Failure to recognize when an aerosol isn't a droplet, but without the stubborn dissagreements. 7

[moon161]

For discussion of the primary matter of this thread, but the stubborn dissagreements can remain there.

https://www.eng-tips.com/viewthread.cfm?qid=483537

 

[waross]

I come away with the feeling that what the WHO does well, they do well.
When new information is presented, the WHO tend to regress into hubris and politics.

Does this sum up the content of the article accurately.
Many years ago, it was found that tuberculosis was spread by aiborn particle but that due to the method of which tuberculosis infected the lungs, only particles or aerosols smaller than 5 microns caused infection.
This is a characteristic of tuberculosis, not of aerosols.
Thus was born the erroneous 5 micron cut-off.
Now tests have shown that aerosol transmission of COVID is possible with particles up to about 100 microns.
Experiments have shown that aerosol transmission of COVID is possible with particles up to about 100 microns.
Physics has shown that aerosol transmission of COVID is possible with particles up to about 100 microns.
Airborne COVID virus can be spread by ventilation systems.
Dr. Fauci has accepted that aerosol transmission of COVID is possible with particles up to about 100 microns.
The WHO have accepted that aerosol transmission of COVID is possible with particles up to about 100 microns.
The research has shown that aerosol transmission or suspension in the air is possible for 100 feet.
I note with interest that the opposition to the new evidence comes from those who have not done any valid experimentation.
Everyone scientist who has looked at the experiments without bias or hubris has accepted that COVID is transmitted for up to 100 feet by aerosols .
Bottom line:
Wear a mask.





Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[dik]

Thanks Bill... been wearing N95 masks since Feb of last year... and only go out once or twice a week for food...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

To be honest most doctors don't actually say the public wearing of surgical masks is anything to do with preventing the wearer from catching covid. Apart from a small help stopping them doing direct hand to mouth contamination off public unclean surfaces

They are to stop you spraying and contaminating everywhere if you have it but don't know it.

So it limits the aerosol dispersal because it hits the mask as you breath out.

The PPE gear they wear on the wards to prevent the staff catching it is a completely different kettle of fish.

 

[moon161]

Yeah, if you're not working in a COVID hospital it seems the big non-vaccine fixes are source control (put a mask on for other people) and dilution (air changes and social distancing). Where I work, we went from masks and fairly strict distancing in the office to no masks is OK if you've had the vaccine. I don't know how many cases have originated at the office, we are not told.

Masking has been relaxed pretty quickly in NY state in general, following the CDC order that fully vaccinated people don't have to. So far, the number of cases in the US is going down.

 

[moon161]

It does shine a light on how the science can get pretty deep pretty fast. One interpretation I took away from the article, is that the 5 micron limit was generalized from TB which requires a very small particle to get deep into the lungs and spread. Focussing on a different contagious disease would probably have lead to a different conclusion.

 

[Alistair_Heaton]

measles is the big one where I am. TB also rears its head but its not in the same league as Measles.

Basically they want a glass window to isolate the person.

Quick google says that for 2 hours after an infected person leaves the room with measles an unvaccinated person has a 90% chance of catching it.

We are just about to reopen the offices and vaccinated is a requirement. If 1 person is not vaccinated then the whole office has to revert back to the distancing/mask reg's .

Its now a feature of all job specifications for hiring that the person needs to be vaccinated with at least the first shot and I suspect during interview they will be asked about when they are getting the second.

I suspect there will be a bit of a melt down soon with the anti vaxers because their lives are going to become very restrictive very quickly. And although its illegal to sack someone for refusing to get vaccinated the other restrictions make working next to impossible.

 

[IRstuff]

To be honest most doctors don't actually say the public wearing of surgical masks is anything to do with preventing the wearer from catching covid.

The PPE gear they wear on the wards to prevent the staff catching it is a completely different kettle of fish.

That's a bit inconsistent. Masks are not Maxwellian demons

Apart from a small help stopping them doing direct hand to mouth contamination off public unclean surfaces

That's never been demonstrated to be significant risk for COVID

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[moon161]

Measles was a disease from the history books for me (age 50+)until there was a critical population of anti vax people I think in Oregon starting a few years back.

 

[FacEngrPE]

Masks are still useful for source control, but for vaccinated people, the risk of being a transmissible source is much less.

A growing body of evidence indicates that people fully vaccinated with an mRNA vaccine (Pfizer-BioNTech and Moderna) are less likely to have asymptomatic infection or to transmit SARS-CoV-2 to others. Studies are underway to learn more about the benefits of Johnson & Johnson/Janssen vaccine. However, the risk for SARS-CoV-2 infection in fully vaccinated people cannot be completely eliminated as long as there is continued community transmission of the virus. Link

Transmissiblity after Vaccination is still not a fully answered question, but the indications are better than hoped for.

[link //www.health.com/condition/infectious-diseases/coronavirus/spread-covid-after-vaccine]Can You Still Spread COVID-19 Even After Getting Vaccinated? Here’s What We Know So Far The CDC released new information Thursday on the transmissibility of COVID-19 in vaccinated people. By Colleen MurphyApril 02, 2021[/url]

 

[TugboatEng]

Big question, how does the risk of being a transmissible source compare for vaccinated and asymptomatic persons?

 

[FacEngrPE]

Vaccinated and asymptomatic persons are reported to shed fewer if any viral particles. - It is a subject of current study.

 

[Alistair_Heaton]

A lot of this stuff is what they have discovered for flu over the years. its as good a starting point as any.

Btw where I am there is no flu what's so ever this winter.

The STD doctors are also well happy with the pubs and night clubs all being shut for several months as their case load has dropped to fractions of the pre covid levels.

Here is the same with the measles as soon as the vac rate dropped below 75% they started having huge out breaks. They are thinking about making it mandatory for kids going to school.

Personally I don't know what the huge fuss is about wearing the masks. Its more of a social issue of the modern world of people objecting to being told to do anything for what ever reason and then bitching like hell they they were not told something when hind sight its discovered they should have been. Its a no win situation. There is no harm wearing them so I just do it.

 

[RedSnake]

In Sweden we haven't had any mask requirements, in the beginning it was only for elderly homes and homecare personal and of course in hospital, intensive care since there t's not possible to keep the distans that was required for everybody else.
It is only now after new year it is needed in public transports.

They court on quite early that the infection risk was higher in IC units then in other places, which is due to the respirators needing pressurizing to get the air down to the lungs.
I guess this also makes the risk for air born droplets larger.

We have almost not had any of the other usual flues either, it was the same during the swine flue, people toke much greater care of washing there hands often and now also keeping the distance and staying home when feeling sick.
So that simple messures can go a long way is at least a good thing as long as people keep to them.

Same here the police haven't impounded as many weapons and narcotics in years as this last one, they have also taken allot more sex buyers, since they do not need to use there resources for drunk weekend scuffles or kerfuffle's.

I love that word , hi hi thanks pete.

/A



“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

They are talking about vaccine only venues and schools here.

Which the anti vaxers are dead against.

The rest of us think its quite a good idea. Nothing to do with covid. It just gives us a place to go and send our kids without a certain type of person or parent of kid.

Win win as far as I can see.

 

[RedSnake]

Do you mean to wear a mask?

/A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

They are talking Vax passport for entry and cert for the kid to be accepted into a school.

Beginning of next month if a whole office is vaxinated then all social distancing and masks protocols are removed.

If even one person is not vaccinated then everyone has to comply with the whole lot.

It's going to be the same with public venues as well.

 

[FacEngrPE]

Tugboat offered a suggestion in the other thread that we should consult paint booths experts with regard to how to set up ventilation to control COVID transmission. This suggestion reminded me of the expert I have consulted many times.

https://portal.acgih.org/s/store#/store/browse/detail/a154W00000BOavHQAT[/URL]]Industrial Ventilation: A Manual of Recommended Practice for Design

This has been my go to reference anytime I needed to know how to control dusts and vapors for an industrial process.

The [link

https://www.acgih.org/

]American Conference of Government and Industrial Hygienists[/link ] are experts in paint booths and all sorts of industrial exposure engineering controls. Here is a link to an older version

https://archive.org/details/gov.law.acgih.manual.1998/mode/2up.

They (ACGIH) have now published some COVID-19 Resources which are very to the point.

 

[Fischstabchen]

FacEngPE,

Focusing just on the filtration negates anything that has to do with the virus getting to the proper cell receptors or more simply put being contagious.

I have wondered if running a humidifier is enough or has a huge affect on transmission. Transmission rates dropped after July and picked up in September/October in Texas and if there is a state with a huge population of virus deniers, it is Texas.

 

[TugboatEng]

The paint booth engineer faces an interesting challenge. In their case the droplet needs to stay airborne long enough to make it from the paint gun to thr painted surface while the aerosol needs to either get exhausted or fall to the floor so it doesn't contaminate nearby surfaces.