A new study has found that even low levels of prenatal PFAS exposure – from chemicals commonly dubbed ‘forever chemicals’ – can significantly disrupt the development of infants’ immune systems.
Researchers from the University of Rochester Medical Center (URMC) monitored 200 healthy mother-infant pairs, discovering that PFAS compounds cross the placenta and are transmitted via breast milk, affecting critical immune pathways in babies.
This study adds to a growing body of research linking PFAS exposure to long-term health effects and emphasises the importance of minimising exposure during critical periods of early development.
PFAS explained
Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals found in thousands of consumer products, including nonstick cookware, food packaging, waterproof clothing, and even some personal care items.
Known for their persistence in the environment and the human body, these chemicals have long been associated with health risks – but this new research brings clarity to their subtle and early impact on infant immunity.
Immune cell shifts observed in the first year of life
The URMC research team measured maternal PFAS levels during pregnancy and analysed infant blood samples at birth, six months, and one year.
The results were striking: by 12 months, babies whose mothers had higher levels of PFAS in their blood during pregnancy showed noticeable imbalances in their immune cell populations.
Specifically, these infants had a significantly reduced number of T follicular helper (Tfh) cells. Tfh cells are crucial for assisting B cells in producing strong, long-lasting antibodies – a key part of a healthy immune response.
At the same time, the infants displayed elevated levels of Th2, Th1, and regulatory T cells (Tregs), each associated with potential immune-related complications if present in excess.
Th2 and Treg increases are linked to allergic inflammation and immune suppression, while Th1 elevation raises concerns about future autoimmune issues.
Implications for vaccine response and long-term health
The reduced number of Tfh cells could explain previously observed weaker vaccine responses in children exposed to higher levels of PFAS.
These cells are essential in developing immune memory to vaccines like those for tetanus or measles. When these immune building blocks are altered early in life, the effects can be long-lasting.
Increased Th2 and Treg cells suggest a greater susceptibility to allergies and less effective immune defence, while too many Th1 cells may elevate the risk of developing autoimmune diseases such as type 1 diabetes or juvenile arthritis later in life.
The immune system in infancy is a delicate balancing act, and prenatal PFAS exposure may be tipping the scales at a critical stage.
How families can reduce PFAS risks
Although Rochester’s municipal water complies with federal safety limits, PFAS is still found in many everyday products.
Notably, mothers in the study had relatively low levels of PFAS compared to national averages, yet the immune effects in their infants were still significant.
Families can take proactive steps to reduce PFAS exposure, especially during pregnancy and early childhood.
Switching to stainless steel or cast iron cookware, avoiding nonstick pans that are scratched or damaged, using water filters certified to remove PFAS, and storing food in glass or ceramic containers can all help lower exposure levels.
Continued research and monitoring
The URMC team plans to follow the children into toddlerhood to examine whether these immune changes persist and lead to greater susceptibility to illness, allergies, or autoimmune conditions.
Future research aims to measure PFAS directly in infants and better understand the molecular mechanisms behind the immune disruption.
As the health impacts of prenatal PFAS exposure become clearer, this research highlights the urgent need for public health strategies to minimise exposure and monitor vulnerable populations, starting before birth.
