An interesting study in the journal Physics of Fluids concluded that simply walking behind a fast-walking person infected with SARS-Co-V2 in a narrow corridor inside a building can raise your risk of getting infected from that source.
According to the computer simulation in this study, a coughing person walking fast in a narrow indoor space sets up a “wake” of exhaled particles and droplets behind them, much like a moving boat sets a wake behind it.
And it’s a pretty long waist-high wake, this study concluded.
Which would make the threat much greater, of course, for a little person – say, an elementary school student – walking behind a taller coughing person, say, a teacher than a 6-footer covering the same distance.
Just another thing to be aware of, I guess.