3 Takeaways - The Hidden Plastic Inside Us (And Why It’s Rising Fast) (#292)

Episode Date: March 10, 2026

Scientists are finding tiny fragments of plastic inside the human body - including the brain.Dr. Matthew Campen of the University of New Mexico explains how they get there - and why the biggest source may surprise you.

Scientists have found plastic in human hearts, blood, lungs, placentas, and even brains. We've created a material that never truly disappears. It just gets smaller and smaller until it ends up inside us. What is that doing to our health? And is there any way out? Hi, everyone. I'm Lynn Toman, and this is three takeaways. On three takeaways, I talk with some of the world's best thinkers, business leaders, writers,

politicians, newsmakers, and scientists. Each episode ends with three key takeaways to help us understand the world and maybe even ourselves a little better. Today I'm excited to be with Dr. Matthew Campin. He's a professor at the University of New Mexico and the director of the New Mexico Center for Metals in Biology and, and medicine. He's a toxicologist and his research is changing how we think about plastic as a public health threat. His team developed a new way to measure plastic particles hundreds of times smaller than the width of a human hair and what they found is alarming. They detected microplastics in every human brain they tested. Even more disturbing brain tissue from people with dementia contained up to

10 times more plastic than healthy brains. And this problem is accelerating. The amount of plastic found in human brains increased by 50% between 2016 and 2024. Welcome, Matt, and thanks so much for joining three takeaways today. Thanks for having me on, Lynn. It is my pleasure. Let's start simple. When people hear microplastics or nanoplastics, what are we actually talking about? The plastic objects that you deal with in your life, whether they're your plastic bags or the coffee maker or your bumper of the car, those are macroplastics. They're big. They're not a health hazard immediately, but they will eventually be thrown away. And once they're thrown away, they're going to start degrading in the environment. UV light from the sun and oxygen from the

atmosphere will break those chemicals down slowly and they get smaller and smaller and smaller. And eventually they become what we call microplastics. And we define that as a scale based on how physically big the diameter of those particles is from one micrometer to five millimeters is usually how it's defined. And then they can break down smaller into the nanoplastic scale, which is now smaller than the cells of your body. And, you know, a lot of what we've seen that are actually the size of viruses. Wow, smaller than the cells of our body. You developed a new way to measure plastic in human tissue.

What makes your approach different? A lot of the conventional research in and around the field of microplastics was using a visual means of detection, and that means they use a microscope with a laser, and that laser reveals a spectra from the plastic, which is a very chemically specific way of finding them. But the problem with that is there's limits to the size. You can't go very small with that technology. And we needed something that would allow us to look at those nanoscale things that are actually getting across our intestinal tract. Our system, it's called pyrolysis gas chromatography, mass spectrometry.

It's sort of a cumulative picture of all the plastic that we can isolate from the body or from a tissue that's donated. The reason it's important from our standpoint is we want to eventually link whether or not the plastics in your body associate with health outcomes, counting the number of plastics and saying, oh, we saw five plastic particles. It doesn't really lend itself well to population health studies. When you tested brain samples, you found plastic in every single one. How much plastic are we talking about? We've put out there this idea that there's a plastic spoon of material in your brain. And that's in some ways a horrible way to phrase it because there's a lot of unsubstic. certainties in the way we measure this. And plastics, when they get this old, because that's

what's happening is they're degrading over decades before they get into our body, they're so old, they don't chemically look the same as they used to. So there's a lot of assumptions we've made head to head from one group to another. I think it's very fair to compare between groups with this method. So when you said there was a 50% increase over eight year period, I think that's a very valid conclusion from our method. But when we talk about absolute mass of plastic, it's really, really difficult to make that assumption with our method. It's not going to be like the physics constant for the speed of light. It's going to vary from person to person and different plastics will reveal themselves more confidently than others. So I hesitate to make that plastic spoon

analogy. The amount of plastic in human brains that you tested increased 50% in just eight years. What do you think is driving that rise? Everything we are looking at suggests it has to do with the amount of plastics in our environment. We have been making more and more plastics since the 1950s. The amount of plastics we create doubles every 10 to 15 years or so, so it is an exponential curve. and the delay from when we make the plastic to decades later when that plastic gets thrown out and it becomes micro-nanoplastic. You know, you're talking about a 30 or 40-50-year delay between the creation to the formation of these nanoplastics that get into your body. Everything we're looking at says the increase in our brain just completely mirrors that increase of our exposure. But that leads to the biggest concern we have, which is if we figure out,

that plastics are bad for our health. We need to make decisions about plastics policy now to affect our grandchildren. The curve of increasing micro and nanoplastics is not going to stop just because we stop making plastics. Before we talk about what we can do to limit the plastics in our environment, you found microplastics in many organs of the body, but the brain had the highest concentrations. Why do you think that is? There's a number of hypotheses we have. half. Probably the biggest one is that the brain, pound for pound, is the most metabolically active organ of our body. We suspect that these plastics are being delivered through the circulation, through your blood, and your brain, despite being only one and a half kilograms, so about three

or four pounds of your body, it receives 30% of your blood flow. So we think that's probably the main reason. The other aspect is the brain has a really bad clearance system. Your liver and your kidney are designed for clearance. They remove toxins from your body. But the brain has sort of this privileged space in your skull and it uses a sim, we call it the glymphatic system because it combines like a lymphatic system with the glial cells and it's complicated. But ultimately things have a potential to build up because that clearance pathway from the brain is not as robust as other organs. brain tissue from people with dementia had up to 10 times more plastic than healthy brains. What do you think is happening there?

We are still leaning on the idea that our study was cross-sectional and that means it's associative. It's a chicken or egg issue. So we're not prone to jumping to the conclusion that plastics cause dementia. Dr. Alzheimer diagnosed his first case in, I want to say 1902 or 1907 or something like that, way before there were plastics on this earth. What happens in dementia is that your blood vessels become leaky. The blood-brain barrier, as we call it, tends to become impaired. And what we've seen, anatomically speaking, is that there does seem to be a build-up

of little plastic particles in and around the blood vessels. And then again, to the clearance aspect, dementia is a disease where the clearance is impaired and proteins and other things are building up. We also see plastics in and around areas of inflammation within the immune cells that are trying to clean up things in the brain. So it's very possible that the disease of dementia simply creates a really welcoming environment for the plastics to absorb into. So we have to be really thoughtful about what we have seen and what we have shown with this latest research. What do we actually know about what these plastics are doing once they're inside our bodies? We don't know much.

Plastics are very inert. We like to use the term harmful or safe as absolute terms, but I'm a toxicologist, and in our world, everything is potentially a toxicant at a certain dose. We put stents into coronary arteries that are made out of plastic, and they give people life. They give people like years and decades of life after an angioplasty. Plastic parts are used for hip replacement and other devices that can be put inside the body. So we have to be aware that plastics are used because they're inherently something that the body doesn't respond to. Once they've broken down, once they've degraded, there's a different chemistry about them. And there's a lot we just don't know.

So could these aged plastics from the environment to get into our agricultural system somehow? Could those have a different overall response potentially? Colleagues at Duke have shown that they can cause aggregation of proteins in the brain. We've seen that they can alter the behavior of immune cells. We've seen that they can be obstructive to flow. There could be a lot of other immune or biochemical reactions that we just haven't studied yet. How is plastic getting into our bodies in the first place? Is it food, water, air?

Our research right now says it's food. and we're staring at this data, knowing that it'll cause a bit of a kerfuffle, I'm sure. But processed foods, processed meat seem to have the highest amount of plastic. When you compare, say, a beef stick, you know, really highly processed meat versus venison that was harvested out in the Gila Mountains of New Mexico, there's just magnitudes different levels of plastic. Fresh grass-fed beef is relatively quite safe. we haven't been able to do head-to-head comparisons between meat and vegetables because we have to process those differently in our methods.

So we're still working out how to do those comparisons. But our conjecture right now is that vegetables are going to be lower concentration and safer. Meats and processed meats will be progressively worse. Inolation is so very small concentrations that you're breathing into your body compared to what's in the food. So that's where we are right now with that science. So interesting. So for food, is that also chicken and farmed fish? We haven't looked extensively at fish or seafood. We've been able to work with colleagues and we've looked at whale blubber and it wasn't nearly as high as we would have expected, although it was higher than venison. Are you seeing high levels in water? Not as much. We think what's happening is we're really focusing plastics into our food chain.

The water that we drink is actually quite low in plastics relative to what we're seeing in meats. So what can people realistically do today to reduce their exposure to micro and nanoplastics? Limiting meats and eating more vegetables is probably the most realistic solution I can advise at this point. We get into this discussion so often just among people, within the media, where we're talking about what individuals can do. That's not how we win environmental problems. Clean Air Act was signed into law in 1972 by Richard Nixon because the air pollution was really, really bad in this country in the 1950s and 60s.

And there was no individual choice that was going to do anything about it. Like you could not just go to the car dealership and say, I want one of the clean cars. There weren't any clean cars. We had to have legislation. that said all y'all, GM, Ford, whoever, y'all got to put a catalytic converter on your car. That price just got passed off to the consumer, but it was a standard and it worked great. And that public policy, it reduced air pollution 90, 95 percent in this country.

We have really good quality air in this country now. We fight about it as if the EPA needs to be thrown away. That's crazy. Maybe we revision the EPA and figure out what they do. now that they've done such a good job. But that's how environmental policy works and can be really effective. But we need that kind of level of attention, comprehensive policy to address microplastics. And Matt, specifically, what kind of a policy do we need? Comprehensive. So we need to address many aspects of this. We need to talk about caps, limits to production and use of plastics.

We need to talk about the real world of recycling. Less than 10 percent of plastics get recycled. months, which means less than 1% of plastics get recycled twice. It's a fib we've been telling ourselves. You dooffully recycle. And this is the crazy part is please keep recycling, keep trying to do this right. We need to have these behaviors in our system. But sometimes that doesn't even make it to a recycling plant. It just gets thrown into landfill or it gets shipped across the Pacific.

Recycling needs to be fixed. And then I have a perspective, which I know a lot of my environmental friends don't agree with, but I feel like we need to invest in waste to energy treatment plants. A lot of very modern cities around the country, around the planet, I should say, use waste to energy very effectively. This gets rid of the problem. It creates an economic drive to create plastics, and I appreciate that, but it solves a lot of the long-term problems. And given the politics and the economic forces involved with petrochemical industry, it might be the easy button to solve a big. bigger problem.

How does it work? You burn plastics to make energy. Sounds bad, but we burn coal. You know, it would offset coal. It would offset natural gas. So you would be burning something else. Our nation doesn't immediately need more energy. We just need to titrate over the next few decades to where more of our energy comes

from the waste that we create. But burning plastics just not release toxins? Burning anything releases toxins. If you incinerate at a very high temperature, most everything will become carbon dioxide, then we're still in the climate change. Yeah, we get to worry about that as usual with any energy source, but also elemental carbon rather than toxicants. But coal creates toxicants too, and we filter a lot of the particulate out and the sulfates

are taken out. And the other trick is if we're just landfilling, all the waste we landfill, which includes compostable things and cardboard and all that, it creates methane. which is far worse for global warming. So instead, we're just moving it to CO2. It's not a very popular idea among the plastics environmental world, but I don't know how we get away from it. Matt, you believe that we need to limit plastic production.

What more specifically are you talking about? No more plastic containers, no more synthetic fabrics in our clothes. what are you hoping to see that we'll have a real impact? I'm actually hoping that my team's research, as well as other groups, are able to sort of pinpoint which plastics might be the worst culprits for human health, whether it's that they're more toxic or that they are more resilient and they stick around in the environment longer. If we can identify those, then that gives us sort of easy fodder to say,

okay, you know, there's these specific types of polyethylene that have highly crystalline that might be more durable, so HDPE, maybe that is something we should use less, and maybe we should use PVC more. So maybe there's a way we can strategize what's going to be the safest for the environment and for human health. Beyond that, we've got to prioritize just looking at hospitals. I get that IV bags, you want them sterile, plastics are great material, but they have plastic bedpans.

What's the point? A metal bedpan worked absolutely perfectly. there's no need to replace that with plastic. And there's a lot of other dumb things we do where it's single use, throw it away, and it's goofy. I think there's a lot of sensible policies that can be enacted that approach it from, like I said, a comprehensive level. And it's not just one-off policies about plastic bags or straws or things like that that don't really move the needle at all. What is the one thing that you wish more people understood about plastic and human health? that it's not really coming from the fresh bottles and the cutting boards and things like that.

Most of the research around those topics has been really, really large plastics that you don't absorb into your body. That's one aspect I think is not well appreciated. And I guess the other thing is we're doing okay. I think there's a lot of panic around this issue. And if you look at the overall longevity in our country, it looks a little weird and bad over the past few years. but if you take out opiate problems in our country, if you take out COVID and you take out handgun use and you take out automobile accidents

and alcohol related accidents, take out those things. People in this country are living a very long life. We shouldn't jump to conclusions about the microplastics and the chemicals associated with them as being some scourge that are destroying our humanity and creating untoward health problems. We need to address these things rationally.

We need to use sensible data. I know that people will judge me as being an alarmist because of the research we put out. But we really do think that moving forward with sensible scientific research and decision-making derive from those data will get us to a healthier place. I don't think you're an alarmist at all. The only thing you are talking about is purely your research and your actual findings from your research. And you're not extrapolating or assuming or projecting, or projecting, future? We're very evidence-based. Yes. And Matt, what do you do to reduce your intake of micro and nanoplastics? I try not to stress about it on a day-to-day basis. I try to maintain a healthy,

low-carbon footprint. I walk to work. I've got solar panels. I compost. When I go to the grocery store, we take our reusable bags and I don't put fruits and vegetables into individual bags. They'll be fine. Caneloop has a shell that I'm not going to eat. It's a But I try not to panic about these things because I know people really do stress about it. And cortisol is bad for your health, you know. So I hope people can make sensible decisions and not panic. The grocery stores do not give you fair choices when it comes to things wrapped in plastic. Everything's in plastic containers.

You can lose your mind around this topic. Matt, what are the three takeaways you'd like to leave the audience with today? Plastics are going up in the environment. and they're going up in our bodies as a result of that. We don't know that there are health effects from micro and nanoplastics yet, but there's some compelling evidence, and the research over the next few years will really illuminate the issue pretty dramatically. And the last thing is this is not something that individuals can win the day on.

This is not an individual choice. Plastic producers have won the argument by making us talk about it like that. It has to be something we address as a nation to more comprehensively figure out how to limit plastics, how to recycle them properly, and how to dispose of them properly. Matt, thank you so much for your research. And thank you for our conversation today. Thanks for having me on, Lynn. If you're enjoying the podcast, and I really hope you are,

please review us on Apple Podcasts or Spotify or wherever you get your podcasts. It really helps get the word out. If you're interested, you can also sign up for the Three Takeaways newsletter at three takeaways.com, where you can also listen to previous episodes. You can also follow us on LinkedIn, X, Instagram, and Facebook. I'm Lynn Toman, and this is Three Takeaways. Thanks for listening.