Shining a Light on Cleaner Air:
A Dive into Far-UVC and the Complexities of Mould-Related Illness
In our ongoing mission to improve the quality of air in our built environment, we constantly explore the tools and knowledge at our disposal. From established ventilation principles to cutting-edge technologies, the conversation is key to our collective success. Two recent episodes of our podcasts delve into distinct but crucial areas of indoor environmental quality, highlighting both a promising technology and a complex public health debate.
In the main Air Quality Matters episode, I was joined by Janet Price, PhD , Chief Science Officer at Visium , for a fascinating 101 on Far-UVC technology. Then, in a recent One Take episode, we unpacked the highly polarised and timely discussion around mould, mycotoxins, and Chronic Inflammatory Response Syndrome (CIRS).
Unveiling the Potential of Far-UVC with Dr. Janet Price
For years, UVC light has been a known tool for disinfection, but its application has been limited, often confined to unoccupied spaces or upper-room fixtures to avoid direct human exposure. The emergence of Far-UVC technology, specifically light at the 222-nanometer wavelength, is changing that paradigm. But what exactly is it, how does it work, and is it truly safe for occupied spaces?
Our discussion covered several key themes:
1. The Fundamentals: What Far-UVC Is and How It Works We started with the basics. Dr. Price explains where Far-UVC sits on the spectrum. Interestingly, while our sun produces these wavelengths, they are entirely absorbed by our atmosphere and never reach the Earth’s surface. This means any Far-UVC light present in our environment is man-made.
The conversation moves to the mechanism of action. Unlike traditional UVC, which primarily damages the DNA and RNA of microorganisms, Far-UVC acts as a "sledgehammer," attacking pathogens on multiple fronts. It not only disrupts their genetic material but also breaks down the protein structures that are essential for their survival and function. This dual-action approach makes it incredibly effective against a wide range of pathogens, from viruses and bacteria to more resilient organisms like mould spores.
2. The Critical Question of Safety If Far-UVC is so destructive to microorganisms, why isn't it harmful to us? This is perhaps the most important question surrounding the technology. The answer lies in its short wavelength. While highly energetic, this light has extremely poor penetration. It can’t get through the outer layer of dead cells on our skin or the protective tear layer of our eyes to reach living tissue. In our discussion, Janet explains how our own biology provides a natural defense, allowing this technology to be used in spaces while people are present—a game-changer for real-time air and surface disinfection.
3. Practical Applications and Design Considerations The potential applications for Far-UVC are vast, from healthcare settings and schools to athletic facilities and even animal husbandry. However, it's not a "plug-and-play" solution. Like any engineered system, its effectiveness depends on proper design and installation. We discussed how factors like room geometry, ceiling height, shadowing from objects, and even ambient humidity can impact performance. This part of the conversation underscores that Far-UVC is a technical solution that requires thoughtful integration into a space to achieve the desired outcomes. An intriguing aspect we touched upon was its potential co-benefits, with emerging research suggesting Far-UVC could even help break down proteins found in common allergens like pollen and cat dander.
4. The Future: Standardization and Equivalent Air Change Rates One of the most forward-looking parts of our conversation centred on how Far-UVC fits into evolving building standards like ASHRAE 241. This new standard introduces the concept of equivalent clean air delivery rates, moving beyond simply counting air changes per hour (ACH). We explored how the pathogen-inactivating power of Far-UVC can be quantified and translated into an "equivalent" ACH, offering a low-energy pathway to achieving clean air targets that might be difficult or costly to reach with ventilation alone. Hearing Janet explain the calculations and the ongoing work to establish a fair proxy organism for testing across different technologies provides a glimpse into the future of holistic IAQ design.
As Janet aptly puts it, it can be hard to convince people to use an "invisible light to kill an invisible organism that if it works, nothing changes."
One Take: Navigating the Polarized Debate on Mold and Chronic Illness
In a recent One Take episode, we shifted focus from technology to a contentious medical debate recently brought into the spotlight by public figures: Chronic Inflammatory Response Syndrome, or CIRS.
This episode unpacks the core of the conflict. On one side, you have patients suffering from debilitating, multi-system symptoms they attribute to mould exposure in water-damaged buildings. They are supported by a group of practitioners who propose that a genetic predisposition prevents about 25% of the population from clearing biotoxins, leading to a runaway inflammatory cascade.
On the other side, mainstream medical and toxicological bodies remain unconvinced. They argue that the levels of mycotoxins in a typical indoor environment are orders of magnitude too low to cause such severe systemic effects, citing the core toxicological principle: "the dose makes the poison." They also point to a lack of large-scale, independent, and replicated studies that meet the rigorous standards for medical evidence.
To navigate this impasse, the episode examines a pragmatic approach taken by the Australian government. After a formal inquiry, they acknowledged the real suffering of patients but ultimately sided with the established scientific consensus. Their solution was to create a national clinical pathway that guides doctors to take exposure history seriously while focusing on evidence-based diagnosis and treatment, providing compassionate care without endorsing a scientifically contested diagnosis.
This deep-seated debate highlights the chasm that can exist between lived experience and the burden of scientific proof. It’s a crucial conversation for anyone in the indoor environment sector, as it shapes how we communicate risk and manage buildings where mould is a concern.
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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