AEROSOL TRANSMISSION—we need to keep hammering this. Key takeaways by @jljcolorado to avoid places:
📌if it's crowded
📌if cannot keep distance
📌if it's a long time
📌if low ventilation
📌if not wearing masks
📌if people singing, yelling or also breathing hard. #COVID19
📌if it's crowded
📌if cannot keep distance
📌if it's a long time
📌if low ventilation
📌if not wearing masks
📌if people singing, yelling or also breathing hard. #COVID19
2) Link to NPR audio. npr.org/2020/09/07/910…
3) Also, @linseymarr points out that the key danger of aerosols are that they can be “Wafted by air currents and travel around the room and be inhaled by other people” — and this 6 feet distance indoors is not enough protection. And stay afloat 20 min - 4 hours, says @kprather88.
4) Air exchange frequency is important. Experts recommend 6 or more per hour. Also here is a calculator for aerosol transmission risk for classrooms.
5) Filtration of air is likely also key. MERV13 graded higher is the best. I was shopping for HVAC filters and most are not up to par—except for the highest. The 3M 2200 filtration level or higher is equivalent to MERV13 though. But most air filters way below this. 
6) Here is the comparison chart for 3M Filtrete filtration levels can MERV ratings. Technically 1900 filtration is also MERV13. But some stores only sell 1500 and then 2200. So go for >1900.
(FYI I don’t own any stocks or equity in 3M or any filtration products or company).
(FYI I don’t own any stocks or equity in 3M or any filtration products or company).
