The recommendations changed when it was discovered that this particular virus is prone to widespread asymptomatic airborne spread. It's that simple.
One of the things that I have wished the media talked more about was the actual risk for certain activities. I have wanted more information, and I think it would help people understand the masks more. However, I have been reading a lot, and trying to find doctors and health experts on Twitter and such, and eventually the rabbit hole found a personal blog that I think does a really great job of presenting information. But since it's "only" a personal blog, I didn't want to post it before, but now people are talking about masks.
This person "does the math" regarding droplets released via coughs, sneezes, breathing and talking, and therefore the minimum time you would need to do these things to be infected. I think everyone gets coughing and sneezing risks.
So the interesting ones, are breathing. It would take a minimum of 50 minutes of exposure with an infected person, if people were just in the same area, only breathing. That is reassuring, that the intermittent exposures during shopping and picking up takeout shouldn't be risky. But the implication for transportation like trains and airplanes, Broadway shows and movie theaters is not great.
However, for talking, it only takes 5 minutes of exposure. For a place like Disney, people are constantly talking around you, and if you are in a queue with someone you would certainly be exposed for 5 minutes. This also explains why office workplaces, family gatherings, church services, eating at a restaurant, these are all potential spreading situations. Getting your hair or nails done, if neither person wore a mask. Just the normal chit-chat can be more than 5 minutes. Asymptomatic spreaders and talkers = masks, either that or people have to just not talk to each other. Pick your poison.
Please read this link to learn about the author and background to these posts. It seems many people are breathing some relief, and I’m not sure why. An epidemic curve has a relatively predictable upslope and once the peak is reached, the back slope can also be predicted. We have robust data from...
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