Apparently, it is not the recirculation of air that causes the spread of disease in aircraft. Rather it is more likely the direct transmission of disease between persons even up to several rows apart, either through air transmission or mutual contacts. Why could this transmission be by the air route and why is it so noticeable after flying? There are several reasons:
- The diversity of sources and lack of immunity to the various pathogen exposures encountered in aircraft with the intermixing of persons from different population centers and continents is uniquely high for air travel in comparison with other venues such as theaters or classrooms where the occupants come from one geographic region.
- The filtered air supply rate to aircraft passengers is low (e.g.1/6th that provided to office workers).
- The volume of air surrounding passengers for buffering contaminant spread is relatively low (e.g. 1/30th that of the buffering zone for office workers and 1/10th that available in classrooms).
- The relative humidity on flights is lower than in most other environments (e.g. it is less than 20% on overseas flights versus 30-40% in buildings in winter and 50-60% in summer), and lower humidity has been shown to favor the airborne transmission of certain pathogens including influenza A virus.
I would be interested in your thoughts on the above so feel free to leave a comment. If you are interested in trying the PEACE device let me know by filling out the VEFT Aerospace Inquiry Form so that you can be informed when it is available.