quote:

Originally posted by sdy:
Why do people question the effectiveness of N95 filters?

HEPA filters are rated at 0.3 microns because that is near the worst case particle size for penetration. Filter effectiveness is better at greater than .3 microns and also better at less than .3 microns.

To echo what SC said...An N95 is not a HEPA filter. It will filter 95% of airborne particles. The 5% that gets through will be mostly the small stuff, i.e. <0.3 microns. The coronavirus particle is about 0.1-0.2 microns.

(HEPA filters must remove at least 99.97% of airborne particles down to the size of 0.3 microns.)

quote:

Originally posted by kkina:The coronavirus particle is about 0.1-0.2 microns.

Would a truly bare virus particle actually travel without being "on" something?

quote:

Originally posted by MNSIG:

quote:

Originally posted by kkina:The coronavirus particle is about 0.1-0.2 microns.

Would a truly bare virus particle actually travel without being "on" something?

Yes, that's the very definition of "aerosolized". It is known that earlier strains of coronavirus do travel this way. It is not known if the novel coronavirus does. It is not actually known if they are vectored on moisture droplets either. We're not sure if it's airborne at all, although it wouldn't be surprising.

How could a virus or anything really, not be able to be airborne? Serious,question.

quote:

Originally posted by 6guns:
How could a virus or anything really, not be able to be airborne? Serious,question.

That I don't know. Would have to look into it. As a guess I'd think it would have to do with the affinity of the outer lipid layer to moisture, and the electrostatic nature in free air. That kind of stuff. Then whether the virus itself can remain viable under such conditions.

While I understand the idea of minimizing interaction of people to lessen contact to help stop the spread of disease, this was NOT the way to go about it Beshear and Fischer.

It is one thing to use governmental authority as a “bully pulpit“ for persuasion. It is totally something else to use governmental power as a cudgel to bludgeon reluctant individuals into compliance.

“Judge Walker called Fischer's decision ’stunning,’ and ’beyond all reason, unconstitutional,’ according to court documents. ’On Holy Thursday, an American mayor criminalized the communal celebration of Easter. That sentence is one that this Court never expected to see outside the pages of a dystopian novel, or perhaps the pages of 'The Onion',’ Walker said.”

Judge grants Louisville church's temporary restraining order against Mayor Fischer to allow drive-in service

quote:

Originally posted by 6guns:
^^^ I was reluctant to even open the link!

The bat lady researcher opening the Pandora's Box was highly featured in the video that wcb6092 posted this morning. I may start calling it the CCP virus also.

It has been mentioned several times (but perhaps not in the 20 minutes or so), that the known, or strongly believed anyway, primary method of transmission of the disease among individuals is via mucus or saliva droplets from coughs or sneezes. Those droplets contain the virus and are large enough to be stopped by an effective mask. Based on what was reported before, there isn’t much likelihood that viruses are free floating without being attached to something like that. And, of course, even if there are, what’s better, to stop some of the threat, or none? Police wear soft armor because of its ability to stop most handgun bullets, not to stop rifle bullets. Should they just say, “Ah, screw it. This won’t stop a 50 BMG, so why bother?”

I am reading the book Pale Rider by Laura Spinney which is about the so-called “Spanish” influenza pandemic. (The book was published in 2017, so it doesn’t have any COVID-19 agenda.) In it she notes that places that early on instituted wearing even the primitive masks of a century ago had lower death rates than similar places that didn’t. I understand why people don’t want the inconvenience and coolness factor-killing of wearing a mask today, but I am mystified why they would discourage other people from wearing them. Even if we accepted the ridiculous notion that they only prevent infectious materials from traveling one way (out), that should still be reason enough for the rest of us to want those who might be infected to wear them.

^^^ Maybe I'm behind the times or didn't get the most recent memo, but I thought the primary source of infection was from contaminated surfaces to hand to face? Isn't airborne transmission still somewhat in question?

quote:

Originally posted by sigfreund:
It has been mentioned several times (but perhaps not in the 20 minutes or so), that the known, or strongly believed anyway, primary method of transmission of the disease among individuals is via mucus or saliva droplets from coughs or sneezes. Those droplets contain the virus and are large enough to be stopped by an effective mask. Based on what was reported before, there isn’t much likelihood that viruses are free floating without being attached to something like that. And, of course, even if there are, what’s better, to stop some of the threat, or none?

There is also some evidence of a dose response curve. If you get infected with a single virus particle it may not be sufficient to cause disease (due to the innate immune system). A bigger inoculum may cause disease but possibly it would be less severe than someone exposed to a large dose of virus. So even if the filtration is not absolute it may shift the burden from needing ventilation in an ICU vs. sheltering at home with chicken soup.

quote:

Originally posted by 6guns:
^^^ Maybe I'm behind the times or didn't get the most recent memo, but I thought the primary source of infection was from contaminated surfaces to hand to face? Isn't airborne transmission still somewhat in question?

That was my understanding, as well. I agree with the rest of his post, however.

quote:

Originally posted by 6guns:
Isn't airborne transmission still somewhat in question?

Nope. There are well documented cases of airborn transmission. The best example is of a choir in Mount Vernon, WA (IIRC) where they held a rehearsal and were spaced apart and all wore masks. About half of the choir came down with the disaese.

Mrs. Mike and I went to the local Target today for “alleged ” TP....they were out...we are down to nine rolls

90% of the people had some type of mask. ....from a standard paisley handkerchief (imagine robbers), N95, soft cloth, dust masks, etc....

I saw one. One person who had the mask fitted properly. I could see people with their noses above the mask, people with gaps around the nose where you could see their nostrils and some that were so large that anything could have gotten around the mask.

I was in the service and we were fit tested for our NBC masks.
I was a shipboard firefighter that wore a mask for air...
I was a cop that was annually fit tested for masks ....

On all of them we used smoke from banana oil burning to let us know if the mask fit ...

None of these people walking around would have been able to stop anything from entering themselves thru the airway...

Complete waste of time.

We are all gonna get it.

quote:

Originally posted by sigfreund:
I understand why people don’t want the inconvenience and coolness factor-killing of wearing a mask today, but I am mystified why they would discourage other people from wearing them. Even if we accepted the ridiculous notion that they only prevent infectious materials from traveling one way (out), that should still be reason enough for the rest of us to want those who might be infected to wear them.

My sense (from articles linked in this thread and others) is that the dust masks that I have available will do little to protect me other than remind me to keep my paws off my face, but that they may protect others from whatever cooties I may be distributing. (ETA: by minimizing distance anything gets distributed. A dust mask won’t prevent anything from getting out, but it should prevent it from shooting straight out.)

My first thought is that “little” is not “nothing”. My second thought is that if I’m going in the grocery store or somewhere else inside where I may find myself close to others it might be considerate to do simple things that may protect them. My third though is that unless I throw away and replace the masks after being around others, (or quarantine & sanitize them) they may be a negative in terms of risk if I take it off when I get back in the car, then put it back on at the next stop.

Honestly, I think I’m pretty much over worrying about the beer flu. I’ll mask or not mask as seems appropriate, wash or sanitize hands regularly, but I think I have “COVID-19 exhaustion” and am not able to really worry about it anymore.

quote:

Originally posted by 6guns:
Isn't airborne transmission still somewhat in question?

There is evidently common confusion about what “airborne” refers to. The below link to a W.H.O. article explains the difference. In short, “airborne” refers to smaller particles that the virus can attach to and that can remain in the air for an extended period. “Droplets” are larger and are of the sort we can actually feel if we cough or sneeze on our hand, for example. This is what the article says about them:

“Respiratory infections can be transmitted through droplets of different sizes: when the droplet particles are >5-10 μm in diameter they are referred to as respiratory droplets, and when then are <5μm in diameter, they are referred to as droplet nuclei. According to current evidence, COVID-19 virus is primarily transmitted between people through respiratory droplets and contact routes. [Emphasis added.] In an analysis of 75,465 COVID-19 cases in China, airborne transmission was not reported.

“Droplet transmission occurs when a person is in in close contact (within 1 m) with someone who has respiratory symptoms (e.g., coughing or sneezing) and is therefore at risk of having his/her mucosae (mouth and nose) or conjunctiva (eyes) exposed to potentially infective respiratory droplets. Transmission may also occur through fomites in the immediate environment around the infected person. Therefore, transmission of the COVID-19 virus can occur by direct contact with infected people and indirect contact with surfaces in the immediate environment or with objects used on the infected person (e.g., stethoscope or thermometer).”

https://www.who.int/news-room/...tion-recommendations

I would also point out that if an unmasked infected person coughed or sneezed on the soup cans or plastic meat wrappers in the grocery store, then those viruses will be transferred to my hand when I pick them up myself. That’s why I wear gloves in places like that, but I and all the other shoppers would be better off if that person had been wearing a mask to intercept the droplets.

Anyone who has ever covered a cough or sneeze with a napkin or handkerchief was doing so to stop the larger droplets from contaminating a dinner table or entering the eyes, nose, or mouth of a dinner companion. And in any event, even if the airborne or aerosol transmission route is still not proved, it has not been disproved, either.

Louisville's Mayor fisher threatened to have police scan license plates at a drive in Easter service and force those attending to quarantine for 14 days. Judge strongly overruled him.

https://www.wdrb.com/news/judg...7d-3b6ca408b33c.html

Judge grants Louisville church's temporary restraining order against Mayor Fischer to allow drive-in service

FTA:

LOUISVILLE, Ky. (WDRB) -- A Kentucky judge has granted a temporary restraining order filed by a Louisville church against Mayor Greg Fischer to allow drive-in service on Easter Sunday.

On Fire Christian Center filed a lawsuit asking for the temporary restraining order against Fischer on Friday for not allowing drive-in church services on Easter, "seeking to block his prohibition on churches holding drive-in services during the COVID-19 pandemic," according to the First Liberty Institute, which filed the lawsuit on behalf of the church.

Judge Justin Walker of Louisville granted the order Saturday, which prevents the city from "enforcing; attempting to enforce; threatening to enforce; or otherwise requiring compliance with any prohibition on drive-in church services at On Fire," according to court documents.

Walker called Fischer's decision "stunning," and "beyond all reason, unconstitutional," according to court documents. "On Holy Thursday, an American mayor criminalized the communal celebration of Easter. That sentence is one that this Court never expected to see outside the pages of a dystopian novel, or perhaps the pages of 'The Onion'," he added...

quote:

Originally posted by 6guns:
^^^ Maybe I'm behind the times or didn't get the most recent memo, but I thought the primary source of infection was from contaminated surfaces to hand to face? Isn't airborne transmission still somewhat in question?

Yes, there is no consensus on whether coronavirus uses airborne transmission. To the best of our current knowledge it is primarily transmitted via droplets expelled from coughs and sneezes. But such droplets fall quickly, and are then picked up by people touching contaminated surfaces. This isn't airborne transmission in the strict sense of the word.

The church choir incident has too many unanswered questions. Did they really maintain separation? What did they touch during the rehearsal? What comes out of a person's mouth when they're singing? It may have been airborne, but it's not definite.

Personally, I am proceeding under the assumption that there is airborne transmission, but it is a secondary vector and droplet not aerosol. That means I don a P95 respirator when going out.

Thanks for the replies.

quote:

Originally posted by MikeinNC:
I saw one. One person who had the mask fitted properly.

Hell, I've seen people with 'em down around their necks. Lot of good they're doing there.

Worse: One guy, I jokingly said to him as he passed by me, "That mask'd probably be more effective if you wore it," with a smile. He laughed, said "You're right," then proceeded to use the hands he'd just used to handle product, money/card, and take the bag from the cashier, to put the mask in position.

Uhm... No, dude. Just... no

quote:

Originally posted by MikeinNC:
I was in the service and we were fit tested for our NBC masks.
I was a shipboard firefighter that wore a mask for air...
I was a cop that was annually fit tested for masks ....

Advantage of having been in roles where you were required to learn that.

quote:

Originally posted by MikeinNC:
On all of them we used smoke from banana oil burning to let us know if the mask fit ...

Banana oil? Ha! Ours were tested in enclosed spaces with CS gas. If you didn't have it right, you found out damn quickly

quote:

Originally posted by slosig:
My third though is that unless I throw away and replace the masks after being around others, (or quarantine & sanitize them) they may be a negative in terms of risk if I take it off when I get back in the car, then put it back on at the next stop.

We put 'em on when we leave the house, before even entering the car, then they're the last thing off after we get home. We hang 'em outside, in the sun, to disinfect. In any event: We don't go out where we need to wear 'em more than once a week, at the most. So even if we didn't hang them out in the sun, where UV could get to them, they'd be idle for longer than the length of time the virus is believed to remain viable on such materials.

Saw some articles coming out about the use of ventilators...interesting that its now becoming more questionable to use them. a very smart dr put PM Boris Johnson on oxygen and not a ventilator. thank that doc.
i searched back a couple of pages, sorry if a repost. i also tried to just link the videos, and not embed.

NYC Doc on Ventilator Protocol

Anticoagulation; Can Mechanical Ventilation Make COVID 19 Worse?