A nationwide study by the RIVM has found that PFAS is present in the breast milk of all women tested, though in 82 percent of cases the levels remain below the risk threshold. Researchers also report a decline in concentrations compared with earlier international measurements.

The study analyzed breast milk from 1,629 women collected in 2021. It is part of a broader research program by the RIVM examining PFAS levels in the bodies of people in the Netherlands, alongside earlier studies on blood and food contamination.

According to the findings, when PFAS concentrations in breast milk fall below the risk value, no harmful effects for the child are expected. This was the case for 82 percent of participants. In the remaining 18 percent, levels exceeded the risk threshold, meaning potential health effects for infants cannot be ruled out.

PFAS exposure can negatively affect the immune system by reducing antibodies, making the body more vulnerable to illness. However, the RIVM emphasized that PFAS in breast milk does not directly mean a child will become ill. Outcomes depend on multiple factors, including genetics, diet, and living environment.

The substances are a group of synthetic chemicals used in products such as raincoats, firefighting foam, and nonstick cookware coatings. They enter the environment and reach humans through food and drinking water.

The RIVM found that PFAS levels in breast milk have decreased compared with a 2014 analysis conducted by the World Health Organization (WHO). Researchers suggest the decline may be linked to regulatory measures, including European bans on PFOS, PFOA, and PFHxS in consumer products. Authorities say these restrictions aim to reduce environmental and human exposure, though the RIVM stressed that further action is still needed.

Despite the findings, the Dutch Voedingscentrum said the results do not change official breastfeeding guidance. The organization continues to recommend breastfeeding for at least the first six months when possible.

“Babies who are breastfed also benefit from important substances and protective effects in breast milk,” said Wieke van Vossen, a food safety expert at the Voedingscentrum. “For example, breastfeeding supports a baby’s immune system through the presence of antibodies and immune cells.”