In this interview with Dr. Cora Young from York University, she and Paolo discuss her work in environmental chemistry to quantitate and do forensic tracing of persistent and problematic pollutants. This touches on the laboratory, modelling and field-based aspects of her work, which includes locations from the Arctic to the home kitchen.
If you thought a career in science means spending your best years in a dark laboratory for long, boring hours doing routine experiments, think again! Dr. Cora Young, from York University in Toronto, does a significant part of her environmental chemistry work in the field. From measuring air quality in residential and business spaces, to going high altitude on airplanes, or doing measurements in forests and even in the Arctic.
In this episode, we discuss research in the growing field of environmental chemistry, how it differs from traditional analytical chemistry, and what it means bringing high precision analysis out of controlled laboratory environments. Dr. Young sheds light on how analyzing air quality can have a profound impact on international regulations and quality of life. From understanding emissions of worrisome pollutants such as polyfluoroalkyl substances (PFAS), to how cooking at home can affect our health, this is a fascinating discovery of the chemistry of air.
Dr. Cora Young 0:06
And the indoor environment as we're learning now, and when we're all trapped indoors is really important even in regular times, we spend more than 90% of our time indoors. And so from a health perspective, indoor air quality is extremely important, but poorly characterized
Paolo 0:28
That's Dr. Cora Young associate professor and Guy Warrick Rogers chair in chemistry at York University in Toronto. Our understanding of indoor air quality is improving every day. That work along with her developing and applying new analytical techniques to study climate change and pollution is what secured her place on the Chemical and Engineering News' 2019 Talented 12, a list of brilliant young scientist taking on some of the world's toughest problems with clever chemistry. In episode three of this Science with a Twist series, Bringing Chemistry to Life, we speak with another member of the Talented 12 about their work and trends in the field. I'm your host, Paolo Braiuca, Senior Manager of global market development at Thermo Fisher Scientific, we begin by asking Dr. Young about how she came to be an environmental chemist.
Dr. Cora Young 1:19
Environmental chemistry is really an emerging discipline in chemistry. And when I was younger, I didn't know it existed. I was always really interested in the environment. And when I started my university career, I was planning to go into environmental science, or something like that. And I was taking my first year of chemistry at the University of Toronto, and I just loved it. And at that time, they were actually hiring a bunch of environmental chemists into that department and they were advertising it heavily. And that's when I actually learned that environmental chemistry was the thing. And so I was able then to combine my love of environmental science and my love of chemistry into the career that I have.
Paolo 1:58
That's interesting. And I guess great timing right for our sort of new discipline, and being being there at the right time will always help. So congratulations for that. If I look at your research group's website, I was fascinated by your photo gallery there. It's quite amazing. It's very different from the typical one you find in these types of websites. Typically, you see boring images or fume cupboards, scientist in lab coats in there, I can see beautiful landscapes forest, it all seems exciting, adventurous.
Dr. Cora Young 2:36
Yeah, I mean, we do get to visit lots of interesting places. In order to get the samples that we need, we often go and get them. We take our instruments where the pollution is, and and we do those measurements. So it can be going to the Arctic, we work with ice cores that have been drilled from ice caps in the High Arctic and the Antarctic as well. I don't get to drill those myself. Although I have been to the Arctic. It's it's not as glamorous, as it always looks in the photos. But it is it is it is fun.
Paolo 3:06
I guess you need to live with some quite incredible people who go there regularly. I guess
Dr. Cora Young 3:12
it is very expensive to travel there, of course. So we now send people who are much more qualified than I am to actually collect the samples, drilling and ice cores is it's very technical work. I don't get to do that.
Paolo 3:24
So the way the way works, is that some specialist drill and get the samples and then they get delivered to your lab where you do all the analytical work. Is that is that correct?
Dr. Cora Young 3:33
Exactly. With ice cores that's that's how we work. This is one of the reasons that environmental chemistry is actually quite a collaborative discipline. Because in order to get these really interesting samples, we want to work with the experts. If I went myself and tried to drill an ice core, I would probably bungle it. So we like to work with the experts to make sure we get high integrity samples that we need
Paolo 3:55
any of those other interesting place you have gone to do your fieldwork.
Dr. Cora Young 3:59
Well atmospheric chemists, we often end up in very polluted locations. So we take our instruments to measure places where there's a lot of pollution or some kind of interesting pollution. So I've spent time in some really, really polluted areas. So it's it's it's interesting to talk to the people who live there. Right? So that's their everyday.
Paolo 4:20
Yeah, and it must be fascinating to think that you can understand what's going on there and potentially suggest solutions for some truly the biggest problems we have on our planet.
Dr. Cora Young 4:34
That's one of the things that motivates me is is is helping to improve people's lives if we can through understanding the chemistry that's happening and and hopefully, improving regulation or allowing companies to change their practices to make things better.
Paolo 4:49
Let's jump into the science a little bit and let's try and understand a bit better how actually what environmental chemistry really is and how research is done in that field. I was looking at your presentation for the Talented 12 awards, and I liked your way of describing as a stool with three legs. Can you can you tell us more about that?
Dr. Cora Young 5:13
Yeah, so environmental chemistry, we can think about as this three legged stool, we need to combine really the three legs, which are laboratory experiments, field measurements, and modeling. And this allows us to, to really understand the complexity of environmental systems, each on its own isn't enough. And we really need to combine them all so that we can really understand what's happening in a complex environmental system. And environmental chemistry is sometimes thought about or marketed as environmental forensics, we identify the problem, and then we try to throw all of our tools at it to try and understand the chemistry that underlies that problem.
Paolo 5:53
So you mean that when you do your lab experiments, you try and test the analytical methods or try and see the chemical aspect of it, and then you go out in a less controlled environment and try to see what's really going on.
Dr. Cora Young 6:05
So yes, we we test our analytical capabilities in the lab. But we also need to do things like measure rate coefficients, and test the reactions. You know, in my lab, we have something called a flow tube, which is where we basically try to mimic environmental or atmospheric reactions in the lab. So then we can control all the reagents, we get rid of a lot of the complexity, and then we can if we can understand the reactions in a simple environment, then we can see if this actually represents the real environment.
Paolo 6:34
How do you take into account the environmental variability, when you then take your knowledge developed in vitro, let's say out in the field,
Dr. Cora Young 6:44
it is challenging. This is one of the reasons that when we go to make measurements in the field, we try to get a really good sample size. For example, if we're trying to study air quality, every single day is different because meteorology changes day to day, right? So what we really like to do is measure for long enough that we get days that are similar, so that we can actually have the statistics that we need. So we want to try and decouple meteorology from chemistry. And that can be really a challenge.
Paolo 7:13
And when you then collect all this data, and you you think you have statistical significance in in your data set, and you go to the modeling, what's your objective there? Is it trying to forecast or predict what can go on? Or how, you know, changing some variable can affect the overall effect.
Dr. Cora Young 7:31
So what we do with the models is really try to bring together our lab and field measurements. So you know, we measure all these rate coefficients in the lab. And if we put them into our model, then can we actually replicate the measurements we made in the field? So do we actually understand the chemistry from our lab measurements, such that we can explain what we observe in the real environment.
Paolo 7:55
So having access to real data, measured in the environment allows you to validate your model, so you can actually immediately understand if what you have in hand is is valid?
Dr. Cora Young 8:06
Yeah, the model really allows us to demonstrate that we understand the chemistry.
Paolo 8:11
And understand, let's go into one specific example. And I think starting from your work on the polyfluoroalkyl substances, how you called them the PFAS?
Dr. Cora Young 8:22
Yeah, PFAS is the is the new term that we use. Yeah.
Paolo 8:26
Okay, that I was eating that that work. And that was, well, one new consideration for the Talented 12 last year, if I'm not wrong, he was quite alarming to read that if I'm honest, at least my eyes of non experts. Can we start from defining what these PFAS are?
Dr. Cora Young 8:44
So PFAS are poly and perfluoroalkyl substances. They're commercial substances. So these are all used in different products. They don't exist naturally. They're made by us for different applications. And basically, we take our chemicals and replace all of the hydrogens with fluorines or most of them and once we poly or perfluorinated a molecule, we end up with the unique properties that are conferred by fluorine. So the carbon fluorine bond is is unusual and it makes PFAS molecules, both hydrophobic and lippo phobic and these unique properties are what are exploited in several commercial applications, for example, stain repellents.
Paolo 9:24
So they are very common everywhere, right? We have them as coatings on our pans and pots and as you say, flame retardants, etc. So why are they dangerous?
Dr. Cora Young 9:36
Yeah, so dangerous isn't necessarily the word I would want to use. Problematic I would say, All of these chemicals that are present at low levels in the environment everywhere have the potential to be harmful, although it's very difficult to constrain because anything that we're subjected to at low levels for a really long time, it's difficult to tease out what effect that might have. What we do now about PFAS is that it's Extremely persistent. We have these carbon fluorine bonds that of course, are very, very strong. Many PFAS chemicals will not degrade under environmental conditions. And because they're so persistent, that means they're essentially accumulating in the environment as we use them. The other thing about PFAS is that they accumulate in living things. Many of them are bio accumulating and bio magnifying in the environment. So this means that there's additional potential for problems.
Paolo 10:28
So if I think about the typical commercial applications of these substances, they seem to be solid materials. While if I understand correctly, you've been focusing on the volatiles ones that are present in the atmosphere. So what are these coming from?
Dr. Cora Young 10:45
And this is kind of where the forensics comes in. So the real mystery that that brought me into studying PFAS was that these chemicals were present in the Arctic. And that doesn't really make sense based on what we knew about their physical properties and their applications. So we had to try and figure that out using using chemistry. And it turns out that some PFAS chemicals are volatile. So of carbon fluorine bond mean makes chemicals more volatile than their hydrogen analogues. And so even quite large molecules can be volatile. And these chemicals can actually oxidize in the atmosphere. And then they form extremely persistent, water soluble ish, these end up everywhere, that's a lot of what I've been looking at is, is the chemistry that happens in the atmosphere, how these volatile chemicals can convert into really persistent chemicals.
Paolo 11:36
It's interesting. So are these coming as the composition products or soup products of the commercial applications? Or are they coming from the commercial products production, for instance, as byproducts or as just normal pollutants in industrial process?
Dr. Cora Young 11:54
There are certain PFAS chemicals that are volatile and used in that in that way. So an example is, you know, CFC replacement chemicals. Okay? Yeah, so those are coolants. They're inherently volatile. That's the commercial product. But when we think about that sort of non stick industry, a lot of these volatile chemicals are actually incorporated into polymers in the commercial products, that volatile chemicals are released during the production, they can also be released from the commercial products that could be present as residuals in the commercial polymers. And also those polymers could break down.
Paolo 12:31
It's very interesting and quite alarming again. So what were the learnings of the study?
Dr. Cora Young 12:37
So what we have found through several studies in the Arctic is that these volatile chemicals do contribute to the global dissemination of PFAS. So that's something we want to eliminate, of course, and and there have been some regulations that have worked to eliminate that.
Paolo 12:53
Well, those can be understood, or you need to still understand all this.
Dr. Cora Young 12:58
One thing that we have to think about an environmental chemistry that isn't something that traditional chemistry disciplines necessarily have to think about is who's making this these chemicals? And where are they coming from? When chemicals are produced in North America and Europe, we tend to have reasonable information about emissions and production volumes and things like that. There are other parts of the world where that data is not as well kept, there are chemicals that are being released that we don't, we don't know about. So a lot of what we are doing now actually seems to be trying to track down where these chemicals are coming from, we don't necessarily think they are coming from where they used to be coming from. So it's a forensic exploration. Yeah.
Paolo 13:39
It's interesting. So what you're saying is that society needs to understand this problem, and implement some regulations and policies. Because whenever these compounds are handled, or producing a certain part of the world, that is not just a problem of that part of the world. But you have actually demonstrated that this compound somehow migrates all over the planet. And you can even find them in the Arctic, which is, which is very alarming. So something has to be done.
Dr. Cora Young 14:08
Yeah, I mean, atmospheric pollution has no borders. Once things are in the atmosphere, they can become globally disseminated very quickly. And so we need to work on this as a global problem. And we can't just work on it regionally, that won't solve it. That's something that I feel very strongly about,
Paolo 14:23
of course, and are there I assume there are several other chemical classes with potentially the same sorts of behavior and global impact. Is there anything specifically you're looking at or you think to explore in the future?
Dr. Cora Young 14:38
So there are other chemicals that do disseminate globally. PFAS is is, in my view, as a chemist a little bit more interesting because there are a lot of chemical transformations involved and the unique aspects of the carbon fluorine bond really lead to that. So we are exploring some of the more subtle impacts of PFAS specifically because that's where my major interest lies and trying to understand now that we know, these volatile chemicals are source can we understand a little bit better how PFAS actually moves around in the atmosphere so we can predict it better. I am involved with some work looking at some other chemicals in Arctic ice cores. Again, this has to be a big collaborative endeavor. When we collect ice cores, we'd like to try and collect several and look at anything we can think of to make sure that we, it's non trivial to go up and get them. So we want to, we want to use them for as many things as we can.
Paolo 15:29
I'd like to move to something that to me, sounded slightly less dramatic than the global problem with it with the PFAS was really intrigued by your work on the indoor environmental oxidants. There was a very interesting study, if I understand correctly, you studied the interdependency of three main compounds, right, ozone, nitric oxide and nitric dioxide. And how their relative ratios vary depending on what happens, whether, you know, depending on the environment, whether our windows or a door is open with us humans activities in the environment, etc. Can you describe us that work and and why that was novel?
Dr. Cora Young 16:12
Yeah, so it seems like these are things we would understand very well. But it turns out that most of our understanding of air quality is really the outdoor environment. And the indoor environment, as we're learning now. And when we're all trapped indoors, is really important. Even in regular times, we spend more than 90% of our time indoors. And so from a health perspective, indoor air quality is extremely important. But poorly characterized. Yeah, some of my work in the past few years has been trying to understand that a little bit better. So oxidation, chemistry, indoors is totally different from oxidation, chemistry outdoors. And the real driver for that is that there's not very much light indoors. So oxidation, chemistry outdoors driven by light and indoors, we don't have that. So the chemistry is really different. And to me, very, very interesting. So the study we're talking about with opening the windows and various things was really to try and understand how ozone behaves indoors where it's coming from, what happens when we turn on a gas stove. So a gas stove is a really big source of indoor pollution. And that can really change the dynamics of the of the pollutants indoors.
Paolo 17:21
So what were the learning, I confess that I was a bit puzzled because if I cook, I generate nitrogen monoxide. And then you know, I'm tempted to open the window, then ozone comes in, and you know, the nitrogen oxide is going to titrate my ozone or ozone is going to be titrated by the nitrogen oxide, I'm gonna generate a nitrogen dioxide. But they all look equally bad to me. So I'm not quite sure if I have to open the window or not.
Dr. Cora Young 17:51
Yeah, so this is this is a good question. I would say that what you want to do when you're cooking with a gas stove is vent it. Having a rangehood is extremely important, is what you really want to do is vent that outdoors without bringing in all of the outdoor pollution by opening your window. In particular, if you have a gas stove, you want to make sure you have a really good range hood above your stove.
Paolo 18:15
isn't any other study around air quality, particularly indoor what can affect everyday life. That is you know, you're looking at this relevant you want to share.
Dr. Cora Young 18:25
Yeah, so there's a lot of research being done right now. Really, this this field has exploded over the past few years, and we're understanding a lot more. The two main things that can affect your air quality indoors, are cooking and cleaning. When we clean with any kind of cleaner using a bleach cleaner, obviously, we can smell the impacts of that. Or even a non bleach disinfectant. Those are normally based with hydrogen peroxide. When we use these cleaners, we end up releasing things like hydrogen peroxide, chlorine gas, hypochlorous acid into our into our environment. And as chemists, we recognize those the names of those chemicals and that's not really stuff we want to breathe in. These are things we're learning the impacts of now. And air exchange, we've we've been hearing a lot about that with respect to the Coronavirus. It's also really important for chemistry. If I clean with bleach in my house and I release a whole bunch of Cl2 and HOCl the impacts of that are really going to be determined by my air exchange rate.
Paolo 19:25
It's interesting because I'm a chemist myself, but I never actually thought about it and you can, as you say you can really smell the effect of the cleaning agents you're using. If I draw a sort of conclusion and trying to be funny, I need to clean less and get more ozone in. Am I right?
Dr. Cora Young 19:43
Yeah, less cleaning is definitely one way to yeah to change your your indoor air quality for sure.
Paolo 19:53
Okay, so you're not only trying to measure and understand the environment around us. And the gases that are the main components. But you're also studying how to try and remedy as the environment from the pollutants. And I'm sure there are many studies and in a lot of lines of research that you're getting on, I just read one where you were removing the nitrous acid if I'm not work if I'm not wrong with with a metal frameworks, that's an interesting approach, because on one hand, you have understanding what's going on, on the other hand, is, what can we do about it? Right, and it's certainly the policies and preventing the pollutants to be generated. But it's also potentially removing them. Well, anyway, can you tell us a bit more about the remediation work and, and how the different aspects of this problem can come together?
Dr. Cora Young 20:48
Yeah, so this, this is a collaboration that I'm working on with material scientist, Michael Katz, who's at Memorial University, and we're really trying to combine my knowledge of the chemistry that happens outdoors with his knowledge of how we can use materials. So a lot of remediation chemistry has really been looking at specific products that we see in high concentrations in the environment, the approach that we've been taking, is there certain chemicals that are really almost catalytic, in how they affect air quality. And so nitrous acid or HONO, is one of those chemicals. And so, by targeting something like HONO that's actually present at fairly low levels, in most locations, but is catalytic. If we can remove that then it actually could have an impact on air quality. And it turns out that HONO is one of those things that becomes really important indoors. In terms of remediation for outdoor work. I mean, that doesn't, it wouldn't really make sense. remediating outdoors is just too great of a challenge. But remediating indoor air quality is something that we think could be feasible. So making sure the filters we have when we're exchanging air actually remove pollutants that could be harmful is something that would be achievable.
Paolo 22:05
So do you foresee some significant progresses in material science that could really help with the air quality in our houses?
Dr. Cora Young 22:13
Yeah, I think there's a lot of really great work being done right now. And I think, certainly with the increased interest right now in in air quality indoors, we're going to see some real progress being made on improving the quality of the air that we breathe inside
Paolo 22:28
is fascinating. And I have to confess that I really feel like I don't know enough about the analytical chemistry, chemistry that goes behind the scene. But how do you really detect these components? Because I'm assuming you are measuring extremely low concentrations, right? So our audience can be fairly technical. Can you tell us a bit more about the analytical methods you use typically for these studies.
Dr. Cora Young 22:54
So when we look at chemistry in the environment, we have really complex matrices, we need to have techniques that are selective and have good detection limits, we have two approaches. When we are when we're looking at these problems, we either collect samples and bring them back to the lab, or we make an in situ measurement. So we take our instrument out, and we make a measurement in the real environment. When we're bringing samples back to the lab, we use a lot of traditional techniques. So we're using extraction, you know, liquid chromatography with tandem mass spectrometry, that type of thing. When we go out into the field, when we're doing in situ measurements, then we use a variety of different techniques. So in order to reach to achieve the selectivity and detection limits that we need, it really varies from chemical to chemical, we use spectroscopy. So in my lab, we have some cavity ring down spectroscopy, we also use mass spec. So we have ambient pressure and ionization mass spectrometers that we take out into the field. Those are the main techniques that we use. And of course, they also have to be robust, because we're going to take them places. And that can be an additional challenge is, you know, your fancy mass spec that you have in your lab might be really sensitive and selective. But if you can't take it anywhere, then it's not going to be as useful as you might like.
Paolo 24:09
It sounds incredibly complicated, because all the analytical chemists, I know, they fight to keep the environment they're working as controlled as they can. And they and you know, and they are very picky in getting all their analytical reagents with extremely low level of impurities. Why you seem to be taking your mass spec outside enough for summer. Yeah, it's mind blowing.
Dr. Cora Young 24:34
Yeah, so we really have to push on selectivity. And that's, that's the big, that's the big one that we really use in our communities. So, for example, the mass specs that we use, we use chemical ionization typically where we have very selective ionization and that really helps us to get rid of those matrix effects that otherwise could be extremely problematic.
Paolo 24:53
Yeah, indeed. So if your noise is going to call it your the signal you want to measure then obviously nothing. Nothing can be done. Do you use commercial equipment for that? Or do you somehow build your own stuff?
Dr. Cora Young 25:06
Yeah, so we use a mix of both. Yeah, my lab is kind of a mix between a wet chemistry lab and a workshop, we do build our own our own stuff, or we modify commercial instruments. One thing that we really exploit in atmospheric chemistry is, for example, how easy it is to measure certain chemicals. But one example of that is NOx. So we can really easily measure NO2. So if we want to try and understand concentrations of different nitrogen containing species, one thing we can do is try and convert it into NO2, and then measure it, you know, often we make will buy a commercial NO2 analyzer, and then we'll put some kind of fancy converter on the front, so that we can convert whatever chemical we're interested in, into NO2 and then measure it easily. We sometimes have our hybrid sort of macgyvered instruments that we bring.
Paolo 25:57
I said at the beginning Cora, you know, it all sounds exciting and adventurous. And it's beautiful, to see how, you know, you need to make a strengths from your necessity, right? And, and some somehow we improvise, while keeping an exceptionally high level of scientific relevance, because you still need to measure things in a part per billion. And I suppose, even smaller than that, right? Which is incredible. And let me ask you these, this is certainly new and unusual, right? Is the chemical market position properly to support these kind of work? So do you find easily what you need from chemical suppliers to be able to do efficiently what you're trying to do?
Dr. Cora Young 26:41
Hmm, often, yeah, we'retrying to buy things that are a bit unusual, I'd say it's a mix. So sometimes we are able to find the things that we're looking for. And sometimes, we really have to modify, because even the intended application for a chemical isn't really how we use it. And so we have to be quite creative. Sometimes getting standards can be quite challenging. One thing that that we've been working on recently is hypochlorous acid. So HOCl. It's, as far as I can tell, pretty much impossible to get a pure, gaseous standard of HOCl. And that would be really useful for us to calibrate some other instrumentation. So, you know, it can be challenging.
Paolo 27:23
Yeah, I hear you. Do you believe that suppliers of chemicals, analytical chemicals, standards and other materials, could make an effort to try and engage in a conversation with people doing innovative research of the kind you're doing and trying to reposition the chemical market to enable you to get your results more easily?
Dr. Cora Young 27:47
I mean, we're a bit of a niche market. And we recognize that so I do speak with my, you know, chemical reps and and sometimes we do custom synthesis, they do work hard for us to try and fit whatever products they have into a, it's so that they will work for our applications. It's a challenge. And when we could we could do better if we talk to each other more. Yeah.
Paolo 28:09
Well, at least I'm glad to hear that there is the willingness to support and you know, and there is a communication channel there. So you know, as part of the chemical market community, I mean, that's really why I like to hear. Anyways, as we get to the end of our chat, there's a question I always like to ask, is, you know, you're a young scientist already very accomplished, you know, you're working on some exciting things. And you you know, what you do have the potential to change the world. What's the one piece of advice you'd pass on to a young chemist, or general scientist who's just starting with their career?
Dr. Cora Young 28:44
So the thing that I find has been the most important and influential for me in my career has been the people around me, my advice would be to surround yourself with positive supportive mentors and friends, your friends can be your mentors, of course, as well. And for me, in particular, in my field, because we're so collaborative, I mean, having the those people around you to act as a support system and to be your collaborators because they have complementary expertise, that for me, it has been the biggest contribution to the success that I've had.
Paolo 29:23
That was Dr. Cora young associate professor and Guy Warrick Rogers chairing chemistry at York University in Toronto. And one of Chemical and Engineering New's Talented 12 thanks for joining us for this episode of Bringing Chemistry to Life. A Science with a Twist series. We'll bring you more conversations with the Talented 12 every other week. For new episodes, subscribe wherever you get your podcasts, and you can visit labchemresources.com for more information about Thermo Fisher Scientific laboratory chemicals. This episode was produced by Matt Ferris, Gabriel Orama and Emma-Jean Weinstein.
Transcribed by https://otter.ai