Adds to reminder by @IAQinGWN at #AAAR2022 yesterday that investing in filtration can realize $10-100 return per $ spent e.g. via ⬇️ absences. theconversation.com/investing-in-i…
Well-maintained HVAC filters or portable air cleaners can “also clean the air of pollen particles, mold spores & pollution from car exhaust and industrial operations. And in areas where wildfires are common, filters reduce the concentration of smoke particles inside buildings.”
A family emergency means I’m flying today for the first time since 2019. Fortunately I’ve got my N95 to reduce my inhaled dose as much as possible + my CO2 meter to gauge air.
Short 🧵 to occupy me while on a layover.
The CO2 was nicely & low in the Shreveport, LA airport (1/x) 2/ On this tiny United commuter flight, 45 minute flight time from Shreveport to Houston, no one with N95 masks. Maybe 2 w/ surgical masks.
Boarding & taxi process, the #AirplaneCO2 briefly peaked at 1600 ppm, but mostly in 1100 range. Obviously higher than ideal, but not bad.
Apr 4, 2022 • 11 tweets • 5 min read
Excellent OpEd by @linseymarr & @jljcolorado on the early and persistent confusion around the word "airborne" wrt the pandemic. It's a short overview on the effects of these miscomms across medical & disciplinary boundaries.
Some salient quotes, links (1/) time.com/6162065/covid-…2/ “This fundamental misunderstanding of the virus disastrously shaped the response during the first few months of the pandemic & continues to this day. We still see it now in the surface cleaning protocols that many have kept in place even while walking around without masks. …”
Clarifies N95s aren't in short supply & can be worn again!
It's still not perfect, but it feels like we're at least inching in the right direction. Some thoughts via a🧵. 2/ New statement that most respirators (i.e. #N95s) "are disposable and should be discarded WHEN they are dirty, damaged, or difficult to breathe through."
Improves a procedure to expose surrogate proteins to urban air (especially NO2, O3) to quantify changes in protein nitration ➡️ allergies, etc.
1/🧵 2/ @DaveyRachel1 did a great job of quantifying & improving each step of the #bioanalytical procedure; ozone loss across PM filters, extraction & detection efficiencies, even good old analytical #FiguresOfMerit sensitivity & limit of detection. rdcu.be/cEJN7
Jan 6, 2022 • 4 tweets • 4 min read
If you have more experience & credibility than Dr. @brosseau_lisa on topics of industrial hygiene, aerosol science & mask use, etc. - then by all means speak up.
Otherwise, dispense w/ silliness that surgical masks are safer than N95s. Use #BetterMasks.
It's frustrating to see pervasive misunderstanding that N95 masks (respirators) need to be fitted or they are useless. Some of the same people champion surgical masks instead.
Illogical - If N95s don't work unless prof. fitted, how could surgical masks w/ big gaps work better? 1/
2/ The chart & thread here gathered by @akm5376 helps add perspective. Yes, a professionally fitted N95 provides tremendous protection! But even a un-fitted N95 is better than almost anything else, b/c the filtration is great & fit is already good.
Another good study simulating effects of masks, HEPA cleaners, ventilation in a small meeting room. By NIOSH team incl. Lindsley, et al. mdpi.com/1999-4915/13/1…
🔸 Masks reduced aerosol by 50% +
🔸 Additive further exposure reduction w/ any combo of HEPA, ventilation
Summary 🧵 2/ For reference, this is essentially the same NIOSH team that did some other really nice work on masks and air cleaners:
"... face masks sign. reduce the risk of SARS-CoV-2 infection compared to social distancing. We find a very low risk of inf. when everyone wears a face mask, even if it doesn’t fit perfectly on the face." 1/🧵 2/ The authors perform "upper bound" analyses to get around complexities in modeling risk.
"We conclude that wearing appropriate masks in the community provides excellent protection for others and oneself, and makes social distancing less important." pnas.org/content/118/49…
Dec 2, 2021 • 10 tweets • 6 min read
The #Omicron variant has been found in Colorado, thx to thorough surveillance by @CDPHE.
Omicron cases now detected in three counties in the US. I live in one of them. Seems like a great*time to take both individual & collective responsibility to slow spread. How?
Short 🧵 2/ Don't freak out. It's "not a time for panic, a time for caution." You have some indiv control over your COVID health risk:
✅ Vax + boost yourself & family
✅ Wear a tight-fitting, high-quality mask
✅ Avoid crowded areas
✅ Move meetings outside
✅ Open windows
This is equally unsurprising & disappointing. I'm torn by thoughts that districts often:
* are overwhelmed
* largely ignore airborne prevention
🧵⤵️ coloradosun.com/2021/11/29/col…2/ There have been *countless* sources for good, data-backed science on how to radically slow COVID spread in schools. Pick from any number of excellent Colorado experts or widen the net to advocates & experts all over the country and world.
The solutions are ready to be applied.
Nov 29, 2021 • 16 tweets • 10 min read
Never been a better time to help improve indoor air quality:
* Schools may see COVID increases from holiday travel
* Omicron variant threatening
* Black Fri & Cyber Mon deals at play
If you have any $ margin, consider buying a HEPA filter or two for your local school.
(Short 🧵) 2/ Many commercial HEPA air cleaners you can choose from. Choose:
✅ Enough CADR for room (~2/3 of room area)
✅ HEPA (& ignore ionization/plasma)
✅ Look for lower cost & sound
Several counties in Colorado put a #MaskMandate order into effect starting today: cpr.org/2021/11/23/den…
It's a great time to remind people that masks aren't all the same. Any mask is more effective than no mask, but better fit & filtration quality upgrades protection.
I can't believe Colorado is actually having mtgs to draft possible care rationing plans before seriously working towards preventing people from being infected in the first place.
How is this the 21st century? We effing know how to slow it down, people. 1/ denver.cbslocal.com/2021/11/11/cov…2/ “I would hate to see… sending someone home who’s homeless”. Um, ya. I think that would pretty well violate medical oaths!
"On Friday night, Colorado’s COVID-19 modeling team released a new report warning that if nothing changed, 1,393 people could be hospitalized with the virus by late Nov.
It took less than three days to exceed that projection."
Many are fighting hard at local levels for improved indoor air quality in schools (wrt COVID & beyond). One prejudice against portable HEPA purifiers is perception of "high-cost vs minimal benefit."
A few resources below. Do you know other/better arguments? 🧵
2/ On the cost-effectiveness of HEPA filtration & ventilation. This @JohnsHopkinsSPH report from May 2021 touches into the cost of purchase & replacement for schools (+ much more).
The movement to bring #CO2 sensors to school empowers parents, students, & teachers to advocate for their health; Reveals invisible factors of air quality & helps see how well ventilation is matched to room activity.
Great article by @EmilyAnthes. (1/🧵) nytimes.com/2021/10/10/hea…2/ If you are able to buy or borrow a CO2 sensor, stick it in the mesh water bottle pocket of your kid's backpack, pin into their shorts, or send in their lunchbox. Be creative. Make sure it isn't sealed away; the more airflow the better the reading.