Today’s AAQD is special, not just because of the topic but because of the guest. I asked my dear friend and Environmental Toxicologist Dr. Kimberly Garrett to grace me with her presence, and she accepted. Dr. Garrett and I met during undergrad at Allegheny College. I studied Creative Writing and she graduated with a Bachelor of Science in Environmental Health. After Allegheny, Dr. Garrett went to the University of Pittsburgh and earned a Master’s in Public Health, where she studied the impact of permafrost thaw on potential disease outbreaks in slightly subarctic Alaska.
She also attended Pitt for her Ph.D. in Environmental and Occupational Health, studying poisons that are similar to cyanide (Kim tells me these are poisons called azide and phosphine) and finding antidotes for them. Now, Dr. Garrett is in Boston, MA at Northeastern University in their Social Science Environmental Health Research Institute where she studies PFAS chemicals, which you may have seen in the news are called forever chemicals, and are a “really big environmental problem right now.”
This conversation was a delight. We talk about being a detective of sorts, modern snake oil salesmen, the train derailment in East Palestine, OH, and even get into snake venom. I hope you enjoy this one as much as I did.
Dani Janae:
Our first question is just a general one: throughout your school and throughout your professional background, what exactly stood out to you about toxicology? Why did you zero in on that field?
Dr. Kimberly Garrett:
I think it was that I've always had this understanding of how the environment impacts our health. Growing up in western Pennsylvania, I had asthma. I still have asthma and a lot of environmental allergies and so I could see that if I changed certain things about my environment, I would feel better. And so I think I had that baseline understanding, but I was also very into detective shows and wanting to be a detective when I was a kid. I always played detective. And I feel like toxicology is getting to do that at the scale of environmental pollutions and combining those two interests together. I was really interested in the fact that I know all of these principles from chemistry class, but they really inform the way that we interact with our environments and the ways that the environments impact our bodies.
Dani Janae:
Totally. Sorry. My phone needs to charge.
Dr. Kimberly Garrett:
That's okay.
Dani Janae:
For those that may not know, can you provide a quick summation, definition of what toxicology is?
Dr. Kimberly Garrett:
Sure. I should preface this by saying I'm an environmental toxicologist, which is different from a medical toxicologist. Medical toxicologists, we think of people working in hospitals and on the pharmacology side along with doing things like drug tests. I do what is called environmental science or environmental toxicology, which looks at the ways that different chemicals interact with our bodies. But generally, toxicology is the study of doses and outcomes of certain chemicals. So the first tenet of toxicology is that the dose makes the poison. And there are some exceptions that we're learning about where there are essential levels of certain vitamins and things like that, but for the most part, there is a lethal dose of every chemical agent and even some non-chemical agents like sunlight or heat and noise. Those can all be harmful to our health. And so what toxicologists do is they look using different models to see what leads to those adverse outcomes associated with those individual exposures. And we can think of that on, I guess the inverse, the positive side where pharmacologists and drug developers use that to the advantage to see what's the dose that brings about a particular outcome that we want to see. Whereas in environmental toxicology, I tend to err on the negative side of saying how much hurts.
Dani Janae:
Yeah. Totally. Awesome. I have a little bit more questions about stuff that we have talked about privately or things that I'm just curious about. But the first one is that we have discussed this new age-y, nebulous threat of people who are ... They're not health professionals, they're just basically wellness influencers that have this thing about “there's toxins in everything that you eat, everything's a carcinogen, here's how to detox your body of the toxins that are in there” and all that sort of stuff. So I want to talk a little bit about that and your thoughts on that and how people can ... Well, I'll get to that later, but just wanted to get your general thoughts on those discussions online and in print.
Dr. Kimberly Garrett:
Yeah. Absolutely. I have a lot of thoughts about the detox tea or all kinds of pseudoscience that you see floating around. And first I want to recognize that I understand why people will buy into these. Our medical system is not accessible. Especially as a queer person, and I know for your audience as well, not necessarily being welcomed to learn all about your body and things that can be different from what's expected. And so it can be really hard to access evidence-based medical care. And so I want to recognize that as an issue. And so I don't often blame individuals for buying into these pseudo-scientific cures when our system is set up so they're the most accessible option.
Dani Janae:
Yeah. Totally.
Dr. Kimberly Garrett:
Or they come in and say, "Well, the medicine you're going to have to buy is $300, but have you considered this detox tea which you can buy a subscription to," or things like that. But that's not how that works. Basically, my main response when someone asks, "Oh, well, have you seen these foot patches that take all of the heavy metals out of your body?" I say, that's not how that works. Part of what we learned in toxicology and what I wish was taught in general science curriculum are the ways in which our body systems work and our body systems work to keep us safe. And if one of those body systems are not working, you'll know. I see one a lot where they say, “oh, it boosts your liver function.” If your liver is not working, you'll know. You'll turn yellow. Jaundice.
And just all of these quack medicines, pseudoscience "medicines" are based in a rich history of grifting and I really love to learn about all of the historic grifters. There was a man who convinced people to get goat testicles attached to their bodies for virility and things like that. That was in the heyday of patent medicines. There are all kinds of old time-y medicines that you can go and see. I actually have a bottle from one of them that is called Hazeltine & Co Piso's Cure. Which I found at an antique store and washed it out. But it says for consumption. And it was a blend of cannabis, alcohol, opium. And those levels varied. They didn't have to say how much of each thing was in it. And it was sold during the time, late 1800s. I guess mid to late 1800s, early 1900s when consumption, which we now know as tuberculosis, was rampant and so people were desperate to find these easy fixes or these quick cures. And so, predatory salesman just came in and took advantage of that. Snake oil is usually what we call that, but it's still alive and well today. And I don't think our medical system is doing that any favors by continuing to be exclusive.
The fact that we have to have health insurance ... I'm a big universal healthcare proponent because that is a great public health intervention. I think that our current system allows these things to happen and I think it's really dangerous. So some of the issues around dietary supplements, detox teas, things like that, they're not regulated by the FDA. If you get a prescription for a medicine, you can be assured that it has been vetted by the FDA in the United States, and you can find a batch number. If you think something is wrong with your medicine there are lots of numbers that you can call. You can call poison control. There are avenues to find out what is wrong. And there are years and years of studies that are done to see what the side effects are and to make sure that the medicine actually works. And ideally, there are really high burdens of proof and standards of proof placed on pharmaceutical manufacturers to make sure that their products are consistent, they balance risk versus reward, and they contain what they say they contain. And that is also the case for most over-the-counter medicines like Advil. Things that we say are OTC or over the counter. However, dietary supplements which are allowed to be sold in the same area as OTC products are not regulated by any of those same governing bodies or even standards setting organizations.
I heard a lot about standards setting organizations recently with the submarine implosion or the submersible implosion where the entrepreneur in pursuit of innovation said, "No, we don't need these standardizing bodies to tell us what is and what isn't safe." Well, dietary supplement manufacturers take the same action, if not intentionally. So dietary supplements are not regulated as pharmaceuticals in the United States, and they are only regulated by the Federal Trade Commission, which you may recognize as advertisements. So the Federal Trade Commission, their only real oversight is reactionary in that dietary supplement manufacturers, they can't claim that their product will cure a disease. They can suggest that it will help with symptoms and they basically figured out how to get the rhetoric directly around that limitation. But the only substantial action that the FTC can take is after evidence of harm has been brought to them.
So in order for the FTC to act, someone has to get hurt. And that in and of itself is unethical to me and I don't think that dietary supplements should be seen as neutral because of that. And also because they have no regulations, they can contain literally whatever because no one's going to check up on them. There are lots of cases of people getting heavy metal poisonings because arsenic can get pulled up into plants, and these are seen as herbals and they get up into plants, and then the manufacturers don't have any standards, so they just put however much of the plant in there, and then people get heavy metal poisoning, arsenic poisoning, lead poisoning. And that in and of itself is really toxic. And a lot of these things are branded on being so clean and safe. Well, we don't know, and there are absolutely no standards. So that's part of my little rant, but I could go on more about those. But I have trouble because I understand why people get into these ideas, but that's really not how the body works. And I'd be happy to talk about some of those systems that help to keep us safe. Our lungs are really incredible, for example. They have all different kinds of security systems that keep toxins and particulates out and keep the good air that we need in.
Dani Janae:
Totally. Yeah. I would love to hear a little bit more about those other systems in the body that are in place for that measure.
Dr. Kimberly Garrett:
Sure. Yeah. So I guess this gets into the second tenant of toxicology, which is exposure route really, really matters. And an example that I like to give to get people into toxicology in social settings and at parties is that there are memes that go around that basically say if you smoke marijuana, you get high faster, but if you eat an edible, it takes forever to make you feel that high. And that's because of exposure route. So exposure route has to do with how fast and how easy something can get from outside in the environment into your bloodstream and to its target organ. And the bloodstream is really the highway that moves anything all around your body. And if it can get past the liver, if it can go through your bloodstream before getting to your liver and kidneys, then it can be way more potent. So this has to do with the ways in which your blood flows around your body, the directions and things like that.
But long story short, your skin is a really strong barrier against your bloodstream for certain molecules. Certain molecules have to have a certain polarity, different solubility in order to get through your skin barrier. But then once it's in there, there are different solubilities and so it can be really hard to absorb certain chemicals through your skin. Your lungs are a really close connection to the bloodstream, which is why we can breathe. So you inhale air and it goes down through your lung structure, which has an increasingly narrowing ... It narrows its diameter as you get lower in the lungs, so it keeps things like dust particles out. It unfortunately doesn't keep things like asbestos particles out, but that's why you cough and you sneeze because you have something called the mucociliary escalator which traps those particulates in mucus and escorts them up and out.
And so only certain things can get down into the sensitive area of your lungs, which has a direct connection to your bloodstream. And so if you smoke something that has a psychoactive effect, you're getting it to your bloodstream really fast. And so that's the case with smoking marijuana. The GI system or ingestion or eating goes through a kind of arduous process of digestion where you swallow and then it hangs out in your stomach for a little bit, and while it's in there, it's subjected to really acidic conditions, so some parts don't survive. And then other particles and other materials can survive the stomach and make their way into your GI tract. After going through the liver and kidneys, they get down into the intestines, and that's where a lot of the nutrient absorption happens. And so you have to wait awhile for the thing you ingested to get all the way down to where it can finally start to get close to the bloodstream. And because it goes through the liver and kidneys, it has a little bit of a molecular change. And so the molecule itself is a lot different than the one that you inhale. And so that's one of the reasons why. You know those memes that say, oh, this edible isn't hitting, or whatever?
Dani Janae:
Yeah. Exactly.
Dr. Kimberly Garrett:
And then of course we have intravenous administration, which can be either the most efficient for something like a medicine or the most dangerous for something like an illicit drug or some kind of old-timey poison.
Dani Janae:
Totally. Thank you for diving into that.
Dr. Kimberly Garrett:
Yeah. Thank you for letting me talk about that because I love the talk about the mucociliary escalator.
Dani Janae:
That's a cool name. Yeah. Okay. You answered that question. Okay. I believe it was Norfolk Southern. Is that the name?
Dr. Kimberly Garrett:
Yes. The train derailment.
Dani Janae:
Yeah. When that happened in Ohio, you were one of the environmental toxicologists that was interviewed by a few outlets. So I was wondering, do you know anything about where the town stands today or can you share a bit about the experience of being interviewed by these outlets and things like that and what you shared?
Dr. Kimberly Garrett:
Yeah. Absolutely. It has been a really interesting and a really impactful time for me in my professional development. I hadn't been encouraged to do any science communication while I was in grad school, but as soon as I saw that this happened ... And it happened about 30 minutes away from where my parents live, so it's about halfway between where they live in Pittsburgh, and I was familiar with the area, and I saw this happen and I said, “oh, wait, I have expertise here.” And I talked to my parents on the phone and they had some questions. And so I was talking to them, and then as supportive parents do, they said, "Oh, this is really wonderful. I wish other people knew about this." So I said, "Well, I'll get on Twitter." So I got on Twitter. The artist formerly known as Twitter, I guess. And I just made a series of tweets about what was going on, at least from my limited perspective not being involved in the surrounding area directly or any of the decision makers.
The thing that caught my eye was that they were going to do a controlled burn of all of the chemicals. And I looked at a list of the chemicals that were on board, and I thought about it, and then I said, "This is going to look really scary, and I would like to at least let people know what's going on from my perspective." And so I made a Twitter thread about what the main concerns are, why someone might decide to do this kind of controlled burn and it really took off. It was my first viral tweet. And I was happy to answer questions. I had folks from the community reach out to me, and I've been able to establish ... with residents directly, but I also saw a lot of misinformation. And misinformation is really my pet peeve. And so whenever I see it and I have the ability to counteract it, I like to do so.
And so I saw some figures that said that the entire Ohio River watershed was going to be exposed, and they showed areas that were clearly upstream from this area, and that's not how pollution works. And so responding to things like that. Then some news outlets reached out to me, and at first I said, "I'm not on the ground. I'm not in that community directly, so please if you can talk to someone who's closer to it." But then more folks started reaching out to me saying, "No, we want to speak to you specifically." And I was very flattered. So I got to share more about what was going on. And it's really been an exercise in, I guess, reflexivity as well, because with any unfolding disaster, things always change. We make decisions based on the information that we have available to us. And so while my understanding of the controlled burn was from my outside perspective, it's not the same as the lived perspective of people on the ground. Their houses still smell of different post burn contaminants and people don't feel safe going back to their homes.
Then there was some discussion about EPA standards. Whether or not the machinery they were using was sensitive enough to pick up on certain chemicals. And then there's also the complication of chemical mixtures. So we can say, we know that this much impacts this organ in this amount, and so if we do that in a lab, we can get a number. But that's not necessarily exactly what happens out in an atmosphere in which so much is going on. We don't know what that chemical does in combination with another. So what I've been encouraged to see was a lot of researchers coming in from different academic institutions to as soon as possible start interviewing people, ask about their symptoms and doing independent testing and so that's been really neat to see in partnership. Or I guess the data that I would see would be the independent researchers and you're able to compare that to what the EPA contractors and the Norfolk Southern contractors were putting out.
Dani Janae:
Yeah. Totally.
Dr. Kimberly Garrett:
Yeah. But for now, it seems to still be a politically divisive issue in the area. Norfolk Southern has come in and sponsored baseball teams and done a lot of PR activity to try to say, "Hey look, we're still a good neighbor." When they contaminated this community. And they have paid for some of the cleanup, but the transparency hasn't been as great as we would hope. And so there's an issue in the town now where some folks are like, "Oh, Norfolk Southern did sponsor these things. That's enough for me. I'm satisfied." But then there are other people who are still saying, "I'm not comfortable coming back to my house." So that's an interesting intersection of the chemical world and the social science and public world.
Dani Janae:
Definitely. Thank you for sharing that. So this is a recent addition, but you said we could talk about snakes, so I wanted to talk a little bit about snakes and venom and stuff.
Dr. Kimberly Garrett:
Yeah. Absolutely. So you had posted an Instagram story about a man who was bitten by a snake. And I said, I don't know a lot about snakes, but I know some interesting facts about snakes and they’re poisonous, or they’re venomous, because it's a pedantic discussion about venomous versus poisonous. So you eat something that is poisonous, something that is venomous eats you.
So there are so many different kinds of snakes and snake bites are actually a huge public health issue, and we don't necessarily think about them as a huge public health issue in the United States, maybe more so in the southern United States. But in South America and Africa and more tropical areas of the world, snake bites are really dangerous and really common. It's where the most toxic snakes live. They have the most potent venom, and in a lot of these areas, it's where there's a lack of healthcare infrastructure to deliver antidotes.
I know that snake bites are a focus of a lot of international public health research, and there have been large strides to develop more accessible antidotes. Some that are maybe shelf stable so you don't have to have them refrigerated, and some that can just be carried by EMTs in an area if an area has EMTs. Or it can be stored at a community center or anywhere that people who are going to be out and likely to be exposed to snakes will be. Which as it turns out, you don't have to be out in the wilderness to be exposed to snakes in many areas. My partner's sister lives in Australia, and apparently they just show up in your house. So I don't want to frame this as a necessarily rural versus urban issue.
Dani Janae:
Yeah. Totally.
Dr. Kimberly Garrett:
Yeah. But snake bites are a huge environmental health problem but what is very interesting to me is how the venoms work. I used to be really afraid of snakes, and I made an active effort to say hello to snakes whenever I saw them, and now I'm not so scared of them. And I became more interested in learning about how their venoms work and how we can counteract them. So I took a trip to Florida two years ago and I got to see a diamondback rattlesnake, and that is the most venomous snake in North America. And I said hello to her. She was very beautiful. And if you don't pester them, they won't pester you. And so I kept my distance, said hello, and kept walking.
So snake venoms, for the most part, act as chemical mixtures. So I mentioned we can know about how one chemical interacts with your body, but snakes are levels above that. They have different proteins and different compounds in their venom that launch a complex attack through your bloodstream. And I really think of snake venoms as kind of a bull in a China shop where once that gets in, the compounds go in all different directions. Some make it so ... They're anticoagulants so your blood doesn't clot, and so your blood thins out, and if you sustain a different cut, then you might bleed out from there. And others attack different functions of your cells. And so they do this all at the same time, and they're really complex. And so you can imagine that developing an antidote to counteract that is very difficult. And the way that we do that is an example of the dose making the poison. So in order to develop an antidote to such a complex toxin, we often harvest antibodies and other defensive molecules from something that has been exposed to poison.
You can't do that in a person because people have relatively small body volumes, blood volumes. And any useful dose or any dose that would yield a useful amount of antidote would be very harmful to the person. And so we take big animals and we give them a little bit of venom and it's not enough to hurt them, and they generate the defense systems that we can then use. And we use horses. Horses have a lot of blood, and they can sustain a little bit of snake venom. I guess horses can have a little bit of snake venom as a treat. And so then we harvest the immune and defensive molecules from horses, and then we store them to give to people so that those defenses can be available for injection into people so they don't have to make their own over a long period of time.
Dani Janae:
Wow. I didn't know that.
Dr. Kimberly Garrett:
Yeah. It's interesting. And I wonder as we move away from using animals for our consumption and things like that, if there're going to be more lab-grown versions or if there's a way to do that. I don't want horses to get hurt, but it's really a risk-benefit relationship right now because we also don't want people to get hurt. That's always on the mind of ... At least my mind, and other toxicologists that I know, how do we limit our use of animal testing and animal products, even though they still remain really necessary for protecting human health?
Dani Janae:
Totally. Yeah. Okay. Awesome. So I'm going to skip down to the Instagram questions right now and then close with my last question. Just because I think it'd be a good last question. Someone from Instagram wants to know anything about aspartame. How much diet coke do you have to drink to be harmful?
Dr. Kimberly Garrett:
I'm so glad someone asked this. So this gets into how we classify carcinogens. And so I'm going to be honest, I haven't really read into this. I have known that aspartame has been considered ... They've been considering designating it as some kind of carcinogen class for a long time, but I do not know the specific study that they used for this decision but I can tell you about how they classify carcinogens and it has to do with rhetoric and logic. So while it is easy to show if something is a carcinogen... I say easy lightly. Some of the most potent carcinogens that we know of, tobacco smoking, sunshine, those have very clear exposure to tumor development relationships. And there's been a lot of research into elucidating those pathways and the mechanisms both in order to understand how that happens and understand how to treat it. And so that is what is the highest level of carcinogen. You can say this is a carcinogen. We have seen it happen. If you get a little lower on the scale, you have things that under certain conditions lead to that relationship, at least that we've observed.
And so those are possible human carcinogens. No. I'm sorry. Those are likely human carcinogens, which we can't say we have the strength of evidence between exposure and the outcome like we do for cigarette smoke, UV radiation, or asbestos. But be careful. It's likely and under certain conditions. Maybe there are certain risk factors like a susceptibility gene or something like that. Down the scale from that is potential or possible human carcinogens, which is where all of the other chemicals are, except for a few. If you don't have the research to say this is a carcinogen, it's really difficult to prove that something is not a carcinogen is basically the argument here. So in the absence of evidence to the contrary, everything is presumed a possible human carcinogen because we don't know every single outcome that you could have. If we all moved to Mars and then got exposed to a chemical up there, maybe something in the environment leads to that being a carcinogen. We don't know every single exposure pathway.
And so it's a real challenge just getting over that rhetoric and that logic. And on the lower level, there are certain chemicals that have been assessed and are low likelihood to be human carcinogens and so those are seen as unlikely human carcinogens or not likely to be carcinogens. And so there are very few chemicals there, just again, because we don't know every exposure route, we don't know every individual susceptibility. And so when someone says this causes cancer, I want to know are we talking about possible human carcinogen, likely human carcinogen or a known human carcinogen? Because the number of known human carcinogens is really low compared to the number of chemicals that we use, which shows obviously we need more research and more information to see what is safe and what isn't. But a lot of science communication in the media doesn't take such a nuanced stance. And cancer is terrible and very scary, and I don't blame anyone for being scared by headlines that say something is called a likely human carcinogen. Aspartame is one such chemical in which it is not in the known human carcinogen category, but it has been brought into presumed and or possible and likely. And so that's where the discussion has come out around there.
It's also an individual risk decision. If something being a likely or a possible human carcinogen is really unsettling to you and you don't want to take that risk, by all means, change consumption habits and things like that. But I am not incredibly alarmed. I think there are lots of other things that we're exposed to every day that warrant more alarm than aspartame.
Dani Janae:
Awesome. Thank you.
Dr. Kimberly Garrett:
That's just my opinion. Yeah.
Dani Janae:
Yeah. Okay. So the second question is how common is serotonin syndrome? Is it deadly? So many people on SSRIs?
Dr. Kimberly Garrett:
I actually don't know too much about that. That would be a good question for a medical toxicologist. I do know that it is described as a crash in serotonin after exposure to something that changes your body's serotonin levels. Basically, your body has gotten a little lazy in its ability to produce serotonin or it's gotten used to a higher level. I'm on an SSRI, and I know that if I don't take it every day, my brain starts to have side effects that I don't like. And so I think that's because it's had that particular neural pathway operating in a specific way for so long that as soon as that goes away, it doesn't know what to do. Oh, no. I need a brain zap. I mostly know about that from personal experience, but I know that there are certain things that folks who are on SSRIs should avoid. Any recreational drug that's going to change your body's interaction with serotonin should really be avoided. I think it's MDMA that can impact your serotonin in a way that can be very risky. And I think LSD but I should look that up before saying that more explicitly, but that's just what I've heard. Yeah. So I unfortunately don't have a big answer for that question.
Dani Janae:
That's fine. Thanks for giving what you did.
Dr. Kimberly Garrett:
Yeah.
Dani Janae:
Okay. So my last question is how can everyday people spot misinformation more clearly when they encounter it online or in conversation?
Dr. Kimberly Garrett:
My biggest piece of advice is to watch out for absolute certainty. Any scientist worth their salt understands that science is an ever-changing area of knowledge where our intention is to be as accurate as possible under the conditions that we have. And so like I mentioned with the carcinogens, there is a large burden of evidence that allows something to be called a known human carcinogen. And so I can say asbestos is a carcinogen because there is a lot of evidence to back that up. A lot of peer-reviewed rigorous evidence. And I can't say that for something like aspartame. The information's just not there yet. So as scientists and as science communicators, it's our ethical responsibility to present information as accurately and with as much nuance as possible, which makes us end up sounding like big dorks.
And so I'm always hesitant of things that say they cure a disease and they don't give a lot of evidence for it. Or if someone is absolutely certain that some exposure causes some other kind of health outcome that may be contested or I guess something that can be used for political means. Speaking specifically about anti-vax sentiments. When I hear someone talking about anti-vax anything, I honestly pick my battles a lot of the time. But I would say it's not helping anyone to believe this. There is so much evidence, so much rigorous evidence that vaccines are helpful to the population. Their risks are very, very low. And I would also question their reasoning behind things like autism or other disabilities. Is your child getting the mumps a better trade-off for a child with a disability? Is a child with a disability worse than ... I don't know.
I think that it really stigmatizes disabled folks and neurodivergent folks to have this kind of conversation, and it really just hearkens back to eugenics. If they're saying, I don't want this because I don't want my kid to have a particular disability, but I'm fine with them getting the mumps and maybe dying, that's just absolutely bonkers to me, and I don't understand it, and it's really an ethical problem. So I get really frustrated when I am in conversations like that. Yeah. I like to sprinkle a little bit of medical ethics wherever I go, so you'll find eugenics all over the place. I hate that for us.