New Testing Reveals Widespread “Forever Chemical” Exposure

Babies born between 2003 and 2006 were exposed in the womb to significantly more “forever chemicals” than previously estimated, according to a new study published February 18 in Environmental Science & Technology.

The chemicals, known as per- and polyfluoroalkyl substances (PFAS), include thousands of synthetic compounds still widely used in consumer and industrial products. Because scientists do not yet fully understand their long-term health effects, accurately measuring prenatal exposure remains a priority.

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 newborn PFAS exposure using advanced chemical detection tools on umbilical cord blood samples.

PFAS are found in products such as nonstick cookware, stain-resistant fabrics, food packaging and firefighting foam. They are often called “forever chemicals” because they degrade very slowly and accumulate in the environment and in human bodies over time.

Advanced Analysis Identifies Dozens of Compounds

The researchers analyzed stored umbilical cord blood collected between 2003 and 2006 from 120 infants enrolled in the Cincinnati-based HOME Study. Since those children are now adolescents, future research can examine potential long-term health effects.

Instead of relying on traditional testing panels that target a limited list of known chemicals, the team used a non-targeted chemical analysis method capable of screening hundreds or thousands of substances simultaneously. This broader approach detected many more PFAS compounds than standard screenings typically identify.

In total, the team identified 42 confirmed or suspected PFAS chemicals in the cord blood samples, including newer and less studied compounds. These included perfluorinated chemicals, polyfluorinated chemicals and fluorotelomers, many of which are not routinely measured in clinical or environmental assessments.

Developing a PFAS “Burden Score”

To estimate overall exposure, the researchers created PFAS-omics burden scores using item response theory methods. These scores provide a cumulative snapshot of a newborn’s PFAS exposure at a single point in time.

When applying this comprehensive measurement, the team did not observe differences in PFAS exposure between first-time mothers and those with previous pregnancies. Earlier studies using narrower chemical panels had suggested such variations.

“When we look more comprehensively, we see that babies are exposed to far more PFAS chemicals before birth than we previously realized,” Liu said. She added that broader measurement methods may alter previously understood exposure patterns.

Health Implications and Future Research

Pregnancy is a sensitive developmental window. Prior research has associated prenatal PFAS exposure with lower birth weight, preterm birth, altered immune responses, metabolic changes and other developmental concerns.

Although exposure to PFAS is not routinely evaluated in clinical practice, the study’s methodology may eventually help clinicians identify individuals with higher cumulative exposure, monitor at-risk populations and guide preventive strategies.

The research team plans to investigate whether higher early-life PFAS burden scores are associated with adverse health outcomes as children age. They also aim to examine newly identified compounds and refine tools that support environmental risk prevention.