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Joseph Allen Profile picture
Joseph Allen
@j_g_allen
Assoc Prof @HarvardChanSPH; Direct Harvard #HealthyBuildings Program; Lancet @CommissionCOVID; Coauthor of HEALTHY BUILDINGS @Harvard_Press; WaPo, NYT, HBR
16 subscribers
Sep 8 • 12 tweets • 2 min read
In @AMJPublicHealth I make an argument that adding in an economic lens is good public health practice, and I leverage an excellent article by @celinegounder and @Craig_A_Spencer.
🧵 Image In the 1980s and 1990s, the then-new field of IAQ generated research documenting that ventilation rates above this minimum standard were associated with many health benefits.
Sep 7 • 10 tweets • 2 min read
The triple-digit temps in the southwest are catching headlines ("Record-breaking heat wave expected to extend stay in the West"). Dangerous heat, for sure, but, if you look at wet-bulb, you'll see that the headlines should be about the heat wave in the West **AND** Florida🧵 Image How we talk about hot weather is seriously flawed. As heat waves become more intense and more frequent because of climate change, we need to change the way we think about outdoor temperatures.
Sep 6 • 9 tweets • 2 min read
In my Editorial for @AMJPublicHealth on the history of ventilation, I share a story not many people know...

--> In late 2020, the ASHRAE Epidemic Task Force convened a group of experts and gave them an explicit task of making recommendations on ventilation rate targets...
🧵 Image This team submitted their first recommendations to the ASHRAE Epidemic Task Force in 2021...

...but the recommendations were never released to the public.
Sep 4 • 4 tweets • 1 min read
The history of ventilation is fraught, indeed. And it hasn't been told through a public health lens. I was invited to write an Editorial for @AMJPublicHealth. My reflections on how we got here, and what needs to happen next.
🧵 Image We are in the sick building era, ushered in by a historic mistake in the 1970s with the promulgation of a standard that lowered ventilation rates in nearly every building we spend our time, and which represented a gross departure from earlier health-focused higher ventilation targets.
Aug 24 • 4 tweets • 1 min read
This is bad public health. "Everyone stay indoors after 6pm for the next six weeks" (also happens to be the absolute nicest time of year in Massachusetts...) Totally unrealistic, totally unnecessary, and also will just be ignored, anyway. (A major contributing problem in Massachusetts is that we have **351** local boards of health...)
Jul 19 • 6 tweets • 3 min read
NEW from our Harvard Healthy Buildings team

We used CFD modeling to evaluate the effectiveness of portable air cleaners to help remove airborne pathogens and mitigate disease transmission in schools

[tl/dr: portable air cleaners work]

THREAD Image Portable air cleaners work!

We found that portable air cleaners w a clean air flow rate of 2.6 h−1 reduce mean aerosol intake of all students by up to 66% Image
Jun 15 • 13 tweets • 4 min read
On H5N1, milk and this NEJM letter
There are some really important points being missed. It's worth reading the whole letter, including the supplemental info (the authors do a good job of explaining everything); it's not very long...
1/n
 nejm.org/doi/full/10.10… Relevant background
There are two main commercial pasteurization approaches: 63C/30min or 72C/15 secImage
Apr 7 • 4 tweets • 2 min read
The Lancet Commission on Lessons for the Future from the Pandemic

The multiple failures of intn'l cooperation include
1. lack of timely notification of initial outbreak
2. costly delays in acknowledging the crucial airborne exposure pathway of SARS-CoV-2
thelancet.com/journals/lance… Do you know how we got this "costly delays in acknowledging the crucial airborne exposure pathway of SARS-CoV-2" into the manuscript? Steady work by this incredible Lancet Task Force (you'll recognize the crew) Image
Apr 3 • 4 tweets • 2 min read
Build buildings? Operate buildings? Invest in buildings? Work in buildings? Don’t sleep on this. Consensus that:

1) Current ventilation rates are too low
2) 30 cfm/p is a good target Image Members of the Lancet Covid-19 Commission Task Force on Safe Work, Safe School, Safe Travel

--> Report citing 30 cfm/p
static1.squarespace.com/static/5ef3652…Image
Jan 27 • 28 tweets • 9 min read
"Popcorn Lung" was coined when workers at a microwave popcorn packaging facility developed the disease after inhaling diacetyl, one of the chemicals used to create fake butter flavor. Diacetyl, and its many chemical cousins, create candy flavors, too. Fine to ingest; dangerous to inhale.

These same chemicals are often found in e-cigs/vapes. I wrote about "Popcorn Lung" and the flavoring chemicals used in e-cigs/vapes a few years ago:
nytimes.com/2018/04/04/opi…
Image
May 12, 2023 • 6 tweets • 3 min read
Historic day. For 40 years we've been saddled with bare minimum ventilation standards that were not designed for health. Today, CDC released the 1st ever federal guidance on higher ventilation standards, and ASHRAE also released a doc for public comment🧵
cdc.gov/coronavirus/20… CDC specifies 5 ACHe.🙌 This is exactly in-line with the recommendations from our Lancet Covid-19 Commission. It's smart. It's evidence-based. It's understandable. It's actionable. It's achievable. It will keep people healthier.
Mar 26, 2023 • 8 tweets • 4 min read
Current ventilation rates are not designed for Covid-19 (or any other respiratory pathogen)

That's why our Lancet Covid-19 Commission Task Force on Safe Work/School/Travel published this report.
🧵 Task Force had widespread agreement on:

1) current targets too low
2) getting bldgs off current minimums would lead to big gains
3) coalescence around target values, across experts and metrics
4) we want to propose something that moves this convo forward
5) there is urgency
Mar 20, 2023 • 4 tweets • 2 min read
Higher ventilation rates in schools associated with better math test scores.

This study, and many more, in the Harvard Healthy Buildings program report, "Schools for Health": schools.forhealth.org 5% decrement in "power of attention" in poorly ventilated classrooms...researchers equate this roughly to how a student might feel from skipping breakfast. schools.forhealth.org
Mar 9, 2023 • 7 tweets • 3 min read
1/ "It is imperative that orgs like ASHRAE, CDC, WHO, NIOSH create, adopt, and disseminate health-based standards for ventilation.

These orgs cannot continue to tell people to “bring in more air” without answering the critical question: “How much?”
harvardpublichealth.org/environmental-… 2/ Is there an answer to "how much"? Yes! Check out latest article by @dyanilewis. She cites the work of our Lancet @Commissioncovid Task Force that published ventilation targets and other groups.

nature.com/articles/d4158…
Mar 3, 2023 • 5 tweets • 2 min read
1/ Measles spreads through the air. I’m going to take a professional gamble here and, **prior to reading the article** (I swear), am betting that there’s no info on ventilation. Not measured; not discussed. washingtonpost.com/health/2023/03… 2/
Vaccine: ✅ (most important)
Ventilation: ❌

(So close, too, because the article has this: “Measles is a respiratory virus that is spread through the air. “)

Has anyone looked into ventilation here??
Mar 1, 2023 • 6 tweets • 2 min read
The First Four Healthy Building Strategies Every Building Should Pursue, from The Lancet Covid-19 Commission Task Force on Safe Work, Safe School, and Safe Travel 🧵 1/ Commission or Recommission Building Systems
Feb 26, 2023 • 18 tweets • 3 min read
1/ When our Lancet Covid-19 Commission Report came out, it got a lot of positive reviews, with the one exception being the "The Origins of SARS-CoV-2" section, which came under attack. We had it right. Look at the balanced presentation here:
thelancet.com/commissions/co… 2/ "The proximal origins of SARS-CoV-2 are still not known. Identifying these origins would provide greater clarity into not only the causes of the current pandemic but also vulnerabilities to future outbreaks and strategies to prevent them.
Feb 20, 2023 • 4 tweets • 2 min read
1/ This is *really* smart.

“Ms. Guglielmo, 67, was not satisfied. Instead, she paid $900 for an independent contractor to analyze the air in the store, Wristbands America, and was planning to pay to test her inventory of silicone bands.”

nytimes.com/2023/02/19/us/… 2/ Silicone wristbands act as passive chemical samplers (chemicals in the air absorb into them). We use them in our research. 👇

hsph.harvard.edu/healthybuildin…
Feb 17, 2023 • 13 tweets • 3 min read
1/ Everywhere I go these days I see portable air cleaners turned off and/or shoved in the corner. We need to address the noise issue. ANSI standard for background noise in unoccupied classroom is 35 dB(A), but many (most) devices are 55+. The CADR of a device that's off is...0 2/ The ANSI standard also says diff between teacher and student shouldn't exceed 15 dB(A). If device is on in back of room humming at 55 dB(A), a teacher will have to be speaking at >70 dB(A)* or student will have trouble hearing/comprehending speech.
Feb 16, 2023 • 10 tweets • 3 min read
1/ I disagree with this assessment. Here's why:

I previously mentioned a train derailment 10 years ago in NJ with a similar release of vinyl chloride... 2/ Important caveat that I make at end of thread - these are different situations, but the health evaluation done in NJ is informative...
Feb 15, 2023 • 5 tweets • 2 min read
1/ EPA released a statement about the air quality monitoring in East Palestine after the train derailment. A thread with their statements, and some questions I have... Image So, it looks like they were on-site quickly with real-time air quality instruments. But...

Q1: Has anyone seen the data?
Q2: Notice the gap in info? Feb3: on-site taking measurements, Feb 8: "not detected". Does this imply levels *were* above health concern Feb3-Feb8? Image