New study finds PFAS exposure during pregnancy costs the U.S. $8 billion a year

There’s increasing concern about the health impacts of being exposed to the class of chemicals known as PFAS.

And a new study finds exposure by pregnant women to the so-called "forever chemicals" increased the chances of their babies being born prematurely and with low birth weights; it also increased the risk of infant mortality.

The data come from New Hampshire, and one of the researchers says the study tried to isolate the effects of PFAS by themselves.

Derek Lemoine and Ashley Langer are among the authors of the study; they’re both economics professors at the University of Arizona and co-directors of the Consortium for Environmentally Resilient Business. They joined The Show to about what they found,

Full conversation

MARK BRODIE: Derek, let me start with you and how you went about doing this research. As you’ve written, you clearly cannot intentionally expose humans to PFAS, but you found a place where you could really measure the health effects of people who had exposure versus those who did not.

How did that come to be?

DEREK LEMOINE: So if you want to think about what do PFAS do to human health, you might imagine taking people into a lab and giving them PFAS. But as you said, we’re not going to do that. We wouldn’t, and we couldn’t, for all kinds of reasons.

So we want to find an experiment, what we call a natural experiment, some messy real world data, something that looks like an experiment, where some people were exposed to PFAS, some weren’t. Ideally they don’t really know who they are. They basically went about their lives the same as each other, except that some were drinking water that plausibly had more PFAS in it and some didn’t.

The trick was that we found a setting in New Hampshire where there were mothers living near contaminated sites, and we were able to get data on where their wells were, and the wells that were serving them were, and some of their wells were upstream in groundwater terms from the contaminated sites, and some were downstream. And that was the variation we used.

MARK BRODIE: And Ashley, it sounds like the findings were pretty dramatic in terms of the health impacts on newborns based on whether or not their mother lived upstream or downstream from these contaminated wells.

ASHLEY LANGER: Yes. We were very surprised at how substantial the effects were, how big they were. You know, we thought that there might be an effect on infant health.

But we were fairly astounded by the fact that infant mortality was three times almost higher for the mothers who were receiving water from wells downstream of these contamination sites relative to very similar mothers at a similar distance from the contamination site, but who were receiving water from wells upstream.

These were shocking to us.

MARK BRODIE: Ashley, obviously, you know, real world data can be a little bit, as Derek described it, messier than lab data. But is it possible, or how much of these numbers, how much of these findings do you think is attributable to PFAS versus any of the other variables that these mothers could have been affected by?

ASHLEY LANGER: So we’ve done a lot of checks and robustness, and really dug into these because we really wanted to make sure what we were getting at was PFAS and not something else.

So these mothers, they were controlling for things like whether they’re differences in wealth, or education, or maternal health, smoking behavior, things like that. We don’t see any difference between the mothers who are receiving water upgradient from these sites relative to downgradient in those types of demographic outcomes. We don’t see differences in education, in any of these things, home values. So we are fairly convinced this is coming from where they’re getting their water from.

Now, we are looking particularly at contamination sites that had these older types of PFAS, that are now generally not used. There’s some chance there are other types of PFAS that are released at the same time that could be in drinking water, but we ruled out a lot of other potential avenues by which these results could occur.

MARK BRODIE: So Derek, one of the things your paper looked at is the cost, the economics of this. And I want to ask you about that, because cleaning up PFAS is, of course, expensive. There’s been a lot of talk about that around the country and here in Arizona.

But you found the health costs of not cleaning up the chemicals are higher than the costs of actually cleaning them up.

DEREK LEMOINE: Yeah, thank you for bringing this point up. So as economists, we bring two things to this study. So one is a focus on like really nailing the causal effect of PFAS in the data.

And the other is, once we’ve gotten an effect on health, we really want to monetize that. Because that’s the benefit of cleaning up PFAS is avoiding these negative health outcomes for mothers and infants, and then in addition to any other negative health outcomes PFAS might cause.

And so we want to be able to compare that to the cost, and ask whether policies to clean up PFAS make sense. And any regulator such as the EPA right now that’s thinking about cleaning up PFAS would do the same calculation.

So we use outside estimates of the cost of being extremely, for instance, low birth weight. So that imposes costs on babies throughout the rest of their lives in terms of higher healthcare costs, greater risk of mortality in the first year. It imposes costs in terms of lower wages later in life, and this is all an average, obviously.

And we use outside estimates of those costs. We can then extrapolate from our estimates in New Hampshire to the rest of the country, how many extra births of each type do we think there are. We can take our cost per type of birth, and combine them, and then we can get the total extra burden due to PFAS.

It’s a coarse estimate, but it’s a back-of-the-envelope calculation based on something that we believe in pretty well for New Hampshire. The number we get is at least $8 billion. The idea is that it’s almost surely greater than that because we know we should add different kinds of costs, we just don’t know how to add, whether everything in one category is also in another category or to what degree they overlap.

But it’s at least $8 billion a year, and the estimated cost of cleaning PFAS up or complying with the recent EPA rule to clean PFAS up are under $4 billion a year. So that makes it look like a pretty good deal to bring PFAS toward that rule, if that rule is sufficient to avoid a lot of these negative outcomes we’re finding for mothers and babies.

MARK BRODIE: Ashley, when you look at those numbers, roughly $8 billion in costs, health-related, little less than $4 billion to clean. What comes to mind to you in that calculation?

ASHLEY LANGER: So we think that this $8 billion number is really conservative as the potential benefits of removing PFAS from drinking water in these places where it’s contaminating the drinking water. That’s just for these outcomes, for infant health.

And so that doesn’t address any of the other health outcomes that could happen. We’re not looking at long-run cancers or any adult impacts that other studies have suggested might be there.

As economists, we generally think about weighing costs and benefits. And here, if the costs of removing the PFAS are only $4 billion, and the costs of leaving it in are at least $8 billion, this looks like a really good deal and a really good way to help infants over their entire lives.

MARK BRODIE: Derek, I’m curious how you would hope that this data would be used outside of the sites that you’re looking at in New Hampshire, given sort of what we know and what we don’t know about PFAS and where it is and how much exposure people might have to it.

DEREK LEMOINE: Yeah, there’s a few ways that we would like to see some of these numbers used. So one is, as Ashley was saying, there’s a burden for any new rule to clean up PFAS. That burden is going to fall on water utilities and therefore on their customers. There’s also a health burden from having PFAS in the water that falls on their customers.

And so one implication is that this study can inform ways of weighing those burdens. Are the costs customers pay worth the benefits they’re going to receive? Another is that the kinds of PFAS we’re studying are what are called long-chain PFAS. They really haven’t been produced much or at all in the U.S. since about 2010.

But they are all throughout the soils. And so they’re basically more or less nationwide. Their soils contain a large mass of these, and they’re slowly migrating down toward groundwater. So these are going to be entering groundwater over the next decades and centuries.

Not only are there implications for utilities cleaning up, but these kinds of PFAS can be cleaned up fairly effectively by the types of carbon filters that a lot of people have in their homes and pitchers, or in their refrigerators. So there is also the idea that you could, if we know that certain populations are especially vulnerable — and in our case we’re looking at a population of pregnant mothers that we show is fairly vulnerable to PFAS — then you could also just have much better testing and information that we currently have about who is exposed to PFAS, and allow households to then take the actions at the household level to clean up some PFAS.

So information itself might be a fairly cheap policy that could go a long way.

MARK BRODIE: Derek Lemoine and Ashley Langer are economics professors at the University of Arizona and co-directors of the Consortium for Environmentally Resilient Business.