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To: Grandpa Drudge
If you are infected and contagious the mask will not make you safe to be around.

Any aerosol virus you exhale will go out through your mask just as easily as it can come in, so the mask might slow the exposure a little, but it will NOT stop it.

Actually, I found three review papers that specifically address the question of how masks affect transmissibility of Covid-19. All of them concluded that masks inhibit transmission of Covid-19.

Also, I found another paper about the survivability of viruses in different environments. One limitation of this paper was that most of the studies were looking for viral RNA remaining in the environment, but the presence of RNA is not an indicator of infectivity. The following passage from that paper, Stability and infectivity of coronaviruses in inanimate environments leapt out at me:

Infectivity of HuCoV- 229E was undetectable after drying on aluminum, sterile latex surgical gloves, and sterile cotton gauze sponges at RT for 3 h; HuCoV OC43 survived 1 h or less[34]. Contaminated droplets will be absorbed faster on cotton materials than on fluid-repellent materials, and cotton gowns offer protection against droplets bearing viruses. Droplets or fomites that persist on a nonabsorbent disposable gown or gloves may be a risk to contaminate the environment.

SARS-CoV strain GVU6109 was isolated from a lung tissue specimen of a SARS patient during the SARS outbreak in 2003[35]; its infectivity at 10^4 tissue culture infection doses (TCID50)/mL vanished within 5 min after drying on paper or a cotton gown at RT[35], showing that the viral infectivity perished faster on the cotton gown than on an impervious surface (e.g., the disposable gown) (5 min vs 60 min at 10^4 TCID50/mL, 1 h vs 24 h at 10^5 TCID50/mL )[35].

Note: these studies used commonly circulating coronaviruses; the behavior of the Covid-19 virus should be similar.

In other words, the cotton material used in masks helps to dry (and kill) the virus quickly. This is nice to know, since I just ordered 8 yards of pure cotton cloth to use to make masks.

177 posted on 06/28/2020 4:37:22 AM PDT by exDemMom (Current visual of the hole the US continues to dig itself into: http://www.usdebtclock.org)
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To: exDemMom
Confusion again!

Covid-19 is another name for Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Covid-19 (SARS-CoV-2) is an RNA virus, with viral RNA

And from that same article you quote: Stability and infectivity of coronaviruses in inanimate environments
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7190947/

"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that can transmit through respiratory droplets, aerosols, or contacts.

SARS-CoV-2 can be sustained in air (airborne aerosol) in closed unventilated buses for at least 30 min without losing infectivity. The most common coronaviruses may well survive or persist on surfaces for up to one month.

The half-life of coronaviruses in aerosols was reported to be 86 h at 80% humidity in the environment" (note: italic phrase (airborne aerosol) added by me

And finally, if you believe your cotton mask will absorb and block moisture droplets efficiently I suggest a simple test: Go outside on a cold day (below 32 degrees F) and exhale through your cotton mask. See if you see any fog. (you will).

188 posted on 06/28/2020 4:33:20 PM PDT by Grandpa Drudge (Just an old man, desperate to preserve our great country for my grandchildren.)
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