Chris Iddon
Music, walking, ventilation.
Research fellow
Chair of the CIBSE natural ventilation group
- Competition design for apartments in Switzerland by FHV Architects Beneath the complexity, the design has no corridors, and permits virtually all homes to be dual aspect - meaning better access to light and ventilation
- New study looking at influenza transmission 1 infected person shared small low humidity and poorly ventilated room with 8 uninfected subjects (plus 2 observers). Chatting, playing uno, bit of exercise 5000+ppm CO2 no one got infected 🧵 1/n
- Sigh ... Another paper on C19 vax vs unvaxed (here finding vaxed having more psychiatric events) which passed the review process at a major publisher (@nature.com) without any correction for C19 vax biases, ie that vaxed show lower mortality AND higher incidences Useless paper 1/
- More good news: As of 3 January 2026, Covid-19 has fallen below Influenza as a cause of death in the US, on a year-round (52-week) basis. 1/
- It doesn't always happen, it often takes considerable time, but bad papers can eventually be retracted. www.tandfonline.com/... 1/2
- When it comes to damp and mould - beware quick fixes and remember, it is what is in the air that is truly dangerous. This story about a family whose health was seriously harmed by an inappropriate fix should be a big warning: www.insidehousing.co.uk/insight/indo...
- Pre-sale for our big (really big) Alexandra Palace celebration of 10(+1) years of The Race For Space begins this Monday at 10am GMT. If you'd like access to it, and aren't already signed up to the mailing list, have a go here: publicservicebroadcasting.os.fan/trfs-signup Lots of love, PSB HQ xxx
- @mackayim.bsky.social it's very interesting. Take a look.
- We just published our “Insights from lack of transmission in a controlled transmission trial with naturally infected donors” in the journal PLOS Pathogens. I've summarized it in a Substack post. "How not to catch the flu?" profairborne.substack.com/p/how-not-to... #Influenza #AirborneInfection
- We came away with two main insights that can help us avoid catching and transmitting influenza. First is that infected people who cough are the most contagious. Second, it probably takes a high dose to get infected with seasonal influenza viruses.
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- Here's actual data from Ontario. Covid-19 is the green line. In the last year there have been 6,797 Covid-19 hospitalizations, down a factor of 7 from 2022 (47,994 covid hospitalizations). 3/
- Just announced - The Race For Space at Alexandra Palace, a 10(+1) year celebration. Join us if you can, please (and bring a friend). www.youtube.com/watch?v=udeP... Pre-sale starts 10am on Monday 26 Jan; general sale starts 10am on Thursday 29 Jan. FAQ here: www.patreon.com/posts/148198...
- 16+ venue, my kids will be disappointed. Any other gigs in the pipeline?
- It's in the FAQ sir.. www.patreon.com/posts/148198...
- Fascinating piece about how the fear of microplastics is almost certainly overblown. One takeaway for me is that even the scientists behind the microplastics=bad papers are VERY reserved about whether these findings are really problematic. www.theguardian.com/environment/...
- I usually ignore this, but I have to point out how bonkers these numbers are from @michael-hoerger.bsky.social (3-4% of ALL people in N.E. US currently have covid!) When we test people who ACTUALLY HAVE respiratory symptoms in New England, we find 5% have covid, and... 28% of them have flu!
- Want to get the data out of a PDF figure? As in, the actual data – not a rough trace-along-the-lines version? I made an app you might like: adamkucharski.github.io/pdf2plot/ It all started a few years ago... 🧵
- This is very cool stuff - forensic statistics to look for fraud and related problems in trials.
- Infectionradar are about 10.000 people who test for respiratory viruses. There is a characteristic seasonal pattern of those with airway infection symptoms. At all times, around 2.5-10% of people are infected with symptoms. Which viruses are these? What is the SC2 trend? 1/6
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- What it suggests is that people get symptomatic infection less often in 2023, 2024 and less in 2025. This has happened despite new subvariants and viral evolution continuing. This is in line with hospitalisations and ICU visits, with deaths much reduced as well. 6/6
- An under-appreciated (good) news story of 2025: ➡️Covid-19 has still not reached endemism, and continues its steady march to extinction. (long thread) 1/
- So the countervailing trend to this is people being born - that's negligible over 5 years, but soon starts to accumulate and may be enough to allow for some endemic level of infection.
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- It is a lot better than I expected! Thanks!
- 📢 Introducing CHEPA: a free, easy-to-use tool for #schools and local authorities! Calculate how a #HEPAfilter would affect your classroom #AirQuality and energy use. 🍎 ✔️ Easy-to-use ✔️ Evidence-based ✔️ Classroom-specific results Try the #CHEPAcalculator today: www.coschools.org.uk/CHEPAcalcula...
- Great to see this tool out from the SAMHE team to support air cleaner selection in schools. Based on the model we published in Indoor Environment www.sciencedirect.com/science/arti...
- 📢 Introducing CHEPA: a free, easy-to-use tool for #schools and local authorities! Calculate how a #HEPAfilter would affect your classroom #AirQuality and energy use. 🍎 ✔️ Easy-to-use ✔️ Evidence-based ✔️ Classroom-specific results Try the #CHEPAcalculator today: www.coschools.org.uk/CHEPAcalcula...
- Study indicates 'prolonged exposure in shared, poorly ventilated spaces, which potentially includes several infectious sources, drives respiratory virus transmission more than close contact.' Banholzer, Munday et al. @natcomms.nature.com #AirQuality #Ventilation www.researchgate.net/publication/...
- A powerful approach to facade design in Iranian apartments - where privacy, shade and ventilation are prioritised Brick apartment building in Dezful, Iran, by Bio-Design Architects
- Australia's wild flu season continues: Flu at epidemic levels in New South Wales heading into the first week of summer, sending more people to ED weekly than covid did at any time in 2025. This is driven by the new subclade-K variant of A/H3N2. 1/
- Influenza A still going up in Victoria, Australia, at winter levels well into November (late Austral spring). Flu notifications more than 4X higher than covid in Victoria and NSW last week. This appears to be driven by the new subclade K of A/H3N2. www.health.vic.gov.au/infectious-d...
- Ventilation shaft for the Queensway Mersey Tunnel photographed in 1934.
- The stuff you find when you actually read the RCTs in a systematic review... This paper is one of the foundational studies on vitamin D to prevent respiratory infections in kids. Cited 1,400 times as per Google Scholar.
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- I would guess that most peer reviewers, particularly in 2009, never check pre-registrations and are so not aware that researchers have switched their outcomes.
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- There were 18/167 Influenza A infections in the intervention and 31/167 in the control. There were 39/167 influenza B infections in intervention and 28/167 in the control. Overall lab-confirmed influenza was 57/167 vs 59/167. About as null an effect as you can imagine.
- SARS-CoV-2 is not “airborne HIV” and I will not permit this narrative on my feed. It’s an irresponsible and harmful claim made by people who understand nothing about viruses.
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- A galaxy of discovery awaits! 🪐 Don't miss the 2025 Christmas Lectures, supported by CGI, as space scientist Maggie Aderin-Pocock takes us on a whistle-stop tour of our universe, searching for evidence of extra-terrestrial life. www.rigb.org/christmas-le...
- Y por esto siempre, siempre, siempre necesitas un grupo placebo.
- Es triste que durante la pandemia solo se publicaran estudios que no servían de nada (modelos, obviedades), con un par de excepciones. Ha habido que esperar a que terminara para que saliera lo bueno. Un fracaso y una oportunidad perdida.
- Our CFD study modelling the complexity of ventilation on respiratory viral exposure is out today. This shows that while ventilation is undisputed as important, the short term and local effects can be less predictable 1/ www.sciencedirect.com/science/arti...
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- If all the virus is in particles that start less than 20 micron then ventilation is always beneficial. But if there’s virus in larger particles- which we know there’s some - the effect of ventilation with distance and time is less consistent. 5/
- This brings it only halfway! It has been hilarious reading, with moments of amazement at how little they understand, how mean they are in presenting a false narrative. But I may need a break for a little while before I can continue. marcveldhoen.substac... 1/2
- I can´t believe any peer review was involved @ajpmonline.bsky.social, @ajpmfocus.bsky.social for this junk. The references used do not support, and often undermine, the claims made. "Immune function after COVID-19 infections is characterised by increased risks of infections" 1/2
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- Ref 65 is their own conspiracy on their own WHN webpage! This is so bad!
- One reference is (64), a review only, in Frontiers. They seem to think that counts as evidence. And yes, no kidding, it is about influenza virus infections, which, during the acute phase, and IFNs, can result in secondary infections. WHN amateurs. www.frontiersin.org/... 2/2
- I've written a lot about accounts that publish dubious original research to prop up a narrative that Covid-19 rages on, at levels similar to 2022. But, maybe it does? Maybe we just don't test for it so we don't know? Here's strong evidence that that's not the case. 1/ bsky.app/profile/mich...
- I was looking at some Scottish cause of death data yesterday and the extent to which transport accident deaths in young men have all but disappeared is pretty remarkable. Nice to find a good news story in this data for a change.
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- Using the "just asking questions" technique to get this into the literature, where they will then use it as proof that their answer to the question was justified. Peer review failure.
- Updated. There is so much misinformation, misinterpretation and overinterpretration as well as the WHN collective not having the basic understanding that I only made it halfway the first section: "Immune System Dysfunction in HIV and SARS-CoV-2: Parallels and Divergences" @ajpmonline.bsky.social
- A lot of the analysis on this misses the mark: • “They weren’t on” — maybe, but filtration data says otherwise • “Too small / not ASHRAE 241” — data disagrees. And none of it actually says anything about transmission of respiratory illnesses. 🧵1/n
- HEPA purifiers not tied to less #viral exposure in elementary classrooms, analysis finds #HEPA purifiers were associated with a 33% decrease in viral diversity, but the reduction wasn't linked to fewer school absences. www.cidrap.umn.edu/i...
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View full threadThe results show an interesting spread of viruses that change in prevalence over the year (note there is no SARS-CoV-2 bcos this predates the pandemic, plenty of other coronaviruses tho) 4/n
- This is super interesting - do you know how much it costs to get a dataset like this? I'm wondering if it would be viable for community surveillance.
- Expertise has entered the chat
- This must be the #OvertonWindow, then?
- New Fellow: Professor Malcolm Cook FREng is an expert in indoor air quality, ventilation and low-energy building design. In the Covid-19 pandemic he played a key role in the reopening of large entertainment and sporting venues. @lborouniversity.bsky.social raeng.org.uk/about-us/fel... #RAEngFellows
