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Linsey Marr linseymarr.bsky.social
6,953 posts
Linsey Marr linseymarr.bsky.social
@linseymarr
Engineering professor @virginia_tech with expertise in airborne transmission of viruses and air quality. Avid recreational athlete.
- New study showing that always wearing a good mask (respirator: N95,KN95) in indoor public settings is associated with much lower odds of +Covid test. Real-world evidence confirms basic principles and lab studies. washingtonpost.com/health/2022/02… comments from @jljcolorado and me
- CDC finally recognizes that the risk of transmission by touching contaminated surfaces is very low. Credit for changing horses midstream. Now everyone should revert to regular cleaning (stop overcleaning) and pay attention to the air instead (ventilation + filtration). No excuses
- Outrageous! I'm getting on a bus in Canada and was told I need to remove my N95 and put on a loose surgical/medical mask instead. @GovCanHealth needs to fix this. @DFisman
- Don't remove your mask to talk. This is the most important time to wear it! You release a lot more respiratory droplets and aerosols when talking than when just breathing. This school outbreak was caused by unvaxxed teacher who "read aloud unmasked." Had symptoms.🤦♀️Report on a #Delta outbreak in elementary #school 80% of kids in front 2 rows infected! - Can we pls take school precautions seriously? - Kids <12 yrs unvaxxed & vulnerable - Don't take off your mask (to read aloud)! - Wear a (good) mask **correctly** 👇 cdc.gov/mmwr/volumes/7…
- We started studying cloth masks in March. Preprint now at medrxiv.org/content/10.110… Take-home: Cloth masks are not an N95, but they work reasonably well for aerosols 1-2 microns and larger, which is the size that we think mostly mediates transmission. See thread. /1
- Belgium's plan for ensuring cleaner indoor air is a good model for others: 1) public indoor spaces must display CO2 level 2) risk analysis and action plan 3) targets: level A (CO2 < 900 ppm and clean air provided at 40 m3/h/person) and level B (CO2 < 1200 ppm and 25 m3/h/person)Belgium has finally come up with a solid indoor air policy. This ventilation plan could have been done much earlier and it is not perfect, but it will certainly be a step towards more #SafeIndoorAir. Hopefully it may inspire many other countries! brusselstimes.com/belgium-news/2…
- Great visualization of how aerosols move through an airplane. Air changes out every 2-3 minutes and passes through a HEPA filter that removes aerosols. Very important to minimize mask-off time.
- Travel kit in the age of Covid-19: CO2 sensor as an indicator of ventilation, rapid antigen test, and an extra N95.
- If you can see your breath coming through your N95, does that mean it's not working? No, this is water vapor that passed through the N95 as a gas and then condensed into tiny droplets when it hit cold air. I'm in MI. /1
00:00 - Six feet is not enough. Now at 44 primary cases + 17 secondary. The gym did health screening, cleaning, masks before and after class, 50% capacity, and 6' around each bike. NOTHING ABOUT VENTILATION.
- This is what we need: automated systems to detect the virus in the air.
- Study confirms that HEPA filters work on SARS-CoV-2, of course. Note that antiviral coating doesn't affect removal from air, since it's a physical process. I sketched expected ratio of concentration at time t to initial concentration as function of t. /1 journals.asm.org/doi/full/10.11…
- Over 100 years ago, people accepted waterborne diseases as a way of life. Currently, we accept colds and the flu as a way of life. If we treat our air like we treat our drinking water, we can greatly reduce respiratory infections and associated costs.
