Babies in the womb were exposed to far more “forever chemicals” than scientists ever realized—and we’re only beginning to understand what that means.
Babies born from 2003 to 2006 were exposed in the womb to far more “forever chemicals” than researchers once believed, according to a new study published today (February 18) in Environmental Science & Technology.
These chemicals, called per- and polyfluoroalkyl substances or PFAS, include thousands of compounds that are still widely used. Scientists do not yet fully understand how they affect human health, which makes it especially important to measure how much exposure occurs before birth.
The research was led by Shelley H. Liu, PhD, Associate Professor of Population Health Science and Policy at the Icahn School of Medicine at Mount Sinai. Her team developed a data-driven approach to estimate a newborn’s total PFAS exposure by analyzing umbilical cord blood with advanced chemical detection tools.
PFAS are synthetic chemicals found in everyday products such as nonstick cookware, stain-resistant fabrics, food packaging, and firefighting foam. They are known as “forever chemicals” because they break down very slowly and can build up in the environment and in people over time.
Advanced Testing Reveals Broader PFAS Exposure
To better understand prenatal exposure, researchers examined stored umbilical cord blood samples collected between 2003 and 2006 from 120 babies enrolled in the Cincinnati based HOME Study. Because these children are now adolescents, the team can eventually connect early chemical exposure to later health outcomes.
Instead of testing for a limited list of known chemicals, the researchers used a newer, non-targeted chemical analysis method. This approach screens for hundreds or even thousands of substances at once rather than focusing only on a predefined panel. As a result, the team detected far more PFAS in cord blood than traditional testing would have found, including newer and less studied compounds.
In total, they identified 42 confirmed or suspected PFAS chemicals in the cord blood samples. Many of these substances are not routinely measured in standard screenings, and little is known about their potential health effects. The findings show that babies are exposed before birth to a wide array of PFAS, including perfluorinated chemicals, polyfluorinated chemicals, and fluorotelomers.
A New Tool to Measure Total PFAS Burden
To capture the overall level of exposure, the researchers developed what they call PFAS-omics burden scores using item response theory methods. These scores provide a snapshot of a baby’s cumulative PFAS exposure at a single point in time.
When the team applied this broader measurement, they did not find differences in PFAS exposure between babies born to first-time mothers and those born to mothers who had previous pregnancies. Earlier studies using narrower PFAS panels had suggested such differences.
“Our findings suggest that how we measure PFAS really matters,” said Dr. Liu, first and co-corresponding author of this study. “When we look more comprehensively, we see that babies are exposed to far more PFAS chemicals before birth than we previously realized—and some of the patterns we thought we understood may change.”
Why Prenatal PFAS Exposure Matters
Pregnancy is a sensitive period of development. Previous studies have linked prenatal PFAS exposure to lower birth weight, preterm birth, changes in immune response to vaccines, metabolic effects, and other developmental issues.
“Our study helps show that prenatal PFAS exposure is more complex and widespread than earlier studies suggested,” Dr. Liu said. “Understanding the full picture is essential if we want to protect child health and reduce preventable environmental risks.”
The American College of Obstetricians and Gynecologists has described reducing exposure to environmental toxins such as PFAS as a “critical area of intervention.”
What This Means for Doctors and Families
Despite growing evidence that PFAS can influence multiple aspects of health, exposure to these chemicals is not routinely assessed in clinical care.
The new method offers a way to estimate cumulative PFAS exposure more comprehensively. In the future, tools like this could help clinicians:
- Identify individuals with higher exposure burdens
- Monitor at risk populations more closely
- Guide preventive health strategies
“For now, this work helps lay the scientific foundation,” Dr. Liu said. “Our goal is to move toward earlier identification and prevention, especially during sensitive windows like pregnancy.”
Next Steps in PFAS Research
The research team plans to examine whether higher overall PFAS exposure early in life is linked to negative health outcomes as children grow. They also intend to study the potential health effects of newly identified and understudied PFAS compounds found in cord blood, and to further improve tools that support primary disease prevention.
Reference: “Quantifying PFAS-Omics Burden Scores for Nontargeted Analysis Using Multidimensional Item Response Theory: An Exploratory Analysis of Novel and Legacy PFAS in Cord Blood” by Shelley H. Liu, Yitong Chen, Leah Feuerstahler, Jeremy P. Koelmel, Krystal J. Godri Pollitt, Yingying Xu, Bruce Lanphear, Kimberly Yolton, Aimin Chen, Kurt D. Pennell, Joseph M. Braun and Katherine E. Manz, 18 February 2026, Environmental Science & Technology.
DOI: 10.1021/acs.est.5c06490
Funding: National Institutes of Health
Collaborating Institutions: University of Michigan, Fordham University, Brown University, University of Cincinnati, University of Pennsylvania, Yale University, Simon Fraser University
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6 Comments
But then, our lifespan is the largest our known history as species. Something doesn’t match.
Yeah except that the old people today were born before all this crap…just wait another generation and we’ll see what life expectancy rates look like.
Are certain PFAS a potential cause behind autism?
Everything that we made that wasn’t already here is a potential forever chemical. Nano plastic for example. We just left the century of Chemistry. What else did anyone expect? We’ve got work to do on this and it will step in toes!
That’s a pretty broad brush statement. Many manmade chemicals break down in sunlight, in the soil, or by bacterial action, etc. How about sucralose, saccharine, anticancer drugs, packing materials or bags made of starch, and the list can go on and on. But your point is well taken that many manmade chemicals and materials do have a very long life in the environment, which should not be ignored.
Not a peep from the “MAHA” administration, I guarantee.