#13.2 - Stephanie Taylor: The Role of Building Microbiomes in Our Health, the ASHRAE conference and more. more

Part -2

Stephanie Taylor received her Medical Degree from Harvard and subsequently practised pediatric oncology while researching cellular growth control mechanisms for the next several decades.

While taking care of hospitalised patients, she became increasingly convinced that the
healthcare facility played a significant role in patient healing and in healthcare-associated infections.

Determined better to understand the built environment's impact on patients, she returned to school and obtained her Master's in Architecture.

She is an ASHRAE Distinguished Lecturer and is on the Standards Committee for Performance Metrics for Occupied Buildings. She is also a member of the US Green Building Council technical advisory board on Indoor Air Quality.

In 2019 she founded Building4Health to scale the powerful yet underutilised
approach of managing IAQ from a medical perspective to support occupant health.

She brings together a fascinating convergence of human health, microbiology and architecture, I first met her a few years ago in Athens where she was giving a plenary presentation on the impacts of the microbiom of buildings on human health and it was one of the presentations that has stuck with me ever since.

So it was a real privilege to get to have an extended conversation with her about her journey from medicine to buildings, the philosophy and approach of Build4Health and how these two areas of expertise can come together.

After all, we mostly build buildings for people and a human-centred approach is a perspective we sometimes lose.

Stephanie Taylor -  LinkedIn
Build4Health 

Transcript

Simon: 0:00

Welcome back to Air Quality Matters and part two of my conversation with Stephanie Taylor. So welcome back. It's the first time I've done a part two of anything, so apologies for those that listened to part one. You might be aware that we had a bit of a technical internet issue. I think it goes to show where we are in life that we get frustrated that myself and Stephanie couldn't maintain a video call from opposite sides of the planet of an evening without some technical hitch. So it shows how far we've come, if nothing else. So in between then, stephanie, and now, you've been to the ASHRAE conference and AHA expo down in Chicago. Is that right?

Stephanie: 0:56

Yes, so the annual conference was January. Well, started on January 14th, but the main part started January 19th and went until the 25th, and during that time the enormous expo center was open with all the vendor platforms.

Simon: 1:17

And how was it you were talking? I think you were speaking at the conference.

Stephanie: 1:21

Yes, so I'm a member of a couple groups. One is the standards GPC-45, which is performance metrics for occupied buildings except low rise residential, and I'm a member of that. And then I also gave a seminar titled Building and Mechanical Design Does Effect Occupant Health. So that was an hour long seminar and a couple other people participated in that. So that was great and all in all, I think it's the best experience I've ever had at an ASHRAE conference. I was. It really was incredibly invigorating and inspiring for me, and I can tell you why.

Simon: 2:09

Yeah, I mean, I have to say I was very jealous. I've been more tuned into it this year, I think, than I have previous years, and I'd meant to go and never got organized in time, and so I was just looking at all the posts and the comments coming in through social media, agreeing with Envy, as it sounded like it looked like it was great, you know, and all the usual suspects were there.

Stephanie: 2:32

I think green is the right word, because green building and decarbonization was a hot topic, but in my experience, ashrae is at this intersection between decarbonization you know, trying to protect the outdoor environment, at the same time on the heels of the pandemic, not wanting to seal up buildings and do things that are going to harm the occupant and this time, this trying to figure out how to protect the indoor environment.

Stephanie: 3:01

How to protect the outdoor environment ties in perfectly with what I've been working on, which is, initially, was how do you support occupant health?

Stephanie: 3:11

So not only how do you diminish viral exposure or airborne pathogen exposure, but how do you manage things like humidity and VOCs and ozone and other contaminants in such a way that you don't minimize the our sort of natural protective systems? You don't want to damage the occupant immune system. You don't want to damage the metabolic system of a person or their ability, their brain, to work by the indoor environment, and yet we haven't really had visibility into the relationship between indoor air quality and those physiological processes that we all have, and so ASHRAE is now bumping up against the question of how do you actually manage indoor air quality for human health and the reason. I found it to be an incredibly exciting and inspiring conference is that a couple changes occurred as a consequence of both the pandemic and wildfires and the ability now to quantify the impact of indoor air quality on the human being. So with this ability to quantify that relationship, ashrae is saying okay, this is a way to move forward to truly protect occupants.

Simon: 4:32

Maybe explain for listeners as well. You mentioned GPC 45. So that's like a subcommittee, I guess. Is it a bit like two for one, looking at a very specific area of something, and this is the impacts of performance on health of not low rise buildings. It's quite a specific area of work, is it? Or grouping of people?

Stephanie: 4:58

I guess it is, Simon. It's interesting that you put it in those terms because from my perspective as a physician and then going into architecture, I would say it is the most general and important aspect of buildings. However, based on what you just said, I'm not. You know, my opinion is not everybody's opinion. So whether you call it a specific component of building management or, if you're in my shoes, you call it the most important overriding principle, it doesn't matter that. What does matter is moving forward in such a way that we can manage buildings for human health. And so this GPC 45 standards committee it is a subcommittee for standards, and what we're doing in that committee is addressing components such as indoor air quality. We're looking at water contaminants and light and acoustical components of the indoor environment, and I specifically am on the indoor air quality subcommittee. And so in our meeting I actually presented what I've been doing, which is to understand the impact of individual indoor constituents and contaminants, as well as how those interacting constituents affect your respiratory system and your metabolism and your gut microbiome and all of the different human health processes. So I presented some of that in the standards committee and it was received with a lot of excitement and a great deal of support to move forward with greater disclosure around that process, which is great. I was thrilled.

Stephanie: 6:42

And then two days later I was able to give a seminar on that along with two other folks Andy Persley, and it was supposed to be a lot of ten weeks but she was sick, so Huy Buchanan gave her a component. So in the seminar we talked about ASHRAE's history of trying to address human health, ASHRAE's definition of health, which that is not an easy definition. Is health absence of disease or is health optimal wellness? So some of those seminars was on the history of ASHRAE, some of it was on the definition of health and then my part was on our approach, or my approach, to quantifying the impact of the indoor environment and then remediating. Based on what's going on indoors and your outdoor air constituents, and by looking at holistically at metrics from both the indoor environment and the outdoor environment, you can actually choose the most effective and energy efficient remediation strategies.

Stephanie: 7:46

So you know when to ventilate, when to filter, when to use a source control inside, when to use a breathing zone air cleaning process that doesn't have unintended consequences. So we presented all this and then the very next day the board of directors announced a removal of an embedded I'm not even sure what to call it board of directors, as close as ASHRAE can come to a law, I think. So they removed a clause which essentially had provided, which had restricted which indoor air contaminant measurements could be applied, For example, in 62.1, which is how to ventilate commercial buildings. So they removed restrictive language around what to monitor, and they removed restrictive language around only focusing on ventilation flow rates, and brought and opened the door for really understanding and implementing indoor air quality monitoring for human health and one. So I received an email about this and I was beyond ecstatic.

Simon: 9:05

It sounds like a really profound shift for ASHRAE. That and something that could be quite unsettling potentially. I think the advantage in that with ASHRAE is it tends to move so slowly on things that even with a change in direction, outcomes are going to be a while coming. With ASHRAE, they don't move very quickly traditionally when it comes to defining something or creating a standard, perhaps with the exception of 241, where they really did move very quickly on that one.

Simon: 9:43

What you're saying, then, minds me a little bit of where we were the last time we were talking, stephanie, where we were saying and you'd made the point that we want to be in a position to encourage people to understand the link between building performance and health and be quite inclusive and kind of encourage people along this journey, and that we shouldn't be penalizing organisations for poor health outcomes. But at the same time, the way that standards operate is by setting a floor or creating a threshold that you should achieve, and there's a natural friction there, I guess, between trying to encourage people to be open and transparent about the performance of their buildings and their quality but at the same time not allowing buildings or organisations to put occupants or workers in either acute or chronic risk. Do you know what I mean? It would be interesting to tease that out a little bit, where you see that friction playing out and how we might navigate that.

Stephanie: 11:02

I mean, simon, I think you just articulated one of the biggest conundrums or points of lack of clarity that has obstructed managing buildings for human health, and I think they're, to use your word, friction. I think there are friction points that are significant, and especially in the United States, where lawyers are everywhere and ready to create a case for a client. I think the friction points and I'll speak to the US, although I don't think this is exclusive in our country one is buildings are designed by architects, mechanical systems are designed by engineering, and the education does not include human health. It might. It includes comfort, which is something that's actually a component of health, but not the whole picture. It includes real estate values and things that are perceived to be valuable to the building owner or to the building occupants, such as views of nature, things like that, which are quite separate from human health. Again, they're related. It's good to be happy, it's good to feel comfortable, but there are other invisible constituents, especially with indoor air quality, that affect our health. So I think one of the blockades in the past to managing buildings more clearly for human health is one it's not part of the educational process of the building industry and unfortunately you don't find a lot of physicians who are trained in physiology, thinking about environmental hygiene. There are some people, but in general it's not an emphasis in the medical education. So there's an educational distance that keeps the building industry and medical professionals apart. In addition to that, the building industry has progressed the way it has for centuries and now all of a sudden we're saying well, here's a whole new, very important component that we would like you to consider.

Stephanie: 13:13

So a lot of people are just they tune out or it doesn't grasp their area of interest. So in this country there's another problem, which is if you gather data that relates indoor air quality and human health and you have a suboptimal indoor environment and somebody gets sick or they have an early delivery of their pregnancy, then you're at risk for being sued. So a lot of building owners will say we don't want to have the data because it could be drawn into court, it could be subpoenaed and even though people don't usually articulate that concern right up front, if you work with them long enough, they will share that. That is something they're afraid of.

Stephanie: 13:59

And then thirdly, simon and this is the one that's hardest for me to articulate, but there I think there's almost a human desire to not think about our mortality and our health in everyday life. If you come up with a cancer diagnosis you're obviously going to think about it and it's going to be devastating and you have to rearrange your psyche. But people who aren't in the medical profession often don't really want to think about health, or it seems too complicated or the language is too intricate. But I find that there's almost a psychological guardrail that keeps people away from thinking about health and I don't fully understand it.

Simon: 14:40

No, I don't think many people in the indoor air quality world do we know, and we experience this very particularly with radon risk in homes and businesses. We know, particularly in the UK and Ireland. The EPA, the Environmental Protection Agency, has done a lot of work and research in this area, trying to understand how to sort a problem out. That is a very specific problem in particularly in Ireland and parts of the UK, and people just do not want to know about radon risk and you can offer free tests. It's incredibly easy to do a radon test on your home. People don't want to do them, you're not obligated.

Simon: 15:25

You can sell a home in the UK and Ireland that has known very high levels of radon, a real health risk to the next occupants, and that does not have to be disclosed in any document or survey when you're selling a property. Even and they've done studies where they've even offered free remediation or significantly discounted remediation to radon and people didn't take it up. They'd rather just ignore the problem and for me that's an anathema, because in sales it's generally understood that fear sells. It's the most primary driver for decision making, yet somehow we don't see that with air quality and I don't fully understand why either. You know, I think we talk a lot about framing the positive benefits and the outcomes because we feel that maybe out of frame a decision better. But somehow our experience has been that telling people something's dangerous or risky or framing it in the context of the building isn't resonating for some reason, and that speaks to what you're saying there, doesn't it?

Stephanie: 16:43

It does. And again, I think a lot about this all day and sometimes all night how to make indoor air quality and the effect on your body important to everybody. I think about things like the automobile industry, where now again in the US, you have to have your car inspected every year and if you don't pass the mission test, if you don't pass safety test, if your airbag's not working, if your brakes aren't properly kept up, you can't pass inspection. And then if you get a speeding ticket, obviously you're going to be fined and your car's going to be taken off the road. And we now accept that with automobiles.

Stephanie: 17:25

But if we could bring that same thinking into managing buildings for human health, I think we'd be way ahead of where we are now. So I think about do we need increased regulations, such as with ASHRAE or the International Code Council or the UK and Europe? You know around the world different standards. Do we need greater awareness so that this change occurs from the grassroots up? I think in my experience the most motivated customer that we have is a parent with a new baby. You know they'll do anything to keep that baby's room or crib safe.

Stephanie: 18:09

So, somehow we have to unite, like the human emotion, to protect at least our young with the carrot to protect people. We have to balance that with the regulatory stick, so to speak, Like if you don't do this you're going to be in trouble, but do it in such a way that doesn't alienate people.

Simon: 18:29

Yeah, such a good point and I think there's a mix of everything in there, from regulations to social science, to habits, to culture, to demographics and age. You know like that's why it's such a fascinating area, I think, and keeps us all so focused and excited about the potential. I was talking this week to a lady called Priyanka who's a sister professor in Delhi in India, and she's talking about exactly the same things we're talking about, but in the context of unbelievably poor air quality. So things being multiple times worse is not necessarily going to drive a change in behavior, because in parts of Delhi at certain times of year they're talking about, you know, a particular matter in the hundreds chronically 6,700 micrograms per meter cubed of PM 2.5 in dwellings and people being exposed to PM in the thousands while they're cooking. So there's so much baked in around social science and habit and I'm always nervous about drawing analogies.

Simon: 19:44

But you know, I think the car is a really interesting one in the sense that the seatbelt is an interesting story. The success of getting people to wear seatbelts has been a mix of regulations and standards and tests and cultural norms and demographics and age profiles, and you still see a hangover from that. With seatbelts there are certain cultures that don't want to wear a seatbelt and even today, with all of the knowledge that we have over the impact of seatbelts, you still find some parts of society reluctant to put a seatbelt on. And you see kids jumping around the back seat of a car as they're driving along. You know, and you'd think the driver of having a child would be enough to change a cultural norm, but it's not. So do you wear a seatbelt?

Stephanie: 20:40

Simon.

Simon: 20:41

Oh, yes, yes, I do, and it's. You know, that's been a family thing since we were young and it's it's both. You get penalized by the law If you're found not wearing a seatbelt. Your car is tested that it works. There are standards around it. We have children, so we care. All of those things you know. And things can change.

Simon: 21:05

When I was young, you know, we didn't wear seatbelts in the back of the car and we went on long journeys. We were sat on cushions in the back of the car in the absence of booster seats, when they were didn't exist back then, and you know. But but slowly but surely the culture changed and the norms change and now it's just a given everybody gets in the car, the car doesn't go anywhere until everybody's got their seatbelt on, you know, and that's just the way it is. And air quality to me seems a little bit like that. I think it's going to take a very broad mix of standards, awareness raining, awareness raising, cultural norms and acceptability, what is acceptable, and I think that speaks very much to the not penalizing, you know, showing what good is, making it visible for everybody and then drawing a line to health outcomes and providing the evidence and the straight lines from building performance to health, air quality and health outcomes.

Stephanie: 22:08

It's interesting, Simon, I think I'm glad to hear that your family, you know your family rules everyone puts their seatbelt on before the car moves. I I do find myself that if I am going down my driveway to you know, the vet, the veterinary, doctor, my dog, which is only about half a mile away, I find myself thinking, well, I'm not going very far, so I don't need to put my seatbelt on, and I catch myself because I also realize that most accidents occur within two miles of your home. So but it's interesting to me to watch my own resistance to regulations in play, because I don't particularly like to be told what to do and I don't think I'm alone in that. So I think that's part of, I think that is somewhat of a human nature, that's somewhat human nature. But I also think that the air is particularly difficult to regulate, or difficult for people to realize the importance of regulating it, because you can't see it and we are very resilient creatures, as human beings are very resilient. We can have an insult to our body that you're not aware of, but one that can have a significant health impact within hours, but because we're not necessarily immediately aware of it, we don't attribute it to that moment in time, and that's so.

Stephanie: 23:41

I think about that a lot and I think about well, what about Wi-Fi signals in our home or in our businesses, or cellular data If your Wi-Fi signal disappears, just like you and I experienced in our last podcast? You know pretty quickly that you've got an issue. And if you're the stock market, you know the ticker tape stop. And if you're a big server for Amazon, you know lots of functions stop. So you know that there's a problem. So I think about how can we bring that immediate visibility into air quality's impact on your health, and hence I think that indoor air quality monitoring is very important because it creates that visibility. But, like you just said about radon, I'm curious what your thoughts are about why people are resistant to that testing and remediation. But I think because I've always thought that if you could make the connection visible, people would want to know.

Simon: 24:42

I think that that area of human behavior is just so enormously fascinating. And you know humans have survived by being able to perceive and understand risk. You know it's one of our skill sets of being able to frame risk, not only the short-term acute risk, the something pouncing on us and eating us risk, but our ability to trade short-term comfort and value for longer term gains, our ability to frame risk in the longer term. That's enabled us to evolve as a species and put systems in place that provide us with longevity and health, public health being one of the purest examples of that. So we're clearly capable of doing it and there are fascinating stories all over the world whether it's malaria or anti-smoking campaigns or HIV and AIDS that there are incredible stories of successful framing of long-term chronic risk. That seemed unseeable at the time, Yet we found a way to enact enormous health outcomes at a public health level. So it's clearly doable.

Simon: 26:05

I get the sense sometimes we get stuck in this reinventing the wheel the whole time in air quality and I think we could be learning from others so much more. And for me, I always go back to the smoking campaigns. You know, everybody instinctively knows what a darling is because they've had that pushed down their throat with anti-smoking campaigns for decades. I just think it's hard and it needs to be important enough for us to invest the time and value in to achieve it, and I think that's where work, I think that's where linking human health and harm is going to be so key. The risks, the double-edged sword of freaking people out a little bit more, that this air quality stuff can have a long-term impact on your health is worth it, because I think it's the trigger for us to start taking this seriously and investing the type of resources that we need to to getting the change.

Stephanie: 27:03

I think that's right. I like your voice of optimism that we have created change in some very powerful industries. I was also surprised when you said, if you could have your time I'm not sure if you're exact words you would be more involved in education and social science, but I think you are. This podcast is very much, as I see it, an education and awareness-raising endeavor, which I really admire. Yeah thanks.

Simon: 27:34

It's more that the science of human behavior. I find fascinating why we make the decisions we do. I'd love to have learned more about that. If I could do a do-over on it. You know, maybe there's still time. Maybe I will pick up a book or something at some point.

Stephanie: 27:52

Simon. I went back to school in my late 40s for medicine and health protection. So I have very little understanding of your saying if I have time, you have time.

Simon: 28:03

No, absolutely. I mentioned it in my introduction in the first podcast, Stephanie, that one of the reasons I was so keen to talk to you just in general was that the first time I came across you was in an ASHRAE conference again ironically, but in Athens a couple of years ago, and you gave a fascinating talk on the microbiome. So I'd love to talk about that again. Now I've got a chance to talk to you directly about it. What is the microbiome? What is it to the built environment? What is the link and why do we care about the microbiome, both our microbiome and the microbiome of the building?

Stephanie: 28:51

So, simon, this is another incredibly fascinating topic and my understanding is starting around the year 2000, when there was a big push to sequence the entire human genome, to understand all the genes, all the chromosomes that make up people, so that we could then find chromosomes related to disease and eradicate disease. So that was a huge effort in the around 2000 or before to advance the techniques to streamline and make more affordable processes which reveal the human genome. As a consequence of that effort, which we finally did, a couple of things happened. One we found out that human beings only have about as many chromosomes as a flowering plant, and that was sort of a huge insult to the human ego, like, wait a minute, we have to be more complicated than a plant. But in the analysis of all the chromosomal material that makes up people, we learn that bacteria and viruses and fungal organisms are actually part of our, a very key part of our existence and actually a key part of our very structure. So things like retroviruses, which HIV is one of those Retroviruses, have actually incorporated themselves into our reproductive system in a way that's beneficial. So we've learned, as a consequence of that human genome project, that each of us, by cell number, is less than 50% human, but that the other 50% of our bodies, and a component that governs our health, are the microbes, the bacteria, the viruses, the fungi that live in us and on us. So we need these microorganisms. So a microbiome is the name given to the community of microbes that live in whatever system you're describing. So the microbiome of the human gut are all of the microbes that live in our intestines and colon. The microbiome of the human body include all the microbes that live on your skin and on and in the rest of your tissues.

Stephanie: 31:21

But what we've also found out by bringing these genetic analysis and visualization tools into building assessment is that buildings also have a microbiome, and so if you or I enter a room, it takes a matter of minutes for our microbes to go into that room and set up residents, so to speak. And so what do those communities look like in the room? The shape of building microbiomes or the room microbiome is determined by the surface materials. It's determined by the ventilation. So what is the humidity temperature? What are the particulate counts? So, given that we're indoors as much as we are and that our microbes go in and populate a building as well as microbes that come in from the outdoor environment. The microbiome of the building has become an incredibly powerful force that shapes the human microbiome and, given how much we depend on microbes to live or to be healthy or to be sick, it means that the relationship with the building microbiome and the human microbiome is absolutely essential for our survival. So if, then, research is shown, like Jessica Green's work and out of the University of Oregon and Kimball in 2012, a lot of the microbiome work is funded by the Sloan Foundation If you think about managing buildings to support a healthy building microbiome, that is then going to create a healthier human microbiome. It's another dimension of why building management for health is important.

Stephanie: 33:05

However, then along comes this rogue virus, this SARS-CoV-2, devastates human health and the economy and all of the consequences. It's been hard for me personally to talk a lot about beneficial viruses and beneficial bacteria, because it's such a shift in thinking from being afraid of viruses and clearly, sars-cov-2 is a harmful microbe. It's not one of the beneficial ones. It's not one that you want in your air. However, there are many microbes in our environment that we do want, and some of them are very counterintuitive. For example, the whole concept of surface hygiene in everyday buildings I'm not talking about in an operating room or in a bone marrow transplant unit. There you want as few microbes as possible. But in our homes and in our offices, around people, the environments in which healthy people with robust immune systems live, you want exposure to a diverse set of microbes, which really goes against the whole hygiene hypothesis that we've lived with since probably that I don't know if you had Mr Glad in your country, but there were some advertisements where a guy dressed in white clothes would go through your house and eradicate everything. That was the previous thinking. We now know that trying to eradicate all microbes from your environment is not possible and it's not even desirable.

Stephanie: 34:40

One of the studies that I find really interesting was done similar studies in the Amish communities in the United States and in North Central Europe. They found that some populations of children had very low rates of asthma and infections early on in life. In looking into what could be protecting those children, they found out that these kids live in very close proximity to animals, to cows, to goats, to dogs. They roll around in all that goes with cows and goats and dogs and have tremendous exposure early on to the microbes that a lot of which come from the feces of these animals. I'm not suggesting that we bathe our children in feces, but the study shows that early exposure to a healthy microbiome actually trains our immune system to be both robust and not overreacting. In summary, we don't want to eradicate all microbes in our buildings. We want to support the ones that help us live there's so much to unpack there, stephanie.

Simon: 35:55

This is why I found it so fascinating when you were talking a couple of years ago on this. Is that I mean, would you class it as a symbiotic relationship?

Stephanie: 36:05

the microbiome- and us Absolutely 100%.

Simon: 36:09

Yes, here's a question for you. Do you think I mean for me? I naturally get that, but yet that then I'm quite an outdoors person. We've grown up in the mud and dirt and in the woods and the trees and around animals, you kind of. There's this natural sense that kids are supposed to come back covered in crap, right, basically if they're having any kind of fun.

Simon: 36:40

Part of sending your kid to preschool, apart from the education, is to give them a good old dose of everything they come across and to build them up a bit. I think there's this natural understanding of that symbiosis with the microbiome. Could there be an urban and rural divide in this? That people that become detached from nature a little bit are starting to miss that link? Where everything's cleaned within an inch of its life, disinfected within an inch of its life, they're not coming across the nature and the dirt and the mud. Could there be a little bit of that in this story?

Stephanie: 37:21

Yes, I think, absolutely. I think that the concept of dirt or soil and outdoor exposures and animals is beneficial. It's called the old friends hypothesis, that bacteria and viruses are our old friends. You don't want to eradicate those. If you think about your child coming back covered in mud, that's a surface exposure. It's on their skin. Maybe it gets in their mouth.

Stephanie: 37:54

My studies have also moved towards understanding how we get exposed to the microbiome of the outdoor world or the air. If you think about how a microbe could get into your body, you can either ingest it, so in your mouth, gets trapped in your mucus, goes into your digestive system. There are lots of immune cells along the way that those microbes encounter. The microbes and the immune cells talk to each other. That's one root of exposure. Another root of exposure is through your lungs.

Stephanie: 38:28

I think that another reason that indoor air quality is particularly important for our health is that inhaled microbes have a very different process. They have a very different interaction with our bodies. They immediately go fairly deep into your lungs. They don't have the same immune system interaction that microbes that go through your digestive tract do. What does that mean?

Stephanie: 38:54

I think it might mean that there's really perhaps and maybe this is an overstatement, but it might mean that there's no such thing as a good airborne microbe for our health. Microbes that are beneficial are through our digestive system, skin contact. I can't say that with 100% certainty, but another reason that I think we have to manage things such as particle counts in the air, because particles can carry airborne organisms. Humidity is very important because low humidity which a lot of building owners advocate, low humidity allows for airborne suspension of bacteria and viruses and some fungal organisms. That's not good. Low humidity is very harmful to our respiratory immune system. So I think, thinking about the microbiome of the building and human health, it's really important to understand the difference between an airborne exposure and a surface or contact exposure, because when you think about your child going out and coming back covered with mud, that's probably not an airborne, it's probably primarily a digestive system exposure rather than inhaled.

Simon: 40:13

That's a fascinating question to pose whether or not exposure to bio aerosols and the microbiome any amount of it can be beneficial or it's just too much for risk in general. Yet our exposure through our skin and digestion can be. That's a fascinating question to need to unpack, because that speaks to the potential damage we could be doing to the microbiome. For example, with some of the air treatment technologies that we're creating that are designed to obliterate all living things that pass through them as efficiently as possible, like you say, in a surgical environment. Fine. But if we're introducing UVC and ionization and other technologies that are designed to be as efficient as possible at breaking down cell walls and killing stuff, the first question that's asked is what damage does that do to the microbiome, both on the surface but also potentially in the air, and is that going to, on balance, be a positive or negative? That's a really interesting question.

Stephanie: 41:32

Yes, I think we have to be very thoughtful about broad antimicrobial air treatments because, again, in some settings I think they're very, very helpful. But, just like with the development of antibiotic resistance, we have to be careful about how viruses and bacteria and fungal organisms mutate. If we introduce a technology that is going to cause that microbe to evolve to survive, then what does that mean down the road? I think we need to look at studies that are fairly long term, meaning several months, to look at the evolution of airborne microbes to survive some of our air cleaning technologies, and make sure that we're not introducing technologies that are going to ultimately create more pathogenic or harmful microbes, just like with antibiotic resistance.

Stephanie: 42:27

Antibiotics are penicillin. When it came out in the 1940s was very, very life saving to many people, but then bacteria quickly developed resistance and then we brought in other antibiotics to attack bacteria in different ways. But antibiotic resistance has become a huge problem now. So we don't want to go down that same road with air cleaning, disinfection technologies. So I think we have to learn from our history. We have to learn about the agility of microbes to evolve and we also need to understand that there is a huge population of beneficial microbes. So how do we balance a good building microbiome, a good microbiome of the air that will enhance our health? How do we bring recognition of those dynamics in door building management? If you talk too much about beneficial microbes in this day and age, unless you're talking to microbiome people or somebody like yourself, simon, who finds it interesting and important, you talk to a lot of infection control professionals and they don't want to hear about it. They don't want to hear about beneficial organisms.

Simon: 43:41

It's probably a little bit analogous to people starting to glaze over a bit when you start talking about volatile organic compounds.

Simon: 43:47

It's just that the air chemistry and the complexity is just so mind blowing that it just feels like a hurdle too big to get your head around.

Simon: 43:56

And I wonder if there's a little bit of that with the microbiome. That, geez, we're still trying to figure out the impact of air quality and pollutants on our own health. You're now telling me there's this whole other bunch of living organisms that I've also got to take into account in building for health. You know that actually I'm not just interested in the health outcomes of me, I'm also interested in the health outcomes of a bunch of, you know, thousands of other different things. I mean it's probably I don't know if it's a question you can even begin to answer Stephanie but how do you begin to even roadmap learning for the microbiome in that regard? I mean, how do we navigate our way through this that the microbiome is a living organism that has an impact on our health, but maybe many of the things that have a negative or positive impact on our health will also have a negative and positive impact on their health. That's a heady mix.

Stephanie: 44:58

But it isn't. It isn't, I mean, it is a heady mix, but it's also simpler, I think, than we might think. Because if you think about what makes up our bodies, we're made up of cells. Cells have membranes, they have we. Our cells have a cytoplasm, they have a nuclei, nucleus, which is a DNA and RNA the same with microbes, although viruses don't have a nucleus, but the living components are very similar. So if you think about the building blocks of of microbial life and human life, there's there's a lot of crossover and in general we're lucky in that indoor conditions that support human health tend to also support a healthy building microbiome. So we can be thankful that it that the dyn, the indoor conditions that foster the growth of the or the persistence of pathogenic viruses and bacteria, also happen to be the same conditions that are not good for people.

Stephanie: 45:58

So what are some of those conditions? Well, for example, again, low relative humidity indoors fosters the growth of, for the development of, airborne organisms that are protected from a dry environment. So they have, they tend to have, thicker membranes or they form spores which can then be airborne. They're hard to clean, they're hard to eradicate from surfaces. Things like clostridium difficile in hospitals was one of the first organisms that brought airborne exposure, you know, after tuberculosis and measles, into the forefront of our minds and hospitals. But so dry air fosters harmful bacteria and viruses in the air and dry air is also very hard on our bodies from a number of different through a number of different mechanisms, versus that mid range 40 to 60 humidity that I talk a lot about, which is supports a healthy indoor microbiome, it supports a healthy human respiratory system and consequently it's good for microbes and humans. So I think we can be thankful that what supports a healthy human being generally supports a diverse and healthy building microbiome.

Simon: 47:18

And if I was to have to pitch a guess, I would.

Simon: 47:21

I would guess that the inhaled microbiome, on balance is probably not harmful because it would have impacted us before now and our ability to eradicate it before we breathed it in.

Simon: 47:38

Yeah, global pandemics and you know, certain situations aside, generally speaking we're inhaling the microbiome all the time and it I'm guessing it doesn't have a major impact on us. So it's that probably the net result of all of this is it's all about natural balance. You know, like there's a nature's pretty good at delivering an environment that, on the whole, has been pretty good for us and it's most of the problems we create for ourselves is when we shift those environments out of balance, like air condition the hell out of a space and make it dry, or pack people into tightly dense boxes in urban environments or, you know, move around the world too fast to control a global spread of a disease. You know, all of these things are unnatural systems that create environments where we end up with this imbalance. But largely speaking, if you leave kids to run around the woods and the fields and get covered in muck and live their life in balance, usually the outcomes are pretty good.

Stephanie: 48:43

I think you said that perfectly and I agree with what you said. If we think about what you said about, you know buildings, you know out. And let's talk about humidity for a second. Outdoors relative humidity, even in a very cold climate, for example, tends, the relative humidity tends to remain in a fairly mid-range zone because of the temperature, water vapor relationship. But then again, in temperate climates, in the winter, when we happen to get the flu, you seal up your building, you warm the indoor environment to comfort temperatures and what happens to the relative humidity? You know, even if the absolute humidity is the same, the relative humidity which speaks to evaporative forces on our body plummets, and that's when you have, you know, your respiratory immune system is impaired, you have more airborne organisms. So I think mother nature sort of balanced it out outdoors. But then we create these beautiful, comfortable buildings and we disconnect latent heat from sensible heat and I think that drives a lot of our diseases.

Simon: 49:52

Yeah.

Stephanie: 49:52

But you also said something that was really interesting, I think, about travel. If you look at the nasal cavities of well, you can pick humans or animals. There's an antelope that has two branches of the species. One branch evolved to live in very dry desert and the other cousin lives in the grasslands where there's a moderate outdoor water vapor. And over the centuries the nasal turbinates have chained or between those two cousins are very different.

Stephanie: 50:28

So the sinuses and the nasal cavities of the antelope that live in the desert have morphed to be warm. The air is warmed and it's humidified and it's filtered before it goes into the lungs. The cost of doing that for each animal is, you know, the development of these bigger heads, the use of all the minerals that it takes to create the bones that you know round those cavities. But with human beings, if you look at the nasal cavities of, say, people in cold, dry climates versus hot, dry climates, this shape and the movement of air is very different. In those sort of, the air conditioning or the preconditioning of air is very different. So that works as if you settle in a certain geographic area for centuries. But we don't do that anymore.

Simon: 51:22

No. We create these artificial environments that we can switch on and off. You know which doesn't get. There's no time for adaptation there, you know.

Stephanie: 51:34

Exactly so it's. You know, in our modernization we've also impaired some of Mother Nature's natural protective mechanisms, and I think we have to be aware of those, and so we can bring them back into our modern, modernly designed and managed buildings.

Simon: 51:53

Yeah, that's fascinating. Honestly, stephanie, we could talk about this stuff for hours. I find that that whole and it's just another layer of complexity and interest to take on board and to. We can't necessarily engineer our way out of a lot of these problems. We have to take into account Mother Nature and the way we develop as a species and the other organisms that occupy the same spaces as us. It's a fascinating area, but ultimately, we mostly build buildings for us and we need to start thinking from a more human centered approach when we look at building and managing these buildings. Taking into account all that we've discussed on this podcast, I think and start to think about humans at the center of this, principally because it starts to deal with things that we're struggling with, like stakeholder alignment right, that we can start to bridge some of those gaps that we've been struggling to in the past, because now there's a common interest in outcomes.

Stephanie: 53:12

Hopefully, hopefully, it's a common interest. But, simon, I don't want to end with the concept that this is also complicated, that we can't deal with it. Because, again, if we go back to what is our North Star for building design and management, I think it should be health, both human health, which also means the health of the microbiome. But thankfully, with Mother Nature, there are the number of processes which govern natural barriers between pathogens and good microbes and the different spaces in our bodies. The mechanisms are fairly straightforward and fairly simple. So we can ask how do we prevent the penetration of harmful components into our body? And the mechanisms are similar for creating pathogens versus helpful microbes. So, in one sense, if we take a human-centric or a health-centric approach, the guidance becomes simplified through the mechanisms that I just talked about. What determines if something penetrates our body, if polarity, size, what determines those things? Water vapor. So there are only a few mechanisms used by Mother Nature to move compounds from one space to another and, if you're aware of that, it simplifies building management.

Simon: 54:44

I meant to ask you actually from last week. It just goes to show you're always learning in these conversations. I've not heard the term polarity used much before in air quality, but that's twice You've used it in our conversation. What is polarity and what does that mean to the ingress of a pollutant, say, or something that's harmful to the human body? What are you describing there? Because it's not something that's common in air quality conversations.

Stephanie: 55:18

So I think I'm just so. When I say polarity, I mean, is the net charge of a molecule positive or negative? If it's not neutral, then it's polar. But a more day-to-day way of thinking about that is that if something is water soluble, it has a charge. So polar molecules tend to be water soluble and non-polar molecules are lipid soluble or fat soluble Think of oil and water.

Stephanie: 55:47

Water is polar. But then how does that apply to the human body? Well, for example, if you inhale a compound, say sulfur dioxide, which is quite polar and quite water soluble, sulfur dioxide dissolves in the water layer of our upper airway, our sinuses, our nose, our throat, and tends to be absorbed by the water layer because it's polar, so it doesn't reach the deeper depths of our lungs. But then you think about something like nitrogen dioxide. So even though it's a similar, no2, so2, no2 is much less soluble, so it's not absorbed high up in our airways and tends to reach our lungs at a deeper level where it's actually more harmful.

Stephanie: 56:37

And then you think about something like volatile organic compounds, vocs, which I have a carbon backbone, often with double bonds between the carbons, fewer OH groups. So VOCs are quite non-polar, so their penetration tends to be deeper in our lungs or through our skin or through membranes directly, which is one of the reasons that some VOCs like benzene, formaldehyde, toluene, are very dangerous because they go right through our cells, they get into our circulation. They get transferred to our liver fairly quickly. So polar and non-polar really is water solubility for the most part.

Simon: 57:23

Fascinating.

Stephanie: 57:24

Yeah, didn't know that See the oil and water.

Simon: 57:26

Yeah, we never heard that before and it was. That's really interesting, and isn't it funny how two gases or pollutants that often have similar sources sulfur dioxide and nitrogen dioxide can have two separate impacts or be absorbed in separate ways by their nature, yet come from a similar source, potentially. So it goes to you know, maybe it does speak to that simplicity, if you like, that you're pointing to in your approach in understanding the mechanisms of introduction of these pollutants, although on first pass might seem more complicated, but it actually might simplify the hierarchies of control, perhaps, or our approach to risk, because you understand more clearly how that risk is gonna manifest to us as a human, if I don't know if I'm articulated that well enough, but that's where my head?

Simon: 58:30

is going.

Stephanie: 58:31

I was thinking I love the way you frame the things we're talking about, because you put things very clearly into a framework and a vocabulary that I think is understandable to building professionals, and I love to hear you know I'll say something that has to do with physiology or biology and then you frame it around building management. It's brilliant when you do that.

Simon: 58:56

But that's that crossover, isn't it, between disciplines. You know, it's the interdisciplinary approach, that reaching of understanding across the void to go. Ah, okay, that makes sense. Now you know something that seems overly complicated. You're going well, actually, that makes complete sense if you view it through that lens. It is just sometimes nobody's ever offered that lens up before. So let's hope that GPC45 and ASHRAE and other organizations continue to start seeing things through this lens because clearly it opens up conversations and opens up a perspective and a framing that is both needed but I think, will be really desired as well. I think it's something that once people start to think in that way, I think it's gonna set triggers off for people and a hunger to go. Yes, that makes complete sense. Now, stephanie, it's been amazing to talk to you. I hope we continue this conversation off podcasts and offline because it's always interesting. Thanks, samillion, and we'll get you back on at some point to expand this conversation and give us an update of how GPC45 and others are starting to grasp this nettle.

Stephanie: 1:00:25

Thank you so much, simon. It's been a pleasure for me as well, and let's keep up our contact.

Simon: 1:00:30

Brilliant thanks, samillion.