[jonrick46]

Does anyone know how long the aerosol droplets in the μm range last before they evaporate? Once the aerosol outer coating evaporates, the virus degrades and can no longer enter the ACE-2 receptor.

[Grandpa Drudge]

Buried deep in the SOTT article under the heading

Physics and Biology of Viral Respiratory Disease, and why masks do not work

is this statement:
"On average, 64 per cent of the viral genome copies were associated with fine particles smaller than 2.5 µm, which can remain suspended for hours."

And I read somewhere else (but can't find it now) that aerosol viruses can remain viable as long as 16 hours in enclosed spaces.

[exDemMom]

Does anyone know how long the aerosol droplets in the μm range last before they evaporate? Once the aerosol outer coating evaporates, the virus degrades and can no longer enter the ACE-2 receptor.

A few days ago, I read a paper that stated that droplets evaporated by 95% in less than a second (I want to say 1/24 of a second) in a room at 50% humidity.

Clearly, ambient temperature and humidity are going to affect evaporation and virus survival rates.

Another paper said that viruses do not survive very long on the hands, I think it was only a few seconds.

I have read many papers, but unfortunately forget to bookmark them. I will look for the paper that discusses the evaporation rates and post a link if I find it.

Yesterday, I found three papers in which the efficacy of face masks in the context of Covid-19 was evaluated. Yep, the data actually shows that face masks, as well as social distancing and eye protection, work to reduce spread of Covid-19. The blog excerpted at the top of this thread was written by a physicist who has zero experience in infectious diseases. Two of the studies of mask efficacy were written by people in the field (MDs, PhDs, MPHs, MSs); the other was written by economists and statisticians but their references appear to be valid. I did bookmark these papers.

[exDemMom]

Here, I found the paper I referred to in my last post:

Dynamics of infectious disease transmission by inhalable respiratory droplets

And the relevant passage: "Evaporation, being a molecular process, is very fast (Nicas et al. 2005; Morawska 2006); for example, a 20 µm droplet evaporates to a 1 µm diameter droplet within 0.24 s−1 (at 50% ambient relative humidity). Henceforth, we neglect droplet evaporation, and we follow Nicas et al. (2005) to take the post-evaporation diameter (approximately) half the pre-evaporation diameter."