Got it—Singapore study (sorry for the confusion)—start at 28 minutes.
https://www.youtube.com/watch?v=4InhmRCIpow
Got it - thanks!
The slide at 30:17 is the slide to see. No COVID-19 in the air, but testing at air vents showed COVID-19.
I’m hopeful some additional research is ongoing now.
I think staying away from people who are obviously sick, social distancing to the extent possible (to avoid asymptomatic spreaders), and not touching common-use surfaces are all good ways to reduce risk.