Everything you know is wrong:
The risk of being exposed to Covid-19 indoors is as great at 60 feet as it is at 6 feet — even when wearing a mask, according to a new study by Massachusetts Institute of Technology researchers who challenge social distancing guidelines adopted across the world.
- Airborne spread in poorly ventilated areas is the problem.
- They say there was no justification for the “six foot rule”. And in a poorly ventilated area, the risks may be similar at a variety of distances.
- Wearing masks outdoors makes little sense.
- Best thing to do is minimize being in poorly ventilated indoor areas, especially with many other people.
- Corollary: During 2020, lock downs forced many people to remain inside – except when going out for groceries, health care or essential work. They then came back and shared poorly ventilated housing units with others. This did not make sense then and especially now after several studies on airborne spread inside. This may also explain why, last spring, about 2/3ds of cases were contact traced to close family and social contacts.
This study also explains that the value of cloth masks may be little when most spread is via aerosols. The CDC now says droplets and fomites don’t seem to be important vectors. Airborne spread explains how 90+ health care workers working in an ED, wearing PPE, all came down with Covid-19 at the same time – droplet and contact spread cannot explain that.
This Twitter thread argues that distance may still matter in some situations as aerosols dilute with distance. However, in enclosed spaces, where people stay for extended periods of time, and having poor ventilation that may not help a lot as the room’s atmosphere gradually collects aerosols.