Researchers from the Georgia Institute of Technology and Emory University will be studying how infectious diseases can be transmitted aboard passenger aircraft. Shown with a diagram of how SARS was transmitted aboard on aircraft is Vicki Hertzberg, an associate professor in Emory University’s Rollins School of Public Health. Photo: Gary Meek/Georgia Tech
A new study is expected to provide the first detailed information on how
infectious diseases may be transmitted aboard commercial airliners. Sponsored
by aircraft manufacturer Boeing, the research will document patterns of
passenger movement inside aircraft cabins and inventory the microbes present in
cabin air and on surfaces such as tray tables and lavatory fixtures.
The information provided by the three-year study could help improve health
and safety for both passengers and airline flight crews. Researchers from two Atlanta universities, the Georgia Institute of Technology,
and Emory University, are working together on the
project, in collaboration with environmental sustainability personnel from
Atlanta-based Delta Air Lines.
“The ultimate goal of this project is to reduce the transmission of
infectious diseases on aircraft,” said Howard Weiss, a professor in the Georgia
Tech School of Mathematics. “We will learn how people move around in aircraft
and study the microbes that are there at different times during flights. From
that information, we can start modeling the disease transmission and developing
Airborne infectious diseases transmitted during commercial air travel are of
concern to public health officials. In 2002, 20 people on an international
flight were infected by a single SARS patient, which showed how air travel
could serve as a conduit for the rapid spread of both emerging infections and
pandemics of known diseases.
Researchers know that bacteria and viruses can be transmitted in three ways
on aircraft: inhalation of small droplets coughed or sneezed by infected
persons and carried significant distances in cabin air; inhalation of larger
droplets that tend to fall within a meter of their sources, and transfer of
droplets from surfaces into the eyes or noses of susceptible individuals. The
latter—which may account for as much as 80% of the disease transmission—can
occur when passengers touch contaminated surfaces, such as seat tray tables,
lavatory door knobs, or sink handles.
“By understanding the patterns of how infectious diseases may be transmitted
from an infected person to an uninfected person, companies like Boeing may be
able to design aircraft that better protect passengers and crew members,” said
Vicki Hertzberg, an associate professor in Emory University’s
Rollins School of Public Health. “That will put us in a better position from a
public health perspective.”
Using radio-frequency identification tags (RFID), Hertzberg has been
studying how people interact—and potentially transfer infectious diseases—in
medical facilities such as hospital emergency departments. On aircraft,
however, the researchers won’t be able to use such technology because of
potential interference issues.
However, the researchers will use sophisticated sampling equipment carried
aboard the aircraft to gather information about what’s in the cabin air. They
will also swipe certain touch surfaces, and both the wipes and air-sampling
filters will be analyzed by polymerase chain reaction (PCR) and mass
spectrometry equipment to identify the microbes present. To study passenger
movements around the aircraft, the researchers plan to use a modern twist on an
old-fashioned technique: graduate students watching and recording movement on
“They will be actively looking at who’s getting up and down, when they are
doing it, and where they are going when they do,” Hertzberg explained. “We will
need to do this at a fairly high resolution with respect to time and
The researchers plan to put students on eight Delta flights using Boeing 757
aircraft. Filters from the air sampling and wipes from the surfaces will be
analyzed in a California
laboratory that can detect as many as 1,500 different bugs, among them, 300
different respiratory viruses, and 1,200 different bacteria.
Delta has been advising Hertzberg and Weiss as they design the study, and
will allow them to use mockups of aircraft cabins to test and practice their
“Delta has a long history of collaborating with researchers on safety,
health and environmental issues related to passenger aircraft,” said Steve
Tochilin, general manager of environmental sustainability for the company. “As
examples, we are involved in ongoing partnerships with two FAA-funded university
consortia focusing on airliner cabin environments, and noise and emission
reductions. We look forward to working with Georgia Tech and Emory University
on this research.”
Once data on passenger activity is collected and microbes identified, Weiss
and Hertzberg will create a computer model of the social network on an
aircraft. That will allow them to study how infections can be transferred in
the close quarters of an aircraft cabin.
Only in the last decade have researchers had the tools to determine that
human movement differs from that predicted by completely random movement, as
documented with dollar bill tracking, mobile telephone calls, and sensors that
can determine movement among conference attendees and students in elementary
and high schools.
“The most interesting part of this from a mathematical standpoint is that
this may be a new type of social network,” Weiss said. “For many years,
scientists have assumed that people move in a completely random fashion, and
this study will provide data on that for the first time.”
The researchers plan to spend the first six months of the project developing
their research techniques, hiring students, and training those who will do the
research. They expect to begin gathering data sometime next fall—just in time
for annual cold and flu season.
Beyond the public health implications, better protecting passengers and
aircrews could have a significant economic impact for aircraft manufacturers,
airlines, airports, and industries that depend on efficient air travel.
“Everyone wins if we can eliminate or reduce the air travel disruptions that
could result from a pandemic,” Weiss said.
Source: Georgia Institute of Technology