Dr Cathal Cummins, Assistant Professor in the Department of Mathematics and Institute for Infrastructure & Environment from Heriot-Watt University (Edinburgh), and Dr Ignazio Maria Viola, Reader at the Institute for Energy Systems of the School of Engineering from University of Edinburgh, who co-authored the works, said:
“Wearers of face masks need to be made aware that jets of air can leak out of the sides and back as well as the front of their masks. This could be particularly important when using masks on public transport, or when seated on aircraft.
When seated shoulder-to-shoulder, the use of personal protection windows (PPW) in between passengers on aircraft, would reduce the risk of neighbouring passengers being exposed to leaking air from face masks of people seated next to them. It would also provide protection from the frontal jet if adjacent passengers were to speak to each other.
The reduction in risk can only be achieved if face masks are used in conjunction with PPW and not as a replacement for wearing a mask and only if PPW are cleaned after every flight. If all three measures are mandatory, together with good personal hygiene, airlines can increase passenger protection.
Without a plastic barrier installed, such as PPW, passengers wearing a mask (in close proximity to others) could be more of a hazard sitting next to each other than sitting directly facing them. The effectiveness of PPW will depend also on the strength and direction of air currents and extraction within the aircraft. Careful attention must be given to such air flows when using PPW.
In summary, our recommendation is that airlines should make face masks mandatory, and if used in conjunction with PPW and regular cleaning of PPW, COVID-19 contamination risk is kept to a minimum.”