PFAS Contamination in Drinking Water Is Quietly Costing the US Billions and Harming Infant Health

The phrase “forever chemicals” sounds dramatic, but new research shows the concern is very real and measurable. A major study led by researchers at the University of Arizona has found that contamination of drinking water by PFAS chemicals is linked to serious infant health problems and at least $8 billion per year in economic losses across the contiguous United States. The findings were published in the Proceedings of the National Academy of Sciences (PNAS) and add some of the strongest real-world evidence so far that PFAS exposure through drinking water can have devastating long-term consequences.

What Are PFAS and Why Are They Called “Forever Chemicals”?

PFAS, short for per- and polyfluoroalkyl substances, are a large group of synthetic chemicals developed decades ago. They were designed to resist heat, oil, grease, and water, which made them extremely useful in products like non-stick cookware, water-resistant fabrics, food packaging, and firefighting foams.

The same chemical stability that made PFAS commercially valuable is also what makes them dangerous. These compounds do not easily break down in the environment, meaning they can persist in soil and groundwater for decades. Once released, they slowly migrate downward, contaminating drinking water sources long after manufacturing has stopped. This persistence is the reason they are commonly referred to as “forever chemicals.”

How This Study Was Conducted

One of the biggest challenges in PFAS research has been proving causation rather than simple correlation. Many earlier studies showed links between PFAS exposure and health problems, but critics often argued that other environmental or socioeconomic factors could explain the outcomes.

This new study addressed that challenge with a clever and rigorous approach. The research team examined all recorded births in New Hampshire between 2010 and 2019, focusing on mothers who relied on private wells for drinking water. Instead of comparing different towns or regions, the researchers used groundwater flow direction to determine exposure.

Mothers whose wells were located downstream of known PFAS-contaminated sites were compared with otherwise similar mothers whose wells were upstream of the same sites. Because groundwater naturally flows in predictable directions, this method created a near-random difference in PFAS exposure while holding many other factors constant. This design allowed the researchers to isolate the effects of PFAS in drinking water more convincingly than most previous studies.

The Impact on Infant Health

The health outcomes identified in the study are serious and difficult to ignore. Infants born to mothers who consumed PFAS-contaminated water experienced significantly worse outcomes during pregnancy and in the first year of life.

The study found higher infant mortality rates during the first year, along with a clear increase in preterm births. Particularly concerning was the rise in extremely premature births, including those occurring before 28 weeks of gestation. These early births often come with lifelong health complications.

Low birth weight was another major finding. Babies exposed to PFAS in utero were more likely to weigh less than 5.5 pounds at birth, and there was also an increase in very low birth weight infants, including those weighing under 2.2 pounds. Low birth weight is closely linked to higher risks of developmental delays, chronic illness, and reduced life expectancy.

Together, these results build on laboratory and public health research but stand out because they are based on real-world exposure across a large population, rather than animal studies or small observational samples.

The Economic Cost of PFAS Exposure

Health outcomes are only part of the story. The researchers also calculated the broader economic impact of PFAS-related infant health problems. When the New Hampshire results were extrapolated to the entire contiguous United States, the estimated cost reached at least $8 billion every year.

This figure includes medical expenses, long-term healthcare needs, and reduced lifetime earnings associated with poor early-life health. Importantly, the authors describe this estimate as conservative, meaning the true cost is likely higher. Many potential impacts, including broader social and family effects, were not fully captured in the calculation.

The study’s authors point out that when these costs are compared with the price of cleaning up PFAS contamination, the economic argument becomes clear. Preventing exposure and investing in cleanup efforts could yield substantial long-term financial benefits alongside improved public health.

Who Conducted the Research

The study was a collaboration across disciplines. Economists Derek Lemoine and Ashley Langer from the University of Arizona’s Eller College of Management partnered with Bo Guo, an associate professor of hydrology and atmospheric sciences. Their collaboration was sparked by an event hosted by the Arizona Institute for Resilience, which aims to connect researchers across different fields.

Additional contributors included economics alumnus Robert Baluja and postdoctoral researcher Wesley Howden. The interdisciplinary nature of the team allowed the study to combine detailed hydrological modeling with long-term economic and health impact analysis.

Why Old PFAS Still Matter Today

The study focused on two long-chain PFAS chemicals, PFOA and PFOS. These substances are no longer manufactured in the United States, but they remain widespread in the environment. Large quantities of these chemicals were historically dumped into soil, where they continue to slowly seep into groundwater.

According to the researchers, the PFAS detected in groundwater today likely represents only a small fraction of what was originally released. Much of the contamination remains underground, migrating downward over time. This means that exposure risks may continue for decades unless active cleanup measures are taken.

Can PFAS Be Removed From Drinking Water?

While PFAS contamination is widespread, the study highlights that drinking water interventions can make a real difference. Technologies such as activated carbon filtration, whether installed by water utilities or used in home filtration systems, are effective at removing long-chain PFAS like PFOA and PFOS.

For pregnant women in particular, reducing PFAS exposure through improved water filtration may be a practical and protective step. The findings reinforce the idea that even though PFAS are widespread, local water quality still matters greatly for health outcomes.

Why This Study Matters

This research stands out because it provides strong evidence that PFAS exposure through drinking water is not just a theoretical risk. It is linked to measurable harm to infants and billions of dollars in economic losses every year. By using groundwater flow to approximate random exposure, the study strengthens the case for causation and raises the stakes for policymakers, regulators, and public health officials.

As PFAS regulation and cleanup efforts continue to evolve, studies like this provide critical data to guide decisions. They also underscore the importance of protecting drinking water sources, especially for vulnerable populations such as pregnant women and infants.

Research paper: https://www.pnas.org/doi/10.1073/pnas.2509801122