Concentrations of environmental phenols and parabens in milk, urine and serum of lactating North Carolina women

•Parabens and phenols were detected in urine of 2/3 of lactating moms in MAMA study.•Ethyl, methyl, or propyl paraben, benzophenone-3 and BPA were detected in breast milk.•BPA and benzophenone-3 exposures could not be predicted by single daily collections.•Correlations between chemical and endogenous immune-related biomarkers are reported.

Phenols and parabens show some evidence for endocrine disruption in laboratory animals. The goal of the Methods Advancement for Milk Analysis (MAMA) Study was to develop or adapt methods to measure parabens (methyl, ethyl, butyl, propyl) and phenols (bisphenol A (BPA), 2,4- and 2,5-dichlorophenol, benzophenone-3, triclosan) in urine, milk and serum twice during lactation, to compare concentrations across matrices and with endogenous biomarkers among 34 North Carolina women. These non-persistent chemicals were detected in most urine samples (53-100%) and less frequently in milk or serum; concentrations differed by matrix. Although urinary parabens, triclosan and dichlorophenols concentrations correlated significantly at two time points, those of BPA and benzophenone-3 did not, suggesting considerable variability in those exposures. These pilot data suggest that nursing mothers are exposed to phenols and parabens; urine is the best measurement matrix; and correlations between chemical and endogenous immune-related biomarkers merit further investigation.