Don’t you wish you didn’t have to breathe in someone else’s exhaled air while flying?

Covid-era restrictions on passenger planes, including mask mandates and negative tests, are officially over. Now, any American traveling domestically or returning to the United States from a foreign country does not have to wear a mask, does not have to provide a negative Covid test, and must present proof of vaccination. We have returned to a pre-Covid aviation industry, which presents several dangers as Covid continues to weigh heavily.

As more people return to standard travel practices, Covid transmission on planes will increase. As the government and airlines roll back Covid passenger protections, it is now up to individuals to take all measures to protect themselves from infection. Continuing our series on air travel during Covid, here we will discuss the intricacies of Covid transmission on airplanes and how individuals can protect themselves from Covid on upcoming flights.

Recently, the National Academy of Sciences, Engineering, and Medicine released a report detailing aviation in the age of Covid-19. This report presents the science-based risks and mitigations for commercial aircraft passengers, which we will use to guide our discussion.

Being on the same plane as another passenger infected with Covid-19 does not guarantee transmission to everyone on board. The likelihood of infection is low unless you are seated within two or three rows of an infected person. The air on planes has higher CO2 levels than outside or inside, which means your chances of contracting Covid-19 on a plane are higher than at home or at home. park, but still not guaranteed. CO2 in enclosed spaces such as an airplane is usually the result of gas, as well as infectious particles, in other people’s exhalations.

The air you breathe is ventilated, reoxygenated, filtered and returned to the cabin to be breathed again. However, air flows along the circumference of the cylindrical plane, not lengthwise. This means that the air you breathe is mostly shared between those in your row and those directly around you. The process is far from perfect. We recently monitored the CO2 concentration several hours after the start of a flight on a national airline and found that it was four times higher than in the open air.

A study of a Vietnam Airlines flight from London to Vietnam examined the importance of proximity. Of the 217 passengers and crew on board, one passenger showed symptoms of Covid-19 mid-flight. Later, 14 passengers and one crew member tested positive. Notably, 11 of the 14 passengers were seated within two meters of the symptomatic carrier.

These findings are reflected in several studies from the National Academy of Sciences, Engineering, and Medicine report. A simulation revealed that the general probability of Covid infection for a passenger on a full flight is one in 3,900. These chances increase considerably, up to 80% if you are seated in close proximity to an infected person without mask. Notably, the same simulation revealed that rigorously enforced mask-wearing significantly reduces the chances of transmission; however, no US-based airline now mandates mask-wearing.

The SARS-CoV-2 virus is transmitted in three ways. First, via droplets such as sneezes and coughs. Masks would essentially erase the chances of droplet transmission. Still, U.S. District Judge Kathryn Kimball Mielle of Florida has seen fit to strike down the federal mask mandate, which means mask use on domestic airlines is optional.

The second method of transmission is aerosols, which are like droplets but much smaller produced by breathing. Aerosol transmission is how the typical asymptomatic carrier transmits Covid-19. Again, the risks of aerosols would be mitigated by masks.

The third method of transmission is via fomites, or surfaces that infectious particles can latch onto. An infected person can get traces of the virus on their hands by touching their eyes, nose or mouth, and touching an object leaves traces of the virus on another potential carrier. This can manifest itself on an airplane as handing something to the flight attendant, touching the bathroom handle, etc. This method of transmission is easily mitigated by standard hand sanitizer and general health practices like avoiding touching your face.

Depending on the level of community transmission, the likelihood of someone infected with Covid-19 boarding a plane is relatively high. For example, the report notes that in Texas, which at the time of writing had a Covid rate of 73 cases per 100,000 people, there is a 46% chance that a passenger on a 100-passenger plane will have the Covid. This number skyrockets to 96% when you consider that many cases go undiagnosed.

As the federal government and airlines have rolled back almost all Covid-19 restrictions, it is up to the individual to protect themselves against these risks. The report recommends non-pharmaceutical interventions like N95 masks, keeping as socially distant as possible from others, traveling as little as possible on the plane, regularly using hand sanitizer for personal use and on surfaces.

In addition, strategic flight reservations could also reduce the risk of transmission. For example, flights departing on Tuesdays, Wednesdays and Thursdays are less crowded than those departing Friday to Monday. Try to book mid-week flights and select a seat next to an empty middle seat, if possible.

Covid remains prevalent and the risk of in-flight infection is significant, but maintaining safe Covid practices could prevent a case of Covid which would have otherwise derailed your journey and potentially caused long-term problems for months and years. years.