Air Quality Matters

This week, I step back from the interviews to share a personal reflection on the conversations, themes and patterns that have emerged over the last few weeks, both on this podcast and in the halls and sessions of Indoor Air 2026 in Singapore. What if the single biggest barrier to transforming the built environment isn't our lack of scientific knowledge or technology—but our complete failure to recognise the deeply interconnected systemic, linguistic, economic and human forces that keep us locked in the same destructive cycles?

Key Topics Discussed:

The Linguistic Firewall: During the pandemic, we saw in real time how a single word could paralyse global action. The term airborne became a structural firewall. To an engineer, if a particle is suspended in the air and moves with the air currents, it's airborne. But to the medical community, airborne carries a very specific, high-consequence historical definition. Because of that deeply entrenched medical definition, the engineering and building science communities were effectively locked out of the operational response for months.

The Tyranny of Efficiency: For the better part of the last 40 or 50 years, the dominant almost tyrannical metric in our industry has been efficiency. We chased energy performance relentlessly. Energy is a hard measurable cost. You get a utility bill every 30 days. It is incredibly difficult to put a hard financial number on human health. So we optimize for what we can measure.

The Myth of the Average Person: We design multi million dollar HVAC systems to hold a massive commercial floor plate to a highly precise 21 degrees Celsius. The glaring problem is that the average person is a statistical ghost. When you design for the mathematical average, you are effectively designing for nobody. Instead of viewing human comfort and health as a single fragile optimal point on a graph, we need to view it as a geographical landscape.

The Looming Energy Crisis: The IEA warns of the greatest energy security threat in history. When the grid is constrained, society panics. And when society panics about energy, the built environment is always the first casualty. We know exactly what this looks like because we've been here before. In the wake of the 1973 oil embargo, we sealed our buildings up, slashed ventilation standards and triggered an era of sick building syndrome. The temptation to repeat the mistakes of the 1970s is sitting right in front of us. This is an inflection point. The challenge for all of us is to hold our nerve and fiercely defend the invisible air that sustains us, ensuring that as the world changes around us and as the energy grid strains, we never again compromise the indoor environment.

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) - S&P UK (https://www.solerpalau.com/en-uk/)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/)

Zehnder https://www.zehndergroup.com/en

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: Reflections from Indoor Air 2026 and the Power of Conversation
00:01:30 The Crisis Cycle: Why We Design for Emergencies but Operate for Peacetime
00:04:07 The Airborne Language Barrier: When Medical Definitions Paralyze Engineering Action
00:07:11 The Tyranny of Energy Efficiency: How We Optimized Buildings for Spreadsheets Not Humans
00:11:49 The Myth of the Average Person: Why Designing for Statistical Ghosts Fails Everyone
00:16:44 The Comfort Paradox: Is Thermal Perfection Making Us Biologically Fragile?
00:21:46 The Invisibility Problem: Why Data Doesn't Move Hearts and How to Tell Better Stories
00:24:38 Proxies and Noise: The Double-Edged Sword of CO2 Sensors and Simple Solutions
00:27:47 The Accountability Gap: From Run-to-Failure to Mandatory Building Performance Checks
00:32:11 The Global South Crossroads: A Fleeting Window to Leapfrog Western Mistakes
00:35:33 The AI Energy Arms Race: When Data Centers Compete with Humans for Cooling Capacity
00:37:19 The AMR Connection: How Poor Ventilation Fuels the Antimicrobial Resistance Crisis
00:40:10 The Skilled Trades Bottleneck: Why the Workforce Crisis Is Our Greatest Limiting Factor
00:43:09 The 1970s Déjà Vu: Navigating the Energy Crisis Without Sacrificing Human Health Again

This week, we dive into a fascinating study from the University of Southampton and Hampshire County Council titled Preliminary Findings of Storytelling in Schools as a Pre-Heatwave Intervention to Enhance Children's Behaviour to Improve Thermal Comfort, to explore a question that fundamentally challenges how we think about overheating in schools: What if the single biggest barrier to protecting children from dangerous heat exposure in classrooms isn't just our aging building stock—but our complete failure to recognize that empowering children themselves to take simple adaptive actions could be the most immediate, scalable solution we have right now?

Let's face it, our school building stock, especially in the UK, is ageing and frankly poorly equipped for the reality of modern summers. A massive portion of schools, about 40% in the UK like Hampshire, are scholar system buildings thrown up in the 1960s and 70s. They were lightweight with huge amounts of single-glazed windows and very low thermal mass. They were designed to keep kids warm in winter with absolutely no thought given for handling the 30 to 35 degree heat waves we are increasingly seeing.

Key Topics Discussed:

The Temperature Preference Gap: Children actually have a preference for lower temperatures than adults. Studies have shown their comfort temperatures are usually two to three degrees cooler than ours. But who controls the environment in a classroom? Who controls the windows, the blinds, the thermostats? The teachers. So you have adults with a higher thermal threshold making the environmental decisions for children who are already feeling the heat. Younger children, especially those in key stage one aged five to seven, just don't have the agency or confidence to change their environment. They aren't going to stand up in the middle of a lesson and say, Miss, I'm boiling, can I open that window? They just sit there. They overheat. Their cognitive performance drops off a cliff and they become exhausted.

The Storybook Intervention: The researchers designed a low cost, incredibly creative intervention. They wrote a storybook called The Hottest Day at School. It's a simple, engaging story where different characters through history- a Viking in the North Sea, a gladiator in the Coliseum, and a cowboy in the Wild West- use different strategies to keep cool. The story focused on five key actions: using a fan, removing a layer of clothing, moving to the shade, opening a window, and finding a drink of water. The researchers set up a controlled study right before a yellow heatwave alert was issued by the UK Health Security Agency.

The Results Were Fantastic: The children in the intervention groups, particularly the younger key stage one kids, were significantly more likely to take or want to take action to improve their thermal comfort. The kids who heard the story were nearly five times more likely to say they wanted to stay in the shade. They were almost eight times more likely to recognise they should drink cold water. And they were almost 12 times more likely to want to use a fan compared to the control group. They actively remembered and understood the behaviours modelled in the story

Preliminary Findings of Storytelling in Schools as a Pre-Heatwave Intervention to Enhance Children's Behaviour to Improve Thermal Comfort https://doi.org/10.1016/j.buildenv.2024.112337

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) - S&P UK (https://www.solerpalau.com/en-uk/)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/)

Zehnder https://www.zehndergroup.com/en

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: The One Take Format and the Overheating Schools Crisis
00:01:06 The Building Problem: Why UK Schools Weren't Built for Modern Summers
00:01:46 The Agency Gap: When Adults Control Environments Designed for Children
00:02:47 The Intervention: Teaching Thermal Comfort Through Story
00:03:13 The Study Design: Controlled Testing Before a Yellow Heatwave Alert
00:03:58 The Results: Five to Twelve Times More Likely to Take Action
00:04:44 The Bigger Picture: Why We Can't Wait for Billions in Retrofits
00:05:14 Behavioral Adaptation: The Overlooked Tool in Indoor Environmental Quality
00:06:11 From Passive Victims to Active Agents: Lessons for Air Quality

This week, we sit down with Professor Ardeshir Mahdavi, an internationally recognised expert in building science, affiliated with Graz University of Technology and the Vienna University of Economics and Business, to explore a question that fundamentally challenges how we think about indoor environmental quality: What if the single biggest barrier to creating healthy, comfortable buildings isn't our lack of scientific models—but our failure to recognise that the search for optimal indoor conditions may be philosophically flawed from the start?

Inspired by his thought provoking keynote at Indoor Air 2026 in Singapore, this conversation unpacks what happens when we bring philosophy, art and science together to critically revisit the prevailing paradigm in indoor environmental quality research. Drawing on insights from Aristotle, Leonardo da Vinci and Werner Heisenberg, Ardeshir challenges us to reconsider how we define adequate indoor environmental conditions, how we develop models to predict human comfort and health, and whether our obsession with precision is actually preventing us from understanding what truly matters.

Key Topics Discussed:

The Illusion of Sharp Lines: Standards and regulations draw precise thresholds for temperature, humidity, CO2, sound and light. But human requirements are not fixed. They vary by individual, by age, by health status, by time of day, by culture. We all agree people are different, yet we expect models to deliver universal answers. This cognitive dissonance shapes everything from thermal comfort research to building commissioning. Leonardo da Vinci's sfumato technique offers a metaphor: nature doesn't have sharp lines, and neither do human needs.

Plateau and Escarpment, Not Bell Curves: The traditional view of human response to indoor conditions assumes a bell curve with an optimal peak. But research in lighting and other domains suggests a more accurate model is the plateau and escarpment. Over a wide range of conditions, performance remains stable.

Health Versus Comfort, and the Ethics of Manipulation: Some argue that comfort is not necessarily healthy. That we should design buildings to challenge occupants thermally, to exercise their metabolic and immune systems. But who decides what is good for people? Designing stairs to be more attractive than lifts, separating buildings to force movement, installing acoustic masking systems without informing occupants.

The Heisenberg Metaphor and Model Uncertainty: Heisenberg's uncertainty principle states that you cannot simultaneously measure the position and momentum of a particle with unlimited precision. The more precisely you know one, the less precisely you know the other. This offers a powerful metaphor for indoor environmental quality models.

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GUEST:

Professor Ardeshir Mahdavi

Graz University of Technology | Vienna University of Economics and Business

Indoor Air 2026

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) - S&P UK (https://www.solerpalau.com/en-uk/)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/)

Zehnder https://www.zehndergroup.com/en

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: Meeting Ardeshir Mahdavi and the Philosophy of Indoor Environmental Quality
00:02:35 The Risk of Narrow Focus: Why Building Science Needs Philosophical Thinking
00:15:55 Da Vinci's Sfumato: Sharp Lines Versus the Reality of Human Experience
00:22:45 The Problem with Precision: Standards, Negotiation and Boundary Conditions
00:36:16 Aristotle's Wisdom: Matching Methods to the Nature of the Inquiry
00:41:45 Models and Constructs: The Difference Between Weight and Comfort
00:50:01 The Plateau and Escarpment Model: Rethinking Distribution Curves
00:59:09 Physiology and Compensation: Why Humans Aren't Precise Instruments
01:03:17 Health Versus Comfort: The Ethical Question of What Buildings Should Provide
01:07:16 Manipulation and Agency: Staircases, Sound Masking and Cultural Differences
01:33:32 The Global South Challenge: Beyond Smart Buildings to Urban Systems
01:47:04 Heisenberg's Uncertainty: Precision Limits in Human-Centric Models
01:54:22 AI and Understanding: Tools Versus Delegation of Thinking

This week, we dive into a study published in the Journal of Environmental Research titled Summer Heat Wave, Ozone Pollution and Ischemic Stroke Mortality: An Individual Level Case Crossover Study, to explore a question that fundamentally challenges how we think about climate, air quality, and public health: What if the single biggest barrier to protecting vulnerable populations isn't our lack of understanding about heat waves or air pollution individually—but our complete failure to recognize that when they occur together, they create a deadly synergy that multiplies stroke mortality risk?

Key Topics Discussed:

The Perfect Storm for Clotting: When you are exposed to a heat wave, your body kicks into thermoregulation mode. You sweat, you lose water. And if you aren't replacing that water, your blood viscosity goes up. Your blood literally gets thicker, which promotes the formation of clots. At the same time, short term exposure to ozone enhances the blood coagulation process. It triggers systemic inflammation and oxidative stress. You have the heat making your blood thicker and the ozone promoting a chemical pathway for clotting. Put them together in a human body and you have the perfect storm for a cerebrovascular event.

The Synergistic Effect: When you have a heatwave and high ozone levels at the same time, the effects don't just add together, they multiply. It's not 1 plus 1 equals 2, it's 1 plus 1 equals 3. The paper estimates that up to 4.19% of ischemic stroke deaths in their study could be attributed to these joint exposures, and the majority of those exposure attributed deaths were due to co exposure of extreme heat and high level ozone. The study tracked over 59,000 ischemic stroke deaths across four years in Jiangsu province, China.

The Elderly Are Most Vulnerable: The study broke the data down by age and sex. While gender didn't make a huge difference, age absolutely did. The elderly, specifically those aged 85 and older, were at significantly higher vulnerability to these co exposure events. As we age, our thermoregulatory capacity declines. We don't sweat as much, our skin blood flow is reduced, so our bodies struggle to cool down. Older adults are much more likely to have pre existing conditions like hypertension or atherosclerosis. Add social isolation or limited mobility into the mix, meaning they can't easily leave a sweltering apartment or get to a cooling centre, and the risk profile skyrockets.

The Ventilation Paradox: If we are relying on natural ventilation, opening windows to deal with summer overheating, what happens on the day when there is a heat wave and an ozone spike? You open up the window to let the heat out and you let the ozone in, or you keep the window closed to keep the ozone out and the building overheats. It reinforces the need for mechanical ventilation strategies with proper filtration and thermal conditioning in our homes, particularly in social housing and care facilities where the most vulnerable populations live. We cannot rely on building envelopes alone when the outside air is effectively dangerous on multiple fronts.

Summer Heat Wave, Ozone Pollution and Ischemic Stroke Mortality: An Individual Level Case Crossover Study  https://doi.org/10.1016/j.envres.2025.120818

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) - S&P UK (https://www.solerpalau.com/en-uk/)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/)

Zehnder https://www.zehndergroup.com/en

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: The One Take Format and Compound Environmental Risks
00:00:35 The Study: Summer Heat Waves, Ozone and Stroke Mortality
00:00:53 Beyond Buildings: The Broader Public Health Question
00:01:20 Understanding Ischemic Stroke: The Second Leading Killer Globally
00:02:32 The Research Setting: 59,000 Deaths in Jiangsu Province
00:03:13 The Methodology: Comparing John to Himself, Not to Dave
00:04:08 The Findings: When 1 Plus 1 Equals 3
00:05:33 The Biology: Blood Thickening Meets Clot Promotion
00:06:29 Who's Most Vulnerable: The Elderly in the Eye of the Storm
00:07:24 The Built Environment Challenge: Windows Open or Closed?
00:09:03 The Future: Creating Safe Harbours From Deadly Outdoor Conditions

This week, we sit down with Dr. Ranga Reddy Burri, a physician from Hyderabad, India, President of the Infection Control Academy of India, and Honorary Professor at the University of Hyderabad, to explore a question that fundamentally challenges how we think about public health in rapidly developing economies: What if the single biggest barrier to improving health outcomes in the Global South isn't a lack of scientific knowledge

Key Topics Discussed:

India's Demographic Window: India has a two to three decade window to get things right before the demographic dividend disappears. The fertility rate is declining. The young population bulge is shrinking. The population over 50 is growing. Within decades, India will have an inverted population pyramid with fewer productive workers supporting a graying population.

Antimicrobial Resistance: The Silent Pandemic: Antimicrobial resistance is officially recognized by WHO as one of the top 10 global health threats. In some Southeast Asian countries, every second antibiotic prescription is now failing. Pathogens that once responded to antibiotics are now resistant, spreading through hospitals, communities, agriculture, food systems, and the environment. Without effective antibiotics, cancer treatments fail, transplants become impossible, and simple surgeries like cesarean sections or appendix removals turn deadly.

The Convergence Between AMR and Indoor Air Quality: Indoor air quality and antimicrobial resistance are deeply interconnected. Poor ventilation accelerates infectious disease transmission, increasing antibiotic use and driving resistance. Without source control through improved indoor air quality, hand hygiene and antibiotic stewardship alone will never solve healthcare associated infections.

GUEST:

Dr. Ranga Reddy Burri

https://www.linkedin.com/in/rangareddy/

Indoor Air 2026 https://www.indoorair2026.org/

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) - S&P UK (https://www.solerpalau.com/en-uk/)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/)

Zehnder https://www.zehndergroup.com/en

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: Meeting Dr. Ranga Reddy Burry and the Global South Challenge
00:04:27 Breaking Down Silos: Why Indoor Air and Healthcare Must Converge
00:06:15 The Scale of the Crisis: Two Billion People and Competing Priorities
00:09:12 The Equity Problem: When Clean Air Is a Luxury Not a Right
00:11:06 India's Paradox: Economic Powerhouse Meets Public Health Crossroads
00:13:50 Growth at What Cost: Measuring Success Beyond GDP
00:16:39 Singapore as Model: Balancing Prosperity and Well-Being
00:18:30 Quick Wins and Big Impacts: The LPG Revolution and Sanitation Success
00:22:32 The Demographic Time Bomb: India's Two to Three Decade Window
00:26:17 Trading One Risk for Another: From Infectious Disease to Chronic Illness
00:30:47 India as Diabetes Capital: 600 Million People and Dropping Ages
00:32:55 The Westernization Trap: Finding India's Own Modern Future
00:34:13 Antimicrobial Resistance Explained: The Silent Pandemic Killing 10 Million Annually
00:37:53 The Magic Bullets That Stopped Working: Every Second Prescription Failing
00:49:54 The Quadripartite Approach: Human Health, Animal Health, Agriculture, and Environment
00:55:49 Superbugs Everywhere: From ICU Rails to Doctor's Hands
01:08:54 The AMR and Climate Change Parallel: Multi-System Crises Requiring Everything Everywhere All at Once
01:10:18 The Venn Diagram Overlap: Where Indoor Air and Infection Control Converge
01:12:08 Source Control: Why Air Quality Is Essential to Solving AMR
01:14:19 Making the Invisible Visible: Communication Strategies for Abstract Threats
01:20:08 Beyond Doomsday: Positive Communication About Misery Not Extinction
01:22:21 The Modern Medicine Reversal: What Happens When Antibiotics Fail
01:26:16 Risk Reimagined: When Simple Surgery Means Losing Your Leg
00:39:57 The Next Generation: Young Indians Choosing Quality Over Accumulation
00:47:50 Reverse Migration: When Young People Choose Rural Over Urban
01:29:24 From Science to Action: Converting Evidence Into Concrete Interventions
01:30:12 The Universal Desire: Healthy, Long, Productive Lives for All