Abstract View
Quantifying SARS-CoV-2 Infectious Particulate Exposure Risk, Mixing, and Removal Using DNA-Tagged and Real-Time Fluorescent PSL Microsphere Tracers in Wide-Bodied Boeing 777 and 767 Airframes
SEAN KINAHAN, David Silcott, Blake Silcott, Ryan Silcott, Peter Silcott, Braden Silcott, Steven Distelhorst, Vicki Herrera, Danielle Rivera, Kevin Crown, Gabriel Lucero, Joshua Santarpia, National Strategic Research Institute
Abstract Number: 573
Working Group: Infectious Aerosols in the Age of COVID-19
Abstract
Airplane travel provides a unique potential for exposure to infectious aerosols because of long flight times and densely packed seating. In this study fluorescent (one micron) and DNA-tagged (three micron) PSL tracer beads were used to mimic the spread and removal of small aerosols in Boeing 767 and 777 airframes. Tracer particles were released from a medical nebulizer mounted in a mannequin mouth to simulate a single infected person seated during flight. Releases occurred in multiple sections of the planes and from multiple seats during ground and in-flight testing. A combination of Sartorius MD-8 Airport collectors for the DNA-tagged tracer and real-time light-induced fluorescence (LIF) Instantaneous Biological Analyzer and Collector (IBAC) sensors placed in nearby seats from the simulated infected individual quantified the number of particles reaching each breathing zone of the simulated non-infected individuals.
In-flight, for both the 767 and 777 airframes, the minimum observed concentration of one micron aerosols from the infectious individual to the breathing zone of a non-infected individuals seated immediately adjacent was reduced by 99.54% during all testing. For all other proximate seats (two forward and aft, two to the side, and the diagonals), the average reduction of one-micron aerosols were 99.98±0.0027% (n=177 seats) and 99.97±0.0086 (n=152 seats) in the 767 and 777, respectively. High reduction rates are attributed to the 30 air-change-per-hour exchange rates and limited longitudinal air movement integral to the aircraft design.
The results of the present study support the existing epidemiological data that large-scale transmission events during flight are improbable. Notably, the present study only investigates small particles to simulate infectious aerosols. Other factors, such as the amount of SARS-CoV-2 shedding from an individual, viral fate in the air, infectious dose via the aerosol route, and potential non-aerosol (droplet or fomite) transmission are important when assessing the overall transmission risk.