Study: Unborn babies exposed to far more ‘forever chemicals’ than previously known

Babies in the womb are exposed to a far broader range of toxic “forever chemicals” than scientists previously understood, according to a new study that used advanced screening methods to measure prenatal chemical exposure more comprehensively.

The study, published Wednesday in the journal Environmental Science & Technology and led by researchers at the Icahn School of Medicine at Mount Sinai in New York, identified 42 different per- and polyfluoroalkyl substances, or PFAS, in umbilical cord blood samples. Traditional testing methods typically screen for only a small, predefined list of these compounds.

PFAS are a large class of man-made chemicals used in products such as nonstick cookware, stain-resistant clothing, food packaging and firefighting foam. Often referred to as “forever chemicals,” they persist in the environment and the human body.

Researchers analyzed archived umbilical cord blood samples collected between 2003 and 2006 from 120 newborns enrolled in the HOME Study, a long-running research project based in Cincinnati. Instead of testing only for specific known chemicals, the team used a non-targeted chemical analysis technique capable of scanning hundreds to thousands of substances at once.

That broader approach captured many PFAS compounds, including newer and lesser-studied ones, that are not commonly screened for in standard testing.

“When we look more comprehensively, we see that babies are exposed to many more PFAS before birth than we previously understood,” said lead researcher Dr. Shelley H. Liu, an associate professor of population health science and policy at Mount Sinai.

The researchers also developed what they call a “PFAS-omics burden score,” designed to summarize a newborn’s total PFAS exposure in a single measure. The tool could eventually help clinicians identify patients with higher exposure levels and monitor populations that may be at greater risk.

One notable finding: When researchers applied the broader testing method, they did not observe differences in PFAS exposure between babies born to first-time mothers and those whose mothers had previous pregnancies. Earlier studies relying on more limited PFAS panels had suggested such differences existed.

Why it matters

Pregnancy is considered a particularly sensitive window for chemical exposure. Prior research has linked prenatal PFAS exposure to low birth weight, preterm birth, altered immune responses and metabolic changes.

The American College of Obstetricians and Gynecologists has identified reducing exposure to toxic environmental chemicals such as PFAS as a critical area of intervention.

Despite growing evidence of potential health effects, PFAS exposure is not routinely measured in clinical care.

“Understanding the full picture is essential if we want to protect child health and reduce preventable environmental risks,” Dr. Liu said.

What comes next

The researchers plan to examine whether the higher cumulative PFAS exposure detected in the cord blood samples is associated with health outcomes in the now-adolescent participants from the original study. They also aim to investigate the potential health effects of the newer and lesser-known PFAS compounds identified through the expanded screening method.

The study was funded by the National Institutes of Health and conducted in collaboration with researchers from the University of Michigan, Brown University, Yale University, the University of Pennsylvania, the University of Cincinnati, Fordham University and Simon Fraser University.