Since the uncertainty about whether to wear a mask during the initial outbreak of COVID-19 last year, face masks have become the main content of an epidemic-ridden world. With the launch of the vaccine earlier this year and the cancellation of the directive, the mask disappeared briefly, and it seems that the COVID era is approaching.

But before entering the second pandemic winter, cases across the country were again on the rise, and a new variant omicron appeared. omicron was first discovered by South African scientists on November 26, and has since been discovered in many countries/regions including the United States, Israel, Australia, Canada, and Europe. Health officials and doctors are still uncertain about the key details of the new variant, including its infectivity and virulence. However, many experts recommend that individuals be vaccinated or boosted, and continue to wear masks to prevent the virus.

Dr. Abraar Karan, an infectious disease researcher at Stanford University and a former doctor at Brigham and Women's Hospital, wrote on Twitter that since details about omicron may not be known for a few weeks, people should take immediate action to improve their cover.

"A few weeks are too long to take risks, especially for high-risk groups," he said. "If you can upgrade your mask for indoor/crowded environments, please do so now."

We will not learn the key details about #Omicron in a few weeks, such as infectiousness and virulence. Several weeks are too long to take risks, especially for high-risk groups. If you can upgrade your mask for indoor/crowded environments, please Do it now #covid19

According to a study of community masks in Bangladesh, cloth masks are obviously not as effective as surgical masks. Scientists found that cloth masks have a filtration efficiency of 37%, while surgical masks have a filtration efficiency of 37%, and surgical masks have a filtration efficiency of 95%. Even after 10 washes, the efficiency of surgical masks is still higher than that of cloth masks, at 76%. 

Armbrust American is a Texas-based company that produces surgical masks and respirators and tested hundreds of masks of different brands. Among the seven cloth masks tested, only one had a PFE of more than 50. %. PFE stands for Particle Filtration Efficiency, which evaluates the filter efficiency of the filter in the mask for inactive particles.

Karan said the ideal mask to switch to is N95 or surgical-grade mask with a mask holder to reduce airflow around the edges. According to Armbrust American, N95 has been approved by the National Institute of Occupational Safety and Health, and its PFE is 99.95%. 

According to the Centers for Disease Control and Prevention, a key part of a protective mask is the fit of the mask to the human face. A well-fitting mask should not leave spaces around the nose or mouth where air particles may enter.

Other alternatives to N95 include surgical masks, such as KF94 and KN95. They are less effective but still protective and have ear hooks. According to mechanical engineer Aarons Collins, he has tested the effectiveness of many different types of masks.

Collins called for the development of a "general population mask standard" to make the mask guidelines clearer.

“There are many things we cannot control about COVID-19, such as poor ventilation in buildings or whether other people have been vaccinated, but in addition to ensuring that you and your family are vaccinated, wearing high-quality masks is the most important thing people can do An important thing to protect themselves and their children," he told the New York Times.

According to the New York Times, when buying surgical masks online, buyers should be careful of brands that are flagged as counterfeit.

According to the CDC, 60% of KN95 respirators sold in the United States are counterfeit products.

The signs that may be counterfeit N95 include no mark on the filter mask respirator, no approval number on the respirator or headband, no NIOSH mark, decorative materials on the mask, and child approval statement (NIOSH does not approve any type according to the CDC The claim is to provide children with respiratory protection), or if the mask has earrings instead of a headband.

Collins also warned buyers not to go to Amazon, eBay and Etsy to buy masks.

Kimberly Prather, an aerosol expert and atmospheric chemist at the University of California, San Diego, told Scientific American that trustworthy surgical masks can be found on websites such as Project N95, Bonafide masks, and DemeTECH.

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