As the US vaccine rollout accelerates, almost all Covid restrictions have been lifted for those who have been inoculated and it’s increasingly more common to see bare faces than a sea of face masks. But there’s one glaring exception: Airplanes, airports and other forms of public transportation still require face coverings. And as the economic reopening pumps up travel demand at a faster-than-expected pace, the contrast between laxer rules elsewhere and a need to keep air travel safe is creating a frustrating side effect: unruly passengers.
The number of air rage incidents has exploded this year. The Federal Aviation Administration has recorded more than 3,000 reports of unruly passengers through mid-June. It has identified potential violations that merit investigation in 487 incidents — the most for any year in data going back to 1995 — and has proposed a total of $563,800 in fines. Many of the outbursts are linked to failure to comply with mask mandates. The US Centers for Disease Control and Prevention continues to require all people, regardless of vaccination status, wear masks in public transportation settings, including on planes. The Transportation Security Administration extended its mask mandate through Sept. 13. This rule is federal, meaning it supersedes any individual state guidelines. It also outranks personal preferences.
I can’t believe I even have to write this sentence, but it’s never OK to assault fellow passengers or interfere with the flight crew’s ability to do its job. If you don’t want to follow the rules — whether that’s wearing a seat belt or a mask — stay home. That being said, there does seem to be plenty of confusion even among those who aren’t inclined to be unruly as to why masks are still mandated on planes when they are no longer required in restaurants, gyms, offices and even basketball stadiums for those who have been inoculated. Indeed, the business of making and supplying face masks for the US has lost its luster, with companies writing off excess stockpiles and shutting down factories. Aerospace executives have been loudly proclaiming the benefits of jet ventilation systems to anyone who will listen throughout the pandemic. So why then do you still need to wear a mask on a plane?
Airplanes are riskier environments because of the proximity of passengers over an extended length of time, Dr. Andrew Pekosz, a professor of molecular microbiology and immunology at the John Hopkins Bloomberg School of Public Health, said in a phone interview. (The Bloomberg School of Public Health is supported by Michael R. Bloomberg, founder and majority owner of Bloomberg LP, the parent company of Bloomberg News.) In a restaurant, for example, you typically face — and breathe toward — your own party, but sit back-to-back with other patrons. Waiters and busboys will stop by the table but they won’t be there for very long. On an airplane, the odds are higher that your seatmate is a complete stranger from another part of the country and you’ll be with them at least an hour. And there are certain unique situations on airplanes where people lean across each other — to accept a beverage or a bag of peanuts, for example, or to put luggage in the overhead bin. The longer the flight, the more opportunity for infection.
A study published in the CDC’s Emerging Infectious Diseases Journal last year linked a single symptomatic individual on a 10-hour flight from London to Hanoi in early March of 2020 to at least 12 other Covid cases among other passengers in the business-class cabin where she was sitting. The risk “during long flights is real and has the potential to cause Covid-19 clusters of substantial size, even in business class–like settings,” Dr. Nguyen Cong Khanh, an epidemiologist at the National Institute of Hygiene and Epidemiology in Hanoi, and colleagues wrote. A separate analysis used contract tracing and genetic sequencing to connect Covid infections for two flight attendants to a couple flying from Boston to Hong Kong, also in early March last year. “ The only location where all four persons were in close proximity for an extended period was inside the airplane,” Dr. Edward M. Choi of the London School of Hygiene & Tropical Medicine and his fellow researchers wrote. “Their virus genetic sequences are identical, unique, and belong to a clade not previously identified in Hong Kong, which strongly suggests that the virus can be transmitted during air travel.”
Importantly, face masks weren’t yet commonplace at the time of either the London-to-Hanoi or Boston-to-Hong Kong flight. Rather, those studies underscore the risk of doing away with nose and mouth coverings too soon. As successful as the US vaccine rollout has been relative to other countries, America still hasn’t reached a level of inoculations that would indicate herd immunity, and the highly transmissible delta variant strain first identified in India is spreading in undervaccinated pockets of the country. “In any given plane, half the people may not be vaccinated and therefore they do represent a risk of spreading the virus to other people,” Pekosz said. “You can’t think about situations as black and white. There are gradients of risk. Even with a good ventilation system, it’s clear that airplanes represent one of those high risk scenarios.”
Airplane ventilation systems are indeed quite good. Boeing Co. 767 and 777 models exchange air at a faster rate than what’s recommended for hospital operating rooms and patient isolation units, according to a Department of Defense study published last fall with assistance from Boeing and United Airlines Holdings Inc. Aircraft also use high-efficiency particulate air (HEPA) filters which are capable of capturing particles as small as the coronavirus. These systems work extremely well in diluting and cleaning the air of the cabin and preventing an infected passenger from spreading disease to an individual a row or two back, said William Bahnfleth, a professor of architectural engineering at Pennsylvania State University and the chair of the epidemic taskforce for the American Society of Heating, Refrigerating and Air-Conditioning Engineers. But the best ventilation system in the world can’t do much if an unmasked infected person sharing your armrest starts coughing or sneezing, especially in an enclosed environment like an airplane, he said.
That same Defense Department study found that only about 0.003% of infected particles on average cross into a passenger’s breathing zone — but importantly, that’s when the passenger is seated and wearing a mask continuously. The study also focused on aerosol transport and didn’t account for virus spread via large droplets, such as those expelled when someone coughs or sneezes directly on you. As such, the researchers recommended disinfectant cleaning of the aircraft and continued mask-wearing. They noted that face coverings reduced exposure to cough droplets by more than 90% in some of the tested scenarios. Other studies have attributed the lack of Covid spread from infected patients on planes to masks.
It’s worth noting that at no point have the airlines advocated for the mask mandate to be dropped. Nothing would kill the snapback in air travel like a super-spreader flight. For every boisterous protestor, there are plenty of other passengers who prefer the added protection and are simply grateful for the opportunity to travel again. Mandating masks also gave airlines cover to start selling the middle seats again, which boosts both their revenue and profits. With Morgan Stanley planning to ban unvaccinated employees from entering the office and JPMorgan Chase & Co. heading in a similar direction, it’s unlikely that those banks or other major employers would be comfortable sending their workers into a maskless free-for-all on planes. It’s equally impossible to envision a scenario in which international borders are reopened without mask policies for travel. The alternative is to start requiring proof of vaccination or a negative Covid test before boarding a plane — something that is required in certain states for large indoor arenas.
“I can understand that people do find the rules a little bit confusing. We’re at a stage in the guidelines where things are nuanced,” Dr. Jessica Justman, associate professor of medicine in epidemiology at Columbia’s Mailman School of Public Health, said in an interview. “But I have to ask the question — is wearing a mask really a hardship?”
Bloomberg
