Don’t end the mask mandate for US airlines

Pressure is intensifying to end the masking requirement on U.S. airlines set to expire on April 18. The U.S. Senate called for an end to the mandate in a 57 to 40 vote, as have the CEOs of 10 U.S. airlines in a letter to President Biden. The flight attendants of Southwest Airlines, weary of dealing with unruly mask resisters, have done the same. Unfortunately, though, ending the requirement now would be a serious mistake.

It is argued that on-board masking should end because the indoor mask mandate is essentially gone, the air in airplane cabins is exceptionally clean, and “air rage” confrontations have spiked during the pandemic. None of these positions is irrational, but none of them is convincing.

First of all, the Centers for Disease Control (CDC) has not suggested an end to all indoor masking. Its recommendation was limited to fully vaccinated people in regions with lower rates of COVID-19 hospitalization. But not all air travelers are vaccinated, and passengers come from all areas of the country. As of now, there are about 800 U.S. deaths per day from COVID-19; vaccine effectiveness is waning; and the most contagious variant of COVID-19 so far, Omicron BA2, is growing rapidly in the United States. The case for ending the mandate is no stronger today than at many earlier points in the pandemic, when it was always deemed prudent to continue the requirement.

To be sure, airplane cabins are less hazardous than certain other indoor venues where people go maskless, like mobbed concerts at which fans sing at the top of their lungs. But potential superspreader events should not set the standard for what exposures are considered safe.

And while the HEPA (high energy particulate air) filters on most (although not all) U.S. aircraft are effective, they are not panaceas. The peer-reviewed medical literature contains numerous reports of COVID-19 transmission on airplanes with functioning HEPA filters. They include a flight to Vietnam on which one COVID-19 carrier infected 15 other passengers, an Australian flight in which at least 8 travelers became infected, and an Irish flight in which COVID-19 among passengers caused 46 follow-up infections to people on the ground. These were all long flights, but there was also a two-hour Japanese flight in which an infected passenger transmitted COVID-19 to 14 other passengers.

Nor should masking be viewed as a simple matter of personal choice because those who want to wear masks on planes can continue to do so. Masking is highly effective if all passengers take part. Even masked travelers are at higher risk if others on board are infected and unmasked.

It would certainly be good to see the end of on-board disruptions caused by the mask requirement. But what price in extra hospitalizations and deaths should be paid to meet that objective? Who would want the police to stop anti-crime patrols to avoid unpleasant encounters with lawbreakers? Continued enforcement of the mandate might likewise be the lesser evil.

Practically no one wants masking to continue forever, and the federal government should set forth quantitative criteria for reducing and then eliminating the requirement. Masking should presumably be gone once death rates from COVID-19 drop to the levels associated with seasonal flu. But COVID-19 mortality rates now are eight times as high as those from the flu. We just aren’t there yet.

A decision to extend the mask mandate beyond April would surely be unpopular. But it would be the right decision.

Arnold Barnett, Ph.D., is the George Eastman professor of management science and a professor of statistics at the MIT Sloan School of Management whose research specialty is applied mathematical modeling with a focus on problems of health and safety as they relate to policy. Barnett has a long-term research interest in aviation safety and was recognized with the 2002 President’s Citation from the Flight Safety Foundation for outstanding contributions on behalf of safety. He has worked for 13 airlines, five airports, the Transportation Security Administration and the Federal Aviation Administration.