Views:0 Author:Site Editor Publish Time: 2021-01-06 Origin:Site
A lot of people doubt whether the face mask can prevent COVID-19 effective. According to scientific research, the face mask is effective. Now we will talk about the face mask effectiveness in 4 parts:
Source control prevents outgoing viruses
Filtering to protect individuals
COVID-19 infections are mainly spread by respiratory droplets produced when people cough, sneeze, sing, talk, or breathe. CDC recommends the use of face masks in the community, especially non-valved multi-layer cloth face masks, to prevent the spread of COVID-19. The primary purpose of face masks is to reduce the release of virus droplets (" source control "), which is particularly relevant to asymptomatic or pre-symptomatic infected wearers, who feel fine and may not be aware of their infectivity to others, and are estimated to account for more than 50% of transmissions. Face masks also help reduce the wearer's exposure to these droplets (" personal protective filters "). The cover-up of COVID-19 control over community interests is due to a combination of these roles. As more and more people use face masks consistently and correctly, personal prevention benefits will increase.
Multiple layers of cloth face masks prevent exhaled respiratory particles and the microbes they carry from entering the environment. Cloth face masks are effective not only at blocking most large droplets (that is, 20 to 30 microns or larger) but also at blocking the exhalation of droplets and particles smaller than 10 microns. It increases with the number of sounds and the specific types of sounds. Multi-layer cloth face masks can block up to 50-70% of small droplets and particles and limit the forward diffusion of uncaptured particles. Blocking rates have been achieved 80% in human trials, which have measured all respiratory droplets blocking, and in some studies, a face mask has been as effective as a surgical mask as a barrier to source control.
Studies have shown that the face mask material also reduces the wearer's exposure to infectious droplets through filtering, including tiny droplets and particles smaller than 10 microns. Throughout the study, the relative filtration effects of various face masks have changed significantly, largely due to the experimental design and changes in the analyzed particle sizes. Compared with single-layer cloth face mask with lower line count, multi-layer cloth with higher line count has shown excellent performance, in some cases, filtering out nearly 50% of fine particles less than 1 micron. Some materials (such as polypropylene) enhance filtration by producing a frictional charge (a form of static electricity), which enhances the capture of charged particles, while others (such as silk) help repel wet droplets and reduce the wettability of the fabric, thereby maintaining breathability and comfort.
Experimental and epidemiological data support community cover-ups to reduce the spread of COVID-19. The preventive benefits of face masks come from a combination of source control and personal protection for mask wearers. The relationship between source control and personal protection may be complementary or synergistic, so personal interests will increase with the increase in the use of masks in the community. Further research is needed to expand the evidence base for the mask's protective effect, in particular, to identify combinations of materials that maximize the barrier and filtration effects as well as fit, comfort, durability, and consumer appeal. Adopting a common face mask strategy can help avoid locking in the future, especially when combined with other non-drug interventions (such as social evacuation, hand hygiene, and adequate ventilation).