HOW LONG DO MERV 16 FILTERS LAST 🏃🏃‍♀️🏃‍♂️? CDC researcher Christopher Barnes and I decided to find out: 2 DIY SAFE boxes in elementary school 🏫 (16 months) vs 3 DIY SAFE boxes (4 months) in middle school 🏫 All used daily (per teacher reports).

J Haz Mat (April 5, 2025): "Our study is the first to directly compare the relative effectiveness of GUV devices (upper-room 254 nm and whole-room 222 nm) and HEPA filters to remove/inactivate model virus laden aerosol in an occupied clinical room."

2 YEARS UPDATE on DIY: This week I tested 10 DIY purifiers in 4 classrooms (160 in use). Still working great!! ✅ CDC & CDPH say we need 5+ air changes per hour (ACH). 🌪️ When I tested $1000+ district-supplied HEPA only 2.5 ACH (sp 2) vs 6.3 ACH for $400 DIY (sp 1) 👀 (1/4)

New review in BMJ by @trishgreenhalgh.bsky.social says for respiratory protection from viruses/bacteria in air: N95 > surgical > cloth masks > nothing ❗️but only if continuously worn not intermittently. (e.g. taken off for discomfort/eating) www.bmj.com/content/388/...

According to Quinn, “apart from an elevated risk of venous thromboembolism within 1 year..” “many of the post-acute consequences of COVID-19 may be related to the severity of infectious illness necessitating hospitalization rather than being the direct consequence of infection with SARS-CoV-2.”

Pay attention to *all* variables. If you get in trouble but your cell phone has no service -- you're still in trouble. If you have cell service but EMS is 1 hour away -- you're still in trouble.

Starting to heat up. Share this informative infographic I created for heat waves. There are many variables to consider. Stay safe!

From COVID-19 hospital wards in Greece: • "Air viral load in COVID clinic ranged from 25,9 to 1123,7 copies/m3." • "Air cleaner showed an effective reduction of air viral load, reaching 98.1%." www.sciencedirect.com/science/arti...

1/ The CR Box behind me has been operating for well over 3,000 total hours over the past year (avg about 65 hours per week). It's definitely not looking shiny new. Nonetheless, I just did triplicate measurements of ultrafine particle (UFP) concentrations outside and inside the box ..... more

This WHO video seems to attribute particulate air pollution to smokestacks and vehicles but as we are finding out, are wildfires, land fires, and burning of vegetation a more significant source of particulate pollution globally? www.nature.com/articles/s41...

Refreshing message from WHO

Thanks to Amudalat Ajasa for this story about the significant benefits of CR Boxes for wildfire smoke particles and other indoor aerosol particles (including virus-laden respiratory aerosol particles, pollen, mold, particles from cooking, etc.). www.washingtonpost.com/climate-solu...

In Nature Medicine, we highlight 8 steps to prevent H5N1 🦅 🐄 🐓 (bird flu) from becoming a pandemic. Free access at rdcu.be/ea153 w/ @ranudhillon.bsky.social @abraarkaran.bsky.social Robert Garry

Free access to the article here rdcu.be/ea153

Our commentary in Nature on immediate steps to combat the #H5N1 bird flu outbreak. @ranudhillon.bsky.social @sri-srikrishna.bsky.social www.nature.com/articles/s41...

If H5N1 evolves to spread between people, it could spur a pandemic In @naturemedicine.bsky.social, @sri-srikrishna.bsky.social Robert Garry @abraarkaran.bsky.social & I discuss the mutations it may take for this to happen & what we could do now to stop it & be prepared in case it does rdcu.be/ea153

🎯 Absolutely brilliant 👇 Link: govwayback.com

I’m relieved that MMWR is back online, but I’m worried about what’s next. From what I understand, three articles on H5N1 were supposed to be published before the administration paused public health communications.

Not too surprising that pollution 🔥 💨🚬 🚘 (PM 2.5) is linked to lung 🫁 cancer, but why would it increase risk of ANY CANCER? “for every 10 microgram per cubic meter (µg/m3) of increased exposure to PM2.5, risk of dying from any cancer rose by 22 percent.”

Interesting 🧵 by @sri_srikrishna (on X) about #IAQ: "BIG NEWS: Yesterday California public health 🥑 just recommended to at least 5 air changes per hour in ALL ROOMS (occupied). Seismic..." threadreaderapp.com/thread/18801...

Thanks to a Nature editorial, this paper by Richard P Sear has caused a stir. The study is helpful, but the mathematical modelling is only as good as the underlying assumptions. 🧵 journals.aps.org/pre/abstract...

In summary: great study but it should have modelled fit factors of 3 (typical of a surgical mask or KN95), 10 (poorly fitted earloop FFP2), 30 (modestly badly fitting FFP2), 70 (modest failure) and 100 (bare pass). www.nature.com/articles/d41...

1st study found Covid risk was flight duration-dependent, 25x on long vs short flights, inconsistent with boarding and deplaning being higher risk than inflight. “each hourly increase in flight duration increased the incidence rate by 1.53-fold.”