New peer-reviewed research shows that fetuses likely have much higher levels of Pfas, “forever chemicals,” in their blood than previously thought.
Cord blood tests typically look for a small amount of common Pfas compounds, such as Pfoa and Pfos. However, there are thousands of Pfas and a new Mount Sinai study analyzed 120 umbilical cord blood samples that previously contained up to four compounds.
The expanded “non-targeted analysis” identified 42 Pfas compounds in the 120 samples, and the total level of Pfas in the blood was much higher than previously found.
The findings suggest that “infants are exposed to many more Pfas than we previously thought,” said Shelley Liu, co-author of the study and associate professor at the Icahn School of Medicine at Mount Sinai.
“It’s particularly important to understand because it’s a very vulnerable period when fetuses are exposed,” Liu added.
PFAs are a class of approximately 15,000 compounds that are most commonly used to make products that are water, stain, and grease resistant. The chemicals have been linked to cancer, birth defects, lowered immunity, high cholesterol, kidney disease, and a variety of other serious health problems. They are called “forever chemicals” because they do not break down naturally in the environment.
Fetuses are widely exposed to Pfas through umbilical cord blood. A review of 40 studies found that researchers had collectively detected Pfas in each of the 30,000 cord blood samples they analyzed. Elevated levels of Pfas in mothers are associated with increased infant mortality, as well as low birth weight and obesity later in life. Studies have also linked fetal exposure to cancer, neurological problems, and cardiovascular disease later in life.
“Legacy” compounds such as Pfoa and Pfos were the most widely used until the last decade. These have been phased out and replaced by newer generations of Pfas that chemical manufacturers claim, often without evidence, are less toxic. Meanwhile, Pfas can break down into new compounds once in the environment or human body.
Regulators’ methods of monitoring blood, water and other media for these new Pfas have been slow to keep up with the change. The U.S. Environmental Protection Agency, for example, typically only checks water samples using a testing method that looks for 30 to 40 compounds, although independent researchers have found thousands in water. A 2022 Guardian analysis found that regulators frequently underestimated Pfas levels in water.
The Mount Sinai study effectively compared cord blood samples using the old assay and the broader “non-targeted” assay that looks for thousands of compounds.
As expected, more extensive testing found more Pfas, Liu said. The EPA recently certified a blood test that will detect 53 compounds. Liu said the expanded list is an improvement over more limited testing, but Mount Sinai’s non-specific analysis found 31 compounds not included in the EPA’s test.
What does this mean for babies? The study did not look at health problems, and Liu said the impact is “a little confusing,” but higher levels of Pfas in the blood are generally associated with a higher risk of health problems.
The blood the researchers analyzed was drawn as part of the federal government’s Home study, which tracks people’s exposure to Pfas and their health outcomes across the lifespan. The Mount Sinai authors will likely try to understand the health implications.
The study shows how “the harms to babies contaminated with an entire mixture of Pfas chemicals have likely been underestimated due to the inability to measure these compounds,” said David Andrews, acting chief scientific officer at the nonprofit Environmental Working Group, who was not involved in the study.
“This document is a stark reminder of the importance of health protection regulations and how lax oversight can result in babies being born pre-contaminated with harmful chemicals like Pfas,” Andrews added.
