Breast milk samples from Seattle mothers contained alarming levels of dangerous hormone-disrupting chemicals, including BPA, BPS, melamine, cyanuric acid, and triclosan, a new peer-reviewed study found.
These chemicals pose a serious risk to infants because they are likely to interfere with hormones essential for the proper development of newborns and have been found to be harmful even at very low levels of exposure. About 92% of the 50 samples were contaminated with at least one of the antimicrobials or plasticizers the researchers tested.
The same milk samples were previously found to contain potentially dangerous levels of PFAS “forever chemicals” and flame retardants, which are also endocrine disruptors.
Mixtures of endocrine-disrupting chemicals are “concerning for a number of reasons,” said Ryan Babadi, lead author of the peer-reviewed study and senior researcher at the nonprofit Toxic Free Future.
“This concerns infants and children, who are the most vulnerable group in terms of health effects, as they are at a stage of rapid development regulated by the endocrine system,” Babadi said.
While previous studies have shown individual chemicals in mothers’ bodies, the new study is one of the first to detect melamine along with multiple other endocrine-disrupting chemicals in breast milk.
Babadi stressed that breastfeeding remains the healthiest option for infants if possible, as it is the most nutritious and generally the safest option. Many of the same chemicals are also included in the formula. But Babadi added that the findings highlight “broad systemic problems” as chemical companies use the compound extensively and regulators have failed to curb its use.
Endocrine disruptors are regularly added to everyday products across the economy to achieve a variety of purposes. The antibacterial triclosan is often included in some personal care products. The plasticizers melamine, BPA, and BPS are used in resins for purposes such as preventing products from sticking to packaging, giving shape to plastics, or providing UV protection.
In this study, BPA and BPS were detected in 74% and 78% of the samples, respectively. These chemicals have been found to cause a wide range of developmental and reproductive harm in epidemiological studies, and BPS is thought to be associated with weight loss in young children. BPA is associated with neurodevelopmental disorders, asthma, and obesity.
The researchers also found triclosan in 62% of the samples and melamine in 92%. There is a lack of research on the health effects of exposure to mixtures of endocrine-disrupting chemicals, but limited studies have linked it to lower birth weight and height.
The authors of the study note that the small sample size is a limitation. This included a wide range of mothers who were highly educated and had high incomes. Some of the compounds were detected at levels below the World Health Organization’s acceptable daily intake, but still at levels that previous studies have shown can cause illness, the study noted.
Taking steps like not buying plastic can help mothers avoid chemicals, but the compounds are so ubiquitous in consumer products that people “can’t shop around and get out of this,” Babadi said.
The findings come as the Trump EPA launches a multi-pronged attack on chemical regulations. It is moving to remove restrictions on many toxic chemicals and carcinogens in consumer products and water. It is also weakening the regulatory process as Congress considers watering down the nation’s laws on toxic chemicals.
Babadi said the findings show “these policies need stronger protections, not rollbacks.”
“That would further exacerbate the exposures seen in this paper, worsening the health of not only children but also adults, workers and communities,” Babadi added.
