Think Out Loud

Researchers investigate long-lasting ‘fluorinated substances’

By Elizabeth Castillo (OPB)
Dec. 1, 2021 7:59 p.m. Updated: Dec. 8, 2021 10:45 p.m.

Broadcast: Wednesday, Dec. 1

The Oregon Health Authority and the Oregon Department of Environmental Quality are collaborating on testing 150 drinking water systems across the state for per- and polyfluorinated substances, known as PFAS.


The substances can be found in the blood of people and animals all over the world. They are found in water, air, fish, and soil in places around the country, according to the Environmental Protection Agency. What are these substances exactly and how concerning are they? Jennifer Field is a professor at Oregon State University and Robyn Tanguay is a distinguished professor at the school. The researchers join us with details.

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Note: The following transcript was computer generated and edited by a volunteer.

Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. We end today with a conversation about per- and poly- fluorinated substances known collectively as PFAS. These chemicals can be found in water, air, fish and soil around the country, according to the EPA. They can also be found in the blood of people and animals all over the world. Now, the Oregon Health Authority and the State’s Department of Environmental Quality are collaborating to look for PFASs in 150 drinking water systems across the state. So what exactly are these chemicals? And how worried should we be about them? Two professors from Oregon State University join me now to talk about this. Jennifer Field is an Environmental Chemist. Robyn Tanguay is a Toxicologist. Welcome to you both.

Jennifer Field: Thank you for having us.

Robyn Tanguay:  Absolutely.

Miller: Jennifer Field, first. What is a PFAS?

Jennifer Field: PFAS is a term that we now use to capture a whole lot of chemicals. So it’s really a catch-all term that has many classes or families of chemicals inside of it. And some of the classes have some well known members. Maybe people have heard of pETPhos. It is a Sultanate and or PFOA which is a carboxylate, so those are different members of different families.

Miller:  What kinds of products are these chemicals found in?

Field: These chemicals have proven to be so useful since they were first created many, many decades ago. So, products that you might be familiar with, especially here in the Northwest, that are rain and / or water and oil repellent, they tend to be coated with these materials because these chemicals are so interesting that they really don’t like interacting with basically anything. So that means they’re very good at shedding water, shedding oil. So there’s many products in homes in schools, commerce, automobiles that have these water and oil repellencies and they’re most likely created out of these or included with these families of chemicals.

Miller: Robyn Tanguay. What do we know about the effects of these chemicals on our bodies?

Tanguay: That’s a terrific question. Jennifer alluded to the fact that these compounds have been around for decades. And I think the chemist with the expertise of Jennifer and others who can detect these chemicals in various tissues that’s been way ahead of the curve in terms of what these chemicals do to biology.

Miller: In other words, it’s easier to find them in bodies

Tanguay: Yes. That’s correct.

Miller: than to say this is exactly what it does to the body.


Tanguay: Exactly. So what’s happening now, the field is at the point where there’s enough evidence to demonstrate that these compounds are prevalent in the environment and in tissues like you mentioned in the introduction. Now we’re trying to understand whether or not these chemicals all behave the same way. Jennifer mentioned that there’s thousands of chemicals that in this large umbrella of PFASs  and their structures are very, very different.  They have some common features. What the biologists and toxicologists are not trying to do is get their hands on as many of these individual chemicals and compare them to determine whether there could be some compounds that are more hazardous or toxic, and some that may be less toxic. So there’s certainly been many studies in laboratory studies, for example, where they do low to very high concentration studies and they see effects of these compounds. But really the data is just starting to be collected from the biological perspective to these compounds.

Miller: What are some of the early findings in nonhuman studies?

Tanguay: So again, the tricky part of toxicology is, as they say, the dose makes the poison. So at very high concentrations in studies there’s been cancer endpoints in mammalian bodies, some reproductive and developmental effects, developmental immunological effects, as examples. In the human situation, it’s even more challenging, as you can imagine, you can’t control these studies very well. So you find associations between detection of these compounds in tissues and some adverse effects. There’s been some reports of cancer relationships. But again, those studies aren’t necessarily causal yet. I think there’s enough concern to really put a lot more effort into understanding the true risk of these compounds to humans and the environment.

Miller: Jennifer Field. One of the things that struck me so far in my conversation with both of you is that there are so many chemicals that fall under this gigantic umbrella term – a kind of family of families, if I understand it correctly – that I’m wondering if it’s even a helpful term. If we’re talking about thousands of chemicals, all of which may behave very differently in our bodies. Is it helpful to talk about them with one four letter acronym?

Field: Well, that’s a super good point. I think we use it for convenience to begin to start to communicate with people. But as Robyn was saying, there’s a large amount of effort both in the toxicology side, the biology side and the measurement side of trying to understand the environmental, and I think folks that are involved in that kind of research do have an appreciation that these sub families are not alike. And then even some members within families aren’t alike. So we do embrace that difference and we aren’t trying to bunch them all together, there’s definitely an awareness. But I think in a program like this, we are trying to talk about a complex subject. The term is useful.

Miller: Oregon DEQ and the State Health Authority, as I mentioned, are focused now on drinking water supplies. But in 65 public water systems in the state that were monitored back in between 2013 and 2015, none of these chemicals were found, if I understand this correctly. I’m wondering, Jennifer Field first, if you’re expecting something different this time around.

Field: Well, I’m not aware of what those 65 locations were, but we have certainly learned since 2013 and 2015, about a different location or activities where these chemicals might be found. So it sounds to me that Oregon is casting a bit broader net probably based on knowledge informed by that 65 sites from several years ago and with new knowledge and using that to again, cast a broader net. So I think it’s great that we don’t have those hits for the first  65 sites, but we have more sensitive methods, now, the methodology has changed a bit, over time, and it depends what they’re actually looking for. So I guess it’ll be interesting to see what they actually find in this next round.

Miller:  Robyn Tanguay. Given that these chemicals are in tons and tons of products that we use in our lives, why is it that drinking water would be the main concern right now as opposed to, I don’t know, some non-stick frying pan or a raincoat or tires or I get the sense it’s in so much stuff. I’m just making these products up. I imagine these are all over the place. So is drinking water your main concern?

Tanguay: It’s an excellent question and certainly going back to your issue, lots of these compounds, lots of diversities, compounds and lots of products around the world. When we do label them all as just PFASs, like Jennifer mentioned, you lose that resolution of the chemicals that are present in the water might be very different than the PFAS compounds that would be found in your popcorn bag or your bottom of your pizza box, and those may be a higher source of exposures. So there’s a lot of effort, international effort to just deal with these as a large group, regardless of where those exposures might occur, to try to get them out of the marketplace. I think there’s a lot of effort in that area with the assumption that if they’re detected they’re probably hazardous. I don’t know if I entirely agree with that conclusion, but the safest bet would be to reduce the use of these compounds in products, and they wouldn’t end up in consumer products or in the water. I think that’s probably the rationale there.

Miller: Were those two examples you came up with, the bottom of the popcorn container, and other food containers, were those made up? Or are these chemicals currently being used in stuff that touches the food we put in our bodies?

Tanguay: Jennifer, perhaps you’d want to take that one.

Field: Well, the FDA has undertaken quite a bit of an evaluation of the chemicals that they approve, and I’m not an expert in that particular area, but in our own work here at Oregon State University, we have detected these materials in textiles, in paper, some of which are associated with food contact.  Are they deliberately added, or are they making their way into contacting these materials as they work their through the supply chain? That’s actually an open question. And so some of the materials, you know, they are detectable, but again, this is on the FDA’s radar screen and I believe there’s quite a bit of activity, right now, questioning this and because the public wants to know where if these continue to be used in the food contact paper industry.

Miller: Just briefly, Robyn Tanguay, this is more of a political question, but the sense I get from you both is that there are huge questions, we just don’t know how dangerous these are, and yet these are in products right now, do you think it makes sense as a precautionary stance to sort of, to remove these from a ton of products until we know more?

Tanguay: You’re right, it does- Atlantic Ocean separating those different views on how we handle chemicals.

Miller: Literally Europe.

Tanguay: Very literally, correct. The precautionary principle in Europe really, the assumption is these chemicals are hazardous unless proven safe, and generally in the United States, these types of consumer products, these chemicals, they just have to be effective in their performance in the examples that we just gave, and they don’t really have to demonstrate safety to get these types of chemicals in common and commerce use. And so there’s certainly some regulatory changes happening in the US to put the burden of demonstrating safety of any chemical before it’s used. But that is not the operating principle in the United States right now.

Miller:Robyn Tanguay and Jennifer Field, thanks very much for joining us.

Tanguay: Thank you.

Field:  Thank you.

Miller: Jennifer Field and Robin Tanguay are Professors at Oregon State University.