[JSH]

Originally Posted by Xist

Source?

We exhale droplets every time we breath or talk. They can hang in the air for hours. That is plenty of time to migrate to the other side of a sneeze guard.


https://www.nature.com/articles/d41586-020-02058-1

"Many researchers concerned about airborne transmission point to the example of a fateful choir rehearsal that took place an hour’s drive from Seattle, Washington, on 10 March. Sixty-one members of the Skagit Valley Chorale gathered for a practice that lasted two and a half hours. Despite there being hand sanitizer at the door, and choir members refraining from hugs and handshakes, at least 33 choristers contracted SARS-CoV-2, and 2 eventually died. Investigators concluded that the virus could have spread in aerosols produced by singing, and a ‘super-emitter’ who produced more aerosol particles than is typical, although they couldn’t rule out transmission through objects or large droplets3.

But Morawska has modelled the conditions in the rehearsal hall, and says there is no need to invoke the idea of a superspreader4. Inadequate ventilation, the long exposure time and the singing were sufficient to explain the number of people who became infected. And no amount of ventilation could have reduced the risk to an acceptable level for the two-and-a-half-hour rehearsal, she says".