[Goose]

I think passing somebody in a parking lot without a mask would be extremely low risk, unless they coughed right in your face.

It is a tricky balance, because it's all about a threshold of risk based on incomplete information.

Consistency and simplicity are the key things. But the risk is a spectrum, and you have to make arbitrary decisions, like the 6 foot rule, that are only loosely based on science. 

I don't think there is anything special about 24 hours. If you see a covid positive patient for 5 minutes on three consecutive days, are you more or less at risk than 15 minutes in one go? I don't think that is knowable at this time.

I really like this post because it points out the uncertainties involved in almost all of the mitigation strategies we are using. In many instances, we just don't know. All the recommendations involve arbitrary decisions and trade-offs. How much better is 7 feet than 6 feet? Nobody really knows, although there are models (that may or may not be any good) that attempt to tell us that. The public hates uncertainty. However, asserting certainty when it actually doesn't exist eventually destroys credibility. The public health secor has a reall tough job here.

[Goose]

I think passing somebody in a parking lot without a mask would be extremely low risk, unless they coughed right in your face.

It is a tricky balance, because it's all about a threshold of risk based on incomplete information.

Consistency and simplicity are the key things. But the risk is a spectrum, and you have to make arbitrary decisions, like the 6 foot rule, that are only loosely based on science. 

I don't think there is anything special about 24 hours. If you see a covid positive patient for 5 minutes on three consecutive days, are you more or less at risk than 15 minutes in one go? I don't think that is knowable at this time.

I really like this post because it points out the uncertainties involved in almost all of the mitigation strategies we are using. In many instances, we just don't know. All the recommendations involve arbitrary decisions and trade-offs. How much better is 7 feet than 6 feet? Nobody really knows, although there are models (that may or may not be any good) that attempt to tell us that. The public hates uncertainty. However, asserting certainty when it actually doesn't exist eventually destroys credibility. The public health secor has a reall tough job here.