The main routes of transmission of COVID-19 are respiratory droplets and contact transmission. Aerosol and fecal-oral routes of transmission need to be further clarified. Epidemiological investigations have shown that cases can be traced to close contact with confirmed cases.
How to deal with the new type of COVID-19 infection should pay attention to the following points. The first point is to fully maintain the strength of your own immunity, try not to stay up late, avoid excessive drinking, and fatigue, so as to ensure the strength of your own immunity. Secondly, try to avoid contact with the environment that may be infected by the virus, and avoid places where people gather. The third point is to protect yourself. When going out to a place with a lot of people, try to wear a mask, as this can effectively prevent the virus from spreading. Fourth, it is recommended to ventilate in time when at home. Fifth, hand hygiene should be maintained. Usually contact transmission is often transmitted through hands. Wash hands frequently according to the standard seven-step hand washing method.
When did people start using face mask?
This first goes back to the two pioneers who first discovered bacteria-Pasteur and Koch.
At first, similar face mask, veils, etc. did not appear for the purpose of blocking viruses. It wasn’t until the 19th century that Pasteur and Koch discovered through microbiological research that many pathogens came from bacteria, and face mask came into being. After the Spanish pandemic in 1918, people were forced to wear face mask, which was the beginning of the widespread spread of face mask. Since then, not only has medical science developed rapidly, face mask have also become an indispensable medical and health tool and have been widely used.
We started to familiarize ourselves with face mask. It was mainly during the SARS period in 2003 that face mask were widely used. After several flus, such as the 2009 A HINI flu, face mask reappeared.
Why do face mask work?
Face mask work by blocking the source of the virus by isolating tiny particles. The earliest face mask were mainly gauze when they first appeared, but nowadays medical face mask generally use polypropylene meltblown cloth.
Meltblown cloth is mainly a structured loose material with a pore size of 1-5 microns, which also has good air permeability, so it is often used as a raw material for face mask.
In the process of transmission, the virus is not transmitted alone, but it is often transmitted through the air during breathing, chatting, coughing, and sneezing. Among them, large particles of droplets when coughing and sneezing. A sneeze may produce 40,000 micron-sized droplets, which naturally also contain various pathogens.
In addition to sneezing, there is a high risk of infection simply standing by the patient. Some studies have placed influenza patients in an indoor environment for a period of time and tested the virus in the surrounding air. This is also a recommended safety distance for people who do not wear face mask.
Imagine that you are in the supermarket, subway, train, or you are sick when you go to the hospital. Can you always keep 1m away from the people around you?
NIOSH divides the standard of face mask into three categories, namely N series, R series and P series. N is for protection of non-oily suspended particles without time limit. R and P are for protection of non-oily suspended particles and sweaty suspended particles, but R The level of protection of oily particles can only be eight hours, and the P level has no such limitation. These three categories have three types of filtration efficiency standards of 95 (95%), 99 (99%), and 100 (99.97%), so a total of nine Kind of mask. Since the biological particles are mostly non-oily particles, N grades can be used. The N95 level means that the filtering efficiency of non-oily particles can be protected to 95%, and N95 is a very basic level among all certification levels.
N95 is one of nine dust face mask certified by NIOSH (American Institute of Occupational Safety and Health). N represents that its material is only suitable for filtering non-oily dust, and 95 represents that its filtering efficiency is at least 95%.
Other countries N95 grade filter standards
1.EU EN149 standard
FFP1: filtering effect> 80%
FFP2: filter effect> 94%
FFP2: filter effect> 97%
2.Australian AS1716 Standard
P1: filtering effect> 80%
P2: Filter effect> 94%
P2: Filter effect> 99%
3.Japan MOL Standard
DS1: filter effect> 80%
DS2: filter effect> 99%
DS3: filter effect> 99.9%