From office settings to plastic recycling, workers were exposed to at least 14 chemicals in their daily lives, according to a new study from the International Pollutants Elimination Network. To measure exposures, participants in the study wore silicone bracelets which are able to mimic skin. This technology was invented at Oregon State University and has been used not only to measure human exposures to pollutants, but for animals such as cats and dogs as well. Kim Anderson is the director of OSU’s Food Safety and Environmental Stewardship Program and is a professor in environmental and molecular toxicology. She also invented this method with her graduate students. She joins us to share more on what we’ve been able to learn through this technology and how often someone faces an exposure.
Note: The following transcript was transcribed digitally and validated for accuracy, readability and formatting by an OPB volunteer.
Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. The International Pollutants Elimination Network put out a study in November focused on people in Thailand who do plastic waste or recycling work. They used office workers as a control. They found that everybody, whether they work with plastic waste or not, was exposed to at least 14 different potentially hazardous chemicals. This was just one study of many that relied on a technology pioneered at Oregon State University ‒ silicone bracelets that can absorb a wide variety of chemicals. Kim Anderson is a director of OSU’s Food Safety and Environmental Stewardship Program and is a professor in environmental and molecular toxicology. She helped invent this method with her graduate students and she joins us now. It’s great to have you on Think Out Loud.
Kim Anderson: Thank you.
Miller: Why silicone? What makes it a good material for measuring chemical exposures?
Anderson: Several features. First and foremost, it’s a really good mimic of our biological cells. So we want to know not only what’s in the environment, but another piece of that is from the environment, what gets into the body? And that might be through dermal skin cells, or it might be through our lung cells. And so the polymer that we make with the silicone is a very good mimic of those cells in our body. When we use it in the environment, we’re not only measuring what’s in the environment, but we’re measuring what can make that transition into the body. And that’s, of course, where potentially negative effects can happen.
Miller: What did environmental scientists use in the past to model chemical exposure? What are the other popular models?
Anderson: Well, that’s sort of another feature of the of wearing an individual silicone wristband, because the previously, how we would determine what your chemical exposures would be is, for instance, put a air sampler in Portland or in a large city, or put several, and then extrapolate from that stationary air sampler. You might live two blocks from that air sampler, or you might live two miles or 20 miles from that air sampler. And so you’re trying to now estimate what is that exposure from just the atmospheric portion of what your environmental exposures are. And it might not be a very good measure of your individual exposure. If we think about how much time we spend inside, that monitor in Portland might not be a very good representation of your environmental exposures.
One of the things the wristband does is it really allows you to look at the individual. If you spend time by that sampler in Portland, that’s great. But if you spend a lot of your time away from that sampler, or in your house ‒ most people spend 15, 16, 17 hours indoors. So we don’t have samplers potentially indoors. So that’s one of the things that the individual sampler can do is it can show you your individual exposures throughout your entire day or week as you wear it.
Miller: Why make this a wristband? You’ve talked about why silicone itself is a helpful material. But why a wristband as the form of that material?
Anderson: Yeah, we had played around with a lot of different… I come from the world of making samplers, and in particular what’s called passive sampling. It’s this idea of mimicking the biological cells. And so we tried different formulations. And one of the early formulations I tried was a necklace in the early 2000s. But at that point, a lot of demographic groups really weren’t into necklaces or bling. I was actually at a football game and I saw a lot of football players wearing silicone wristbands, and I knew that I could make my silicone into a wristband. And then it really opened up the world that it just isn’t people who would, who wouldn’t maybe accept a necklace, but that the wristband was just so non-invasive. It didn’t really make a statement one way or the other, so it would be widely accepted. And that’s what you really want to have, is a technology that’s easy for people, doesn’t bias against any particular group, so that we can understand what the breadth of chemical exposures are for everybody.
Miller: What is the range of chemicals that these bracelets readily absorb?
Anderson: It’s organic chemicals. So things like pesticides, polychlorinated biphenyls, often abbreviated PCBs. Polycyclic aromatic hydrocarbons, things from combustion, personal care products, home products that you use in your home, flame retardants, phthalates, caffeine, nicotine. It’s a really broad range. That’s one of the attributes of silicone is that it absorbs a wide range of chemicals. And that’s important because a lot of times you get stuck in a silo of just thinking “I’m really only interested about pesticides.” But let’s think broader. We’re exposed to a lot of chemicals, and we really don’t know what that space looks like because we’re not looking more broadly. And that’s one of the things that this particular technology affords, we can look at a really wide range of chemicals and the mixture of those chemicals for each individual person.
Miller: That recent application of your bracelets that I mentioned, the one that was in Thailand, it found whether people worked with plastic waste or not, that they were exposed to at least 14 different chemicals, and on all the classes that you just described phthalates ‒ PAHs, bisphenol, flame retardants. What stood out to you in this recent study? And I noted this is just one among many. But what do you notice in this one?
Anderson: The 14 that showed up in everybody. We have seen this kind of similarity in a wide range of communities, whether they’re in Africa or Europe, Asia, North America, South America. And I think that’s what’s really interesting is it’s kind of like opening the blinds to seeing all the chemicals that we’re exposed to. Many of them are not sort of on anyone’s list to be concerned about. We don’t have a lot of toxicology information about these chemicals because they really haven’t been identified as a common exposure. So I think that was very interesting. Again, I wasn’t part of the study.
One of the other things is while they were looking for things like phthalates, which are common component of plastics, is that everybody had phthalates in their wristband. And that did not surprise me because a lot of other products besides plastics have phthalates.
Miller: Just to take this among all the others, what are the potential health effects of phthalates in a human body?
Anderson: Well first and foremost, largely not known. That’s one of the reasons why we would want to know that. There’s tens of thousands of chemicals in commerce. Which one should we spend our time studying to understand the health effects? So many of these phthalates, we don’t have a lot of information. But some of them, we have a little bit of information, like that they can be endocrine disrupting, other kinds of health issues. But it’s largely a lot that’s not known, as compared to some of our other chemicals that we more commonly think of.
Miller: And is it your argument that one of the potential follow-on applications of this kind of work is for regulators to say, “Alright, we now know that these classes of chemicals are in humans everywhere, and if we don’t know their effects, let’s start with these since they’re in everybody’s bodies.” Is that essentially what you’re saying?
Anderson: Exactly. Doing one chemical at a time when there’s literally tens of thousands of chemicals that haven’t been tested, we need a way of prioritizing. One prioritization would be chemicals that are, that we have experience, and that many people have exposures to. And in mixtures, in addition to just the single chemical. So if we have to prioritize, one aspect of prioritizing would be chemicals that so many people have exposures to.
Miller: I don’t know if I’m alone in this, but I was just as you were talking, I was looking at the studio around me ‒ the desk which has some kind of plastic cover. I’ve got a keyboard here which is all plastic, I’ve got a mouse and screens. There’s some metal a little bit on a music stand where some pieces of paper are. But basically, I am in a sea of plastic, and I’m not alone. Many people listening right now are wearing versions of plastic or have plastic all around them. And that’s just one version of our chemical lives. It’s overwhelming if I stop to think about it. How do you think about the stuff in our lives, the question marks about safety, and the places where there aren’t even question marks, where we know there are dangers, but nevertheless these things still make up, sometimes literally, the fabric of our lives, or figuratively the fabric of our lives.
Anderson: It can feel overwhelming. And I think we have to start just parsing that out bit by bit, step by step, and progress will be made step by step. And I think that one of those pieces, as you alluded to earlier, is informing people just how many chemicals they’re exposed to, and maybe not the usual suspects as it were. And by informing people, we can hopefully motivate, through the process of citizens involved, and motivate agencies that have these responsibilities for developing safety, we can motivate all that through a ground up approach.
But I think also we do know something. Like you said, your office has a lot of plastic. So you could do the exact same thing when you go home ‒ look at everything around you, whether it’s flame retardants in your couch and your mattresses, but also looking at the products that you use. So as you’re applying lotion or as you’re applying a fragrance or the products that clean your home. You might spend eight, nine, 10 hours a day in that home with little circulation. When you apply a lotion on your skin, that is about as direct input of chemicals, and if phthalates, for example, are a part of that lotion, you’re applying those phthalates right into your body.
Miller: Is that necessarily put on the label?
Anderson: Sometimes it is. Oftentimes it is. So in the case of an air freshener, that might be listed. A fragrance, that may or may not be listed depending on how the company has identified it as an important ingredient. But a lot of times they are listed. And those are choices that you could make. Again, it’s step by step. There’s choices that we make as a society to get moving in the right direction and identify priorities, and there’s choices we can make as individuals to prioritize. So you could choose not to use that air freshener. There are other air fresheners that don’t have that ingredient. You could choose not to use that lotion or that fragrance. So there’s different ways in which, as an individual, when you get your results back, or as a society, we can start making these steps forward to improve our environment so that we’re not negatively affecting our health with some of these chemicals.
Miller: So not to put all of the onus on us all as consumers, as the public. But for years, the Environmental Working Group has put out a list of what it calls the Dirty Dozen, lists of fruits and vegetables with the highest levels of pesticide residues. Is there anything similar for some of the other chemicals in our lives that are associated with the highest known risks?
Anderson: I’m not aware of that. And I feel like we’re focused on the usual suspects that we’ve ignored some of these other chemicals that we have actually a lot higher exposure to, and know less about from a toxicity standpoint, health standpoint, long term implications standpoint. We don’t know the same thing that we do, for instance, from the Environmental Working Group when it comes to pesticides. We know a lot less.
Miller: What do you see as the next frontier of your own research?
Anderson: Right now, I’m looking at developing analytical techniques, where we take the chemicals from the wristbands, we actually look at ways, using something called stable isotopes so that we can look at see where the source is of these chemicals. So the question I get is, what am I exposed to? How does that relate to my community or other communities? So that’s important to get a broader perspective of. Like you said, 14 were the same in everyone. And so that’s an important question, what does that look like? But then the next question I always get is, where is my exposure? So by looking at these stable isotopes, I’ll better be able to tell the actual source. Is the source from the highway next door? Or is the source from the natural gas that you use in your home to cook with? So those are the kinds of things I’m working on right now ‒ to better understand sources of those chemicals to that we can get at, hopefully, modifying those sources, reducing those sources.
Miller: Kim Anderson, thank you so much.
Anderson: Thank you.
Miller: Kim Anderson is director of OSU’s Food Safety and Environmental Stewardship Program. She is a professor in environmental and molecular toxicology at OSU.
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