Dr. Gupta reacts to the abrupt end of the use of masks in public transport 2:03 (CNN) –– The mandatory use of masks imposed by the Joe Biden administration on airplanes and other means of public transport was rescinded, after that a federal judge in Florida review a ruling and vacate the order. Some passengers applauded the decision on Monday, while others decided to continue using the means of protection. Masks offer the most protection against the spread of airborne virus-carrying particles when everyone wears them. But some research also suggests that they can themselves protect the wearer by acting as a barrier between particles and the nose and mouth. “I was actually traveling by plane yesterday when the requirement to [uso de] masks on public transport. I definitely kept my mask on the entire flight,” Chris Cappa, a professor of civil and environmental engineering at the University of California, Davis, who studies aerosol particles and face masks, shared in an email Tuesday. While traveling from Sacramento to San Diego, Cappa watched as the number of riders keeping their masks on dropped sharply, “I will continue to use my N95, for a while, as I travel. Personally, I’m more concerned when I’m in small, crowded spaces like airplanes than when I’m in large, relatively open spaces like airports,” Cappa said. Individual mask use Some airlines no longer require masks: see passenger reaction 0:50 When one person wears a mask and others do not, it is called individual mask use “The level of protection from individual mask use depends largely on two factors: how well the mask fits you and with how effectively the mask material filters out particles that can carry a virus. Generally, masks like N95s and KN95s will provide more protection than surgical or cloth masks because they can create a tighter seal against your face. And surgical masks tend to filter better than cloth masks with a similar fit,” Cappa wrote. “However, different masks will fit different faces better or worse, so it’s important to find one that fits you well. For example, you could adjust the ear loops to make the mask fit more,” he said. “Even the best mask is only as good as its fit. But a well-fitting N95 can reduce the amount of potentially infectious particles you breathe in by more than a factor of 20,” he added. Cappa noted that even if everyone around you is without a mask, wearing a well-fitting N95 can reduce the amount of infectious particles you could breathe in. “If, hypothetically, there were 100 infectious particles that you were about to breathe in without a mask, you would only inhale five or fewer of them with a properly fitted N95,” he explained in his email. Cloth face coverings — which were recommended earlier in the pandemic when other protections were in short supply — can filter large droplets, but the most effective masks, like N95s, can filter those as well as smaller aerosols or particles that infected people can exhale, Erin Bromage, an associate professor of biology at the University of Massachusetts Dartmouth, explained in December. to below mask mandate in transportation 1:14 N95 masks that have been approved by the US National Institute for Occupational Safety and Health (NIOSH) can filter at least 95% of the airborne particles when used correctly, according to the Centers for Disease Control and Prevention (CDC). Surgical or disposable masks are 5% to 10% less effective than N95s, Bromage noted. A CDC study, published in February, found that people who said they always wore a mask indoors while out in public were less likely to test positive for COVID-19 than people who did not wear a mask between February and December. 2021. A new @CDCMMWR study shows that people who reported always wearing masks or respirators in indoor public settings in California were less likely to test positive for #COVID19 compared with those who reported not wearing a face covering. Learnmore. https://t.co/T8gaqiPHyI pic.twitter.com/6UJ9cs60NK — CDC (@CDCgov) February 4, 2022 Among more than 500 people who reported the type of mask they use, wearing them “decreased the chances of testing positive” to COVID-19 by 56% among those wearing cloth masks, 66% among those wearing surgical masks, and 83% among those wearing N95s or KN95s, compared to people not wearing them, according to the CDC. Now, “if everyone else stops wearing masks, those percentages could go down,” Cappa warned CNN. Dr. Preeti Malani, director of healthcare for the Division of Infectious Diseases at the University of Michigan in Ann Arbor, has been treating people with COVID-19 for more than two years. Her patients often don’t wear masks, but she does. “To my knowledge, I have not had covid-19,” Malani said. “So the personal protection of masks works very well, especially when combined with vaccination and good ventilation.” Malani added that she feels it is safe to travel, even for those who might be at higher risk of more severe COVID-19 illness. Especially if they follow mitigation measures like getting vaccinated, getting tested, and wearing high-quality masks that fit well. Yes, even if those around them are without masks. “It doesn’t mean you can’t use public transportation. It means you have to think about it,” she said. In that sense, she added that she is more concerned about the spread of covid-19 in a crowded bar than on a plane where the air ventilation is of high quality. Other methods of protection Philadelphia imposes use of masks due to increase in cases 2:24 “When you use a mask in addition to vaccination, ventilation, possible tests and social distancing, it can keep that risk manageable,” Malani said. “What I don’t want to see is people suddenly being so afraid of covid-19 that they don’t travel anymore.” This week, she will travel to Lisbon, Portugal, to attend a meeting of the European Congress of Clinical Microbiology and Infectious Diseases. “I plan to wear my mask on the plane,” she said, not because she’s worried about getting seriously ill from covid-19, but because she doesn’t want to delay the trip home if she catches it abroad. Cappa wrote in her email that the “riskiest” time for pathogens to spread during travel is when people are “stationary.” For example, when everyone lines up to disembark from a plane. “This is because air exchange — which helps keep the air clean — inside planes, buses and trains tends to be greater when (the vehicle) is in motion,” she said. “On an airplane, you can open the vents (if your plane has them) and direct them towards you, because the air that comes out has been filtered. Also, if you’re talking to other people, it’s always helpful to keep some distance,” she added. . “Of course, that’s not always possible on public transport, in which case it can be helpful to try to avoid direct breath from your neighbors,” she said. On the other hand, Dr. Vivek Cherian, a Chicago-based Internal Medicine doctor and father of three young children, believes it’s too soon to reverse mandatory mask-wearing for travel. “In my view, we should not suspend mask mandates in this country until everyone who wants a vaccine has access and opportunity to receive one, including children under the age of five,” Cherian wrote in an email. , this Tuesday. “If you are immunosuppressed or have family members who are immunosuppressed or unvaccinated, individual mask use can still be effective. The key is to use the best mask available, preferably one with an N95 respirator, as they offer a high degree of protection.” , he explained. “I continue to wear masks because my three children are under five years old and are not eligible for vaccines at this time,” he completed. CNN’s Kristen Rogers contributed to this report.