, large aerosols become trapped in the nose and throat (pharyngeal space) and in the upper airways of the lungs, trachea, and large bronchi.
Therefore, the N95 respirator is designed to filter out the smallest particles, helping to prevent droplets from carrying the virus down the alveoli.
Large droplets in the nasopharynx, by contrast, can be blocked by any physical barrier, such as a medical mask. Of course many aerosol drops during exhalation or coughing may not contain the virus, but some will. In the case of the SARS-Cov-2 virus, we do not know what is the minimum infectious amount (the number of viral particles needed to initiate the pathogenesis stratification that causes clinical disease). On the other hand, research by the US CDC indicates that the alveoli are the destination of droplets that transmit the virus. Therefore, even for aerosols, using a medical mask is still effective, and still better than nothing.
The FFP2 respirator can filter out more than 99% of particles (thus, reducing the aerosol load by 100 times). With medical masks, the number of aerosol droplets on the back of the mask is reduced by 4 times compared to the outside of the mask. For larger droplets from coughs, the difference between a medical mask and a respirator is very small. Interestingly, when it comes to the ability to limit the spread of the virus to the outside, the effectiveness between masks is not too different.
From that, it can be seen that medical masks or ordinary cloth masks can also help protect us, at least when we keep a "safe distance" of more than 2 meters from others and do not use our hands. touch eyes, nose and mouth. The likelihood of being infected will be reduced by 4 times if you wear a medical mask and 3 times if you wear a regular cloth mask. Therefore, wear a mask often when going out, especially in public.
Wearing a mask in public is a way to protect the health of yourself and the community. Whether using anti-toxic masks, medical masks, cloth masks, wear them correctly, in the right circumstances. It is the measure we all need to take to reduce the spread of Covid-19.