1) Masks get saturated by large "respiratory droplets" containing viral molecules. Air turbulence against trapped droplets may create aerosols that eventually diffuse around edges. Continued...
COVID Masks: Mechanistic View: Part 2: Fine Aerosol Emissions:
Masks may increase fine aerosol emissions from: 1) nebulization of large droplets into fine aerosols, or 2) friability of certain mask materials creating "aerosolized fomites."
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Here are the studies:
1) Masks get saturated by large "respiratory droplets" containing viral molecules. Air turbulence against trapped droplets may create aerosols that eventually diffuse around edges. Continued...
Study: Ha'eri 1980
Title: The efficacy of standard surgical face masks: an investigation using "tracer particles"
Albumin tracer particles put inside a surgical mask were dispersed into the room by breathing.
https://t.co/Ll5CfBPVj6
Study: Liu 2020
Title: Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals.
SARS-2-COV sub-micrometer aerosols not tightly bound to surfaces, get airborne when PPE is taken off.
https://t.co/GK9SeOwgcj
https://t.co/qlzLK1N1Aw
Do our masks stop large droplets or do they nebulize them into Aerosols? From my emulsion days, best way to get a monodispersed emulsion is to force H20 through a pore sized membrane that has a different phase (oil or air) on the other side of it. https://t.co/Y9UCmWZ7uT pic.twitter.com/bGZBxI6lUT
— Kevin McKernan \U0001f642 (@Kevin_McKernan) October 24, 2020
2) "Aerosolized fomites" from the mask material itself (e.g. cotton or fabric) are shed during breathing. These tiny organic particles - fomites - are contaminated by even smaller viral molecules.
Friability of mask materials: Cotton or fabric may emit fine particles < 1 um, possibly spreading viral contamination. This study found breathing through DIY masks of cotton or fabric increased forward emission of fine aerosols.
https://t.co/nks9rCb6Ox
Cotton or cloth releases tiny organic material - aerosolized fomites - that can potentially serve as a conduit for viral molecules.
Limitations:
Only measured 2 minutes of emissions
Only measured forward emissions; not emissions around edges; may underestimate total emissions vs no mask
Could not tell if medical-grade masks also increased aerosols when fully contaminated with droplets
Title: Influenza A virus is transmissible via aerosolized fomites
Found that non-respiratory "aerosolized fomites" (organic debris) contaminated with a virus can infect other animals. May play large role in viral transmission.
https://t.co/p3lRxeqOiA
So masks might capture some viral debris, but emissions might be in a more easily transported aerosol.
It's analogous to someone mistakenly power sanding lead paint to remove it. The total amount is reduced, but remaining portion is in a more hazardous form.
More from Society
This is a piece I've been thinking about for a long time. One of the most dominant policy ideas in Washington is that policy should, always and everywhere, move parents into paid labor. But what if that's wrong?
My reporting here convinced me that there's no large effect in either direction on labor force participation from child allowances. Canada has a bigger one than either Romney or Biden are considering, and more labor force participation among women.
But what if that wasn't true?
Forcing parents into low-wage, often exploitative, jobs by threatening them and their children with poverty may be counted as a success by some policymakers, but it’s a sign of a society that doesn’t value the most essential forms of labor.
The problem is in the very language we use. If I left my job as a New York Times columnist to care for my 2-year-old son, I’d be described as leaving the labor force. But as much as I adore him, there is no doubt I’d be working harder. I wouldn't have stopped working!
I tried to render conservative objections here fairly. I appreciate that @swinshi talked with me, and I'm sorry I couldn't include everything he said. I'll say I believe I used his strongest arguments, not more speculative ones, in the piece.
My reporting here convinced me that there's no large effect in either direction on labor force participation from child allowances. Canada has a bigger one than either Romney or Biden are considering, and more labor force participation among women.
But what if that wasn't true?
Forcing parents into low-wage, often exploitative, jobs by threatening them and their children with poverty may be counted as a success by some policymakers, but it’s a sign of a society that doesn’t value the most essential forms of labor.
The problem is in the very language we use. If I left my job as a New York Times columnist to care for my 2-year-old son, I’d be described as leaving the labor force. But as much as I adore him, there is no doubt I’d be working harder. I wouldn't have stopped working!
I tried to render conservative objections here fairly. I appreciate that @swinshi talked with me, and I'm sorry I couldn't include everything he said. I'll say I believe I used his strongest arguments, not more speculative ones, in the piece.
I appreciate his intellectual curiosity and effort. I have quibbles. But my big disappointment is there was no mention of unintended consequences, which we discussed and which are kind of THE core conservative concern on this issue.
— \U0001d682\U0001d68c\U0001d698\U0001d69d\U0001d69d \U0001d686\U0001d692\U0001d697\U0001d69c\U0001d691\U0001d692\U0001d699 (@swinshi) February 18, 2021