Good morning everyone! I’m excited to be doing today’s #GuerillaPublicHealth on COVID transmission and the 6’ “rule”. You can check out Jack’s other works below https://twitter.com/jacktheneuroeng/status/1297959731898834945

@JackTheNeuroEng always has coffee for these so I will locate my new French press and give it a go

Never forget where you put your electric kettle. Anyway, coffee is made and guinea pigs are fed so time to science!

Okay so the 6' rule: what is it and should we be following it (hot take)

6' comes from a 1941 study by Marshall Jennison that used high-speed photography to visualize sneezing

They were able to see droplets from a sneeze and found that these droplets tended to fall 3-6' away from the point of origin (person who sneezed). This is where "cover your nose/mouth when you sneeze/cough" was born

But "tend to" is a way of saying that most droplets fit this conclusion. Most, not all

Okay so what would make droplets carry farther than 6'? Yelling is a good example, but basically anything in which you could imagine more forcefully sending droplets as you speak/sneeze/cough etc.

The good news (!) is that masks work like more effective elbows at covering your nose and mouth so the spread of any droplets, even ones with the potential to travel very far without a mask, will be greatly reduced

So then why am I even talking about the 6' rule today? Various authorities have incorporated this into their reopening protocols as a way to ensure safety. But as I will discuss, 6' does not necessarily mean "safe"

The 6' rule is strictly applicable to droplet transmission and does not apply to aerosols. We know it's possible for COVID-19 to be spread through the air, but we do not know how likely the disease is to spread this way

So then how do we make informed policies? An article from Business Insider argues the distinction comes from a change in perspective https://www.businessinsider.com/6-foot-distancing-rule-is-outdated-oxford-mit-new-system-2020-8