To Mask or To Shield: Which Is Safer Inflight?
By Robert McGarvey
Tens of millions now are mulling – maybe obsessing about – a simple question: Can we safely breathe the air on a plane?
According to a recent survey, 37% of us are worried about airplane air – and 65% of us are worried about sitting next to an infected person.
Understand: what airline we choose and how we decide to protect ourselves (and others) inflight matter. There are decisions that we can make that work. And others that don’t.
For instance: read a Travel Pulse story, where a University of Alabama professor of medicine and infectious diseases, Dr. Michael Saag, offered the explosive opinion that on some airlines – he singled out Delta with its CareStandard program – the air is in fact very clean. Saag told Travel Pulse: “If passengers are spread apart and wearing masks, then it is very safe on an airplane.”
The Delta system filters cabin air every two to five minutes and removes 99.99 percent of particles.
One conclusion: whatever you do don’t fly American or United – both refuse to commit to blocking middle seats. Delta and Southwest both say they are. Easy choice about which to fly. Physical distancing remains our single most effective way to stay healthy and I am not surrendering that safety to prop up a carrier’s profits. Give me an empty middle seat or give me my money back!
The next big question is a non question because the answer is plain: To mask or not? Good news is that nowadays most carriers actually enforce a face mask policy. Sure, there are troglodytes who insist they have a right to not wear a mask but that viewpoint is absolute nonsense.
Mask up to stay safe and keep those around you safer.
Which brings us to a question of the moment: are face shields better than masks? Suddenly mask proponents are confronted with what might be the better option: a shield that usually is easy to wash, easier to breathe in, and for many just more pleasant.
Qatar is now requiring shields for economy passengers – no US carrier is. But, anecdotally, I hear more passengers on US carriers are wearing them. Should we join that club?
According to experts cited in a Washington Post story, shields may in fact offer more protection: “Face shields are a physical barrier that can provide travelers an extra layer of protection, according to Nahid Bhadelia, the medical director of the Special Pathogens Unit at the Boston University School of Medicine.
“‘I’m glad to see that a lot of airlines have mandated the use of masks, and the use of face shields is even better,’ Bhadelia said.”
Masks excel at protecting others from droplets you may expel – but shields do better at protecting you from the droplets others around you may expel.
Are face shields flat out better than masks? You will be hearing that question more – as more of us opt for the shields – and know that at least some experts agree the shields are better.
Amesh Adalja, M.D., a pandemic preparedness expert at the Johns Hopkins Center for Health Security, told AARP, ‘There’s a lot of at least biological possibility to suspect that [shields] are definitely better than homemade face masks, and maybe even better than other types of masks as well, because they not only prevent you from spreading it … [and] because it also covers your eyes, it provides more protection to the mucus membranes of your face where you might be getting infected.’”
A JAMA opinion piece, signed by multiple physicians, agreed about face shield benefits. “They are comfortable to wear, protect the portals of viral entry, and reduce the potential for autoinoculation by preventing the wearer from touching their face.”
The JAMA piece went for home plate with this: “Most important, face shields appear to significantly reduce the amount of inhalation exposure to influenza virus, another droplet-spread respiratory virus. In a simulation study, face shields were shown to reduce immediate viral exposure by 96% when worn by a simulated health care worker within 18 inches of a cough.”
Amazon stocks a variety of shields.
Word of advice for flyers however: Don’t count on airline acceptance of shields in lieu of masks. A particular crew may, another may think different and there are no national guidelines (yes, there should be but the absence is another story of presidential dereliction). So even if you are a hardcore shield person…carry a face mask in a pocket. Just in case.
And know some scientists in fact highly recommend the dual tactic defense. A mask protects others from you. A shield protects you from them.
In a world where a deadly virus is rampaging, a dual protection just may sound mighty good.
If you see me on a plane wearing both, I’ll forgive your giggles.
Just know I am probably safer than you.
I spend 34 years doing aerosol science research at the University of California. I find the advice that face shields offer adequate protection against inhalation of the SARS-Cov-2 virus disturbing. The shields are open on the sides and bottom. They can protect against large droplets that are emitted at high velocity during a sneeze or cough. These droplets with significant momentum can travel a significant distance. A shield would block them. However, we now know people emit small liquid particles while breathing, speaking and singing as reported in the journal Nature https://www.nature.com/articles/s41598-019-38808-z#citeas . It is not possible for a shield to stop the inhalation of these particles – they will flow with the air you breathe around the sides and bottom. WHO now concedes that these small particles may contribute to infection. And in fact, they best explain the occurrence of spreader events indoors at churches, family gatherings etc.
I have been reading the technical literature about viral inoculum in aerosols, which are microscopic droplets that float in air and do not fall to the ground or other surfaces. A face shield does not stop the inflow or outflow of aerosols because the only way to stop aerosols from being inhaled without a mask is to stop breathing.
Only N95 masks filter out aerosols. Cloth and surgical masks do not.
Bottom line: A shield helps keep droplets from spraying onto your face and eyes if you are in the direct line of fire from a cough or sneeze. But you need to also wear a mask behind the face shield to filter aerosols that float around the shield.
I flew back from Asia 4 weeks ago, 16 hours flying plus a 12 hour airport layover.
I had an N95 respirator with valve, covered by a paper surgical mask, plus an adjustable
face shield. And I was still petrified (when I booked the ticket the plane was 1/3 full,
10 days later when I got to the airport, it was completely full, every seat). Everyone had
a mask, but many were crummy, thin cotton masks which are useless, most of the rest
just poorly fitting paper masks. Many people pushed them under their chins, not to mention
removing them for meals and drinks.
There is no way to avoid being exposed to others in such situations. I cleaned my face shield,
replaced my masks, showered and changed my clothes during my airport transfer. And it
was still the most stressful travel experience of my life. Until 7 days after I returned, I was
self-quarantined, and testing my temperature and O2 levels twice a day. Hoping I didn’t wake
up with a fever and cough one morning.
My travel was unavoidable. But it would be hard to put myself into that situation again. If
you think things are safe, just remember the 1000+ infected TSA agents at 4 dozen US airports
(without adequate PPE, procedures, and some even working while sick). There is plenty of
risk out there right now. The thought that I would fly for work is a distant fantasy.