Here's something that could be hung on the wall of every classroom, hospital, or office: a CO2 monitor that would remind us of what good indoor air renewal can prevent: numerous contaminations. It's reliable and inexpensive to manufacture.

A second version of our new CO2 monitor, in the hope of sparking the curiosity of occupants and their interest in learning more about indoor air renewal and airborne diseases.

Since a CO2 monitor is also an educational tool, our latest model displays the standard CO2 thresholds used to characterize indoor air renewal and provides a link to learn more about airborne diseases.

A very useful list of interesting and impactful projects related to COVID-19. These initiatives aim to improve air quality, track COVID-related data, and provide valuable resources for individuals and communities. github.com/medero/covid...

French environment code is the most stringent in the world for air renewal in schools. Le code de l'environnement français est le plus exigeant au monde pour le renouvellement de l'air dans les écoles. Download a summary in english at / Retrouvez un résumé en français sur letsair.org#regulations

To estimate the effort required to improve ventilation in this specific theater, we performed a simulation: for adequate air renewal, the theater must double the capacity of its ventilation system. Values ​​without ventilation are given for information. ACH= Air Change per Hour

Australia to lead first-ever United Nations indoor air quality global pledge: the Australian Academy of Science and Burnet Institute are leading global efforts at the United Nations, to declare healthy indoor air a human right. www.nationaltribune.com.au/australia-to...

We measured the CO2 level in a Parisian theater during a performance: the mechanical ventilation, clearly audible elsewhere, maintained 1,300 ppm, which was the regulatory requirement before COVID. The recommendation is now 800 ppm, which will require significant investment.

In an AIRBUS A320 aircraft, cabin air is fully renewed about every 2 or 3 minutes. Part of this "clean air" is indoor air filtered by a HEPA filter, the other part is fresh air coming from outside.

"Invisible and ignored: why indoor air quality deserves our attention. We think a lot about the food we eat and the water we drink, but rarely do we consider the air we breathe, especially when we are indoors where we spend around 90% of our lives." www.phcc.org.nz/briefing/inv...

Below is a poster featuring our Airborne Diseases guide with a direct link to download it. Other layouts or wording are welcome.

We've released our guide to airborne diseases. Thanks to contributors F.-X. Blanc (Pr of Respiratory Medicine), @ukhadds (Aerosol Scientist), @PascalMorenton (Engineering Professor), L. Vecellio (Aerosol Scientist), and those who do not wish to be named. letsair.org#mediation

To raise awareness about airborne diseases, download our 25-page booklet, written with healthcare professionals. It presents the diseases that can be transmitted through the air we breathe, the risks of contamination, and ways to prevent them. letsair.org#mediation

Improved ventilation is associated with lower odds of SARS-CoV-2 infection: the more you ventilate, the more you reduce the risk of contamination. Data from a study of patients exposed to SARS-CoV-2 in shared rooms across five Canadian hospitals: www.cambridge.org/core/journal...

Back to School – What’s in the Air Your Kids are Breathing? by American Lung Association who proposes ressources on this topic at www.lung.org/clean-air/in... The blog : www.lung.org/blog/school-...

Schools in London’s most polluted boroughs say air purifiers bring “peace of mind” as term starts. A report from The Royal College of Paediatrics and Child Health (RCPCH). london-post.co.uk/schools-in-l...

Nosocomial pneumonias are the leading cause of nosocomial infections and excess mortality in intensive care*. These pneumonias are very often airborne diseases that can be avoided by systematically wearing masks and ensuring excellent indoor air renewal.

Healthy Indoor Air, a high-level side event at UN Speakers from government, UN agencies, academia, healthcare, education, policy, sustainability, and industry will gather to share insights, experience, and diverse perspectives on how they are approaching indoor air quality.

The National Academies' Health in Buildings Roundtable invites you to explore key actions to improve indoor air quality for health and productivity at a workshop on Wednesday, September 17, 2025 from 9am-5pm ET. www.nationalacademies.org/event/45250_...

ROOMVENT 2026 Conference will cover important topics in room ventilation and indoor air quality. It will take place in Prague, Czech Republic, from September 15-18, 2026. roomvent2026.com

In most countries, 75% of classrooms are poorly ventilated. Changing this situation will take years. Setting thresholds for CO2 levels is the simplest part; the real challenge is finding the societal, technical, and financial path to improve QAI and to support the stakeholders.

Check out the USEPA's newest air cleaning allies activity book for children. DJ is definitely the coolest (and with additional filters in parallel - a more effective ally than Aerie).👇 www.epa.gov/system/files...

The list is long: many diseases are transmitted through the air we breathe. Good indoor air renewal reduces the risk of contamination, particularly in hospitals, schools, and nursing homes. For more information, visit our website or read our 25-page guide: letsair.org#mediation

We were asked about the difference between our terminology for airborne tranmission and the WHO proposal. We consider our proposal as a version 2 of the WHO proposal, with the physical behavior of particles in their naming. See below. Our guide: letsair.org#mediation

Good or poor room ventilation: another way to see or understand it. The data comes from two real-life cases.

Which school, hospital, office, or movie theater do you want to spend time in? Spoiler alert: the quality of indoor air renewal in the public places you frequent directly impacts your health, every day.

We have added a page to our guide on airborne diseases: the example of the French environment code on indoor air renewal requirements in schools. It is one of the strictest codes, which raises questions about its implementation. Download our 25-page booklet at letsair.org#mediation

We remind that we are proposing a terminology for airborne contamination that synthesizes many past and current proposals. We believe that the terms should refer to the observed physical behaviors. Our 24-page guide on airborne diseases is available at letsair.org#mediation

On each level of the Lakanal high school (1885), all the windows are surmounted by a small window that can be opened continuously in winter to ensure good renewal of the interior air. At that time, schools were built in compliance with strict hygiene rules.

The Next Hygiene Frontier: Indoor Air Quality (IAQ) as a Strategic Priority in Healthcare. Many hospitals and outpatient facilities still operate with outdated systems when it comes to one of the most important factors in healthcare environments: IAQ hitconsultant.net/2025/08/08/t...

“Indoor environmental quality represents the vital signs of buildings. We take customers on a digital journey to measure those vital signs by learning from their data, including the financial benefits of a healthy and safer space.” said Terrence Defranco. www.unc.edu/posts/2025/0...

Limiting the spread of airborne diseases (flu, COVID, measles...) and improving intellectual performance in the office and at school is simple and well-documented, as this article shows with concrete examples. It is within reach of all decision-makers. www.sciencedirect.com/science/arti...

"As Students Go Back to School, New Study Highlights the Importance of Clean Air in Classrooms. Amrican Lung Association collaborates with Minnesota Charter School and carrier to support student health and learning environments." www.prnewswire.com/news-release...

"We’ve known for 160 years, since Florence Nightingale, that clean air inside hospitals saves lives. Why weren’t we applying that same knowledge to clinical settings and schools?" www.portsmouth.co.uk/news/opinion...

EPA Indoor Air Fact Sheet: www.epa.gov/indoor-air-q...

USA - 10 school districts earn $50,000 each to help manage efforts to improve indoor air quality and reduce greenhouse gas emissions. www.facilitiesnet.com/hvac/tip/Sch...

An Arabic version of our booklet on airborne diseases is now available for download at letsair.org#mediation . Many thanks to Alawiya RESLAN for the important translation work that made this new publication possible. Below are two excerpts from the guide.

The Massachusetts Clean Energy Center is awarding $52 million in grant funding to upgrade public school facilities in need up infrastructure improvements, and Fall River's Greene Elementary School awarded $2M for healthier indoor air. eu.heraldnews.com/story/news/e...

A building is not made up of walls delimiting living spaces, but of living spaces delimited by walls. The quality of the interior environment is now the main challenge of any architectural gesture, well before any other consideration. To ignore it would be sheer folly.

US School Districts Receive IAQ Funding. Organizations are looking more closely at ways the poor indoor air quality in classrooms affects schools — specifically, increased absenteeism, lower test scores and decreased teacher retention rates. www.facilitiesnet.com/iaq/tip/K-12...

Airborne disease prevention is a complex system involving a multitude of stakeholders. No simple solution, whether economic or social, can be implemented on a large scale. The study of this system must be central to all public health policies and research in this field.

The Open Air School located in Harrisburg, Pennsylvania opened in 1918. Medical experts viewed fresh air as a key way to prevent tuberculosis, an airborne disease. Today, mechanical ventilation with heat recovery maintains excellent thermal comfort. www.pennlive.com/galleries/NL...

Update of our list - non exhaustive - of airborne diseases, included in our 24-page booklet available at letsair.org#mediation

Public health is a matter for engineers. We are continuing our inventory of decentralized mechanical ventilation solutions. It's simple, fast, and effective. There's no reason not to consider installing such a system in a daycare, a classroom, an office... letsair.org#ventilation

The Salamanca City Central School District - the only district in New York state - is among the 10 selected to receive $50,000 in grant funding and technical assistance to develop & implement board-approved IAQ Management and greenhouse gas emissions reduction. www.salamancapress.com/2025/06/23/s...

An excellent introduction to decentralized mechanical ventilation has been produced by the English company @breathingbuildings.bsky.social in this document: www.breathingbuildings.com/wp-content/u... Very clear drawings make it easy to understand the proposed solutions. H/T @chrisiddon.bsky.social

We've begun identifying decentralized ventilation solutions for high-density spaces, such as classrooms. It's a quick and easy way to address excessive room confinement. We welcome your suggestions. Visit letsair.org#ventilation

75% of classrooms have poor or no ventilation. This is the case in this middle school classroom in New York, where measuring CO2 levels revealed the extremely confined space inside. The levels reached are worrying and this is not good for students' concentration or their health.

How a Chicago School Optimized HVAC, Energy Efficiency, and Indoor Air Quality for Student Success. Students in well-ventilated spaces can think faster, remember more, stay more alert throughout the school day, and get sick much less often. www.achrnews.com/articles/164...

For her PhD research, Lara Tookey found that when classrooms were at comfortable temperature, had fresh air and low CO2 levels, students performed better on cognitive tests. “Basically, stuffy and uncomfortable classrooms make it harder for kids to think!” www.massey.ac.nz/about/news/p...