Unborn Babies Carry Far More 'Forever Chemicals' in Their Blood Than Scientists Previously Realized

Fetuses Exposed to Alarming Levels of PFAS 'Forever Chemicals,' New Study Finds

Groundbreaking new research suggests that unborn babies are carrying far greater concentrations of so-called "forever chemicals" in their bloodstream than scientists had previously understood — raising serious concerns about the long-term health consequences for the next generation.

The peer-reviewed study, conducted by researchers at the Icahn School of Medicine at Mount Sinai, tested 120 umbilical cord blood samples using a broader, more comprehensive detection method than what is typically employed in standard screening. The results were striking.

What the New Research Uncovered

Conventional testing for per- and polyfluoroalkyl substances — commonly known as PFAS — generally focuses on a narrow set of well-known compounds, such as PFOA and PFOS. However, there are approximately 15,000 known PFAS compounds in existence, and routine screenings barely scratch the surface.

The Mount Sinai team applied what is called a "non-targeted analysis," a much wider-ranging approach capable of detecting thousands of different compounds. When applied to samples that had previously been found to contain just up to four PFAS compounds, this expanded method identified a total of 42 distinct PFAS substances. The overall concentration of these chemicals in the blood was substantially higher than earlier, more limited tests had ever revealed.

"Babies are exposed to many more PFAS than we previously thought," said Shelley Liu, a study co-author and associate professor at Mount Sinai. "It's particularly important to understand because it is a very vulnerable period when fetuses are exposed."

Why PFAS Are So Dangerous

PFAS chemicals are widely used in manufacturing to make everyday products resistant to water, grease, and stains. They are found in everything from non-stick cookware and food packaging to waterproof clothing and firefighting foam. What makes them especially troubling is their persistence — PFAS do not break down naturally in the environment or in the human body, which is why they have earned the nickname "forever chemicals."

Exposure to PFAS has been linked to a wide range of serious health conditions, including various cancers, birth defects, weakened immune function, elevated cholesterol, kidney disease, and cardiovascular problems. For fetuses and newborns, the stakes are even higher.

A comprehensive review of 40 separate studies found PFAS present in every one of 30,000 umbilical cord blood samples examined. Research has also connected elevated PFAS levels in mothers to increased infant mortality rates, low birth weight, and a greater likelihood of obesity in childhood and beyond. Fetal exposure has further been associated with neurological disorders and an increased cancer risk later in life.

Regulatory Testing Is Struggling to Keep Pace

One of the most troubling aspects of this issue is how far behind government monitoring has fallen. Older PFAS compounds like PFOA and PFOS have largely been phased out over the past decade, but chemical manufacturers have replaced them with newer-generation alternatives — substances they frequently claim are less harmful, often without substantial scientific evidence to back those assertions.

Furthermore, PFAS compounds can break down into entirely new chemical variants once they enter the environment or the human body, making comprehensive tracking even more difficult.

The U.S. Environmental Protection Agency, for instance, typically screens water samples using a testing method that checks for only around 30 to 40 compounds. Independent researchers, however, have identified thousands of PFAS variants in water supplies across the country. A 2022 investigation found that regulatory agencies have routinely undercounted PFAS contamination levels in public water systems.

The EPA has recently certified a new blood testing method capable of identifying up to 53 PFAS compounds — an improvement, to be sure. But the Mount Sinai study's non-targeted analysis detected 31 additional compounds that this new EPA test still does not cover.

What This Means for Infant Health

While the Mount Sinai study did not directly assess specific health outcomes, the implications are difficult to ignore. Higher PFAS concentrations in the blood are broadly associated with greater health risks, and the full picture of how a complex mixture of dozens of these chemicals affects fetal development remains largely unknown.

The blood samples analyzed in the study were originally collected as part of the federally funded HOME Study, an ongoing research initiative tracking PFAS exposure and health outcomes across a person's lifetime. The Mount Sinai team has indicated plans to further investigate the potential health consequences of these elevated chemical exposures in future research.

Experts Call for Stronger Protections

Public health advocates were quick to respond to the findings. David Andrews, acting chief science officer at the Environmental Working Group, emphasized that the study reveals just how significantly the dangers to newborns have been underestimated.

"Harms to babies polluted with a complete mixture of PFAS chemicals has likely been underestimated due to the inability to measure these compounds," Andrews said. "This paper is a stark reminder of the importance of health-protective regulations and how lax oversight can result in babies being born pre-polluted with harmful chemicals such as PFAS."

The research adds mounting pressure on regulators to modernize their detection methods and strengthen oversight of PFAS chemicals — before another generation is born already carrying a toxic burden.