Is Flying Hygienic? Common Boarding Method Can Spread Infections, Study Says

The excitement of traveling to a new place is more often than not dampens once you get to know that flying in a plane could give you an infection.

So how do infections spread inside an aircraft? The answer to this probably lies in a recent study that suggests the problem lies in the way airlines board passengers.

Usually, passengers are boarded in three sections of the plane — the front, the middle and the back. This makes the aisle area crowded, making passengers come in close contact with each other, leading to increased chances of infections being passed on, the study said.

The mix of people from different locations during the boarding and journey time facilitates the spread of germs from an infected person to another, and from one continent to another.

The study suggests that airlines should analyze these factors and come up with alternative methods of boarding to minimize chances of infections being transmitted from one person to another.

The study suggested the best way was to divide the plane into two sections, rather than three, and randomly board passengers in those sections.

So how was the study conducted?

Researchers from a cross-disciplinary team at Arizona State University said they used "the computational model to evaluate the effects of passenger movement within airplanes and air-travel policies on the geospatial spread of infectious diseases."

The study was done keeping in mind the 2014 Ebola outbreak in West Africa.

For analysis purpose, a hypothetical case of a passenger with Ebola was evaluated to see how contact with the disease might change and spread based on boarding strategy.

Both the two-section and three-section boarding strategy were used, Business Insider reported.

“We consider the situation with one infected individual with Ebola traveling on a commercial airplane,” the report said quoting the researchers.

“The infective passenger onboard is not identifiable; therefore, we varied the seating position of the infected individual through all the seats.”

They found that when passengers boarded the plane in two sections, the risk of exposure to illness dropped from 67 percent to 40 percent.

Not only boarding strategy, but even the size of the planes matter in the spread of diseases; the study suggested that smaller planes were better as fewer passengers mean fewer chances of an outbreak. Also, passengers spend lesser time in reaching their seats.

One of the researchers, Anuj Mubayi, told Business Insider in case of an outbreak, smaller airplanes should be used, instead of completely banning flights to that particular destination. "That can drastically reduce the probability of introduction of infection," he said.

In response to an email requesting their comment on the study, Southwest Airlines said that passengers board their planes based on boarding group (A, B, or C) and number (1-60). Boarding positions are assigned at check in and are displayed on boarding passes.

In Southwest Airlines, general boarding starts with "Business Select" customers, who are guaranteed positions at the front of the A group, followed by "Rapid Rewards" tier members and the remaining customers in the A group, families with children age six and under, then groups B and C.

They also have an open seating policy, so customers can also choose to sit on any available seat while boarding.

The airlines also told us that their boarding and open seating policy has remained relatively constant over the years based on "Employee and Customer feedback." However, they did not directly comment regarding the study.

Apart from the boarding strategy, travelers can also become sick from the cabin temperature. Often they complain of fever after returning from flight journeys, some might even say that they caught cold due to low temperature, but why do pilots turn down the temperature?

One commercial airline captain told Condé Nast Traveler, a luxury and lifestyle travel magazine, this month that he dropped the thermostat dial when encountering turbulence to cope up with motion sickness.

According to a 2008 study published in American Society for Testing and Materials, "Fainting Passengers: The Role of Cabin Environment," it was found that a cabin that is too warm can increase the chances of a passenger fainting. It is so because each individual's body temperatures are different and airlines prefer to keep the cabin cooler and have passengers be cold rather than having even one passenger faint.

The risk of fainting is "higher aboard an aircraft than on the ground” due to “reduced pulmonary ventilation" or reduced blood flow to the brain, caused by immobility, drowsiness, and the build up of gas in the abdomen, the study suggested.