Emptying airplane middle rows could limit passengers' exposure to the coronavirus during flights by a third, suggests a study released on Wednesday.
The results from the new CDC and Kansas State University study come after Delta became the last major airline to end the practice of emptying middle row seats to physically distance passengers, starting May 1.
"Research suggests that seating proximity on aircraft is associated with increased risk for infection with SARS-CoV-2," begins the study led by the CDC's Watts Dietrich.
However, just how much risk remains unclear.
In the study, researchers approximated airborne dispersion of SARS-CoV-2 in airplane cabins with viruses that attack bacteria to simulate the coronavirus (these bacteriophages are harmless to people). Similar modeling has been used to gauge the risks of anthrax exposure on subways, for example, in the past.
The airplane simulations showed a 23% reduction in exposure for the closest scenario: a person separated from an infected passenger by an empty middle seat, compared against sitting right next to them.
For a simulation of three rows of airline seats, the reduction in exposure was 57% for passengers separated from infected ones by empty middle seats.
Overall, the study suggested that emptying middle seats reduced the risk for all passengers from 35% to 39% on flights with one to three infected passengers.
Worth noting, the study only looked at exposure to viral particles, not actual transmission of disease, where fully vaccinated people should be highly protected. The study also could not factor in the effects of masks in further cutting exposure risks, the researchers noted, but they cited some studies suggesting that masks don't block all viral particles released as aerosols by infected passengers.
"Combining the effects of masking and distancing is more protective than either by itself," they concluded.