@robwiss
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I've written up a more accessible version of the technique I use to perform at-home CADR tests in a test chamber. My current setup is a bit more advanced, it is automated and runs from a raspberry pi. Otherwise, it's the same.
#AirFilterDev
thewiss.blogspot.com/2022/11/at-hom…View quoted post on X
To curb H5N1 threat, @CDCgov urged dairy workers to don masks and goggles
But @CDCFlu's Tim Uyeki conceded this week:
"may not necessarily be practical given the environmental conditions. So throughout the U.S., every day, it’s only getting warmer"
tinalexander.github.io/notes/2024/06#…View quoted post on X![A screenshot of text that reads in part: "Tim Uyeki, CDC [00:50:50] In terms of respiratory protection, the recommendation is an N95 respirator, not a surgical face mask. Definitely the recommendation is for eye protection. And, as I mentioned, we’ve had two cases of workers with conjunctivitis and so goggles or a face shield. But as Dr Maderas recommended, this may not necessarily be practical given the environmental conditions. So throughout the U.S., every day, it’s only getting warmer and more humid. And Dr Maderas mentioned even for healthcare personnel, the challenges of wearing goggles or face shield and fogging up and so forth. So, what we can say is what the recommendations are. We can post all of the PPE that are recommended. We can post the guidance from CDC and NIOSH in there. But we also realize the reality is that workers may not comply. And so I think that we all have to work closely together, including with farm workers and farm owners and the dairy industry to see what](/api/media?url=https%3A%2F%2Fpbs.twimg.com%2Fmedia%2FGQh_nEtW0AA-wWe.jpg)
Today, I continued my examination of respiratory protection equipment.
I observed significant discrepancies between the data from a fit testing device and a particle counter. For instance, when testing the AirFanta 4Lite at a distance of 0cm with the "L" speed setting, the particle counter indicated a protection rate of 50, while the TSI 8020 reported a fit factor of approximately 6.5. At a distance of 30cm with the same speed setting, the particle counter showed a protection rate of 14, and the TSI 8020 indicated a fit factor of about 4.3. @gerard, obtained similar readings.
I acknowledge that particle counters and fit testing devices operate differently. Particle counters directly measure particles larger than 0.3 microns, whereas fit testing devices use isopropanol to pre-treat the particles. However, the crucial question everyone is asking is: which measurement is more reflective of real-world protection against pathogens like COVID-19?
I can offer some insight on this matter. Last year, a certified laboratory, "Guangzhou Institute of Microbiology Group Co., Ltd, National Center of Quality Inspection and Testing on Air Purification Products," conducted a germ filtration test on the 4Lite model, following the GB/T 5365-2019 standard.
The test assessed the density of microorganisms at the filter's entrance and exit. They used "Staphylococcus albus" bacteria and "H1N1" virus for the tests. The average filtration rate for Staphylococcus albus was 98.42%, corresponding to a protection factor of 63. For H1N1, the average filtration rate was 99.51%, equating to a protection factor of 204.
From these results, it's evident that the actual protection factor against COVID-19 and other pathogens is significantly higher than what fit tests and particle counters suggest. Both N95 respirators and the 4Lite device provide much greater protection than fit test results might indicate.View quoted post on X
So I am a bit ashamed to discuss this, but, for those who don't know:View quoted post on X
The first time I got COVID-19 was during the Omicron wave. I was on a 10 day trip in the SF Bay Area in June 2022. I know exactly how I got COVID-19. The one time I took my N95 mask off during the trip was during a job interview, and that's where I got it. (I sat in a room for a while without a mask with someone who tested positive 2 days later and I became sick 3 days later). I had severe #LongCOVID for about a year. I had chest pain, severe insomnia, and tinnitus for a solid month. The first six months I was severely ill - I could not work at all and I could not walk more than a block or two. There's a lot more I could say about this - one of these days I'll finish writing a long post on Medium that goes through the whole story. I was under a lot of stress at the time and I think that contributed to me developing Long COVID (possibly through Epstein-Barr reactivation).
Anyway, about 10 months after my first infection I got COVID-19 a second time at a conference where I didn't mask. It took me at least 6 weeks to recover. I took two rounds of Paxlovid.
The 3rd time I got COVID-19 was about 4 weeks ago. It was also after a conference where I didn't mask. It took 4 weeks or so to recover and I had to take 2.5 rounds of Paxlovid.
So now I mask at conferences. I learned the hard way. I hope others don't have to learn the way I did. COVID-19 is not going away.
Also, I took a hard look at all the scientific literature recently on #LongCOVID risk and the risk of brain damage from COVID-19. If you care about your health, everything I've learned strongly supports strategic masking with a well-fitting N-95 or respirator in high risk environments: moreisdifferent.blog/p/all-of-these…
