Irrational, or rational, people are afraid of getting on planes right now. Some think all travel is bad, while others don’t mind it, provided travel is done safely and responsibly, between two areas with low infection rates and adequate medical facilities. But in both camps, fears around the actual journey still exists. Should it?
A new study from top scientists at MIT has greater insights than ever before into the likelihood of catching covid-19 on a flight, and how travellers are still making their way around the world, even on planes where people may have covid-19, without catching it.
According to MIT Professor Arnold Barnett, the chances of catching covid-19 on a domestic US flight with a duration of two hours, are 1 in 4,300, or 1 in 7,700 if the airline blocks middle seats. The new study caveats results with a margin of error factor of 2.5, but the number are still compelling, if true.
These death-risk levels are considerably higher than those associated with plane crashes but comparable to those arising from two hours of everyday activities during the pandemicArnold Barnett, MIT
The purpose of the study was simple: to settle the debate between whether blocking middle seats actually mattered.
The science behind whether blocking middle seats can make an impact has been highly contested, with top officials such as Dr. Anthony Fauci expressing dismay at airlines, including American Airlines, for refusing to block middle seats, while some say it doesn’t do enough to justify the financial impacts.
According to the results, which are awaiting peer review, blocking middle seats created a safety factor of 1.8, which is a huge margin. In layman’s terms, you’re just under half as likely to catch covid-19 on a flight if the middle seat is blocked, compared to flights where middle seats are not.
It’s the difference between the probabilities 1/4300 without middle seats blocked and 1/7700 if the middle seat remains blocked.
Methodology Behind The Study
The study examined three questions, which even to the non scientific community, seem rather logical. First, the study examined the probability that someone on board may already be infected with covid-19, which particularly in the USA, where probability was determined, is higher than elsewhere.
Second, the study aimed to quantify how successful universal mask and other hygiene and distancing measures could be in curbing the flow of covid-19, in the event of an infected traveller on board.
Finally, the study examined risks associated with where one might be sitting, in relation to the infected person during flight, and whether there was a difference in where the infected passenger was sitting – aka closer to the front of the cabin, middle, rear and so forth.
Air Filters Are No Joke
According to the research, high grade HEPA filters used on board aircraft, which don’t feature on common forms of mass transit are highly effective. The filters are said to make marked difference in stemming spread, even when there’s a covid-19 infected passenger on board, with the study stating…
We posit that the airlines are correct when they contend that the powerful air-purification systems on jet aircraft largely negate the risk of aerosol transmission of Covid-19. Thus, when a contagious passenger is in her seat in row 22, she poses little risk to another traveler seated in row 14.Arnold Barnett, MIT
Going further, the study addressed the elephant in the room, which is the notion that you the passenger may be seated directly next to a passenger carrying covid-19, aka the spreader on the plane. It’s here that strong data science in favor of blocking middle seats is introduced.
A given passenger can get infected, however, by droplets from a contagious passenger in the same row. But the risk depends on the distance between the two passengers. The meta-analysis of more than 100 studies in The Lancet (Chu et al, 2020; ) yields the approximation that infection risk is about 13% given physical contact with the contagious person, and that it falls by essentially a factor of two as the distance from that person increases by one meterCovid-19 Spread Study
As expected, you’re most at risk if you’re literally rubbing elbows with an infected passenger, but with droplet transmission curbed through universal mask wearing, and distance creating an extra barrier, each meter cuts the risks in half.
Would New Seating Solutions Work?
The study surmises that adding plexiglass between each row, a concept which has already actually been introduced by cabin manufacturer Priestmangoode, could be of some benefit to airlines in the fight against covid-19.
Plexiglass barriers between each row are loosely estimated to be 1/4 more effective in blocking spread, though that’s not as wowing as it sounds. That’s because the study estimates standard seat backs to eliminate 3/4 of spread between rows.
It’s not hard to then understand why rigorous aircraft cleaning in between each flight can make meaningful difference.
Is Flying Worth The Risk?
If1/4,300 sounds a bit too close for comfort, the odds of actually dying from catching covid-19 are estimated to be much lower, somewhere between 1/400,000 to 600,000, according to the study.
The odds aren’t as unlikely as being involved in a fatal plane crash, which sit at 1 in 34,000,000, but are far better than the 1/2618 probability of dying from choking on food, the 1/104 chance of dying in a car crash, or 1/118,000 chance of dying from a dog attack.
The study gives nuance the notion that someone catching covid-19 on a plane can go on to cause harm to others outside of the flight, but these scenarios are duly modelled into the results.
Using the USA as an example also makes the study far from a pie in the sky “best case” analysis, given the higher rates of covid-19 transmission in the USA, compared with other countries currently open for travel.
Travel certainly isn’t without risks, or responsibility these days, but the study results, paired with real life data from countries like Australia, where sick people were on board, but no one caught covid-19 signal potential hope for a rebound in travel as practical measures and new treatments mount.