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Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

nature.com

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Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#11

Post by wkat4242 »

nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

It's because ffp3 is a European standard. They're terrible to wear though. I'm glad COVID is over and I only ever wore the absolute minimum required. Only got it once during the mask mandate and that's when I didn't actually wear it in a crowded bar (nobody did so there was no point). I only sniffled for 2 days anyway.

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#12

Post by wkat4242 »

bookofjoe wrote: post #5
nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

10 FFP3 masks from Amazon UK delivered to U.S. cost $30.24 — just ordered them: https://www.amazon.co.uk/FFP3-Masks-Pack-Filtration-Efficien... Thank you VERY MUCH for your comment; I had NO IDEA FFP3 masks are so much better than N95 — and I am a (retired) anesthesiologist who knows a thing or three about masks. I wonder why FFP3 masks aren't made here in the U.S.

Because it's an EU standard. I guess N99 would be similar in the US?

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#13

Post by Vecr »

User3456335 wrote: post #7

> Calculations with an indoor air transmission model showed that if an infected individual with this emission rate entered a room, a susceptible person would inhale an infectious dose within 6 to 37 min in a room with normal ventilation. If this model were accurate, the R would be way higher. So it seems likely that this model misses important aspects.

That's not necessarily true, I have a feeling that I can't really back up that ~all infectious respiratory diseases are airborne (i.e. the infectious particles travel between rooms and linger in common settings), but some combination of infection routes, innate and learned immune responses (actually quite fuzzy when you look at them closely), and human behavior (e.g. "alternate explanations" that epidemiologists come up with like sneezing/coughing) explain why most people don't believe that's the case.

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#14

Post by sschueller »

nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

Doesn’t every additional infection also reduce the likelihood of you getting it again or even noticing you got it as it gets milder?

If I hadn't tested I would not have guessed that the mild cold I just got was my second covid infection. My first covid infection was quite bad even with 3 vaccinations.

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#15

Post by thesaintlives »

wkat4242 wrote: post #11
nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

It's because ffp3 is a European standard. They're terrible to wear though. I'm glad COVID is over and I only ever wore the absolute minimum required. Only got it once during the mask mandate and that's when I didn't actually wear it in a crowded bar (nobody did so there was no point). I only sniffled for 2 days anyway.

Covid over? Not a chance. Still here, still contagious as ever. Media brainwashing may be over, wealth transfer maybe over - Covid no. I have had it 3 times. Every time around 5 days after an international flight with no mask. Mask for me in future and maybe even in the supermarket.Five days in bed I can not afford!

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#16

Post by cge »

Vecr wrote: post #10
wlesieutre wrote: post #4

Earlier quoted context omitted.

Of course these types of respirators have an exhalation valve and would be a dick move to wear anywhere that requires masks. If you’re contagious you’ll be spewing virus all over just like someone with no mask on.

It's only a "dick move" if anyone else actually cares, Zvi's analysis mid 2022 said it would almost never matter, and if it would the other person will tell you.

I wore P100 and FFP3 elastomeric respirators at various times pre-vaccine during the pandemic in California and Europe, as did several of my relatives. Places that understood the problem did care, and many hospitals and medical centres did not allow them for specifically this reason, for example; some accepted them if they were modified to have a filter over the vent, others did not. Most would tell you in advance, but some would not. I came to carry non-vent FFP2s with me as a result, particularly after being harassed by the TSA over it (I suppose they didn't have anything better to do, as I was literally the only passenger going through security at the time, in a major international terminal).

With that said, views on higher spec masks were very arbitrary throughout the pandemic. In one particularly weird case, my partner left a state-run testing centre in Ireland when she arrived with an FFP3 respirator and the staff demanded that she and everyone else wait in poorly ventilated spaces while wearing loose fitting surgical masks they provided because then everyone could be confident everyone was wearing the same masks...

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#17

Post by schiffern »

wkat4242 wrote: post #11
nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

It's because ffp3 is a European standard. They're terrible to wear though. I'm glad COVID is over and I only ever wore the absolute minimum required. Only got it once during the mask mandate and that's when I didn't actually wear it in a crowded bar (nobody did so there was no point). I only sniffled for 2 days anyway.

>They're terrible to wear though.

I'm glad I went "full nerd" early and got a PAPR pollution mask.[1] I estimate I'm getting essentially the same 99% protection, except without the hot stuffy sensation.

The CO2 increase is real, despite propaganda to the contrary. This isn't because a mask "blocks oxygen" (duh), it's just because you're re-inhaling a larger volume of exhaled air, beyond the normal mouth/nose+trachea+unused lung volume.[2]

[1] https://www.amazon.com/BROAD-Purifiers-Rechargeable-Respirat...

[2] https://en.wikipedia.org/wiki/Dead_space_(physiology)

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#18

Post by nikolay »

amluto wrote: post #8
nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

Because FFP3 is a European standard, and you can buy N99 or P100 masks in the US?

3M does not sell in America any disposable face masks above the N95 grade. There are some that are valved, but they are unfair as I don't want to infect others as much as I want others not to infect me.

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#19

Post by nikolay »

thesaintlives wrote: post #15
wkat4242 wrote: post #11

Earlier quoted context omitted.

It's because ffp3 is a European standard. They're terrible to wear though. I'm glad COVID is over and I only ever wore the absolute minimum required. Only got it once during the mask mandate and that's when I didn't actually wear it in a crowded bar (nobody did so there was no point). I only sniffled for 2 days anyway.

Covid over? Not a chance. Still here, still contagious as ever. Media brainwashing may be over, wealth transfer maybe over - Covid no. I have had it 3 times. Every time around 5 days after an international flight with no mask. Mask for me in future and maybe even in the supermarket.Five days in bed I can not afford!

It's not over, and it will never be over if we don't admit that it's here and still killing people, witnessed by the excess mortality. We're like an ostrich with a head in the sand!

Re: Exhaled SARS-CoV-2 aerosol infectivity enables Covid-19 transmission in minutes

#20

Post by nikolay »

sschueller wrote: post #14
nikolay wrote: post #2

My family wore 3M's best face masks for the US market, i.e., N95, and we still got it a few times. We switched to FFP3, equivalent to N99, and there have been no infections so far. I am surprised how bad people are at basic arithmetic! A N99 face mask is 5 times better than a N95 one, not just 4% better! So, I wonder why FFP3 is only available in Europe. I buy the FFP3 face masks, which are manufactured in Poland, fr…

Doesn’t every additional infection also reduce the likelihood of you getting it again or even noticing you got it as it gets milder? If I hadn't tested I would not have guessed that the mild cold I just got was my second covid infection. My first covid infection was quite bad even with 3 vaccinations.

I get palpitations after each infection for at least 4 months. Severe ones, sometimes several per minute. But the worst was after the Pfizer vaccine. I doubt any cardiovascular inflammation could be considered light. Not all people suffer equally, but this is no flu. If you look at excess deaths, it's no joke, and they follow the curve of COVID-19 deaths pretty closely, so it's just undiagnosed COVID-19 deaths, literally.
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