There is growing concern about the health effects of exposure to chemicals known as PFAS.
And new research has found that when pregnant women are exposed to so-called “forever chemicals,” their babies are more likely to be born prematurely and with low birth weight. It also increased the risk of infant mortality.
The data comes from New Hampshire, and one of the researchers said the study attempted to uniquely isolate the effects of PFAS.
The study’s authors include Derek LeMoyne and Ashley Langer. They are both professors of economics at the University of Arizona and co-directors of the Consortium for Green Business. They joined the show to talk about what they discovered.
whole conversation
Mark Brody: Derek, first of all, let me talk about how you conducted this research. As you wrote, it’s obviously not possible to intentionally expose humans to PFAS, but I’ve found a place where you can actually measure the health effects in those who were exposed and those who were not.
How did this happen?
Derek Lemoine: So if you want to think about the effects of PFAS on human health, you might imagine taking people into a lab and giving them PFAS. But like you said, we don’t intend to do that. For various reasons, we did not and could not.
So we want to find some sort of experiment, a so-called natural experiment, some troubling real-world data, an experiment. There, some people were exposed to PFAS and others were not. Ideally, they don’t really know who they are. They lived essentially the same way as each other, except that some were probably drinking water that was high in PFAS, and some were not.
The trick was to find mothers living near contaminated areas in New Hampshire, so they were able to obtain data on the locations of their wells and the locations of the wells that supplied them with water. Some of their wells were upstream of the contaminated area with respect to groundwater, and some were downstream. That was the variation we used.
Mark Brody: And, Ashley, it sounds like the results of this study were pretty dramatic in terms of health effects on the newborn based on whether the mother lived upstream or downstream of these contaminated wells.
Ashley Langer: Yes. We were very surprised at how big and how big the effect was. You know, we thought there might be an impact on the infant’s health.
However, we were quite surprised by the fact that infant mortality was almost three times higher for mothers who were at the same distance from contaminated sites and who were receiving water from wells downstream of these contaminated sites compared to mothers who were receiving water from wells upstream.
These were shocking to us.
Mark Brody: Ashley, of course, as Derek explained, real world data can be a little trickier than lab data. But how much of these numbers can be attributed to PFAS compared to other variables that these mothers may have been affected by?
Ashley Langer: So we ran a lot of checks and robustness and really dug into those because we really wanted to make sure that what we were going after was PFAS and not something else.
In other words, these mothers controlled for differences in wealth, education, maternal health, and smoking habits. We do not see any differences in these types of demographic outcomes between mothers whose water gradients are rising and those whose water gradients are falling from these locations. There are no differences in education or family values. So we’re pretty sure this is coming from where they source their water.
We are currently focusing specifically on contaminated sites where older types of PFAS were present that are no longer commonly used. Although it is possible that there are other types of PFAS that are simultaneously released into drinking water, we have ruled out many other pathways by which these results could occur.
Mark Brody: So, Derek, one of the things your paper looked at is the cost, the economics of this. I would like to ask you about that. Of course, cleaning up PFAS is expensive. There’s a lot of talk about this across the country and here in Arizona.
However, it turns out that the health costs of not cleaning up the chemicals are higher than the costs of actually cleaning up the chemicals.
Derek Lemoine: Yeah, thank you for bringing this up. So, as economists, we bring two things to this study. So one thing is to focus on actually finding the causal relationships of PFAS in the data.
The other thing is, once we see a health benefit, we want to monetize it. Because the benefit of cleaning up PFAS is that it avoids these negative health outcomes for mothers and infants, as well as other negative health outcomes that PFAS can cause.
So we want to compare that to the cost and ask whether policies to clean up PFAS make sense. And regulators like the EPA, which is currently considering cleaning up PFAS, will likely make the same calculations.
Therefore, we use external estimates of the costs of having an extremely low birth weight baby, for example. The baby will therefore be costly for the rest of its life in terms of higher medical costs and increased risk of death during the first year. That would impose a cost of lower wages later on, but obviously this is all an average.
And we use outside estimates for those costs. We can then extrapolate New Hampshire’s estimates to the rest of the country to estimate how many extra births of each type there are. By calculating the costs for each type of birth and combining them, we can arrive at the total additional burden due to PFAS.
This is a rough estimate, but it’s a back calculation based on what we believe pretty well about New Hampshire. The number we get is at least $8 billion. The idea is that you know you need to add different types of costs, but you just don’t know if everything in one category is also in another, or how much they overlap, and how to add them, so it’s almost certainly going to be bigger than that.
But the cost is at least $8 billion a year, and the estimated cost to clean up PFAS, or to comply with recent EPA regulations to clean up PFAS, is less than $4 billion a year. So if that rule is enough to avoid many of these negative outcomes that are being found for mothers and babies, it seems like a pretty good deal to move PFAS to that rule.
Mark Brody: Ashley, if you look at the numbers, health-related costs are about $8 billion and cleaning costs are just under $4 billion. What comes to mind from this calculation?
Ashley Langer: So we think that $8 billion is a very conservative number for the potential benefits of removing PFAS from drinking water in these places that are contaminating drinking water. It is only for these results, the health of the infant.
Therefore, it does not address other possible health effects. We did not look at long-term cancer or the effects on adults that other studies have suggested.
As economists, we typically weigh costs and benefits. And here, if the cost to remove PFAS is only $4 billion and the cost to leave it in is at least $8 billion, this looks like a very good deal and a very good way to help infants throughout their lives.
Mark Brody: Derek, I’m curious about how you want this data to be used outside of the sites you’re looking at in New Hampshire, given what we know and don’t know about PFAS, and where it is, and how exposed people are to it.
Derek LeMoyne: Yeah, there are some ways you can use some of these numbers. One is, as Ashley said, new rules to clean up PFAS are burdensome. The burden will fall on water utilities and, by extension, their customers. There’s also the health burden of PFAS in the water your customers receive.
Therefore, we suggest that this study may provide a way to weigh these burdens. Are the costs that customers pay worth the benefits they will receive?The other thing is that the type of PFAS that we’re studying is what’s called long-chain PFAS. In fact, since about 2010, little or no production has occurred in the United States.
However, they are present throughout the soil. And basically it exists more or less nationwide. Their soil contains large amounts of these, which slowly migrate toward the groundwater. They will therefore enter the groundwater for decades and centuries to come.
In addition to having an impact on cleaning public facilities, these types of PFAS can be fairly effectively cleaned up by carbon filters, the type that many people have in their homes, water jugs, and refrigerators. So if we know that certain populations are particularly vulnerable, and in our case we’re looking at a population of pregnant mothers that has been shown to be quite vulnerable to PFAS, the idea is also that we can get better testing and information that we currently have about who is exposed to PFAS and then enable households to take action at the household level to remove some PFAS.
Therefore, information itself is a fairly inexpensive policy that can have significant effects.
Mark Brody: Derek LeMoyne and Ashley Langer are professors of economics at the University of Arizona and co-directors of the Consortium for Environmentally Resilient Business.
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