@sri-srikrishna.bsky.social
FINALLY, California public health🥑 got it right ✅. Now they show N95 as clearly superior b/c it has head-straps versus KN95/KF94, "They provide less protection than N95s because they have ear loops."
www.cdph.ca.gov/Programs/CID...
www.cdph.ca.gov/Programs/CID...
November 11, 2025 at 4:31 AM
FINALLY, California public health🥑 got it right ✅. Now they show N95 as clearly superior b/c it has head-straps versus KN95/KF94, "They provide less protection than N95s because they have ear loops."
www.cdph.ca.gov/Programs/CID...
www.cdph.ca.gov/Programs/CID...
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).
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).
September 16, 2025 at 4:41 AM
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).
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."
Ultraviolet radiation vs air filtration to mitigate virus laden aerosol in an occupied clinical room
Mitigation measures against infectious aerosols are desperately needed. We aimed to: 1) compare germicidal ultraviolet radiation (GUV) at 254 nm (254-…
www.sciencedirect.com
July 28, 2025 at 9:49 PM
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)
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)
June 8, 2025 at 8:55 AM
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)
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/...
N95 > surgical > cloth masks > nothing
❗️but only if continuously worn not intermittently. (e.g. taken off for discomfort/eating) www.bmj.com/content/388/...
The role of masks and respirators in preventing respiratory infections in healthcare and community settings
The covid-19 pandemic saw frequent changes and conflicts in mask policies and politicization of masks. On reviewing the evidence, including studies published after the pandemic, the data suggest respi...
www.bmj.com
May 31, 2025 at 7:17 PM
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/...
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.”
"The risk for MACEs was elevated in those with COVID-19 at all levels of severity (hazard ratio [HR], 2.09; P < .0005) and to a greater extent in those hospitalized for COVID-19 (HR, 3.85; P < .0005)."
May 13, 2025 at 5:41 AM
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.”
Reposted
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.
April 14, 2025 at 4:48 AM
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.
Reposted
Starting to heat up. Share this informative infographic I created for heat waves. There are many variables to consider. Stay safe!
April 13, 2025 at 7:27 PM
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...
• "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...
“SARS-CoV-2 airborne detection within different departments of a COVID-19 hospital building and evaluation of air cleaners in air viral load reduction”
The pandemic of COVID-19 has brought in light the necessity for the development of novel detection methods for airborne transmitted pathogens, and the…
www.sciencedirect.com
April 10, 2025 at 7:29 PM
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...
• "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...
Reposted
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
March 30, 2025 at 1:14 AM
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...
March 28, 2025 at 3:22 PM
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
Hello, @bsky.app friends!
DYK: Blue Sky = Cleaner Air = Healthier lungs?
I'm joining you today, to ask for your help in supporting @who.int efforts to help everyone #BreatheLife!
DYK: Blue Sky = Cleaner Air = Healthier lungs?
I'm joining you today, to ask for your help in supporting @who.int efforts to help everyone #BreatheLife!
March 27, 2025 at 7:56 PM
Refreshing message from WHO
Reposted
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...
www.washingtonpost.com/climate-solu...
These DIY air purifiers could make clean air more accessible during wildfires
Homemade air purifiers can filter air faster, making them an affordable alternative to more expensive commercial products.
www.washingtonpost.com
March 26, 2025 at 12:13 AM
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...
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 at rdcu.be/ea153
w/ @ranudhillon.bsky.social @abraarkaran.bsky.social Robert Garry
Steps to prevent and respond to an H5N1 epidemic in the USA
Nature Medicine - Steps should be taken now to prevent an epidemic of H5N1 in humans and prepare for an outbreak should it occur.
rdcu.be
March 4, 2025 at 12:49 AM
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 at rdcu.be/ea153
w/ @ranudhillon.bsky.social @abraarkaran.bsky.social Robert Garry
Reposted
Free access to the article here rdcu.be/ea153
Steps to prevent and respond to an H5N1 epidemic in the USA
Nature Medicine - Steps should be taken now to prevent an epidemic of H5N1 in humans and prepare for an outbreak should it occur.
rdcu.be
February 26, 2025 at 7:01 PM
Free access to the article here rdcu.be/ea153
Reposted
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...
www.nature.com/articles/s41...
February 25, 2025 at 11:32 PM
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...
www.nature.com/articles/s41...
Reposted
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
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
Steps to prevent and respond to an H5N1 epidemic in the USA
Nature Medicine - Steps should be taken now to prevent an epidemic of H5N1 in humans and prepare for an outbreak should it occur.
rdcu.be
February 24, 2025 at 4:49 PM
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
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
Reposted
February 8, 2025 at 4:41 PM
Reposted
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.
From what I understand, three articles on H5N1 were supposed to be published before the administration paused public health communications.
February 7, 2025 at 3:12 AM
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.
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.”
“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.”
February 1, 2025 at 9:14 AM
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.”
“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.”
Reposted
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...
"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...
January 17, 2025 at 4:25 PM
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...
"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...
Reposted
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...
Estimating the population-level effects of nonpharmaceutical interventions when transmission rates of COVID-19 vary by orders of magnitude from one contact to another
Statistical physicists have long studied systems where the variable of interest spans many orders of magnitude, the classic example is the relaxation times of glassy materials, which are often found t...
journals.aps.org
December 6, 2024 at 2:13 AM
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...
Reposted
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...
What if everyone had masked up? Analysis of app data has an answer
Modelling study based on almost 250,000 positive COVID-19 tests in the United Kingdom shows that universal masking could have cut transmission markedly.
www.nature.com
December 6, 2024 at 2:58 AM
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.”
Study shows enforced masking on long flights prevents SARS-CoV-2 transmission
A recent study reveals that longer flights without enforced masking significantly increase the risk of SARS-CoV-2 transmission, while enforced masking on long-haul flights effectively prevents in-flig...
www.news-medical.net
December 5, 2024 at 4:32 PM
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.”