#30 - Sotirios Papathanasiou: See The Air - Technological Advances, Health Impacts, and Future Trends

A conversation with Sotirios Papathanasiou

This week, I spoke with one of the leading voices on air quality over the last half-decade.

Sotirios has produced one of the must-read blogs over the last half-decade and published books on air quality for both adults and children. I have been following him for years, so we finally got to sit down and record this long-overdue conversation.

We discussed how the view of air quality has changed and continues to change, and as a communicator in space, his perspective on this is fascinating.

For several years, he has worked with a sensor manufacturer, and we discuss this middle tier of sensors that sit above low-cost sensors, their value in the market, and how this technology is developing, in particular, Particle Matter!

Change is on the horizon for Sitirious, so this is a great opportunity to take stock of the last few years and what might be next.

Transcript

Simon: 0:01

Air quality matters inside our buildings and out. I believe we already have many of the tools we need to deliver better outcomes for many. The conversations we have and how we share this knowledge is the key to our success. I'm Simon Jones and this is episode 30 of the Air Quality Matters podcast Coming up a conversation with Sotirius Papathanassio. I've been following Sotirius for years and his blog See the Air is really a must follow. He is an electrical engineer by trade, but it's safe to say he has been one of the leading voices in the air quality community in Europe and the States for several years. He recently worked for a very well-known PM sensor manufacturer and is now off on ventures new. We discussed how the view of air quality has changed since he started writing and what he sees in its trajectory. Next we discussed this middle tier of sensor technology that sits above low-cost sensors and what value they bring and much more. Thanks for listening. As always, do check out the sponsors in the show notes and at airqualitymattersnet. This is a conversation with Sotirius Papathanassio.

Sotirios: 1:42

When we talk about air quality and PM2.2 values in general, we generally try to describe how good or bad the air quality is right. But with mass concentration values, unfortunately, we lose information about the smaller sizes of particulates, even though if your sensor technology supports and can measure those particles, by converting now those numbers into mass you have zero visibility of how extent. The problem was Okay, interesting. So basically what I propose, and other experts out there, is that we have to look at the number of particles for the different sizes that we can measure with the available technology and of course, if we have technology that they can go to the ultra fine spectrum, even better. But even you know concentrations of particulates.

Sotirios: 2:37

Let's say that we have like 1000 particles at 0.3 micron in diameter. Once you convert that number into mass, you're going to get something 0.0, something very small. It doesn't give you any understanding, right? But if you have a particle of 2.5 microns in diameter and then you convert it to PM, to mass concentration values, then you will get a very high number and that's like a false alarming. Why is the biggest sizes of particles translated? Let's say, well, enough in order to understand the impact they have on human health and why the smaller particles they can penetrate deeper inside us don't get so much attention when we convert them into the mass spectrum.

Simon: 3:27

You're a fellow communicator around air quality and I've been following you for years now, it seems particularly through your blog See the Air. How have you seen public awareness change in that time, both public-public but also the business of air quality awareness change in that period of time?

Sotirios: 3:52

Right. When I first started, there wasn't much of awareness out there. I don't want to say that I created the awareness out there, but indeed from the everyday people, you will see that they had very little knowledge on the on the matter. I will remember like when I was on a younger age, at school, and teachers will try to explain us about air pollution and they will only focus you know, I'm coming from greece, so they will only focus on the effects that air pollution has on the marbles of the ancient marbles, because they create, you know, acid rain and they will destroy the marble eventually, but they will never talk about the impact air pollution has on human health, right? So a few years later, I got into the university electronic engineering has nothing to do with environmental. But around 2010, I realized that something has to happen in the environmental sector and how we perceive air pollution and sensors is the best way to understand air pollution, because in most cases, we cannot quantify how bad the air quality is based on our senses. So at this journey on merging those two things, I decided at the same time that it's time to educate people somehow on the matter. And very, very little happened back then. And very, very little happened back then, but I insisted because I really liked the matter, so why not?

Sotirios: 5:29

So then something happened around 2016,.

Sotirios: 5:33

I will say the technology became more accessible with low-cost sensors, so people started to invest time and effort in understanding more air quality by purchasing low-cost air quality sensors or monitors, and then I gained more traction.

Sotirios: 5:55

Then COVID hit and it was an explosion, right, like you will hear about air quality everywhere, it was directly correlated with you know, aerosol transmission, pathogens, and from then to now, I see an explosion in the business-wide, not only for me, but many people got interested right, and they wanted to explore better air quality, especially indoor, and they wanted to explore better air quality, especially indoor. However, lately, like the last two years, a year ago, I have also noticed a decline in the technology that is available out there, like, for example, many companies wanted to jump into the air quality industry. They will invest lots of money, but at the end of the day, they will create the same sensor but in a different enclosure. So eventually, with this recipe in mind, you fail. You won't succeed. But the scientific community is still holding very strong. They still keep pushing the governments into doing the right thing towards indoor air quality and how important is ventilation. And that's the good side of the story.

Simon: 7:19

Yeah, so it's a very good point. Actually, there's definitely two tracks. The academic track is very strong. I don't think I've ever seen more research and publications on air quality across the spectrum of disciplines than I've seen today. You brought back amazing memories, actually when you said that Sartorius about acid rain. Actually, when you said that Sartorius about acid rain, I mean that's probably my memory and most of us of my generation's memory of air quality was, particularly if you lived in historic parts of the world, the impact acid rain was having on historic buildings was a real thing in the 80s. I certainly remember that. So it's really funny that you mentioned that. I'd never thought of that. I must actually try and get somebody on from the I don't know, the acid rain community. Is it still a thing? Um, have we changed, you know, have we changed something in pollution from cars that stops acid rain now, or something?

Sotirios: 8:20

because we used to talk about nothing but it yes, the chemistry is a bit different right now when it comes to the pollutants out there. Sulfuric acid or gases create the acid rain in most cases. So, yes, there is some change there, but you know there was also a change in the attention Like people are more important than marbles in ancient ancient greece, so let's focus on the effects of air pollution on people yeah, yeah, I mean, I suppose the only thing that trumped acid rain at one point was ozone depletion was another thing we saw, you know.

Simon: 8:59

So when you look back historically, actually we've got some very good examples of understanding the impacts of air pollution both on environmental health and on personal health, from smoking to acid rain, to impacts on the upper atmosphere. We've got quite a good history of getting it into public awareness. Maybe we'll look back at the COVID period and it will be a similar blip where there was a massive interest in a particular sub, this one being bioaerosols and infectious aerosols in the air around us um makes makes you wonder what will be the next big air quality thing to think about. Perhaps it's particular matter, to be fair.

Sotirios: 9:43

I think the awareness is growing increasingly on that yes, and if you've seen, like this year alone we had epa from the us, uh, lowering the standards right, like what? What they consider um a safe limit of pm 2.5. Then europe came along and recently also Taiwan came along by lowering the upper limits of PM2.5. So I see some trajectory there on trying to decrease the PM values for the ambient air quality.

Simon: 10:23

Yeah, and the National Academies came out with a report recently on indoor particulate matter and I think that's starting to ratchet up the awareness of the impact on the indoor environment as well. So it certainly seems to be something that's certainly got a lot of evidence behind it. Even if it is general ambient environmental PM, we do seem to have a lot of evidence of the impacts on health. So, aside from that academic track, you also get the sense that there's been a shift at the other end of the scale, at the the business production of low-cost sensor end of the market post, post pandemic that there was a lot of products hit the market. It was the world, to start with, of some fairly specialist producers of that type of technology, but we're seeing more and more Asian manufacturers coming into play now. Low-cost electronics, that kind of race to the bottom sector where there's as much on the Amazon-type sites as there are from the specialist producers. It's a, it's quite a heady mix out there now of of low-cost sensors, isn't it? In one way or another?

Sotirios: 11:34

um, yeah, many players. But if you open the devices you know I really like opening devices because of my electronic background um, you will see at the end of the day that they have the same technology a low cost sensor that is worth around 15 bucks, let's say US dollars, and it's limited on what it can do and measure and how you can use the data as well. Like, in some cases, I will say, okay, you want to build a device with these local sensors, but then you have to realize that you have to build around this product a way to inform the people in a more curative way. Like, people don't understand what's 10 micrograms per cubic meter, right? So you have to give them a better context on how and when they have to improve air quality. And especially nowadays with AI, machine learning and all of these technologies, it's very easy actually to do this kind of work and inform people better on air quality. Like, for example, if you have a sensor and you cook in your house, you will see that during the cooking process you raise the PM values inside your house. That's normal, especially if you're frying food tons of particles. So by using, let's say, a machine learning model, it's easy to say to the device and to the user eventually, hey, before you go to cook today, make sure you have the fan open, use some leads so you work in a proactive way in order to avoid this pollution be created in an indoor environment. So this is, for example, a simple example.

Sotirios: 13:30

And then you mentioned something about those companies out there like Amazon. Yeah, they just wanted to play along and see if they're going to get any traction and earn some bucks, and that's all that they care. So that's the reason it's very important to investigate, before purchasing products, see if the company is going to be around next year, because if the company is not available next year, this product won't work either. Especially IoT products. They rely on a cloud platform and without this platform around, they are useless.

Simon: 14:08

Yeah, absolutely. And you touched on a really important point there about this communicating risk to people, that at the end of the day, we're not going to stop people from cooking, nor would we want them to. In fact, we want to encourage people to cook right. Otherwise we'd be encouraging a takeaway society which does nobody any favours apart from the deliverers of the world. But the challenge therein is where we seem to come up against the wall and I wonder where the solution for that comes from, in what we can lean on and learn to leverage, how to communicate this risk better to people.

Simon: 14:50

Because it's not, it's a tolerable risk to a lot of people cooking. You know the smell of food in the house is not unpleasant sometimes and it's indicative of. You know smells are very evocative of growing up and that your favourite smells of cooking all can be quite nice, you know. So people will see the risk in a different way. So we have to find ways of both translating that risk in the moment to say to people there are some actions that you can take to eliminate that. There are some actions that you can take to eliminate that. But also we need to get better, I think, at communicating the chronic risk of some of these pollutants, that we find a way of getting people to understand that while we're not saying, don't do something, you've got to understand the compound effect of being exposed to some of these pollutants over the longer term. Exposed to some of these pollutants over the longer term and I think a lot of that comes from storytelling and framing and changing habits over time and general education. There's a lot to be done there.

Sotirios: 15:54

You are absolutely right. That's the number one pain point of air pollution. In most cases there are some exceptions the effects are in the long term. So people are not very smart, I would say, into getting analyzing or understanding the patterns that they are created in order to deteriorate their health. So you may notice effects of air pollution by living many years in a very polluted area and unfortunately your brain does not correlate that this illness may be a result of your exposure to the air pollution.

Sotirios: 16:40

And yeah, it's tough to convince people on that subject. I've tried myself especially when people let's go back again to cooking people that they really like barbecues and stuff like that, right, and they stand on top of the fire or the burning of the coal and they inhale every single particle that comes out of this pit of a fire. Are there alternatives? I won't disagree that the food is very flavor. I'm not going to fall into that direction. But you also have to realize that are you exposing yourself to those pollutions and is it worth the effort at the end of the day, or are there any other alternatives that you can cook the same meal and they won't, you know, create any problems? Uh, to you in a long term?

Sotirios: 17:47

that's something very common and another common problem yeah, another super common problem is I'm sure you know that uh very well, especially in the uk um, wood fires, right, um, for heating purposes, wood stoves and all of those devices that they use out there to heat their houses by burning biomass right, unfortunately, we were sold like it's going to be a sustainable way, but it's not.

Sotirios: 18:21

Of course, this is not a sustainable way to live or heat your house, and when you heat your house by burning wood, you not only deteriorate the air quality inside your house there are plenty of studies that support that idea but you also pollute everyone around you, right, and you create a harsh environment for some people that especially have difficulties or more needs for better air quality than other people. For example, I'm part of the Safer Air Project. It's an Australian nonprofit organization that wants to bring awareness on the fact that there are people with disabilities in the breathing, so they require better quality than other people, and people with disabilities, uh, breathing disabilities, uh, they need access to, you know, good air quality in indoor places and other places as well. Um, and no one looks after uh, after them people with asthma, people with cancer, uh, coppd, etc. They all suffer and they have more strict requirements when it comes to air quality and, unfortunately, when you burn wood, you basically don't take into account their lives and you make their lives even more miserable.

Simon: 19:58

Yeah, it's an interesting one. I can't remember I think it was a conversation I had with Yela Laverge. He was talking about a consideration in Belgium about the legalities of allowing people to smoke in their own homes, and we were talking about the difficulty in crossing a threshold legally, of saying what people can and can't do from a risk perspective in their own homes, and he was saying the position in Belgium was rather that you have an obligation as a parent not to put ill health on your children. You know that there are some things that there's a public good you know nature to air quality.

Simon: 20:41

We all share the air. You know, and as much of an exclusive as it is, that Soterios on this podcast would like to ban barbecuing and wood burning in stoves and immediately turn off half of North America and the UK and Ireland. That's the challenge we have, isn't it? Is that there are things that are objectively harmful at a population level. It's very difficult to say to somebody that having a barbecue and standing over it for an afternoon with all your friends and having fun is going to do you a defined amount of harm. Um, but that's kind of where we need to get to.

Simon: 21:25

I guess, in the same way that we used to have this metric for smoking, that every cigarette costs you seven seconds of your life, that we need to start quantifying the, the harm that this stuff does in a way that resonates with people so they can say okay, I recognize barbecuing is going to accumulatively do me harm over my lifetime. Is this something I should change my habits or behavior around to minimize that risk? Um, in the same way that if I have a stove, is that a decision I'd make a second time around in my lifetime to put another stove in? It's a really interesting one. Do you get much feedback from your blogs and things when you're communicating on air quality, do you?

Simon: 22:12

get that kind of engagement from community with the things that you say and what resonates and what doesn't.

Sotirios: 22:19

Absolutely engagement from community with the things that you say and what resonates and what doesn't. Absolutely, uh, you know people reach me through social media, through my blog, by sending out an email. Uh, you bet, like it's, they're there, they're waiting there. I I've see. Also, you know, when you track, uh, the traffic on your blog, you see exactly where they're landing, what they're looking for and you can understand better what they're trying to do with the information that you share. And, yeah, absolutely.

Sotirios: 22:54

And I think something else that I wanted to talk about, about what you said earlier, like restricting people from smoking indoors. Like that's not the same for all the countries, though. Like here in the US, for example, because of the rights people have inside their houses, no one is allowed to tell them what they're supposed to do indoors, so they can smoke or cook or whatever they want, and it's very difficult for the government to put a stop on that. But you don't want to force something like that to people. You want to educate them right, like throughout their lives, uh, by advertising or any other means that is possible. That this is the right thing to do for you, for your kids and also for the community that you're living. Right, because humans cannot survive on their own. We need the community of people and it's very important to be very respectful of the communities around us.

Simon: 24:03

Particularly in different cultures. You know we've seen how that line has been crossed, particularly in North America, around your obligation to the community when it came to infectious diseases. You know it really divided a nation on what you should be obliged to do and how serious something may or may not be. It's a very difficult line to tread and you can see if you go too far some people within the spectrum of the community will rail against that kind of restriction or enforcement. And yet in other cultures people align with that kind of thing much more quickly. You know I I grew up through the smoking bans of both the island and the uk and you look back on it now and it was as if it was nothing, absolutely nothing. People complained and then when it was in place, everybody went yeah, fair enough. You know it makes, makes a lot of sense, I suppose.

Sotirios: 25:06

And people just got on with it in general yeah, yeah, it's an interesting one not only air quality, like. They don't like chains, they afraid of the chains, they think it's something that's going to make their lives more difficult, but instead we are trying to do something better for the world, right.

Simon: 25:27

Yeah, no, I agree. And practically when we're talking about and I talk about this a lot, particularly when we're talking about air quality in the built environment, there are only so many things we can do in the built environment to minimize that risk anyway. So there's a whole body of work trying to understand the complexities of air quality and there's a lot and their impact on our health. But ultimately, when it comes down to the control of those risks in a space, we're fairly limited to a handful of things that we can do. So as long as we understand well what they are, we can do a pretty good job of eliminating most of the risks that we come across.

Simon: 26:15

You know just good ventilation and decent local exhaust ventilation. You know cooking pollution from hoods or sorry, cooking pollution from cooking, would be far less of a problem if cooker hoods were any good. You know and used but that's half the problem in our part of the world anyway that the risks that we see from cooking pollution is pollutants hanging around in the space because they're not exhausted well enough. I appreciate in parts of the southern parts of the globe a lot of that is down to your exposure with the type of fuels that you use to cook with and your direct exposure to those particulates. But particularly in this part of the world, most of the risk is down to the fact we just don't exhaust pollutants very effectively in the home and a change in understanding and habit around that could have a massive impact at a public health level.

Sotirios: 27:14

I don't know what's the situation in the UK, but here in the US, for example. I don't know what's the situation in the UK, but here in the US, for example, we have a huge problem with exhaust of fumes from the cooking process because most houses here are equipped with microwave rangers, hoods or whatever you want to call them. Their name change all the time. So basically, what? What it is? It's like a microwave on top of your stove and it just take the air, passes it through an aluminum mess with hole of that size and then spill all the air on on the ceiling inside the house in the same location. So basically, you spend electricity to operate this device and, in order to recirculate the air through a mess, a whole aluminum filter and people think that this works right. They don't have the understanding that this is useless and misinformation, misleading and should be banned.

Simon: 28:22

But no, it's, it's there in all the houses and there is nothing I can do yeah, it's a horror show, to be honest, from as far as I can see, in most jurisdictions I look at. You know we have the same here those very cheap recirculating hoods. Um, the decisions on cooker hoods generally are aesthetic. Is it wood for my country kitchen or metal for my modern kitchen? It's an aesthetic choice. Or if it's being installed by a developer, what's the cheapest possible piece of crap that I can put in? Because nobody's going to spend any more on this apartment or house based on the type of range hood that I put in, so why would I spend any money on it at all? And we see very little guidance on regulation other than the flow rates that those devices achieve. So is it any wonder Yet? Yet, ironically, it could be one of the biggest public health measures we could put into place in homes is decent cooker hoods but you very rarely see a specification on one.

Simon: 29:30

I don't. There are a few high-end german kind of bosh melee type products that are advertised as quiet and demand controlled and will come on when you start cooking and things like that. So it's a start. I think it's. There are. There are some solutions out there. But we need, as you say, we need to be far more robust on that direct exhaust to atmosphere of particulate matter from the home. And it's not hard to be fair, most cookers are on external walls or have reasonable access to home. And it's not hard to be fair. Most cookers are on external walls or have reasonable access to an external wall. It's not hard to duct a cooker hood to outside and exhaust it, it's just people don't care.

Sotirios: 30:10

Yeah, there is no framework in order to guide them what they supposed to do and build for the people that are going to spend their life and cook and eat inside this particular apartment. Right, in my case, for example, I struggle with this house as well. I'm lucky enough because next to my kitchen there is the bathroom with a real exhaust, so I will have to turn on the exhaust from the bathroom in order to mitigate some of the pollutants that I create during the cooking processes through the bathroom outside. But again, I have also adapted the means that I cook and what I cook. I will never fry anything, never. It's like. If I fry here, it's unlivable, it's tremendous. I will have to cook in the oven or by boiling stuff safe ways not to create, you know, tremendous amount of pollution indoors it.

Simon: 31:09

It is frightening, isn't it? The moment you start measuring particularly particulate matter and some of the some of the chemicals that are produced when you cook. It is amazing how big an impact frying has, and the numbers do not lie. It's horrific, yet evocatively, that's the smell of bacon wafting up the stairs in the morning or the lovely smells coming from the kitchen is actually what you're. What it is is a load of pollution coming from the kitchen, and I think what people struggle to join the dots on is that those cooking smells, um, aren't healthy to inhale necessarily. You know, particularly when they're attached to microfine particles, that we were never designed to breathe those in and absorb them straight into our bloodstream. So what might be safe enough to eat or come into contact with on your skin is not necessarily safe to be breathing into the deep parts of your lungs, right?

Sotirios: 32:14

right, right, exactly, and it's okay if you do it once, no harm there. But we talk about every day, you eat every day, right like. And if you start doing that constantly, then it accumulates over time.

Simon: 32:29

It's yeah, and I think that translates to the dahlies that we see, the disability, adjusted life years, uh, per 100 000 of the population of particular matter, these frequent exposures to particular matters is what drives the harm. Um, like you could argue, you know, particularly here, if you live in ireland, you know we might have three or four barbecues a year because realistically the weather isn't suitable for it. So am I going to get too concerned about two or three exposures of high levels of particulates once or twice a year? Probably not. But if I live on the mediterranean or in sunnier parts of the world and it's a daily part of our cuisine and cooking is putting things on the barbecue, particularly solid fuel barbecues. You know you, there's, there's a frequent frequency to that risk.

Sotirios: 33:24

All of a sudden, I used to live in spain and you know, especially in the region of malaga, uh, lots of people know from um, you know they, they have like a tradition there and like a tourist attraction as well. They cook fish on an open fire and you sit like next to it and supposedly you enjoy food and you know the environment, but all of those fumes they come to you and it's okay if you do it once, but if you do it like for living, like people there, they really um do that every day, right, like uh cooks and uh the employees that they work on those restaurants.

Simon: 34:08

they they do expose them, their self-seeing, uh lots of particulates yeah, I, I wonder, I wonder if there's anything to learn as we see what the impacts of monitoring things like CO2 more and more, that people get used to those kind of numbers.

Simon: 34:28

You're seeing a general awareness in the population now for knowing that there's something important about a thousand parts per million. They don't really understand why, but they understand that bigger numbers are a problem and we like to keep things below a thousand parts per million Generally. It's quite amazing when you talk to people, particularly if they're exposed to school environments or education environments or office environments where these things are starting to be monitored, you're seeing that recognition appear still at low levels. I mean, I'm not saying you know, if you speak to my mother-in-law that she'll have a clue what parts per million of co2 is, but, like, particularly in the younger generation, you're starting to see it more and more. And I and I wonder if we'll learn some things from that general population exposure to those kind of numbers that we can translate more effectively downstream to some of these specific pollutants of interest so that people start to instinctively know that pm 2.5 above 15 starts to be problematic. You know, and if I see something, at 60.

Simon: 35:37

I know that something's got to change, or you know, whatever it ends up being yeah, co2 is a bit different than pm 2.5.

Sotirios: 35:47

Um, you know, some communities were created out of covid and they really try to educate others as well. Uh, by measuring their quality wherever they go from a CO2 standpoint. So you will see them everywhere having a small device that measures carbon dioxide and they will try to keep themselves as safe as possible from airborne diseases, especially inside closed spaces, airplanes, libraries or bars. I find it very challenging sometimes because eventually, even in a flight, let's say you are on a plane and you wear a mask, you have to drink water, you have to eat something, so you will take off the mask eventually, right? So if there is host of a pathogen inside the plane, I think it's very difficult to protect yourself based only by wearing a mask and keep track of the co2, and that's the reason in most cases, airplanes have very good filters, so you will see very low PM values because they are they trying to trap every particle possible and unfortunately, in a very high altitude, air is not so easy to get from outside, so that's the reason you will see higher levels of CO2.

Simon: 37:19

But that doesn't mean that the air is not safe inside the airplane. Yeah, and I know what you speak to. There is context and it's very hard to translate threshold or basic numbers into context for people that they can use meaningfully. And we see this with co2 all the time, people misunderstanding it as a proxy for risk, um. But then you know, we also have to get over ourselves a little bit.

Simon: 37:47

I think about the imperfectness of field measurement. Anybody that does field measurements of particularly air quality knows how difficult it is to get accurate, meaningful measurements, even if you know what you're doing. And sometimes it's just about translating risk and building awareness. Even if somebody is stood in a an environment where it's just them in a small room and the co2 is going up and they're then panicking that the air quality is bad and they don't really understand what that risk really translates from and to um, at least somebody's thinking about it and it can help. It's it's an intro, I know what you mean.

Simon: 38:27

It's a frustrating thing to watch sometimes when you see people misinterpret air quality.

Simon: 38:34

Um, I think we have to use that and turn it around and understand how we can frame it and create action that helps. Because if we're seeing that with something as simple as co2, it's going to get really hard when we get down to things like formaldehydes and ozones and you know particulate matters and so on. Um, talking somebody about ozone the other day, about measuring ozone, and what one of the common misconceptions is, is that if we see low ozone in a space, that somehow that's a good thing, but actually what could have happened is is all that ozone could have turned into other pollutants? So the low reading is actually an indication that some chemistry has gone on and it's turned into other stuff. So just because you're not measuring ozone doesn't mean ozone hasn't had a really nasty impact in the space. So we've got quite a long way to go, I think, when it comes to how we communicate this in a way that somebody can take something and do something positive with it to get a better outcome.

Sotirios: 39:38

Yes, air quality is quite complex, and the chemistry behind it as well. Right, like pollutants, they will change form over time If there is sunlight or there is not sunlight. Many factors are going to influence what eventually you consider air quality, and you cannot say that only by measuring CO2 or only measuring particulates. You have good or bad air quality. It's a parameter, yes, but it's not the whole picture of what's going on. So when you dive now deep into the ozone that you mentioned, or formaldehyde or any other gas, then it becomes even more complicated and you then need more tools, more instruments to measure accurately the conditions inside the room or outside, even yeah, but also I mean, I suppose on the positive side and you must have seen this in the years that you've been looking at, it's particularly somebody with an interest in electronics how fast this sector is moving forward at the moment.

Simon: 40:44

In electronics, how fast this sector is moving forward at the moment, stuff that we just didn't think was possible even five years ago is starting to appear on our horizon as a possibility of measuring and monitoring and translating information. I mean, you and I are from a time where indoor air quality monitoring was really done with data loggers and academic equipment was incredibly expensive to do and we've seen, literally in the last few years, the evolution of that low-cost sensor technology. Really come on. And yes, there's all sorts of limitations around it, but compared to where we were even five years ago, it's astonishing what we can fit in a little white box now.

Sotirios: 41:24

Yeah, and we do have the low-cost sensors, but we also have lower-cost sensors which are like the middle ground of technology. That allows academics, if you want researchers, to get their hands into monitoring solutions, but without spending like 20 grand or 30 grand in just buying one equipment. Industrial hygienists or other professionals that they need a better grade of instrument that you know can report back to something and it's not going. No one is going to question the accuracy, which is very important, especially with low-cost sensors. You can question how accurate they are, but now, when we talk about the middle range of products of sensor technology, those sensors are, yeah, they are more expensive, but because they go through a process of validation right, and this is very important as well that's a really good point.

Simon: 42:33

Actually, it's something we've not touched on much on this podcast. Is that layer above low-cost sensors that is generally in the hands of professionals, I would say, and academics that understand not only their capabilities but their limitations well, so can apply something that has a much tighter reference on accuracy than the low cost sensors but has gone through a process and is being used, typically in a process that means you can stand over much more the kind of results you're getting. Um, where is that kind of technology at at the moment? What are the kinds of things that it's starting to be able to do? Well, that kind of middle tier of monitoring? Um, particulate matter is one of them. I guess it's starting to break apart particulate matter in a much more defined way than what we would see typically in a low-cost optical reader. That's, that's, making a guess roughly at a reference point of around 2.5 micrograms and making some calculated assumptions on what's above it and below it.

Sotirios: 43:45

These things are doing something differently, I guess they actually do the same thing, but there is a bad there. So we have two type of technologies, right? Uh, we have the photometer or an effelometer, if like, and then we have an optical particle counter, now an ephelometer. It's going to do what exactly you've mentioned it sees a cloud of particles and then, based on algorithms and assumptions, it calculates a mass. Those numbers can be very forgiving, right, especially for the smaller particles, like I mentioned at the beginning of this interview, like when you have 0.3 microns and you convert them into mass, it doesn't matter if you are wrong by a thousand of them, or 2,000, 10,000 of them, it doesn't matter because they are so small. Their conversion into mass won't affect a lot the number, the final number that you will get. So that's the main problem with those sensors, with nephelometers, they see a cloud of particles, they make lots of assumptions and they are targeting in one specific PM value, in most cases PM 2.5.

Sotirios: 45:00

In a recent conference that I was, they were talking about why they are not able to see pm 10. They are not able to give you good values on pm 10 for a various of reasons. I don't know if you're interested in going that route. And then the other technology is the optical particle counters, which this technology they use again the light scattering method, but now they redirect. They have better, let's say, chambers, better airflow, steady airflow, which is very important as well a better laser. And then what they try to do is that they try to count every individual particle, it doesn't matter of the size, count it and size it and classify it in different bins. And they do that by complying to standards. There are some standards out there from ISO and GIS standard from Japan, that they give instructions on the manufacturers, on how they have to produce this product and what they're supposed to measure and what are the tolerances of error, something you don't see with the low cost sensors, but you do see them with those lower or middle rates sensors.

Simon: 46:14

And now, by having you know the exact number of particles in the different sizes 0.3, 0.5,.5, 1 micron, 2.5, 5 and 10 then you are able to calculate the mass, if this is the way you want to use the data, and an even more precise way as well does that standard then mean that if I get effectively two or three different products from two or three different manufacturers if they're following that standard I get effectively two or three different products from two or three different manufacturers if they're following that standard I should get broadly similar results from the same environment?

Sotirios: 46:49

yes yeah yes, according to the standard, they supposed to be plus minus 20, but I can tell you from certainty because I've been working with one of those companies, that they, if you put like different batches of the same sensor, you will see that they are dead right each time. And that happens because those products are also calibratable. You can calibrate them by comparing exactly what you're getting from this instrument to a standard, something that you cannot do with lower-cost sensors. In most cases, they will take a room, they will fill it with a bunch of sensors inside there, they will put only one reference and they will expect all of those sensors to have the same value, something which is not possible from physics standpoint but they consider that good enough to do it, and then they release the product into the market, right?

Simon: 47:49

So what's the use case for that type of technology? We see low-cost sensors let's just stick on particulate matter for the moment that are getting deployed at a low cost uh across wide areas, uh longitudinal in nature. So they're going and being deployed over time to give patterns, and I often describe them as the health wearables of the indoor environment. That they're useful. They show patterns and some things that are going on. But, like health wearables, at some point you should probably go to your GP and get a blood test and see what's actually going on with you. And similarly with low-cost sensors, they'll give you an idea if there's some patterns within the building, but they won't necessarily tell you the nature of it. Where did these types of sensors start to come into the market? That they're the tools of the occupational hygienist and the occupational health and safety person that's coming in and trying to troubleshoot? Is it or enabling companies to meet a certain certification? In a pharmaceutical setting, I take it it's that kind of a level.

Sotirios: 49:01

Yes, exactly, you're right. So you have the industrial hygienist, for example, that they have to have some kind of a certainty when they report data back. But then you also have the clean room industry it doesn't matter if it is a pharmaceutical or even if it is a hospital that has to verify that the operation room is free from particulates, which, by the way, they're directly correlated with outcomes from the surgery. And then you have the academics, which they want to hire great instrument to do some kind of research of their own. Like, for example, I was talking the other day with a researcher from the Oklahoma University. He's using those kinds of instruments to measure exactly how, you know, the toilets disperse water aerosols into the environment, disperse water aerosols into the environment. So he will place, like, many of them inside the room and he will create patterns of how the particles flow inside the room and how far they can reach and infect people with. You know, pathogens that may are present in the business that we're doing. Yeah, nice.

Simon: 50:23

There's no way, no nice way of framing what you're describing there. So I think, well, everybody can leave that one to their imagination.

Sotirios: 50:30

Yeah, indeed but it's very important this kind of research right, because then, once they understand the patterns that they created with the aerosols inside toilets, they can come with solutions and create products or better way to flush a toilet that is going to mitigate that issue.

Simon: 50:52

Have you seen that sector expanding at a similar trajectory to the low-cost sector? Was there a boom during COVID period? That's tailed off now. Has it been more consistent? What does that sector look like compared to what most of the listeners would be familiar with, which is the the low-cost sensor market um?

Sotirios: 51:18

you mean from the academic standpoint?

Simon: 51:20

well, from like, from general for like, if you're, if you're a manufacturer now of that type of technology in the space, is it a market that is steadily growing? That boomed out of nowhere during COVID and then died a death? How's it kind of looking as a market, that middle ground sensor?

Sotirios: 51:38

market. I don't think COVID affects that kind of market a lot. It was growing steadily over the years either way. First of all because they have to comply with some kind of standards. So they have to measure air quality either way. And then if you want to build a good product, you have to measure the air quality as well because it directly affects the yield. Let's say, if we go to the semiconductor industry, you know that if the air is contaminated inside those fubs, those particles can deposit on the wavers and they will lead to lower yield. And it's not only about microchips, applies everywhere, like even in the beverage and food industry. If the air is contaminated and those particles, they can be harmless or they can be full of pathogens. If they land on the beverage or the food they will spoil them faster. So you need to keep those environments cleaner in order to achieve better results for your business.

Simon: 52:47

And is it a sector that we can learn something from when it comes to how we understand pollution risk and communicate it, because there's so much more detail? And communicate it because there's so much more detail? Because, you know, because our frame of reference for communication on indoor air quality typically is being driven, I think it's fair to say, from the low cost sensor end of things. The what we can do with a heat map and a ziggy zaggy line on a screen and an alert in an email is kind of driven from that, let's say kind of reset, kind of level perspective. Is there something we can learn from that middle ground on how to better communicate some of this risk? Because you were talking about, for example, the particular difference between mass and numbers of particulates in a space.

Sotirios: 53:38

I guess there's so much more we can glean from that type of information yes, and you were right, like I think we have already, uh, applying some things from the clean room or contamination space into the air quality, normal air quality, um, and you will see that by by exploring all the green build, green building certificates that are available nowadays.

Sotirios: 54:03

So now you have to comply to some kind of standard, which they are not. But if you want to achieve some certainty of recognition that your building is safe enough, you have to measure the air quality and do some other things as well. But that comes actually from the contamination space, where they have to test the space, validate that there is no pollution, and do that frequently, not by only once and quality day, but like by having once a month. I don't know how often do they do it, but you know eventually, monitor air quality in a continuous way in order to understand better the air quality and report back, inform the public as well at the same time that, hey, I have air quality monitors in my buildings and this is the air quality right now. We have seen those big screens in big buildings. Those big screens in big buildings.

Simon: 55:01

I don't know how common are they in the UK, but here in the US, when you go, for example on a conference, you will always see that they are trying their best to deliver better air quality for the occupants, and it's the same logic right, you have to comply to some kind of a standard, yeah, and we're seeing increasingly regulation starting to describe a minimum entry point for particularly public spaces, that there's at least some monitoring going on of detailed air quality assessments and the lower cost longitudinal kind of public facing data that we see on the screens that we see the likes of well had introduced in v2 where you know there's the longitudinal element that the permanent monitoring and an annual I think it is inspections for a range of pollutants.

Simon: 56:06

I'm guessing the, the pharmaceutical spaces and the medical spaces have been operating in that way for a long time that there's a. They've had to find what the right balance is between the frequency of detailed measurements and the and the proliferation of lower cost monitoring in those spaces. So it's how we see that translate down to the rest of the built environment, because at the moment most of it is just the minimum entry point. You know how many co2 sensors are you going to stick in a public building and do you have to display one of them on a screen somewhere to say that it's below a thousand parts per million? That's kind of where we've got to with the stick, the carrot at the other end, at the kind of the well end of things where they're saying okay, there's a methodology, we'd like you to do this and do this at least once a year and report and upload those results. But it's a big gap between those two in the built environment, isn't there?

Sotirios: 57:01

yes, and you know. First of all, I would like to say that air quality is something dynamic. It changes over time. Uh, it's not going to be the same today and tomorrow. Um, it's not going to be the same now and in an hour. You never know why it's going to change, maybe because I, I don't know a wildfire happened and wind blew all of those particles into your building. So I do believe in continuous monitoring. However, I do understand at the same time that there are some limitations on the budgetary side, like how much money can you spend or can you afford having all of those monitors in your building that they're going to monitor air quality all the time? So I do understand that. So I believe there is. Uh, the solution is finding the middle ground there and and having like a continuous monitor, but doing the periodic inspections as well. But it's not like you need to have monitors in every single room inside your building.

Simon: 58:08

Yeah, I agree, and I think it's like most risk, it's a process of workflows. If you find risk increases, then you increase the frequency of detailed assessment. If you find the risk is decreasing and minimal, then you may be able to back off the frequency of detailed assessment. If you find the risk is decreasing and minimal, then you may be able to back off the frequency of detailed monitoring. It's a risk, is a dynamic thing, particularly, as you say, air quality, and some environments will present a higher risk or have more highly vulnerable people than others. I think what we've just not been very good at is doing those risk assessments and understanding what that building and those stakeholders that use that building need. I mean, if Soterios was the mayor of a US city and you got to write the rules, where do you think that middle ground is? If you were, if you were writing the rules for all public buildings, uh, for air quality monitoring, what would you mandate? What would be the? Where do you think the sweet spot is for monitoring?

Sotirios: 59:15

um, that's a great question, um, but okay. Um, if I was the mayor and I had to implement new rules for buildings, it's gonna be the following having an outdoor monitor, having an indoor monitor and trying to see the difference, deciding between the conditions outdoors and indoors and seeing if it makes sense to recirculate the air or bring more fresh air from outside, filtration systems in place as well, and I will definitely write some standards about what I consider good air quality and acceptable air quality and so on.

Simon: 59:57

Would you mandate annual inspection with an occupational hygienist to measure the top 10 VOCs and particulate matter? And you know, would you say, okay, we want all public spaces to have some form of low-cost monitoring. I would also like all public spaces to at least conduct a test in both seasons, maybe of air quality.

Sotirios: 1:00:27

Yes, I do believe in industrial hygienists and similar professors professions sorry, I think we need experts that they make sense of the data. I do believe that they have to go annually and do inspections and see if what they are measuring with the continuous monitoring systems are accordingly and correct.

Simon: 1:00:54

So, yes, yeah, I, I'd live in your city.

Simon: 1:01:00

Uh, that's very good, and you raise a really good point about the difference between indoor and outdoor. I think that's an often missed opportunity because it's not expensive to do and, if you're lucky, often you'll have very good reference instruments quite close to you and more and more we see that now or at least a network of lower cost sensors that can be referenced against a decent sensor somewhere in your locality. So, like a lot of buildings, to be fair, can get a reasonable idea In some parts of the world. You know there are other parts of the world where this isn't done, but certainly in a lot of Europe and North America you can get a good idea of the air quality america. You can get a good idea of the air quality locally to your building and if you can't, deploying one sensor for a whole building outside to get a good idea of outdoor air quality is not an expensive thing to do comparatively and can give very useful information for making decisions. Like we said earlier, those levers that you can pull do Do I recirculate?

Simon: 1:02:00

Do I need to increase the filtering? Is there certain conditions that I need to prepare for it is a very powerful tool.

Sotirios: 1:02:10

I will disagree a little bit, though, with what you said by relying on air quality stations, government air quality stations for the data for the outdoor data, air quality stations for the data for the outdoor data. The reason is because I have seen many examples, even in Europe, where they will have placed the air quality station inside the forest or inside the park with many trees surrounded, and then they will call that an urban air quality station and supposedly that reflects the air quality on the streets. But it doesn't, because all of the trees are going to create a barrier for the pollution to reach the station and measure appropriately the levels of the pollutants. So for that reason alone, I will suggest having an instrument outside your building, near the ventilation system as possible, and going from there if you really want ICRE data, the environment around an air quality sensor can make a big difference, which is a which is a very fair point.

Simon: 1:03:23

Yeah, you know, and damn it, I'll have to start asking people to deploy more sensors. But let's say at least one of the things we we are starting to see the deployment of these networks and meshes of low quality sensors outdoors that are making a big difference to the granularity of the data that we see, that you can at least reference to things. But, um, yeah, it's a very good point about locating them particularly near the intake to a building, so you understand the air that's coming into the building yeah, yeah, the other day, for example, example, a warning was issued here for high ozone levels.

Sotirios: 1:04:09

So the government said stay indoors. Okay, you stay indoors, but if you want to keep track of your CO2 as well, you're going to bring air from the outside as well. So what do you do there? Are you going to bring the outdoor air inside, or are you going to keep the levels of the CO2 rising indoors? So what's the right solution there? Right? Maybe this is not the right message to say to people, but in my perspective, it will be like avoid doing exercise indoors and outdoors, because you never know how ozone is going to infiltrate inside the building and avoid any, you know activity that is going to force you to breathe deeper and inhale this ozone and, you know, deplete some of the cells inside your lungs.

Simon: 1:05:02

Yeah and I you know that. Some of the cells inside your lungs? Yeah and I you know that. That's the challenge of balancing risk and it's something that I think the academic arenas, particularly as they become much more closely aligned with public health and health which they seem to be doing much more now than they were before we'll start to understand where those balance of risks lie. You know, on balance, the advice you receive as to whether to exercise outdoors or not will be based on the health benefits and mental well-being benefits of exercising versus the potential long-term chronic harm of being exposed to a range of pollutants, from NOx to ozones, to particulate matter and so on.

Simon: 1:05:48

It's going to be very difficult for an individual to make those kind of decisions, but as we get more advanced models and we understand those balance of probabilities, we can automate those, those pieces of advice, much better. And, particularly if you're in a controlled environment like indoors, demand-controlled ventilation will start to factor a lot more than it does currently in making the right decisions for a building. You know, am I more at risk being exposed to 1,500, 2,000 parts per million in a meeting room right now because, because the ventilation system is shut down, outdoor air, because pollution outdoors is so high. You know where does that risk sit. You cannot rely on the technology.

Sotirios: 1:06:31

someone with knowledge needs always to give an input on what's going on. And you know every building I mean I know you know that for sure Like every building is different. It's like unique, with different characteristics and different HVAC system, so you cannot have like a universal formula for all of them.

Simon: 1:06:51

No, I agree, and it's one of the powerful things that Ireland did, actually in the last couple of years, was introduce this code of practice for indoor air quality in the workplace. What's quite powerful about it, even though it's a very simple document, is it in theory, forces employers to think about their building from a risk perspective? Uh, through the air quality and ventilation. How you said earlier that you know you've rarely been into a conference or a hotel in North America that isn't displaying air quality in some way, is that something you're really seeing in the States? Is that public display of air quality in at least the kind of hotels and spaces that you're going to in conferences, because we don't necessarily see that yet in Europe, not to that extent, not so much from hotels but from spaces that they are designed specifically for accommodation of conferences.

Sotirios: 1:07:54

They do have in place air quality monitors and a display at the entrance where the people that they visit they can see the different stats for the pollutants and you also see the logos from well buildings or reset or any other green building certificate.

Simon: 1:08:17

Yeah, that's encouraging. How long have you been over there now in the States? Two years actually how long Two years, two years. Okay, so post-COVID predominantly.

Sotirios: 1:08:30

Yes, 2022. I came here.

Simon: 1:08:33

And where were you before that? Where were you working out of? Before? That was Spain, wasn't it?

Sotirios: 1:08:37

I was in Spain. Yes, south Spain.

Simon: 1:08:41

How did you find moving over there and working? It's a big country to be. They found me. Yeah, have you enjoyed your time over there? Has it been interesting?

Sotirios: 1:08:56

I mean, yeah, you know we are different from Americans. I think Europeans and people from the UK say a little bit more than common, you know ground than the American people. So, yeah, at the beginning it was like difficult because you have to adjust yourself in different ways that they perceive life here. Like, for example, I still to this day I don't drive, I walk to my office. And for Americans this is alarming. They cannot understand it At first. They cannot understand it.

Sotirios: 1:09:37

So a funny story here imagine I go to the gym here as well. So some of my friends that I eventually made at the gym, they will see me walking to work every day. So they assumed that I was poor and I walked to work because I didn't have money. So they didn't know where I work or nothing like that. So they came to me and they offered me a work at their business that they had like, and to me that was very funny. Like I'm working because I choose to work.

Sotirios: 1:10:10

My office is like seven minutes from my home, uh, so I can walk. I don't need a vehicle to go there. Yeah, but at the same time I will see colleagues at my office, for example, that they live in. The same time. I will see colleagues at my office, for example, that they live in the same household and they work in the same office and they will come with two separate vehicles at the office. Yeah, but don't spend uh, you know gas and don't create so much pollution just because you have the commodity here. Just because gas is cheaper in the us than it is in europe and uk, I assume, I will assume right. Um, so yes, there are some differences, for sure whereabouts are you in the states?

Simon: 1:11:00

where are you working? I am in. Massachusetts, outside of Boston oh okay, yeah, so a city really designed for cars as well. So that's the challenge, isn't it often is that a lot of the cities in the States are really car cities and it's very difficult to whereas a lot of Mediterranean and European cities are really not car cities.

Simon: 1:11:21

So everything's set up very hyper localized, you know. So there's that, just that mentality of walking to the supermarket and walking to the gym, and you know walking to public transport is just the way it is. What's what's next for your blog and your kind of communication around air quality. You know your output is incredible and incredibly consistent. I have to say you've been doing this solidly now for two or three years at a really high level. Is that something you continue planning to do, because it's a very well-read blog post, I think, in the community.

Sotirios: 1:12:02

Thank you. Yes, I really enjoy uh writing. You know pieces uh and articles on my blog. Sometimes it comes naturally to me to write something that I have observed and I want other people to learn about, and course, I'm going to continue with that, hopefully for many years. There are some new exciting things coming this summer. I cannot reveal much now, but I'm working on a personal level on some great news for everyone out there related to air quality, always specifically indoor air quality. Uh, that hopefully, uh, many people will appreciate and help me as well. Um, building it, oh, that's exciting.

Simon: 1:12:53

As far as I can go, well, I'll share the link on the uh podcast notes so people can keep keep in contact with you, because that sounds intriguing.

Sotirios: 1:13:02

Um, oh, very cool yeah yes, you know, it's for me like, um, lots of people are following my blog right now and it's very I'm getting. I'm getting such an euphoria when I see other experts in the industry following my blog. Like you will see people from the US EPA or the EPA from Ireland or the European Environmental Agency following the blog, which means that they're going to receive an email from me every week about a specific topic that I'm going to discuss or write about, and that gives me lots of energy and power to continue writing and that gives me lots of energy and power to continue writing.

Simon: 1:13:42

Yeah, particularly when you get such positive feedback and it's worth checking People. Do go and check out Sartorius' blog because it's very wide-ranging. One week you'll be looking at a new monitor that's come out and pulling it apart and getting your screwdriver out, and other times you'll be talking about an EPA policy that's just been released and some thoughts on that. So it's very varied and sometimes deep dives. Other times it's quite a lighthearted look at something, so I'll encourage people to check it out. What do you think the next five years of this sector looks like from from what you've seen so far and where it's going generally? Um, because it is. It does seem to me to be at a bit of a crossroads at the moment, and I'm everybody I speak to has a different thought about where the traction is going to come from. Next, what's your thoughts?

Sotirios: 1:14:47

you know, I have more insight in the technology, so I see companies moving towards new technology like measuring ultrafine particles, which is very important, especially nowadays, when still the automotive industry tries to pollute the environment with different ways by breaking the particles in a smaller size range in order to pass undetectable with the conventional sensor technology that we have currently. So, yes, ultra-fine particle measurement is very important. I see that trending, especially in conferences for aerosols Scientists and researchers. They really want to explore those nanoparticles, but we still don't have lots of information about the effects on human health. We know that they travel deeper and they distribute all over the body. Deeper and they distribute all over the body, but I haven't read many papers on. You know the actual consequences on our health, so we will see that developing as well.

Sotirios: 1:15:50

Then I see that europe is moving away from pm 2.5 values as well. I think they're going to invest more efforts into the particle size distribution, which eventually is going to come in the US as well, but EPA here is a bit more of a stubborn when it comes to that space. I think they may change. Who knows? I have zero influence on them apart from my blog, but yes, and then for indoor spaces. They they're still trying to release some um standards for indoor spaces in europe. I think they're not ready yet. It's gonna take one or two years more, I think yeah, do you think the changes will come with?

Sotirios: 1:17:04

Yeah, Do you think the changes will come with the pressure to the political system and eventually you know, the police makers to create some legislations and frameworks around indoor air quality?

Simon: 1:17:14

Yeah, and in the meantime, because that's quite a slow process, both academically, getting those strong answers, but also then politically, depending on where in the cycle it is change happening. Um, do you think in the meantime we're building up the business case and the public health case effectively enough, or do you think we could be pushing awareness more strongly in certain areas than we are?

Sotirios: 1:17:46

you know, it's not like one person has the definitive answer to this problem. Um, I think it's a collaborative uh work and effort into getting there. Like business wise, I wouldn't suggest someone right now like building a new air quality monitor with the same technology that it's available. Then, if we talk about businesses that they want to create another green building certificate that we saw like an explosion of them as well during covid right, I wouldn't suggest someone doing that either. But I do think that, like, industrial hygienists are gonna have a blast of of work in the future like this kind of works that they have specific knowledge.

Sotirios: 1:18:46

Here in the us are the things are a bit different than europe. We have more businesses around remediation as well, especially because of the way buildings are built, like in comparison with spain, let's say, or g Greece, that the building materials are different, so they're going to influence as well the outcome of air quality as well. Currently, I'm also inside the steering committee with the University of Bath for alternative sustainable material for buildings. They are analyzing different materials and how good they are for indoor air quality and how fast they will degrade over time. So I'm helping with that as well. Yes, so many sectors. They are working towards that direction. Eventually, everything is going to come together, but it's not only one thing. Yeah, right, so, and they all, all of them, have to align and come, uh, in acceptance and, uh, you know, work together, yeah, in order to achieve what we are trying to educate here and it's hard to see the momentum from inside.

Simon: 1:20:01

Sometimes I think it can seem to move very slowly when you're involved daily in it. But you know, I keep reminding people. We only have to look back to 2018, 2019, pre-pandemic, and where we were really both from an awareness perspective, from a technology perspective, from a standards perspective, things move on pretty significantly in five-year chunks and we are moving relatively quickly, I'd say. The built environment's a conservative old place. It tends to move quite slowly and air quality, comparatively I think, has moved pretty fast in the last five years, assisted, of course, by a global pandemic. So we wouldn't wish that on people again, um, but nonetheless, I think it has moved on and I, you know, I'm firmly of the belief that within, certainly within the decade and I've probably been saying this for nearly a decade, so I'm gonna have to check myself at some point but I think within the decade, most of the spaces we occupy will be monitored to some degree and will give a granularity of performance of that space, even if it's not very specific on certain pollutants, we'll have a much better idea how spaces are performing than we would have done 10 years previously, and that changes the narrative. Rather, I think you start to be judged on the ongoing performance of the spaces you occupy or design or manage, rather than on whether you complied with a certain regulation when it was built, and that that's an important shift in perspective, and I'll be interested to see how that translate.

Simon: 1:21:46

And for communicators like yourself, what I think is really interesting is that I I think we're moving into that period of time where we're having to say okay, what next? I think it's becoming easier to collect the data. We're now having to start starting to have to do something with it, and that's a very different ask. Well, look, I. I wish you every success. We'll keep a very close eye on you as into the summer, as we figure out what you're up to um, what's coming um, because that's very intriguing to see, and I wish you all the best.

Sotirios: 1:22:26

Hopefully you can be part of this process. Of what I was talking earlier, I cannot say much, but hopefully you can be part as well. Yeah, it's an open platform.

Simon: 1:22:40

Right Muting mics Right we're back, I know, all about it now. Thanks very much. Yeah, no, really excited for that. Look forward to catching up with you in a few months' time. Listen, thanks a million. I really appreciate you coming on to talk to me. It's been long overdue, mostly on me for not finding a time to sit down and chat with you.

Sotirios: 1:23:01

But look, look, thanks again for chatting and we'll catch up again soon thank you so much, simon, and you know I've been listening your podcast every morning when I walk uh to my office back and forth, um, so I really appreciate the time you took to interview me and other fellow air quality experts, because I really believe that it helps others understand better what's going on out there right now.

Simon: 1:23:28

Brilliant Listen. Pleasure to talk to you. As always, we'll chat soon. Thanks, civilian. Thanks for listening. Before you go, can I ask a favour? If you enjoyed the podcast and you know someone else who might be interested, do spread the word and let's keep building this community. This podcast is brought to you in partnership with 21 degrees, eco, ultra protect and imbiot all great companies who share the vision of the podcast and aren't here by accident. Your support of them helps their support of the podcast. Do check them out in the links and at airqualitymattersnet. See you next time.