@Globalbiosec @doctorahmad75 @trishgreenhalgh @DFisman @ConversationEDU @dystopian_DU requested I give my input on this article. Here goes.

Yes, I agree SARS-CoV-2 is airborne. It is a high-output, low-minimum infective dose pathogen.

But even if N95s perfectly captured 95% in real-world application, which they don’t, here is why they fail 👇🏻👇🏻
1/ @Globalbiosec @doctorahmad75 @trishgreenhalgh @DFisman @ConversationEDU @dystopian_DU

https://twitter.com/mamasaurusmeg/status/1621972612338356228?s=46&t=_6Ikp84PkhY71Gee3-Lw_A

This gets into output, particle to PFU, and minimum infective dose ranges for SARS-CoV-2 versus hypothetical perfect capture capacity for N95s.

But I will continue on your article.
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Part 7 - Glossary

aerosol - particles dispersed in air or gas, defined as less than 5 microns in size.

asymptomatic (spread) - the theoretical concept of transmitting a pathogen to others while not exhibiting any established symptoms of said pathogen.

1/🧵 atmospheric saturation - the amount of viable matter that remains aloft within an enclosed space.

Brownian Motion - the theoretical construct explaining the chaotic, unpredictable movement of particulates under 0.3 microns when at near-zero velocity.

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Part 6 - Why N95s failed/are failing/will fail
This is Part 6 of the 7-part series of matter discussed recently with @drdrew.

For the purpose of an exercise in hypothetical perfect capture capacity, we grant N95s a perfect 95% rate of capture for all particle ranges.
1/🧵 By applying 5% of the MID potential infectivity figures in output ranges A, B, and C, it demonstrates the infectivity of viable virions versus the 5 percent never captured (e.g., no leakage) if a hypothetical 95 percent perfect rate of capture is met.

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Part 5 - Output of viable virions versus Minimum Infective Dose threshold potential

This is Part 5 of a 7-part series of material recently discussed with @drdrew.

By using the figures from Part 4, we can tackle the assertion that N95s provide meaningful protective value
1/🧵 from infectious aerosols by looking at output contributions, infectivity potential of emitted viral matter, PFU ranges, then we can weigh these ranges against a hypothetical perfect capture capacity of N95s capturing 95 percent of matter, versus

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Part 4 - Minimum Infective Dose (MID)

This is part 4 of my 7-part series of material recently discussed with @drdrew
Comparison studies of different viruses + SARS-CoV-2 animal studies are used to contribute to many MID estimates, but I focus solely on human studies AMAP.
1/🧵 “Although the MID of SARS-CoV-2 in humans needs more research, it is expected to be approximately 100 virus particles. The only human study regarding a coronavirus has been reported for HCoV-229E and its MID is 9 PFU. Furthermore, if aerosol transmission is the dominant…
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Part 3 - Understanding virus particles needed to form individual Plaque Forming Units (PFU):

This is part 3 of the 7-part series of material discussed with @drdrew

1/🧵 While all emitted viral RNA and virus particles are not capable of viral replication and the creation of PFUs, it is understood that each PFU is created by one viable viral particle.

The following excerpts discuss the impact of PFUs on viral infections and onset.

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Part 2 - Output

This is a continuation of the 7-part series of material discussed recently with @drdrew.

In research on aerosol output in healthy versus SARS-CoV-2 PCR-positive test subjects, 90 percent of emitted particles by PCR-positive test subjects were under 0.3 µm.

1/🧵 Particle counts were conducted comparing individuals with different severities of illness with PCR-negative subjects. ncbi.nlm.nih.gov/pmc/articles/P…

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Part 1 - Introduction

This is a 7-part series getting into output of infectious matter, particle to PFU ratios, and minimum infective dose for SARS-CoV-2, versus hypothetical perfect capture capacity of N95s for all emissions size ranges, as discussed recently on @drdrew.

1/🧵 We were assured that community masking would halt the spread of SARS-CoV-2.
Yet real-world application data has shown them to fail for personal protection. Miserably.
See:
cochranelibrary.com/content?templa…
And:
acpjournals.org/doi/10.7326/M2…
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The Cochrane meta covers a lot of bases. But it does directly address the erroneous concept of source control.

I repeat, masks and respirators are NOT source control for respiratory aerosols.

1/4

https://twitter.com/gregpiper/status/1620792259682893824

I have addressed the concept of source control previously in this article, but wanted to mention a few additional things.

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rationalground.com/masks-are-not-…

In my article brownstone.org/articles/why-n…, I used EPA handbook’s output ranges for liter per minute (h/t @pettypodcast1). I was reading on NIOSH’s failure to test for ultrafine particles in PPE assessments, and found the following, which magnifies my message on N95 inefficacy:
1/ NIOSH uses a rate of 85 liters per minute, with as high as 182-295 liters per minute.

Let’s dive into what 85 liters per minute looks like by applying the figures discussed in my article.

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