Air Quality Matters

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment.

This week, we're diving into a paper that asks a deceptively simple question: If people could actually see the air they breathe, would they change their behavior? And perhaps more importantly for policymakers—is it worth the money to help them do it?

The paper is titled Making the Invisible Visible: The Impact of Revealing Indoor Air Pollution on Behavior and Welfare, a working paper from the National Bureau of Economic Research by Robert Metcalf and Seffy Roth. And the results are, quite frankly, staggering.

The Central Question

We spend about 90% of our time indoors, and we know that indoor air can be significantly worse than outdoor air. But for most people, it's completely invisible—an unobserved good. You don't know if the air is toxic or pristine unless you have a monitor. And because you don't know, you can't manage it.

So what happens when you make the invisible visible?

The Big Takeaway

This paper moves the conversation from health to economics—and it's sadly the language that often gets policy moving. It suggests that in this specific case, the deficit model—the idea that people just lack information—is actually true. When you give people the information, they do act. They do change their behavior. And that change is big.

This paper tells us we need to stop treating indoor air quality as a private luxury and start treating it as a public health imperative with a massive economic upside. Whether it's monitors or air purifiers (which they also found had an infinite return on investment, by the way), the technology exists. We just need to make the invisible visible.

This is Part Two of a five-part series exploring the psychology and perception of risk around air quality and ventilation.

Making the Invisible Visible: The Impact of Revealing Indoor Air Pollution on Behavior and Welfare

https://www.nber.org/papers/w33510

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

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

Chapters

00:00:00 Introduction: Making the Invisible Visible
00:01:14 The Invisible Problem: Why Indoor Air Quality Matters
00:01:44 The Study Design: A Clever Field Experiment in Camden
00:02:47 The Baseline Reality: What the Data Revealed Before Intervention
00:04:15 The Dramatic Results: 34% Reduction in Pollution Exposure
00:05:09 How They Did It: Ventilation Without Lifestyle Sacrifice
00:06:15 The Economic Case: Infinite Return on Investment
00:08:31 The Energy Efficiency Tension: A Critical Warning
00:09:28 Study Limitations: What to Keep in Mind
00:10:32 The Big Takeaway: Information Drives Action and Economic Value

In this essential episode, we sit down with Parag Cameron Rastogi, Director of Real Asset Analytics at GRESB, to explore one of the most powerful yet often misunderstood forces shaping the future of indoor air quality: how we measure, benchmark, and value the performance of buildings at scale.

GRESB—the Global Real Estate Sustainability Benchmark—has trillions of dollars of assets in its system. It is the machinery behind how pension funds, investors, and asset managers assess risk, performance, and long-term value across portfolios spanning every continent, building type, and climate zone. And it is evolving—fast—from a disclosure-based model to a performance-based one.

The Central Question

We already have the tools and knowledge to deliver clean, healthy indoor air. So why is there still such a persistent gap between what we know works in theory and what actually happens in buildings? And how can we operationalize air quality data in a way that makes it financially material, benchmarkable, and valuable—not just for compliance, but for real-world decision-making?

Key Topics Discussed:

What GRESB Is and Why It Matters: How a standardized survey sent to building owners and managers became the global standard for assessing sustainability risk in real estate—and why pension funds with 50-year time horizons care deeply about the long-term performance of the assets they invest in.

From Disclosure to Performance: The seismic shift happening in 2028, when GRESB moves from rewarding having data to rewarding what that data shows. Why this is a big deal for the industry—and what it means for air quality.

The Binary Nature of Data: Why building portfolios either have full data coverage or almost none—and nothing in between. The fascinating bimodal distribution of data availability, and what it tells us about control, building type, and lease structures.

Relative Benchmarking vs. Absolute Thresholds: Why finance speaks the language of risk, not absolutes. How GRESB uses relative benchmarking to compare buildings in context—and why this approach might be the missing piece in how we communicate air quality risk.

This is a conversation about risk, value, and the machinery of change. It's about recognizing that if we want air quality to matter in the real world, we need to speak the language of the people who control the capital. We need to make it benchmarkable, measurable, and material. And we need to move from fluffy aspirations to hard performance.

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

https://www.gresb.com/

HOST:

Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/

GUEST:

Parag Cameron Rastogi - Director of Real Asset Analytics, GRESB

The Air Quality Matters Podcast in Partnership with

Farmwood - Eurovent - Aico

The One Take Podcast in Partnership with

SafeTraces and Inbiot

Do check them out in the links and on the Air Quality Matters Website.

If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: GRESB and the Global Real Estate Sustainability Benchmark
00:02:00 What is GRESB? Origins and the Investor's Need for Risk Transparency
00:05:30 From Portfolio to Asset Level: The Evolution of GRESB Assessment
00:10:50 The Foundation and the Industry: How GRESB Standards are Governed
00:15:45 Data Coverage: The Binary Reality of Building Performance Data
00:24:00 The Disclosure to Performance Paradigm Shift
00:34:00 Control Structures and the Triple Net Problem
00:44:00 Relative Benchmarking: Why Context Matters in Risk Assessment
00:54:00 The Long Tail of Real Estate: Addressing the Forgotten Buildings
01:03:45 Operationalizing Data: From Collection to Business Value
01:12:00 The Automotive Analogy: Building Feedback Loops for Improvement
01:22:00 Stars, Quintiles, and Narrative-Based Rankings
01:32:00 Sustainability-Linked Loans and the Financial Incentive
01:42:00 Indoor Air Quality's Journey: From Disclosure to Performance Pillar
01:52:00 Beyond Productivity: Health, Harm, and the DALY Framework
01:58:00 The Predictive Future: From Rearview Mirror to Digital Twin
02:03:00 Parag's Journey: From Building Physics to Real Estate Finance
02:07:00 Closing Thoughts: The Power of Scale and Systemic Change

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment.

This week, we step away from the physics and chemistry of air quality and dive firmly into the psychology of how we perceive—and crucially, misperceive—the air around us.

The paper is titled Why Do We Misperceive Air Pollution? A Scoping Review of Key Judgmental Biases, published in Air Quality, Atmosphere & Health, and it systematically dismantles a dangerous assumption many of us hold: that if we just give people the data—the graph, the PM2.5 reading, the red light on a sensor—they'll change their behaviour.

The Central Question

Why do we struggle so much to communicate the risk of poor air quality, particularly in our homes? And why do technical solutions—ventilation systems, sensors, standards—so often fail to deliver the health outcomes we expect?

The answer, this paper argues, is that our brains are essentially wired to misinterpret or even ignore the quality of the air we breathe, regardless of the facts. Information does not equal action. Perception is not reality—but for the person living in that home, perception is their reality.

The Six Psychological Biases That Blind Us to Air Pollution

The Big Takeaway:

Our current approach to communication—largely based on "deficit models" (the idea that people just lack information)—is fundamentally flawed. We can't just put a sensor in a room, point to the red light, and expect people to behave differently. These biases are working in the background to minimize that signal.

If someone has a home halo effect, they'll look at the red light and think the sensor is broken, rather than their air is toxic.

To be effective—whether as engineers, consultants, housing officers, or policymakers—we need to stop treating occupants like passive recipients of data. We need to understand the social and psychological context they live in. We need to acknowledge emotional connections, offer alternatives that provide the same sense of comfort without the emissions, and recognize that unless we bridge the gap between technical reality and lived perception, all the ventilation systems in the world won't deliver the health outcomes we want.

The technical solution is only half the battle. The messy, biased, emotional human element is where the real challenge lies.

This is Part One of a five-part series exploring the psychology and perception of risk around air quality and ventilation.

Why do we misperceive air pollution? A scoping review of key judgmental biases

https://doi.org/10.1007/s11869-024-01650-y

The One Take Podcast in Partnership with

SafeTraces and Inbiot

Do check them out in the links and on the Air Quality Matters Website

Chapters

00:00:00 Introduction: The Psychology of Air Perception
00:01:19 The Assumption We All Make: Data Equals Action
00:02:33 Sensory Capacity: When Our Senses Fail Us
00:03:10 Habituation: The Nose Blindness Phenomenon
00:03:54 The Home Halo Effect: My Sanctuary Can't Be Toxic
00:05:07 Confirmation Bias: Pollution Happens to Someone Else
00:05:44 The Exclusion Effect: Bigger Problems Crowd Out Air Quality
00:06:29 The Affect Heuristic: Emotion Over Evidence
00:07:33 The So What: Rethinking Communication and Engagement
00:09:29 The Big Takeaway: Perception is Their Reality
00:10:15 Closing: Part One of Five on Psychology and Risk Perception

We sit down with John O'Connor, former chair of Ireland's Housing Commission, and Neil Freshwater, Public Affairs Manager for GB and Ireland at Velux, to explore one of the most complex challenges facing Ireland and Europe today: how do we deliver affordable housing at pace while ensuring homes are healthy, sustainable, and fit for purpose?

Recorded at a Healthy Homes Ireland event in Dublin just before Christmas, this conversation tackles the fundamental tensions in housing policy—between volume and quality, affordability and performance, political cycles and long-term planning. With Ireland's new housing plan published, the European Commission preparing its first-ever affordable housing plan, and the revised Energy Performance of Buildings Directive due to be transposed into Irish law by May 2026, the stakes have never been higher.

The Central Question

We've understood for over a century that housing and health are inseparable. Yet somehow, in our rush to solve the housing crisis, we've fragmented that relationship. How do we get back to first principles? How do we ensure that every home—not just the expensive ones—delivers good air quality, daylight, thermal comfort, and the conditions for families to thrive?

Key Topics Discussed:

The Housing Commission's Vision: Why Ireland's housing crisis isn't just about numbers—it's about creating a cohesive society where having a home is a fundamental right, not a luxury. The Commission's recommendations as a long-term, interconnected menu—not a pick-and-mix.

The Forgotten Link Between Health and Housing: How ventilation and daylighting were central to 19th and early 20th-century housing standards—and why we've lost that focus in modern construction. The sobering reality that people John knows are now suffering terminal illnesses due to poor indoor air quality.

Fast, Cheap, and Good—Pick Any Two: The political and economic pressures driving volume over quality. Why "any shelter is better than no shelter" is a dangerous narrative—and how 5,000 children experiencing homelessness in Ireland today (compared to fewer than 100 a decade ago) lays bare the human cost of failure.

The One-Dimensional Trap: How the Energy Performance of Buildings Directive initially focused only on energy efficiency—and why the inclusion of Indoor Environmental Quality (IEQ) in the revised directive is a game-changer, if we can translate it into policy and practice.

Because at the end of the day, it's not about units. It's about homes. And homes are for people.

HOST:

Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/

GUESTS:

John O'Connor - Former Chair, Housing Commission, Ireland

Neil Freshwater - Public Affairs Manager, Velux GB & Ireland

The Air Quality Matters Podcast in Partnership with

Farmwood - Eurovent - Aico

The One Take Podcast in Partnership with

SafeTraces and Inbiot

Do check them out in the links and on the Air Quality Matters Website.

If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.

Chapters

00:00:00 Introduction: Housing, Health, and the Irish Context
00:02:56 Meet the Guests: John O'Connor and the Housing Commission
00:04:39 The Housing Crisis: Numbers, Demographics, and the Meaning of Home
00:09:25 Neil Freshwater: Velux's Origins in Healthy Buildings
00:16:25 The Trifecta Challenge: Fast, Cheap, and Good
00:17:52 The Forgotten Science: Air Quality and Ventilation in Housing
00:21:04 Daylight Inequality and the Quality Divide
00:45:56 The Monitoring Revolution: From Code Compliance to Performance
00:53:03 The Skills and Labour Crisis: Building at Lightning Pace
01:02:41 Modern Methods of Construction: Promise and Reality
01:05:01 Looking Forward: Ireland's EU Presidency and the Path Ahead
01:11:14 Closing: The Charter for Healthy Homes

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment.

This week, we're diving into one of the most complex and urgent environmental dilemmas of our time: the smoke from fires we set on purpose.

The paper, Associations between PM2.5 from Prescribed Burning and Emergency Department Visits in 11 Southeastern US States by a team of researchers from Boston University, Georgia Tech, and other institutions, tackles a critical question: In our effort to prevent catastrophic wildfires through prescribed burning, are we creating a different, more chronic health problem from the smoke of these "good fires"?

The Environmental Dilemma:

Prescribed burning—intentionally setting smaller, controlled fires to clear underbrush—is one of our primary tools to fight the catastrophic wildfires made worse by climate change. But this tool has side effects: smoke containing fine particulate matter (PM2.5). The question is whether we're trading one health disaster for another.

The Study:

Researchers analyzed over 30 million emergency department visits from 11 southeastern US states over nearly a decade—a region where prescribed burning is common practice. Using sophisticated chemical transport models, they "tagged" PM2.5 in the air to identify which portions came specifically from prescribed fires, allowing them to isolate the health signal of just these controlled burns.

The Surprising Findings:

Yes, there is a link. On days with high levels of PM2.5 from prescribed fires, there was a statistically significant increase in emergency department visits for upper respiratory infections and, most notably, ischemic heart disease, which went up by about 6%.

But here's the counter-intuitive part: For the classic signatures of smoke exposure—overall respiratory admissions, asthma, and COPD—they didn't find a statistically significant increase. This is what makes smoke from prescribed fires different from wildfire smoke.

Why the Difference?

The nature of the fires themselves. Wildfires are hot, intense, and chaotic, burning everything from the forest floor to the canopy. Prescribed burns are cooler and slower, designed to smolder through underbrush, grass, and leaf litter. This difference in what's burning and how it's burning creates a different chemical cocktail of smoke. Prescribed fire smoke tends to have lower concentrations of pollutants like carbon monoxide and polycyclic aromatic hydrocarbons (PAHs) compared to wildfire smoke.

The Big Takeaway:

Not all smoke is created equal. The health impact of PM2.5 is not just about the mass of particles in the air—it's about what those particles are made of, and it depends profoundly on the source.

This research doesn't give us an easy answer. It doesn't say prescribed burning is safe or unsafe. Instead, it gives us a much more nuanced picture. It's a powerful reminder that there are no easy wins in environmental management—it's all a game of trade-offs. We're using a tool to reduce the risk of catastrophic wildfires, but that tool has its own health risks, and those risks are different.

This kind of research is absolutely vital for land managers and public health officials because it helps them understand the specific health impacts of their decisions, allowing for more targeted warnings and a better, more honest conversation about the risks we're actually choosing to manage.

Associations between PM2.5 from prescribed burning and emergency department visits in 11 Southeastern US states

https://doi.org/10.1016/j.envint.2025.109770

The One Take Podcast in Partnership with

SafeTraces and Inbiot

Do check them out in the links and on the Air Quality Matters Website

Chapters

00:00:00 Introduction: The Prescribed Burning Paradox
00:01:48 The Study Design: Tagging Smoke from Good Fires
00:02:54 The Findings: A Surprising Health Signal
00:04:02 Not All Smoke is Equal: The Chemistry Matters
00:05:32 The Big Takeaway: Environmental Trade-Offs and Honest Conversations
00:06:40 Closing: Thanks and Next Week