With U.S. airlines now allowing passengers to fly on domestic flights without wearing masks following a ruling from a Florida judge, experts are still urging air travellers to keep their masks on as the BA.2 subvariant of Omicron continues to spread.
The airline and travel industries had been calling for the removal of these mandates for months. Last December, Southwest Airlines CEO Gary Kelly told a U.S. Senate committee hearing that HEPA filters on airplanes capture 99.97 per cent of airborne pathogens.
"I think the case is very strong that masks don’t add much, if anything, in the air cabin environment," Kelly told the committee.
But University of Saskatchewan epidemiologist Dr. Nazeem Muhajarine notes that airplane HEPA filters are only active if the plane’s engines are on. During boarding, deplaning and refuelling, when the engines are off, the filters don’t offer any protection.
"HEPA filters do really a good job of filtration and ventilation. That being said, that air is not being cleaned and filtered and ventilated the whole time a passenger is on board," he told CTVNewsxjmtzyw.ca on Wednesday.
Several studies have concluded that wearing masks aboard a plane can decrease the likelihood of COVID-19 spreading.
A May 2021 study from the U.K. looked at the probabilities of inflight COVID-19 infection in an experiment conducted aboard a Boeing 777 aircraft. For a 12-hour flight, they calculated that wearing high efficiency masks like N95s can reduce the average probability of infection by 73 per cent, while low efficiency masks can reduce infection by 32 per cent.
However, the effectiveness of these masks goes down when factoring in mealtime. If all passengers were to have removed their masks for one hour to eat a meal, researchers calculated that the average probability of infection only went down by 59 per cent for high-efficiency masks and eight per cent for low efficiency masks.
Simulations looking into aerosol spread of COVID-19 aboard Boeing 767 and 777 jets conducted in August 2020 also found that when passengers were wearing surgical masks, the reduction in droplets from coughing was more than 90 per cent.
Muhajarine also noted the rising COVID-19 numbers in much of Canada as well as the U.S. and called the judge’s ruling was "ill-timed."
"COVID-19 hasn’t gone down to the level that it needs to go down to before we before we take a look at mask mandates on flights. Flights are a situation where people are tightly packed," he told CTVNews.ca on Wednesday.
While masks are no longer mandatory, the U.S. Centers for Disease Control is still recommending wearing masks on flights and other indoor public transportation settings. U.S. President Joe Biden said on Tuesday that his administration may appeal the ruling.
The ruling does not affect flights to and from Canada, however, and Canadian Transport Minister Omar Alghabra says there are no plans to lift Canada’s federal mask mandates for airlines and VIA Rail.
The Conservatives have been calling on the Liberals to follow the lead of the Florida judge and lift the transportation mask mandates in Canada. But Muhajarine believes removing the mandates would be "hugely unadvisable" at this point.
"We need to hold on to that for a little bit longer until we see the virus and COVID-19 numbers going down," he said.
If you’re planning on flying within the U.S. aboard a flight of mostly unmasked passengers, Muhajarine recommends getting up to date on COVID-19 booster shots and keeping a well-fitted mask on during the flight.
"Learning to live with this virus is about actually keeping myself and others safe and not just forgetting that virus, thinking it’s gone away. It hasn’t gone away," he said.
Even if you’re the only one on the plane wearing a mask, Dr. Amesh Adaja, senior scholar at the Johns Hopkins Center for Health Security, says "one-way masking" can still help reduce your risk of catching the virus, especially if it’s a well-fitted high efficiency mask.
"One-way masking does work. So, there’s a lot of people worried, but remember that if you’re wearing a well-fitted, N95-type equivalent mask, I think you’re in pretty good shape, especially if you’re vaccinated and boosted, because that’s the most you can do," he told CTV News Channel on Tuesday.
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Travelers enter a security line at Rhode Island T.F. Green International Airport in Providence, R.I., Tuesday, April 19, 2022. (AP Photo/David Goldman)
