The Body’s Battle: Sir Stephen Holgate on Why Air Pollution is a Multi-System Threat

Air pollution is often discussed as an environmental issue, a problem of smokestacks and exhaust pipes that primarily affects our lungs. But what if that’s only the beginning of the story? What if the air we breathe is delivering a toxic payload to every organ in our bodies, silently accelerating the aging process and contributing to hundreds of different diseases?

In a deeply insightful episode of the Air Quality Matters podcast, I had the privilege of speaking with Sir Stephen Holgate, a leading global expert in respiratory medicine and immunopharmacology. Sir Stephen is a figure whose work has not only advanced medical science but has also shaped public policy and legal precedent. As the lead medical expert in the landmark case of Ella Kissi-Debrah—the first person in the world to have air pollution listed as a cause of death—his expertise brought the fatal consequences of poor air quality into sharp, undeniable focus.

Our conversation went far beyond the obvious, exploring the complex, systemic, and often invisible war that air pollution wages on human health.

From the Lungs to Every Organ: A Multi-Systemic Threat

The conversation began by reframing our understanding of air pollution. For decades, the focus has been on irritant gases and the visible particles from sources like coal smoke. But Sir Stephen explained that the most insidious threat comes from the ultrafine particulate matter we can’t see. These particles, born from modern sources like diesel combustion, are so small they bypass the lungs' defences.

As he puts it, they essentially act like a gas, entering the bloodstream and circulating to every organ in the body—the brain, the heart, the liver, the kidneys. These particles are not benign; they are Trojan horses carrying a cocktail of chemicals. Once deposited in our tissues, they release these chemicals, triggering a low-level inflammatory reaction that, over time, damages cells. Sir Stephen offered a powerful and sobering analogy for this process: it is, in effect, an accelerated aging of our organs. This perspective transforms air pollution from a respiratory nuisance into a fundamental driver of chronic disease throughout the body, with recent research associating it with up to 700 different conditions.

The Breakdown of Our Natural Defences

One of the most fascinating parts of our discussion delved into how our bodies become so vulnerable. Sir Stephen explained the concept of the body's "barrier function"—the protective linings of our skin, gut, and lungs that have evolved over millennia to keep harmful substances out. Modern life, however, is bombarding and breaking down these barriers.

To illustrate this, he shared a compelling real-world example of two genetically similar communities in North America with vastly different lifestyles: the Amish, who maintain traditional farming practices, and the Hutterites, who have adopted modern methods. The results are staggering: allergy and asthma are virtually non-existent in the Amish community, while prevalent among the Hutterites. The full explanation for this stark difference, which lies in the complex interplay of environment, microbiology, and the immune system, provides a profound insight into what we have lost in our rush towards industrialisation. It points to a future where prevention, rather than just treatment, could be possible by finding ways to restore this natural resilience.

Bridging the Gap: From Science to Clinical Practice

If the science is so clear, why isn't air pollution a central part of every clinical conversation? We discussed the critical gap between scientific knowledge and its application in healthcare and public policy. The tragic case of Ella Kissi-Debrah revealed that despite numerous hospital visits for severe asthma, the role of air pollution was never mentioned by her medical team—a clear sign of a systemic blind spot.

This has led to a crucial shift, championed by Sir Stephen and his colleagues. In his landmark 2025 Royal College of Physicians report, there is a clear call to move air pollution from being perceived as a purely environmental issue to a core health issue. The conversation explored the urgent need for health professionals to become "trusted messengers" who can communicate the risks effectively, advocate for change, and integrate environmental factors into patient care. The urgency is underscored by a shocking statistic Sir Stephen shared:

"We have got ourselves in a state now where here we are with what we say is a national health service with the highest death rate and the highest hospital admission rates for asthma in the whole of this block [Europe]."

This summary only scratches the surface of a discussion rich with scientific depth, historical context, and a clear-eyed view of the path forward. Hearing Sir Stephen Holgate articulate these complex issues in his own voice—from the cellular mechanisms of disease to the societal shifts needed to create healthier communities—offers a level of understanding that cannot be fully captured in text.

One Take: Is There a Price Tag on a Healthy Building?

In this week's One Take episode, we dissect a fascinating paper that puts a price tag on health in the commercial real estate market. The Indoor and Outdoor Health Factors in the Pricing of Commercial Real Estate study, "Indoor and Outdoor Health Factors in the Pricing of Commercial Real Estate," asks a simple but profound question: are companies willing to pay more rent for an office that is demonstrably healthier for their employees?

Using a clever statistical method known as hedonic analysis—which essentially unbundles a building’s rental price to see what each feature is worth—researchers analysed thousands of US office buildings. They looked at buildings with certifications like WELL and Fitwel and cross-referenced them with a host of outdoor factors, including air quality, hospital access, and, crucially, walkability.

The headline finding is clear: a tangible "health premium" exists. Buildings certified for their healthy indoor environments command a rental premium of between 4% and 6%. This provides a powerful business case for investing in better air quality, lighting, and occupant comfort.

However, the story gets more complex when you look outside. The single most powerful driver of higher rents was walkability. The value of being in a vibrant, accessible neighbourhood where employees can easily get around on foot was priced in even more strongly than the building’s health certification alone. In a counterintuitive twist, the analysis also found that higher outdoor air pollution often correlated with higher rents—not because tenants want pollution, but because pollution is often a proxy for the economic density and desirability of a central business district. The paper concludes that while a healthy building is valuable, the health of the surrounding location is paramount.

The Air Quality Matters Podcast in Partnership with

Zehnder Group - Farmwood - Eurovent- Aico - Aereco - Ultra Protect -

The One Take Podcast in Partnership with

SafeTraces and Inbiot

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

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