Could airline boarding policies help spread communicable diseases? A new study suggests this may be the case.

Researchers at Arizona State University released findings showing airlines help spread disease by shuttling people from diverse origins in close quarters for hours at a time.

Making the problem worse is the common practice of loading passengers in front-to-back order, forcing passengers to stand in the aisles in close contact with each other. ASU researchers said dividing the plane into two lengthwise sections and letting passengers seat themselves randomly would lead to fewer potentially disease-spreading bottlenecks during boarding.

“Surprisingly, changing policies — even those as simple as boarding patterns — can have a significant impact on the global spread of an infectious disease,” said lead researcher Anuj Mubayi, assistant professor, ASU’s School of Human Evolution and Social Change.

The research shows disease is less likely to spread on smaller planes, such as those with 150 or fewer seats. Those planes are likely to have fewer potentially sick people on board for travelers to interact with — and they board faster.

“Using smaller airplanes during an outbreak, instead of completely banning flights to a specific destination, can drastically reduce the probability of introduction of infection,” Mubayi said.