Endocrine-disrupting chemicals that interfere with hormones were found in breast milk and in the urine of children from birth up to six months, according to a study being presented at ENDO 2026, the Endocrine Society's annual meeting in Chicago, Ill., on June 14.
Street and colleagues used data from 336 mother-infant pairs enrolled in the LIFE-MILCH project. Samples were collected one month, three months, and six months after birth. The researchers measured exposure to more than 50 different chemicals, including bisphenols (BPA), polycyclic aromatic hydrocarbons, phthalates and metabolites, parabens, polar pesticides, and pyrethroids.
BPA was commonly found in breast milk one month after birth (51.2%) and at six months postpartum (49.8%). Nearly a third of the infants had BPA in their urine samples following birth. The number increased to 67.6% when the infants were six months old. Bisphenol S was found in breast milk one month after birth (10.7%), at six months after birth (18.3%), and in infant urine samples at birth (22.4%) and at six months after birth (41.2%). Most polycyclic aromatic hydrocarbons were rarely detected in breast milk, but several were consistently found in urine (up to 27.7%).
Methylparaben and ethylparaben were most commonly found one month (51.2%; 42.3%) and six months postpartum (56.2%; 52.6%) in breast milk, with increases observed over time for these substances also appearing in urine samples.
Glufosinate was detected in breast milk one month after birth (27.4%) and three months after birth (31.9%), as well as urine samples at birth (44.7%) and at six months of age (38.2%). Phthalates including dibutyl phthalate were present in 90% or more of breast milk samples early on; levels increased significantly over time for these substances as well.
"Most EDCs found in breast milk and urine samples are associated with nutrition habits and products used for personal and household care," Street said.
Studies have linked exposure to these chemicals with neurodevelopmental issues, hormonal activation at birth, androgenization or development of male reproductive characteristics; EDC exposure can also alter growth, weight, or obesity risk, according to Street.
The study findings have led to a prevention campaign with results currently under evaluation; several stakeholders have signed agreements to monitor and reduce these chemicals within their products specifically within Italy, according to Street, who urged public health officials "to reduce exposure to EDCs" while creating preventive strategies "to protect breast milk."
