Category: Forever

The “forever chemicals” flowing from U.S. wastewater treatment plants are not only more abundant than previously thought, but also largely consist of pharmaceuticals that have received little scientific or regulatory attention, a new multi-university study reveals.  

The research, published in PNAS – and covered by The New York Times and The Washington Post, among other outlets – found that common prescription drugs make up about 75% of the organic fluorine in wastewater entering treatment plants, and 62% in treated water released to the environment.

These findings suggest millions of Americans could be exposed to these persistent chemicals through their drinking water.

“We’ve been focused on a small subset of these chemicals, but that’s just the tip of the iceberg,” said Bridger J. Ruyle, an incoming Assistant Professor in NYU Tandon School of Engineering’s Civil and Urban Engineering department and the study’s lead author. “The research shows that even advanced wastewater treatment removes less than 25% of these compounds before they’re discharged into rivers and streams.”

Of particular concern is that six forever chemicals recently regulated by the Environmental Protection Agency in drinking water make up only about 8% of the organic fluorine found in wastewater effluent. The remainder consists largely of fluorinated pharmaceuticals and other compounds that aren’t currently regulated.

Using a national model that tracks how wastewater moves through U.S. waterways, the researchers estimate that during normal river conditions, about 15 million Americans receive drinking water containing levels of these compounds above regulatory limits. During drought conditions, that number could rise to 23 million people.

The study examined eight large wastewater treatment facilities serving metropolitan areas across the United States. These facilities are similar to those serving about 70% of the U.S. population, suggesting the findings have broad national implications.

“What’s particularly troubling is that these fluorinated pharmaceuticals are designed to be biologically active at very low doses,” said Ruyle. “We don’t yet understand the public health implications of long-term exposure to these compounds through drinking water.”

The research comes at a critical time, as about 20% of all pharmaceuticals now contain fluorine. While this chemical element makes drugs more effective by helping them persist in the body longer, that same persistence means they don’t break down in the environment.

The findings suggest that current regulatory approaches focusing on individual chemicals may be insufficient to address the complex mixture of fluorinated compounds in wastewater. The study also highlights how water scarcity could exacerbate the problem. In regions experiencing drought or implementing water conservation measures through wastewater reuse, there’s less dilution of these chemicals before they reach drinking water intakes.

“These results emphasize the urgent need to reduce ongoing sources of these chemicals and evaluate the long-term effects of fluorinated pharmaceuticals in our water supply,” said Ruyle. “We can’t just focus on the handful of compounds we’ve studied extensively while ignoring the majority of what’s actually out there. We need a more comprehensive approach to regulation and increased attention to the ecological and public health impacts of fluorinated pharmaceuticals.”

The paper’s publication comes on the heels of Ruyle’s November 2024 testimony to New York State lawmakers warning about the threats of forever chemicals passing through water treatment plants. The new findings provide detailed evidence supporting his concerns about the potential prevalence of these compounds in downstream drinking water supplies.

In addition to Ruyle, the paper’s authors are Emily Pennoyer, Thomas Webster, and Wendy Heiger-Bernays from Boston University School of Public Health; Simon Vojta, Jitka Becanova, and Rainer Lohmann from the University of Rhode Island’s Graduate School of Oceanography; Minhazul Islam and Paul Westerhoff from Arizona State University; Charles Schaefer from CDM Smith in New Jersey; and Elsie Sunderland, who holds appointments at Harvard’s School of Engineering and Applied Sciences, Department of Earth and Planetary Sciences, and School of Public Health.

Financial support for this work was provided by the National Institute for Environmental Health Science Superfund Research Program (P42ES027706) and the Water Research Foundation (Project 5031). This study was also supported by contributions from the anonymous participating wastewater treatment facilities.

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B.J. Ruyle, E.H. Pennoyer, S. Vojta, J. Becanova, M. Islam, T.F. Webster, W. Heiger-Bernays, R. Lohmann, P. Westerhoff, C.E. Schaefer, E.M. Sunderland, High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans, Proc. Natl. Acad. Sci. U.S.A.

Research led by the Keck School of Medicine of USC has shown that levels of “forever chemicals” in the blood are linked with disruptions to a fundamental pillar of health — sleep.

In the first study to examine that relationship in young adults, participants with higher levels of four specific types of per- and polyfluoroalkyl substances (PFAS) in their blood experienced worse sleep. The scientists are the first to delve into underlying molecular mechanisms, identifying genes involved with the body’s natural defenses and a hormone that regulates sleep.

PFAS enter the body through contact with consumer items and are even ingested with food and water. They don’t break down easily and can persist in the environment for decades. The vast majority of Americans have detectable levels of PFAS in their blood.

In recent years, forever chemicals have been associated with health harms from cancer and neurological disease to deficits in hormone and immune function. The study, supported by the National Institutes of Health (NIH) and published in the journal Environmental Advances, is among a small body of research concerning PFAS and sleep.

“Because the body needs sleep every day, if PFAS might be interfering with your sleep, that may affect you more immediately than other chronic health issues,” said first and corresponding author Shiwen (Sherlock) Li, PhD, a postdoctoral researcher in the Department of Population and Public Health Sciences at the Keck School of Medicine. “Long term, poor sleep has been connected to outcomes including neurological and behavioral problems, type 2 diabetes and Alzheimer’s disease.”

In addition to providing insight into the biology of PFAS’ influence on sleep, the study may add to evidence suggesting a rationale for closer regulation of forever chemicals.

“Sleep quality is an issue that affects almost everybody, so the impact of PFAS on sleep may have policy implications,” said Li, who is advised by study co-authors Lida Chatzi, MD, PhD, director of the Center for Translational Exposomics Research and professor of population and public health sciences and of pediatrics, and Max Aung, PhD, MPH, associate director of community engagement for the center, and assistant professor of population and public health sciences.

Identifying forever chemicals potentially detrimental to good sleep

The researchers collected blood samples and information about sleep from 144 participants, age 19 to 24, who were part of the USC Children’s Health Study. Two sets of measurements were taken years apart, with about half of the participants contributing to both.

Out of seven types of PFAS examined, four were significantly associated with less sleep or worse quality of sleep — PFDA, PFHxS, PFOA and PFOS.

For the first three of those, young adults with blood levels in the highest one-third slept an average of about 80 fewer minutes nightly than those in the lowest third. High combined levels of PFAS also correlated with shorter sleep. For PFOS, high blood concentrations were significantly linked to self-reported problems falling asleep, staying asleep, waking up or feeling tired during waking hours.

All four forever chemicals — some of which are associated with cancer and neurological disorders from ADHD to Alzheimer’s disease — are considered “legacy PFAS.” Though widely used from the 1950s to the early 2000s, they have since been largely phased out in favor of similar compounds with unknown safety profiles.

“It could be a matter of cumulative exposure over time,” Li said. “What we measured in the blood is likely driven by exposure since birth, or even prenatal exposures.”

Biological clues emerge about PFAS and sleep disruptions

The team analyzed the four types of PFAS using toxicology databases that compile research connecting chemicals, diseases and changes in gene expression. Because no previous research drew together PFAS, sleep and gene expression, the team looked at the overlap between genes affected by the four forever chemicals and genes related to sleep disorders.

The investigators then profiled a panel of proteins — the products of the blueprints inscribed in genes — from participants’ blood samples. Out of 600-plus candidate genes, seven activated by PFAS seemed to influence sleep.

An important factor was an immune-oriented gene called HSD11B1. It helps produce the hormone cortisol, which plays an important role in regulating the rhythm of sleep and wakefulness.

“If the expression of the protein encoded by HSD11B1 is disrupted, that means that cortisol levels could also be disrupted,” Li said. “That, in turn, affects sleep.”

Another gene seemingly prominent in PFAS’ impact on sleep, cathepsin B, is related to cognitive function and memory. The resulting enzyme is a precursor of amyloid beta proteins, which are found in plaques in the brains of Alzheimer’s patients. High levels of the enzyme have been linked to cognitive decline in Alzheimer’s — which has its own connections to sleep deficits.

The investigators will continue to explore forever chemicals and sleep patterns in children as part of the NIH’s Multi-Omics for Health and Disease Consortium. They are also pursuing lab studies into the genes identified in the study and into associations between PFOS and brain development.

About this study

The study’s other co-authors are Jesse Goodrich, Jiawen Carmen Chen, Elizabeth Costello, Emily Beglarian, Jiawen Liao, Brittney Baumert, Sarah Rock, Sandrah Eckel, Rob McConnell, Frank Gilliland, Zhanghua Chen and David Conti, all of the Department of Population and Public Health Sciences at the Keck School of Medicine of USC; Tanya Alderete of Johns Hopkins University; and Damaskini Valvi of the Icahn School of Medicine at Mount Sinai.

The study was supported by National Institute of Environmental Health Sciences (R01ES029944 along with more than two dozen other awards) and the USC President’s Sustainability Initiative Award.