As mask mandates stir debate, many metro Atlantans have already voted

Atlanta Journal Constitution ^ | 7-10-20 | Matt Kempner

[spintreebob]

As more local officials wrestle with whether to mandate mask use in public, metro Atlantans are taking a clear stand with their own mouths and noses: Most already are wearing masks.

About 80% of shoppers wore face coverings inside local groceries during spot checks by The Atlanta Journal-Constitution. The informal checks were made this week of 100 shoppers in each of certain Kroger stores in Duluth, Johns Creek, South Fulton, Marietta, Lithonia and Atlanta.

[Yardstick]

They stop droplets but they don’t stop aerosols (droplets smaller than 10um). Aerosols make up about half the liquid expelled in a typical cough and are known to carry the virus. Aerosols don’t follow a ballistic trajectory to the ground like bigger droplets but instead waft all over the place on air currents. The fact of aerosols plus the massive leakage around most masks makes me think masks are a nice gesture and may provide a sense of “doing something” but aren’t anything like decisive in the course of the epidemic.

[palmer]

provide a sense of “doing something” but aren’t anything like decisive in the course of the epidemic.

Perhaps. I have never seen anyone cough in a mask. Coughing would definitely blow around the mask or even blowi the mask off. Talking may create the same droplets as coughing, but at least not blow air past the gaps as much.