Lazarus Long Profile picture
Aug 11, 2021 29 tweets 14 min read Read on X
A mega thread on the ultimate DIY air filter known as the Corsi/Rosenthal Box (@CorsIAQ/ @JimRosenthal4).

Take it into work. Donate a couple to your school classroom if they'll let you.

Illustrations beautifully done by @ughberta, discovered through @kprather88.

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But my little angels don't transmit CoVid!?

They have ACE2 receptors, which SARS-COV-2 targets.

They get it and transmit it.

And those little bodies have a thermal plume wafting CoVid up to you.

. link.springer.com/article/10.100…
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Always a typo, no matter how many times you go over it....

Sorry - @Poppendieck has a great FAQ here - used up above!



Another classic FAQ is one maintained by about 10 aerosol scientists.


poppendieck.com/IAQ/COVID19%20…
tinyurl.com/FAQ-aerosols
Above...about 40,000 tweets ago, you mentioned 5 microns...and seemed excited about it. Why?

Respiratory aerosols (emitted when we breathe, talk, laugh, yell, sing, cough, sneeze) carry SARS-COV-2.

And 85% of them are 5 microns or smaller.

Used for Bacon. Gets it's very own tweet. Mmmmm. Bacon....

Pulling this up into the thread for optimum visibility.

Thank you, David!

(A great follow!)
Your lungs will thank you!

Next tweet...this is the hand sanitizer for the lungs you've always needed. Just without that bad smell...

This spacing is really excellent.

The one thing I would change, based on @Poppendieck's recommendation is to flip the box to be pointed up.

So any dried respiratory aerosols (carrying SC2) on the ground are not lifted off the ground (re-aerosolized).


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Would these help in a hospital with already great ventilation?
(H/T
)

Yes.

Preprint, but Dr. Marr is serious money:



Great discussion of why they still help in such already great ventilation:


And that tweet author is the lead on this study showing basically the same:


Same study, but a great tweetorial, too.

Ontario, Canada bringing in 20,000 portable air cleaners.
Someone asked how to dispose of the filters.

Put on your N100 elastomeric respirator (more comfortable than N95).



Carefully, pick up the Corsi box and gently take it outside.

Since you used painter tape, gently peel it back to get the fan off.
Separate the filters and gently place in a garbage bag. Do not shove them in as might have virus in them and don't want the garbage bag blowing the virus back on you.

Tie the bag tight. Toss into garbage.

Make new box!

Why not spray disinfectant on it?

Because by the
time the garbage bag degrades the virus will have been activated...

nejm.org/doi/full/10.10…
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Corsi/Rosenthal Thread Update:

Some folks, (mostly teachers) cannot bring in an air cleaner. But can bring in a fan.

Here's a fan that has a filter built into it! So, a stealth air cleaner.

"Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10 Image
Air Purifying Filter"

Won't be as good - but something is better than nothing!



H/T @kprather88 for this. She is NOT endorsing it - I am just thanking her for the knowledge of its existence, and I am the one suggesting it would make a great stealth one.walmart.com/ip/Lasko-FF305…
The filters here: are 13-A - so I would buy one and swap out the MERV 10 that it comes with.



No affiliation, just these are hard to find.
@Al_pha_Q2 @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @CathNoakes might require slower air to do its job. Not as familiar with that tech, so happy to stand corrected if wrong.
@Debbie_Winslow_ @ManTh1ng @tafkak @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @DavidElfstrom But ...I am NOT the expert here, so if any of the actual experts could "like" the above tweet, or otherwise correct my ruminations, I'd be most appreciative :). .
@Karthik07720496 @CorsIAQ @JimRosenthal4 @ughberta @kprather88 improved by implementation of 2 portable air cleaners.

Dr. Schofield's excellent study here - with an explanation of why:


And yes, it will reduce virus transmission by removing the respiratory aerosols that carry SARS-COV-2.

&

@dgurdasani1 @laineydoyle @DavidElfstrom @fischelfe @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @CathNoakes @Poppendieck But round fans are addressed here with some examples:


Overall FAQ here - includes all build instructions for 5/4/2/1 filter versions. (Actually working on finishing up the 5 version).

cleanaircrew.org/boxfanfilterfa…
cleanaircrew.org/boxfanfilterfaq
Mega Corsi/Rosenthal Box Thread Update:

David Elfstrom has done a fantastic triangle filter build with estimated CADR.


It, along with everything else, is now in the FAQ:


One of the FAQ's is the Gallery - check it out!
cleanaircrew.org/boxfanfilterfa…
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Mega Corsi/Rosenthal Box Thread Update - Adding the Baskett Box (3 filter build).

Wow! An update to the Mega Corsi/Rosenthal Box Thread that kind of went a little viral.

Here's a fan that has a filter built into it! So, a stealth air cleaner.

"Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10."

Next tweet - a surprisingly Image

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More from @LazarusLong13

May 28
Ebola - it's not all about respiratory aerosols.

DYK that you, and me, and everybody are Pig Pen from Charlie Brown?

We shed our entire outer layer of skin every 2-4 weeks, about 500 million cells daily.

Your corneocytes (outermost cells) lift off of your body with the
gentlest of micro-air currents. Like a leaf picked up off the ground for the briefest of moments in fall.

They act like 12 micron aerosols in float time, but 25% of total skin flakes are sub 5 microns...and you know what that means. Deep deposition - or shallow as
sub 5 likes to also deposit in the nose.

It's funny...I embrace push-back in debate. Tightens up my game.

Imagine if those skin flakes now have Ebola on them?

Two studies show that Ebola literally oozes through the skin - both ways. In and out.

Not shown in vivo, but
Read 10 tweets
May 23
The WHO forbids contact tracers from masking or gloving up.

"Do not conduct home visits wearing personal protective equipment like masks, gloves, or
gowns."

It gets worse. Do not conduct home visits wearing personal protective equipment like masks, gloves, or  gowns.
They have a handy how to reduce risk of catching ebola at home.

It even has 5 masks listed on it.

But not for the other family members.

"7. If the patient has vomit, diarrhoea or bleeding, a mask or a dry towel wrapped around the face can be used to protect the nose and mouth Image
7. If the patient has vomit, diarrhoea or bleeding, a mask or a dry towel wrapped around the face can be used to protect the nose and mouth when touching the patient or items soiled with blood or body fluids. A waterproof gown, eye protection, gloves and rubber boots should also be worn in these circumstances.
Here are the 5 face masks. Image
Read 9 tweets
May 22
The "epidemiology" of Ebola tells us that it's not airborne. You've heard this over and over.

What drives it? The questions on the contact tracing form.

Quick 🧵. Image
COVID - the WHO and CDC said it wasn't airborne via aerosols, right?

The CDC said it was spread person to person via close contact - within about 6 feet.



And you remember it took FOREVER to get changed.

The contact tracing form was web.archive.org/web/2020032817…Image
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arranged around close contact. These are the questions driving the stats of how many and how are infected.



So, the CDC will only hear back what it's asking. This was the epidemiology of COVID - until it wasn't. web.archive.org/web/2020052514…Image
Read 16 tweets
May 20
Speaking of silly, can we agree that the WHO has Ebola experts?

Let's talk about PPE, and a bias towards "less PPE is better." Image
The WHO EBOLA IPC guidance:


Foreshadow on PPE

"...due to the desirability of an off-
the-face design, and not for protection from aerosols, respirators may be used instead of medical masks"who.int/publications/i…
If you can stay 3 feet away while screening? No medical mask needed. Image
Image
Read 12 tweets
May 10
Great article by @EmilyJoshu here.

Emily, there's another article in this that's even more shocking.

The aerosols from milking have long been discussed by many of us on X.

People like myself, @sri_srikrishna, @AbraarKaran have long advocated for comfortable aerosol
protective gear like PAPRs. But, have been ignored by the USDA who, of course, thought it was only contaminated milking gear like the claw.

But there is one more source of aerosols besides cow breath.

The wastewater. When you spray anything you generate huge amounts of Image
aerosols. And that farm wastewater, filled with milk dumped from being full of H5N1, gets reclaimed and reused.

Those milk and wastewater lagoons are on most dairy farms (my grandfather owned a dairy farm).

And there's something you should know.

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Read 15 tweets
May 7
Humanity's hubris vs the precautionary principle.

The virus, ANDV, will do what it will do. Pandemic? History tells us "NO." But history is in the past.

Let me show you what the studies tell us - and why I am livid that the WHO is insisting that surgical masks are ok.

🧵
Incubation time, or how long until symptoms show up?

The high risk time frame is 14–32 days. Not to put too fine a point on that, but that can mean a full month later

pmc.ncbi.nlm.nih.gov/articles/PMC32…

There have been some out to 8 weeks, but let's ignore those

gov.uk/guidance/andes… Image
Clinical features The most important complication of ANDV infection is HCPS, which is associated with a high mortality rate. Milder illness without significant cardio-respiratory compromise may also be seen. Illness usually develops 2 to 4 weeks following exposure, but incubation periods as early as 4 days and up to 8 weeks have been described.
But, what receptor does the ANDV attach to?

PCDH1 (protocadherin-1) is primarily expressed in the airway epithelium of the respiratory system, especially in the bronchial and nasal epithelial cells, and in pulmonary endothelial cells.

So, that means in the URT and the LRT.
Read 41 tweets

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