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Oby: From the campus of Harvard Medical School, this is Think Research, a podcast devoted to the stories behind clinical research. I'm Oby.

Brendon: And I'm Brendan, and we are your hosts. Think Research is brought to you by Harvard Catalyst, Harvard University's Clinical and Translational Science Center.

Oby: And by NCATS, the National Center for Advancing Translational Sciences.

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Brendon: As we live through the COVID 19 pandemic and the height of the climate change crisis, many are beginning to take a closer look at our exposures to environmental toxins and chemicals in the world that impact health in many ways.

Toxins and harmful chemicals often exist in the buildings we work and live in, the furniture we buy, and the apparel we wear. As part of the Harvard Healthy Buildings Program at the Harvard TH Chan School of Public Health, Dr. Anna Young is conducting research on tracking chemical exposures across different physical environments.

Dr. Young, thank you for joining us and welcome to Think Research.

Anna Young: Thank you so much for having me on your podcast, Brendan.

Brendon: So you're a member of the Harvard Healthy Buildings Program at the Harvard TH Chan School in the Department of Environmental Health. Tell us about this program and why there's a need for research in this field.

Anna Young: Right, so this program, the Healthy Buildings program, is led by Dr. Joseph Allen. I've been a part of the team for about five years now. And what we're trying to study is how we can use buildings as a tool to protect and enhance our health because we spend the vast majority of our time indoors, especially during COVID, so that's where a big portion of our exposures are happening.

And specifically, in my field of chemical exposures, we're trying to conduct research that informs solutions and real world interventions, like healthier materials, to reduce our exposures and enhance health.

Brendon: Excellent, so you started out in computer science, and you now study chemical exposures. What made you want to change fields?

Anna Young: Right, so I started in computer science when I didn't know much about environmental health, and I think, like many people, I assumed that the products we buy on shelves are safe, and that the chemical ingredients in them are tested for safety. But when I worked as a computer scientist at an environmental policy group, I started realizing that that's not true, that there are thousands of chemicals, undisclosed, in products, many of which aren't even tested for safety, and others which we know are harmful to our health and don't need to be added to these products.

And that really concerned me, and I realized that the burden shouldn't be on us consumers to take on this impossible task of figuring out which products aren't toxic. So I wanted to work on research that helps inform solutions, like healthier materials and healthier products, that make this the default option on shelves, not the exception so that consumers can trust that what they're buying is automatically, by nature, safe.

Brendon: So your group, you mentioned, led by Dr. Joseph Allen, you received a Catalyst Pilot Grant through the environmental toxins grant funding round to look at the presence of endocrine disrupting chemicals in office settings and their effects on people.

So tell us a little bit about these chemicals and how they affect people.

Anna Young: Sure, well, first of all, many thanks to the Harvard Catalyst Program for this grant opportunity. We're really excited to get started. So as some background for the motivation for this project, we are exposed to really complex mixtures of hundreds of chemicals in our buildings. They're coming from our furnishings, our building materials, our consumer products.

But what's concerning is that those chemicals continuously travel out of the materials, and they build up in the dust and air in our buildings. And because of that, nearly every single one of us is exposed to these hormone disrupting chemicals, especially because we're breathing and ingesting that dust and air all day long.

And exposure to these chemicals has been linked to effects on fertility, pregnancy success, child development, thyroid function, obesity, and diabetes. So we're really concerned about the hormone disrupting effects of these chemical mixtures.

Brendon: I want to talk about the design of this project, and it's building off of previous work that you've done where you had people, office workers, wearing silicone wristbands to detect the level or presence of certain chemicals. Could you tell us a little bit about the design and why you chose to do that?

Anna Young: Sure, so these silicone wristbands are just like those Livestrong bracelets, but the silicone material can actually absorb chemicals from the air and dust and products we're interacting with while we wear the wristband. So it's a really cool tool to capture our personal exposures to chemicals from the external environment.

They're really simple, and unlike traditional blood or urine samples, they are less expensive. They are not as invasive, and they can actually distinguish and pinpoint exposures just to the external environment. Whereas, blood and urine also capture what you're putting into your body from food and drink, the silicone wristbands help us isolate just one environment.

So in this study that the Catalyst Grant Project is working on, we had office workers wear the silicone wristbands only at work in their office building for one work week. So we were able to specifically pinpoint the office building as an environment through which people are exposed to these chemicals collected on the wristbands.

Brendon: And you looked at differences between countries too, which I thought was really interesting. Talk a little bit about that, some of the differences in exposures.

Anna Young: We found that these office workers in the four different countries, the US, UK, China, and India had really different exposures depending on the country, depending on the building characteristics, and depending on what personal products they were using.

And what was really interesting is that we found that office workers were still exposed to chemicals that had even been banned or phased out decades ago, which just shows the persistence of these chemicals and the persistence of the use of old building materials.

And even when some chemicals are banned or phased out, there are often harmful substitutes to those chemicals, and we found office workers were widely exposed to harmful chemical substitutes.

Brendon: We talked about, when we spoke previously, the actual differences in the types of chemicals. Could you just explain, maybe, the particular differences between the different countries?

Anna Young: Sure, so it was interesting that some regulations in countries meant there were higher exposures and some regulations meant there were lower exposures. So in the US and UK, for example, there were historically more stringent flammability standards that almost necessitated the use of harmful flame retardant chemicals in foam furniture.

And we saw that the office workers in our study, in the US and UK, often had much higher exposures to many of these harmful flame retardants than China or India. Whereas on the other hand, office workers in the study in India were exposed to much higher levels of pesticides, which we think was because of fewer restrictions and also their unique need of pesticides for malaria control, for example.

And so those are just some of the examples showing how different countries can be. And we found that the exposures that differed by country often reflected differences in restrictions.

Brendon: And it just struck me, it's interesting that you talked about pesticides when up till now in the conversation we were talking about things that are in the materials that come as part of the process of building it or making it. But a pesticide is coming in through outside air or is maybe getting tracked in on clothing or shoes, and so it goes beyond just the materials that make up the building. It also expands to just the environment in general.

Anna Young: Right, and we often think of pesticides as something you spray on the lawn or in agriculture, but actually they're sometimes often sprayed in the building for pest control, so that's an indoor source within an office building. We did see that. Some of the buildings, like in India in our study, did spray pesticides indoors.

And sometimes pesticides are even impregnated into materials like textiles or woods. So for the Catalyst Grant Project we're going to bring these chemical mixture exposures one step closer to health by conducting human hormone cell assays of those silicone wristband samples.

So basically how this works is that a lab exposes human cells to the chemical mixtures collected on those wristband samples, and then assesses how much interference there is with hormone receptors. So for example, we can see how much those chemical exposures mimic estrogen or testosterone or thyroid hormone in human cells in the lab.

And what's really unique about this is that usually we talk about the hormone disrupting implications of individual chemicals. We test each chemical on its own in the lab. But this new method we're evaluating reflects the total hormonal bio activities of the entire mixtures of chemicals that people are actually exposed to in the real world.

And those mixtures of hundreds of chemicals include chemicals we don't even know about yet or that we can't even measure in the lab. So it's really reflecting potential hormone disruption of those complex chemical mixtures.

Brendon: Mmm. You said potential hormone disruption. How much is actually known about the ways in which hormones are disrupted by these chemicals? I mean, at the beginning you mentioned that these types of chemicals, and I don't know if we've named any of the chemicals, but I know there's thousands.

And so what-- maybe, if you could give us a little more specifics about what is actually known about this and about these types of endocrine disrupting chemicals.

Anna Young: Right, so there are many studies that have established that these chemicals are harmful to human health. And the way a lot of these studies work is they measure the levels of chemicals in blood or urine in people, and associate that with a certain outcome, like inability to become pregnant.

But what this study is trying to look at is an early marker of the hormone disruption of chemical exposures, specifically in our office buildings. Whereas, those other studies look at cumulative exposure from all routes of how you're exposed to these chemicals.

We're trying to get a little bit closer to the source and inform where and how we intervene on those chemicals. And we know that these chemicals in isolation interfere with those hormone receptors, which can lead to issues with reproductive health.

We measured 100 different types of these chemicals across six different chemical classes. So you may have heard of phthalates, which are plasticizers used in final flooring, cables, food packaging. They're used in cosmetics and all sorts of consumer products.

We also looked at many different types of flame retardant chemicals, which are added to foam furniture, electronics, insulation. We also looked at polychlorinated biphenyls, which are also called PCBs, have been used in building sealants and caulking, and are sometimes in paint.

We also looked at pesticides, which can be applied in buildings or even used in building materials sometimes and can track indoors. That's just a small selection.

Brendon: Which of those are banned? Which of those are banned in the US? PCBs, I would imagine, are, right?

Anna Young: Yeah, so this is really interesting. The PCBs were banned decades ago in the US. But we know that building materials stick around for a long time. I think about half of commercial buildings in the US are at least 50 years old, something like that.

And we saw that these office workers, even in the US, are still exposed to those banned PCBs. And what's also interesting is that there was another type of PCB we found that many of the office workers were exposed to. That's not covered under that ban.

We expect all the PCBs to be banned, but because this is an unintentional byproduct in paint, in buildings, it's not actually covered under the ban. So it's this unexpected use of what we think are banned PCBs.

Brendon: Yeah, and you think about school buildings. If PCBs were banned in schools in the 1970s or something, how many school buildings are older than that? A lot.

Anna Young: Right, the building stock in the US can be quite old, and it takes a lot of money to remediate those PCBs and get them out. So that just shows how important it is to make good decisions now on what chemicals we put in materials, because those chemicals will last a long time. Those building materials will be used for a long time and effect exposures and health of generations to come.

Brendon: As somebody who didn't know anything about this and then started working at an environmental company and learned all about this, was there a moment when you realized, whoa! This is a huge problem I had no idea about, and I really want to do something about it?

Anna Young: I think that was when I found out about this issue of chemical whack-a-mole, we like to call it, where we often phase out or avoid a certain harmful chemical, like BPA. I always looked for BPA free plastic water bottles, for example.

But I soon found out in this program that those chemicals when they're phased out one at a time, they're often replaced with similarly harmful chemicals, often in the same chemical group. For example, BPS, BPF, they're very structurally similar to BPA and used as harmful substitutes.

So it becomes this wild goose chase as we're trying to figure out what's being used next? What are the health implications? And how do we get those chemicals out? Whereas, a more holistic solution would be to remove the entire chemical group because we know the entire chemical group is harmful and similarly concerning.

Brendon: And so can you talk a little bit about the healthy materials movement, or the healthy-- is there a healthy buildings movement? Or is that-- am I just confusing it with the name of the program?

Anna Young: Yeah, I think there's been a lot of effort on the healthier materials movement in the last five or so years, especially, I know Harvard, for example, in the office for sustainability, has worked to update their purchasing standards to only buy healthier materials for certain product categories.

And that's seen as a way to create a signal from the demand side of the market to manufacturers that this is what people want, that you're leveraging all of your purchasing power to push the market to switch to healthier materials.

And so we actually had an opportunity in a recent study of ours to evaluate the effectiveness of healthier materials intervention in real buildings. We studied rooms and buildings where they were renovated with healthier furniture and healthier carpet, that were completely free of all types of flame retardant chemicals and stain repellent chemicals called PFAS.

And we found that the levels of these chemicals in the dust in those rooms with the full healthier materials were more than halved compared to the rooms without those full healthier materials. And that was important because those healthier materials focused on removing the entire groups of harmful chemicals not just one chemical at a time.

Brendon: And didn't the new Science Center, wasn't that built with all healthy materials?

Anna Young: Yes, and that's a perfect example to show that these are actionable, cost effective, real world solutions that actually work. If you can put in all healthier materials in a space like that, where there are offices, cafeterias, classrooms, wet lab spaces, with that many square feet, it just goes to show that these healthier materials work, and you don't have to sacrifice on aesthetics or performance.

Brendon: And so that's something that somebody like Harvard can do with huge purchasing power and money to build new buildings. What can-- I guess, what can people do on an everyday basis? What kinds of things do you do, as somebody who studies this?

Anna Young: Yeah, I think one good tip is to try to avoid the chemical flame retardants in foam furniture, which actually aren't needed. And a way to do that is to look at the tag underneath your couch, for example, and it should have a flammability label that tells you whether or not it has added flame retardants. That's a new label that came out in the last decade.

And so you can look to buy furniture that doesn't have this flame retardants, and you can also search for brands that are trying to remove PFAS stain repellents from furniture, as well.

Brendon: So Dr. Anna Young, from the Healthy Buildings Program at the Harvard TH Chan School of Public Health, thank you very much. It was a pleasure to have this conversation with you.

Anna Young: Thanks, Brendan, for this great discussion.

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Brendon: Thank you for listening. If you've enjoyed this podcast, please rate us on iTunes and help us spread the word about the amazing research taking place across the Harvard community.

Oby: To learn more about the guests on this episode, visit our website catalyst.harvard.edu.thinkresearch.

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