Covid 19: Empty middle seats cuts risk on planes says CDC study

The CDC study concluded that physical distancing shoud be used in addition to facecoverings in plane cabins. Photo / Nicolas Economou, Getty Images

As New Zealanders and Australians prepare to embark on their first overseas flights since the pandemic, a new study has revealed some simple steps that can reduce the risk of catching Covid-19 in plane cabins.

A new report by the US Centre for Disease Control (US) has shown that physical distancing on planes can reduce risk of exposure to the disease. The modelling by Kansas State University and the CDC shows that leaving the middle seat empty on rows of plane seats can reduce infection rates by a third.

However this requirement was dropped from planes in New Zealand, last year under pressure from airlines and local authorities who claimed the measure made air links unviable.

"Research suggests that seating proximity on aircraft is associated with increased risk for infection with SARS-CoV-2" was the conclusion of the CDC's division of Field Studies and Engineering.

The study involved dispersing clouds of harmless bacteria within a test cabin to model exposure and infection rates. It was found emptying middle seats reduced the risk for all passengers from 35% to 39%.

The study also showed that emptying the middle seat reduced the risk of exposure not only for the closest passenger but the whole row – with an empty seat being safer than another person between you and the infected passenger.

The CDC report showed that an empty middle seat reduced exposure risk for the whole cabin. Photo / Supplied, CDC

Last year Air New Zealand and Queenstown Mayor Jim Boult complained that physical distancing on planes was costing the tourism 50,000 visitors a week, during the Spring school holidays.

Jetstar grounded its domestic flights for four-weeks while Auckland was at Level 2, saying the network was not viable while physical distancing was being enforced.

The requirements for physical distancing were eased in September last year, although it is still required while loading and disembarking planes.

Currently the NZ CAA guidance advises carriers to maintain at least 1 metre of distance between passengers during raised alert levels, telling airlines that the "onus is on you as an organisation and/or operator to ensure you have a COVID-19 safety plan in place to meet those rules."

Use of masks on planes

The wearing of face masks is mandatory on Transtasman routes, although physical distancing is not enforced.

The CDC study recognised face coverings as an important, but only part of the solution of reducing transmission.

In the application of the results the report highlighted prior research that showed "some virus aerosol is emitted from an infectious masked passenger, such that distancing could still be useful."

"Combining the effects of masking and distancing is more protective than either by itself," it concluded.

A spokesperson for the Qantas group, which operates Qantas and Jetstar, said there were no caps on seat sales for Transtasman flights. The New Zealand routes are managed under the group's Fly Well policy, which advises "social distancing" in public spaces at airports and check in but not for plane cabins.

The Herald has contacted Air New Zealand for comment.