Fixing the COVID-19 Crisis in 30 days

[RyanB]

An interesting article by Dr Mercola - worth a read.

https://articles.mercola.com/sites/...09Z1&mid=healthrtlucm20200709z1&rid=912632525

 

[PeterNSteinmetz]

Don't know why that is surprising. The cloth masks haven't been touted as effective against preventing you from getting COVID, it's to prevent you from spreading yours around.

I cannot understand that the argument that there should be an asymmetry here. If 90% of the virions will get through a cloth mask in one direction, the same seems like it should be true in reverse.

I can see the argument for two masks are better than one and result in an 0.81 chance of infection rather than 0.9.

 

[PeterNSteinmetz]

AFAIK, it is intended to block the droplets that carry the virions, not the virus particles themselves.

That may be true. I was just taking about total virion count, however carried.

If the mask stops droplets one way, why would it not the other?

The one way I could see this making some sense is if a major absorption route for picking up virions is other than breathing them in. There is some evidence for absorption through the eyes, but I think as a fraction this is fairly smaller route.

 

[PeterNSteinmetz]

You aren't shooting the droplets at other people when you wear a mask, nor the virus particles they carry.

Right. But if one of those droplets hits the other person’s mask, their mask should stop it from being inhaled by them.

If you have some links to scientific publications that describe or document how this works one way, but not the other, I am certainly glad to see them. I have not seen a good explanation when looking.

 

[PeterNSteinmetz]

- Mostly droplets.
- Minor contribution from smaller respiratory aerosols (airborne).
- Possible (but never conclusively demonstrated) entry via the eyes.
- Minor contribution from 'fomites' (contaminated objects).

Droplet transmission can be reduced by social distancing and masks (both as measure of source control but also as PPE for the wearer)

Yes, so it seems like the mask effectiveness, in terms of the fraction of virions which make it through, however they are carried, should be roughly the same in both directions.

If entry via eyes or from fomites were a larger contribution, then I could see how there might be an asymmetry between source and wearer protection. But it seems like it should be quite close given the minor contributions of the other routes.

 

[PeterNSteinmetz]

Science: Mask usage reduces transmission rates from 90% down to less than 5%.

Main Stream Media: Mask usage does not reduce transmission rates down to 0%.

Internet: Even if everybody wears a mask, you can still get COVID-19.

John Q. Public: MASKS ARE USELESS. WHY SHOULD I HAVE TO WEAR A MASK???!?

The use of N95s by professional health care workers likely reduces transmission by about 95%.

There are a lot of differences between that and the general public wearing cloth masks.

I think the failure to recognize this distinction is a cause of a lot of the disparities you note.

Of course, John Q. Public has a very hard time understanding something that involves probabilistic distinctions, rather than simply 2 category distinctions.

 

[PeterNSteinmetz]

The failure to recognize many of these distinctions is willful.

I have some friends who think the failure of the government to tell people about the actual effectiveness of cloth masks versus N95s is willful. I tend to subscribe more to the 'never assume malice when incompetence will suffice as an explanation' crowd.