Increase of chances
If you think about it, it would make logical sense that the chances of getting sick would increase while on a plane. Everyone is confined into a small space and the air from your neighbour will be circulated around just waiting for someone else to breathe it in. Thankfully this is a myth and the air in the cabin doesn't simply constantly be breathed in but rather the airplane has a device near the engine which brings in fresh air from outside. The device heats the air, compresses it until it equalises to cabin pressure and goes through filters to get rid of 99.97% of particles, bacteria and viruses. The problem though arises when you consider that the fresh air is being combined with the air that is already in the cabin.
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