TL;DR The Japan Choral Association have given themselves the all-clear to continue singing by producing a scientific report that focuses on splashes and pretends that COVID19 is not airborne.
CBS reports that the Japan Choral Association has been involved in research on the production of splashes/droplets during singing. They measured droplets singing in 3 languages, German, Italian and Japanese. German produced the most, Japanese the least (the song apparently is a fairly aggressive kids' song).
It's awful because they chose not to measure aerosols. Despite knowing form early on that this was airborne (the 3Cs are precautions for airborne spread), many people in Japan remain super-focused on droplets (I had a nurse friend explain to me how 1 patient infected the 3 others in his room because they all used the same toilet, also the recent Oedo-line dorm faucet event).
There's a bit at the end where it says that it's not yet clear what size droplets are carrying the infection but that most important is thought to be large droplets. If this was true then ventilation would not matter. Non-droplet airborne infection has been demonstrated in the labs between animals. Also in www.superspreadingdatabase.com there is just 1 outdoor event out of 2000+, droplets exist indoor and outdoor, aerosols only accumulate indoors. The many choral (and other) super-spreader events cannot be explained by droplets, with people being infected many meters from the index case.
The safeguards they have developed for singing, spacing and patterning entirely assume droplet transmission.
The original Japanese research findings are here.
Worst of all they demonstrate a mouth shield blocks all splashes (yes it is but that doesn't make it safe).
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