It’s not often that choral singing and meat packing find themselves in the same basket – but the two occupations have been linked by the coronavirus. As epidemiologist Raina MacIntyre said last week at a webinar organised by Gondwana Choirs and the University of NSW, “we’ve seen two types of outbreaks that have really stood out. One is the choirs and the other is the meat packing plants”.

The reason, she explained, is the high concentration of aerosols created by the processes involved at abattoirs, and when people sing.

Gondwana Indigenous Children’s Choir in Vienna in 2017. Photograph © Nathan Kelly

Aerosols are miniscule clumps of liquid or solid particles floating through the air. When people breathe, talk or cough they generate aerosols. But more are generated when people sing because of the deep breathing involved.

Speaking at the same webinar, Professor Con Doolan, an aerospace engineer, explained clearly what aerosols are and why they spread the coronavirus.

“When you sing or cough or sneeze there’s a combination of the breathing with the saliva or fluids in your mouth and in the lungs, and that gets projected out of your mouth and it forms like...