Do face masks work?

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upamfva 16 µŘĹҤÁ 2564 , 09:52:22
Do face masks work?

Since the beginning of the historic COVID-19 pandemic, one of the most hotly debated subjects has been about masks and whether they actually help slow the spread of the disease.To get more news about famous nonmedical mask factory, you can visit official website.
At the onset of the pandemic, there was slim evidence to either prove or disprove the effectiveness of mask-wearing to slow the spread of this particular coronavirus because, obviously, COVID-19 was a new disease. Additionally, there was little research focusing on respiratory disease transmission during a global pandemic of COVID-19’s magnitude — a once-in-a-lifetime worldwide disaster. Naturally, there was little data to go on about the efficacy of mask-wearing during these exact circumstances.

This lack of information was perhaps confusing for many but millions in the scientific community quickly jumped to help the world understand this disease better. They built upon years of existing data on coronaviruses and communicable diseases. While researchers of all 49 studies listed below acknowledge there’s still much more data to be explored, they have all acknowledged the efficacy of mask-wearing to some degree at slowing the spread of COVID-19.
Researchers of one study urge people not to infer when reading studies: “Various authors have justified not wearing masks on four main grounds. Firstly, they claim that there is limited evidence that they are effective. The first argument can be challenged on the grounds that absence of evidence is not evidence of absence.”
Reasons for mask hesitancy and doubt include conflicting data from health officials, political biases and cultural unfamiliarity (studies showed mask-wearing was lower in countries where face masking to prevent disease was not as common as in others). While studies disputing masking claims do exist — as is the nature of scientific research — in researching this piece, the majority explored for this article appeared to conclude either in the affirmative or that more information was needed.

Through the writing of this article, efforts were made to be transparent about publication dates, sources, data sets, and when findings that were critical of mask-wearing appeared. Where they arose, they were included and we worked to give them context.
Researchers (including a CDC doctor) for a February 2021 article published by the Journal of the American Medical Association reviewed data from 10 previous studies conclude mask wearing substantially reduces spread. They write that wearing a cloth mask can reduce transmission of exhaled droplets from infected wearers into the air by around 50% to 70%. Additionally, masks were shown to help prevent uninfected wearers from inhaling large respiratory droplets. Overall, the authors found mask wearing’s main benefit is source control, which protects others by reducing the number of respiratory droplets released, rather than respiratory protection, which protects the wearer. Peer reviewed.
Universal mask adoption for people when in public is recommended by the authors of the “An evidence review of face masks against COVID-19,” first published in January by Proceedings of the National Academy of Sciences of the U.S. Researchers poured over at least 150 other studies, models and findings to draw their conclusion: “The available evidence suggests that near-universal adoption of nonmedical masks when out in public, in combination with complementary public health measures, could successfully reduce virus reproduction levels to below 1, thereby reducing community spread if such measures are sustained.” Additionally, they posit that mask wearing mandates could add $1 trillion to the U.S. GDP by preventing business closures. Peer reviewed.
A high-speed laser-light video experiment in The New England Journal of Medicine caused oral fluid droplets to appear as flashes in the light. When observed, between 227 and 347 oral fluid droplets flashed when participants said the words “stay healthy” without a mask. When the same phrase was spoken with a mask, “the flash count remained close to background level.” Peer reviewed.
A June 2020 University of Iowa study published in the Health Affairs medical journal estimated over 200,000 COVID-19 cases were prevented in May after masking was mandated in several states. For this experiment, researchers used data analysis and models to measure community spread before and after a mask mandate was enacted. Data found that within 1-5 days after a mandate was issued, daily case rates dropped nearly one percentage point. Within 21 or more days, they dropped two. Peer reviewed.
A symptomatic traveler with a dry cough traveled from Wuhan, China, to Toronto, Canada, while wearing a mask, Canadian Medical Association Journal researchers reported in an April 2020 response to a February 2020 study. None of the 25 passengers considered “close contacts” aboard the flight contracted the virus. This study indicated that droplet transmission was likely more prevalent than airborne transmission. Peer reviewed.