Even though polychlorinated biphenyls (PCBs) were banned nearly 50 years ago, these persistent chemicals are still part of our daily environment. In this episode of Plugged In to Public Health, we talk with Dr. Amanda Bullert, neuroscientist and research consultant at the University of Minnesota, about what PCBs are, how exposure still happens today, and what her team’s research reveals about their effects on the brain.

The views and opinions expressed in this podcast are solely those of the student hosts, guests, and contributors, and do not necessarily reflect the views or opinions of the University of Iowa or the College of Public Health.

Hello everybody and welcome back to Plugged In to Public Health. I’m Lauren Lavin, and if it’s your first time with us, welcome. We’re a student run podcast that explores major issues in public health and how they shape the world, both inside and outside the field. Today we’re talking with Dr.

Amanda Bullard, a neuroscientist who completed her PhD at the University of Iowa and now works at the University of Minnesota as a data manager and research consultant, Amanda’s research has explored how exposure to polychlorinated, biphenyls, or PCBs affect the brain. Even though PCBs were banned nearly 50 years ago, they remain in our environment and continue to impact human health.

In this episode, Amanda helps us unpack what PCBs are, how people are still exposed to ’em today, and what her team’s findings reveal about the way they influence metabolism, inflammation, and long-term brain health. Along the way, we’ll also talk about why environmental pollutants linger for decades, what communities are most affected, and what steps individuals and public health leaders can take to reduce this risk.

Now, let’s get plugged into public health. Plugged into public health is produced and edited by the students of the University of Iowa College of Public Health, and the views and opinions expressed in this podcast are solely those of the student hosts, guests, and contributors. They do not necessarily reflect the views or opinions of the University of Iowa or the College of Public Health.

[00:01:14] Lauren: Well, thank you so much for joining me today. Well, I guess, what do you like to go by?

[00:01:20] Amanda: No one really calls me, doctor, but you can. I just go by Amanda most days, so.

Okay.

[00:01:25] Lauren: Well I’ll go with Amanda, but you do have a PhD, so you could be doctor. Yes. Yeah. Could you introduce yourself, a little bit more, what is your educational background? What are you doing now, that type of thing?

[00:01:37] Amanda: Yeah, so I did get my PhD in neuroscience at the University of Iowa. I believe I defended my thesis.

November of 2023. Maybe. It’s been a few years. Well, I guess almost two. Almost two, yeah. Mm-hmm. And so now I’m currently working at the University of Minnesota. My, my position is data manager research consultants, so I do help neuroscience researchers organize and document their data. So not necessarily in the same realm as the topic of today, but it’s still something that like I am very passionate about and still really enjoy discussing with people.

So,

[00:02:13] Lauren: yeah. Yeah. Well, I appreciate you taking your time out of your day to chat with us, and today we’re gonna be talking about PCBs, which, what, what does that stand for?

[00:02:23] Amanda: Yeah, it stands

Polychlorinated Biphenyls. So yeah, I you to

[00:02:27] Lauren: say that first.

[00:02:28] Amanda: Yeah. Which is very chemical and like very, you know, educational structure, which is organic chemistry.

And no one, no one wants to go back to organic chemistry days if they don’t need to.

[00:02:39] Lauren: Could you start off and kind of give our listeners a quick explanation of what PCBs are and why they were used so widely in the past, like a little history?

[00:02:47] Amanda: Sure. I forgot to say thank you for having me by the way.

So there is that yeah. PCBs are a manmade, persistent chemical, so. I use those words intentionally, manmade. ’cause you know, we’re the masters of our own fate essentially. And they are persistent. So they’ve been around for a very long time and they will be around for a very long time. They were produced primarily because they had a lot of great chemical properties.

They were really resistant to heat. They’re really stable compounds. They don’t dissolve in water. They don’t really react. With other chemicals. And so it made them really versatile for a lot of different products, especially in like the manufacturing and the industry, like industrial kind of purposes.

So a lot of those products look like electrical equipment, resins, glues adhesives paint, paint, paint pigment. Excuse me. So they are still like kind of out there and persistent in the environment with us. So yeah, that’s kind of a little bit about PCBs and why we need them. Yeah. Or why we needed them at the time,

[00:03:50] Lauren: . they were banned in the late 1970s, correct?

[00:03:53] Amanda: Correct. The intentional production of PCBs was banned late 1970s. So,

[00:03:59] Lauren: but they are still a concern today.

So can you help us kind of understand how and where might people still be exposed to ’em, even though they were banned? That’s like 50 years ago.

[00:04:09] Amanda: Yeah. Which is still kind of surprising to a lot of people that we’re, it’s still a concern to us 50 years after a ban. Mm-hmm. But the ban was more about the intentional production of them.

And so there is this piece of, there’s. Inadvertent production of PCBs. So when other products are being manufactured now today, PCBs are kind of a byproduct that sometimes are made, and this happens particularly when they’re developing like paint pigments or dyes. So that is kind of one of the like concerns of like, we’re still adding to our PCBs that are in the environment.

And some estimates actually suggest that the inadvertent. Production of them now is like exceeding what was intentionally produced back prior to the 1970s. So that’s exciting.

[00:04:56] Lauren: So where does inadvertent production end up? Like is this a physical material that is like an off, I don’t know, an offshoot?

[00:05:06] Amanda: So, yeah, PCBs, when they’re inadvertently produced, are still like a physical product. And so a lot of times it’s incorporated into products like when you’re using like silicone caulking for instance. Like a lot of times you’ll find it in some of those products or paint pigments. Yeah. Have a lot of PCBs and so.

People can be exposed a lot of times when they’re painting their house a very bright color. Paint pigments with very basic bright colors tend to have higher concentrations of PCBs than those with like more muted tones, like more neutral grays and stuff like that. Not that you can’t use colors to paint your house but when they’re really bright that tends to be a higher concentration of PCBs.

[00:05:51] Lauren: So interesting. Okay, so you have your PhD in neuroscience, and so the study that I found and we’re kind of chatting around today is it looked at how PCB exposure affects gene expression in the brain. So can you talk us through what that study was and what your team found?

[00:06:11] Amanda: Yeah, so there’s a couple of studies that we did that actually looked at gene expression, so I’m not sure exactly which one you’re talking about, but I’m happy to discuss it on more like general.

We did a lot of like different types of. PCB exposure and for like different time timelines and like whether it was male or female exposure and whether it was like dietary or inhalation if they’re breathing in the PCB. And so with that, we then yeah, took their brain samples and we were testing gene expression.

And from those, a lot of the results or genes that seem to be impacted came from things like metabolism in the brain or hormone regulation. Or inflammation even. So how the brain was responding to kind of this external stressor of PCD PCBs being introduced.

[00:07:01] Lauren: How does one take a brain sample?

[00:07:04] Amanda: You expose the animals for a period of time and then you do kind of euthanize them humanely.

Yeah. We always try to minimize pain and like that kind of stuff as much as possible. And then we collect all sorts of samples, so not just brain tissue, but we also collect a lot of other vital organs like the liver and kidneys, lungs. Things like that. And so with that, then you kind of take a small section of the brain and you mush it all together.

And then you read the gene expression through various methods that you can test it for. So.

[00:07:35] Lauren: You also said PCV through dietary exposure. Yeah. Is that something that would happen in humans?

[00:07:43] Amanda: Yeah, that’s a great clarification ’cause I was gonna mention that earlier when we were talking about why pre PCBs were produced and how people are exposed.

So there are three main ways that humans can be exposed to PCBs. The primary way is actually through our diet. So. When PCBs were mass produced or produced for, you know, MA manufacturing production back prior to the 1970s, the byproducts and PCBs would get into the waste.

And so it would go into the water systems, into the soils, and so it would then bioaccumulate into our food chain essentially. So when we’re eating. Different products that have high fat content like dairy or fish or even meat products. A lot of those have higher concentrations of PCBs. And so we can be exposed through our diet.

We’re also exposed through inhaling PCBs when they’re released into the air of different buildings that might have been built with PCB materials. And then there is a third way, but it’s less less common and like not as readily studied. It’s dermal contact. So if you touch a surface that might’ve been contaminated with PCBs, that’s another way that you could be exposed.

So there’s kind of three ways. But primarily two that are of more concern than, than the dermal contact, for instance.

[00:09:01] Lauren: Do you have a general rule of thumb on how to limit exposure through eating?

[00:09:07] Amanda: Yeah, I mean there was actually a recent study well recent as in like 2020 that actually a group at the University of Iowa tested 26 different food types to see what concentrations of PCBs look like in those.

And so any of the foods that really had a lot of high fat content, like I had mentioned with dairy and meat products. Eggs is another one as well as like butter ’cause it’s got high fat. As well, those ones tended to have higher concentrations and so I kind of live by the rule of like everything in moderation.

So you can certainly reduce how much PCB you’re exposed to through your diet that way if you wanted to. And there are certainly. Areas that have really high concentrations in lakes or water systems. And when you’re fishing, they might have a sign that says, don’t eat these. ’cause they might have a higher concentration based on where they’re located near a manufacturing plant or something of that sort too.

So when there’s, when there’s warning to not eat something, I usually generally follow those.

[00:10:10] Lauren: That seems like a good, good practice.

[00:10:13] Amanda: Yeah. Yeah.

[00:10:14] Lauren: You found changes in genes related to inflammation and metabolism. Yes. What does that mean for how PCBs affect health or brain health more specifically?

[00:10:26] Amanda: Yeah, so metabolism really, it stems from a lot of the genes that we identified being impacted by PCB exposure. Was correlated with mitochondria dysfunction. And a lot of us know that the mitochondria is the powerhouse of the cell, right? And rightfully so. It’s generating a lot of necessary energy for cells to function and grow and mature appropriately.

And so if those genes are being impacted, the cell can certainly be on how it’s developing and how it’s growing or how it’s actually functioning. And that might seem insignificant in, you know, on the grand scheme of things, but cells make up brain regions and brain regions make up brain circuits. And brain circuits are how we function as humans and, you know, store memories and regulate our emotions.

And so those granular things can really have a larger impact when they’re, you know, it’s ongoing exposure and higher levels too. So that would be the metabolism side of things. The inflammatory side of things is the brain responding to this thing that’s not supposed to be there. Right? So PCBs are in the brain and it’s like, what the heck am I supposed to do with this?

It regulates and tries to remove those and it also produces just different inflammatory responses to hopefully minimize the impact that PCBs are having on regular brain function. So,

[00:11:49] Lauren: and were there any areas of the brain that were more affected than others?

[00:11:53] Amanda: Yeah, we did test several different brain regions.

’cause this was something I was interested in early on in my thesis work. ’cause I thought, okay, we’re breathing it in so it’s probably coming in through our nose. So things like towards the front of the brain maybe are more impacted. And so after testing and like. Working on different brain regions. We don’t have a lot of conclusive data to say that one is more impacted than the other.

So we’re still trying to pinpoint if there are more vulnerable regions, but that doesn’t mean that there weren’t differences in what we did see impacted. They were just, you know, pretty low level things that were like, okay, this region in particular had, you know, issues with metabolism and maybe a different region had issues with more inflammatory response.

Related things. So there is still that spec specificity with brain region kind of response to PCB exposure, but that’s not to say that one is more impacted than the other, but.

[00:12:51] Lauren: And you mentioned that these chemicals are persistent, meaning that you probably have prolonged exposure or repeated exposure to them over time.

So does this lead to like health problems with these gene changes, and what would you expect to see as a result?

[00:13:07] Amanda: Yeah, so the persistent piece is really. Really a big part of it because it, I mean, we are exposed to PCBs pretty much our entire life. So if mom is exposed, you know, we are also exposed through, you know being in utero.

So, I mean, some of that is already occurring when we’re not even born yet. As well as like, yeah. So then when, once we’re born, we’re exposed through breathing and eating and things like that. And so it is a long-term, you know, low level. Kind of chronic exposure. And so there are different aspects to that of like there’s the one side of like developmentally there are very vulnerable.

Periods in which brain health and like brain growth really need to develop appropriately. And so when those like are being impacted by PCB exposure and we have some of this, you know, me, metabolism related impacts or even inflammatory responses, you know, that might lead to things that are more neurodevelopmentally deficit or having issues with like A DHD or.

Just developing other neuro deficits, which can impact someone’s, you know, life later on as well. But then we also have the flip side of having that chronic exposure. You’re exposed for years on end. And we’ve seen some of the genes that we determined are also associated with like neurodegenerative diseases.

So things that might be, you might be more at risk of developing Parkinson’s disease or Alzheimer’s disease or just you know, cognitive decline. But there’s still a lot of work that needs to be done to, you know, obviously build more evidence towards those things. But we do see those associations in terms of neurodevelopment and neurodegeneration as well.

So

[00:14:53] Lauren: are more are or are certain populations or communities more at risk for these, these types of outcomes?

[00:15:01] Amanda: Unfortunately, yes. Communities that have. Less access to resources. Don’t have that financial backing to remediate or fix buildings that maybe were built with PCBs. And so oftentimes they can’t fix the buildings and they can’t, you know, put in more resources towards Ting.

Any type of building that might have been built with PCBs. And on the other side of it too, there’s like this aspect of communities that have, less financial means might have to live closer to manufacturing plants where a lot of those waste and those resources were being deposited as well. And so the waterways might be de you know, polluted with PCBs as well as in, and so it’s just kind of in the air and kind of in the environment.

And so unfortunately those that are at higher risk are often communities that are a little bit less financially. Well off.

[00:15:59] Lauren: That seems to be a common theme in public health, unfortunately. Yeah. So then how does this research help the community better understand long-term effects of environmental pollutants, like PCBs?

[00:16:15] Amanda: Yeah, so working with PCBs in my thesis work definitely opened my eyes to like this like dichotomy of we. Produce products without really thoroughly testing long-term consequences of those things. There might be a lot of, you know, preliminary stuff of like just immediate contact to skin. How does it affect humans?

Or, you know, just short-term duration exposure and how that might be impacting. But there’s never really this like chronic study or chronic evidence of how it’s going to be impacting humans. And so. I feel like we’re always kind of playing catch up when it comes to manufacturing products or coming up with new things that are on the market that we haven’t thoroughly tested for some of these you know, more chronic exposures that might lead to inflammation and metabolism related things or just chronic.

Issues that humans could hopefully avoid. So that was one aspect of working with PCBs that I feel like has kind of enlightened me to other environmental, environmental pollutants as well. Yeah. And I think another thing too is that surprising aspect of like, it’s been 50 years since we banned it, so they should be gone.

Right? Like, we don’t need to have to worry about the exposure anymore. But I think unfortunately for a lot of persistent chemicals is, is kind of a common theme of like, we might’ve banned it a long time ago, but because it’s persistent like. It’s persistent. It, it’s still there and it’s still, you know, permeating our environment and, and our living spaces and our food sources.

So yeah, it’s this kind of surprising factor of how long things truly stick around. And last. So

[00:17:56] Lauren: is there an estimated lifespan on.

[00:17:59] Amanda: It kind of differs between, so there’s like 209 different PCBs and Oh my gosh. Yeah. And so each one is like slightly different and structural. Like structural composition.

And so depending on their structure, they might break down a lot faster. I have to, I’d have to look at the literature again, but there’s definitely a span of like some last for, you know, up to like 40 some years or I think that’s a half life. Don’t quote me on that.

[00:18:29] Lauren: Okay. But it’s a while.

[00:18:32] Amanda: It is a while. It is, yeah.

[00:18:34] Lauren: Like you said, we’re making more just like inadvertently.

[00:18:39] Amanda: Inadvertently, yes. Mm-hmm.

[00:18:42] Lauren: So I always like to throw in some actionable takeaways for people who are listening. So do you have any advice on how people can reduce their risk of PCB exposure in everyday life?

[00:18:53] Amanda: Yeah. I like this question a lot because sometimes when I talk about PCBs, it can feel all doom and gloom.

Yeah. Kind of everywhere and like we’re exposed daily and all these things. And so there’s certainly like, there’s, there’s hope out there of for sure with minimizing our exposure and. Some of it starts with, yeah, like minimizing the different foods that we might eat that have higher concentrations of PCBs, as we kind of discussed earlier of Yeah, if it has high fat fatty content, then it’s likely having higher PCB concentrations.

So reducing maybe, you know, meats and dairy as well as like fish and eggs. Again, e everything in moderation, right. And then as well as like, yeah, depending on what paint pigments you want in your house is another way you can kind of make choices on how much PCB is really introduced into your home.

As well as like if you know your home was built. A long time ago, and it hasn’t really been remodeled since, you know, the 1970s. It’s possible that there are still products in your house that are, you know, laced basically with PCBs. So you can, you know, remodel and remove those things and try to reduce it that way too.

But again, that takes some financial means. And so a lot of times I just like tell people either reduce like what you’re eating or reduce the amount of time you’re spending in buildings that were built or. Old, essentially if they were built prior to the 1970s. And so a lot of it is gonna be more of like a proactive kind of piece of trying to like minimize where you’re going with older buildings, I guess.

[00:20:31] Lauren: Yeah. Well and every little bit helps, you know, like you don’t have to reinvent your whole life, but if you can just be aware of it, I think that that can be just as beneficial. Yeah. Yeah. So then broadening this a little bit, how can public health practitioners or local governments use this research to inform community health efforts?

[00:20:53] Amanda: Yeah, that, that’s another way that like we can be kind of proactive, right? Is using this research and this evidence and like gathering more information about how PCBs are affecting humans. Or the potential that it’s affecting humans would hopefully help, like people that are there to assess the risk of certain exposures would be able to like.

Inform local or federal governments on how to better protect the public and make, you know, better remediation efforts or, you know, put funding into places where we can have those old school buildings and communities that are a bit more disadvantaged, have them be able to remediate the building to make it safer for students.

So, I mean, hopefully some of this evidence can help, you know, identify where to remediate things or how to remove PCBs and how to safely do that. And hopefully yeah, start to kind of cut down on our exposure as, as a whole.

[00:21:50] Lauren: Again, a good starting place. Yeah. So, in closing, what’s next for your research in this area or future research that you’re doing?

Just kinda give us a little picture of the future.

[00:22:03] Amanda: There’s still a lot that we don’t know about PCBs and how they’re affecting the human health, in particular with the brain. Like we’ve really started to scratch the surface of PCB exposure and, and brain impact. And so there are a lot of things that I’d love to see kind of come out in terms of you know, more data around different brain regions.

Which ones are vulnerable? Like maybe there is ones that we need to really focus on more so, let’s see, what else would I like to see? I don’t know, there’s so many different aspects, but I’m also really interested in , seeing if there’s like sex differences. ’cause we do see this like hormone kind of regulation impact as well with our gene expression study.

And so I feel like there might be some differences in that too, because I mean. We, you know, kids are young and they’re developing and hormones during adolescent period. Like there’s a lot that’s going on there that PCBs could really just be wreaking havoc on the whole system. I’d be really interested in looking at more sex specific differences as well.

[00:23:06] Lauren: Yeah. Adolescents don’t need more things wreak havoc in their lives.

[00:23:10] Amanda: Certainly not. Yeah.

[00:23:12] Lauren: Okay. And then one final like, fun question. What are you currently reading or watching right now and would you recommend it?

[00:23:20] Amanda: Oh, what am I current currently reading? Hmm. Or watching? I’m currently watching Bob’s Burgers.

I don’t know, it’s just one of those like fun, you can like sit down and just kind of tune out. Someone

[00:23:33] Lauren: else had that same response not that long ago. Yeah, that’s one of our other podcast hosts. Mm-hmm. Yeah.

[00:23:39] Amanda: That’s really funny. Yeah, I mean, it’s not super clean, so I mean if you’re, you know, but it’s also not like super vulgar or anything.

Yeah. So it’s a good kind of just like sit down and have a good laugh. Low commitment. So that’s sometimes really nice. ’cause if it gets to be longer than, you know, 30 minutes, my schedule is like, can I fit this into my, can I commit another 45 minutes to something? So,

[00:24:04] Lauren: no, I get that. Well, thank you so much for being on the podcast today.

I really appreciate it. I thought this was really insightful conversation and I’m sure our guests will too.

[00:24:12] Amanda: Yeah. Thank you for having me. It’s been an honor,

That’s it for our episode this week. A big thank you to Dr. Amanda Bullard for joining us and sharing her expertise. Today we learned that PCBs once thought to be a problem of the past, are still being produced inadvertently and remain a concern in our food homes and communities. Amanda showed us how exposure affects the brain through inflammation and disruptive metabolism, and why these changes matter for both development and long-term health.

She also reminded us that environmental pollutants often persist long after their use is banned, and that reducing risk is about awareness, moderation, and proactive public health policies. This episode is hosted and written by Lauren Lavin and edited and produced by Lauren Lavin. You can learn more about the University of Iowa College of Public Health on Facebook.

Our podcast is available on Spotify, apple Podcast and SoundCloud. If you enjoyed this episode and would like to help support the podcast, please share it with your colleagues, friends, or anyone interested in public health. Have a suggestion for our team. You can reach us at cph grad ambassador@uiowa.edu.

This episode is brought to you by the University of Iowa College of Public Health. Until next week, stay healthy, stay curious, and take care. Okay.