Methylparaben and Ethylparaben Exposure Through Breast Milk in the First Six Months of Lactation: A Taiwanese Cohort Study With Estimated Daily Intake for Breastfed Infants.

BACKGROUND: Parabens, alkyl esters of p-hydroxybenzoic acid used as antimicrobial preservatives in food, pharmaceuticals, and cosmetics, are endocrine-disrupting chemicals (EDCs). Stage-specific data on paraben transfer through breast milk and exposure estimates for Taiwanese infants are lacking. METHODS: We quantified methylparaben (MeP), ethylparaben (EtP), n-propylparaben, and n-butylparaben by LC-MS/MS in 63 breast milk samples from 54 Taiwanese mothers within six months postpartum, classified as colostrum (≤7 days) or post-colostrum milk (>7 days). Estimated daily intake (EDI) was calculated and compared with the EFSA group acceptable daily intake (ADI) of 10 mg/kg/day for MeP+EtP. RESULTS: EtP and MeP were detected in 100% and 81% of samples. Both were significantly higher in colostrum than in post-colostrum milk (EtP: 6.35 vs. 1.6 ng/mL, p < 0.001; MeP: 0.75 vs. 0.5 ng/mL, p = 0.028). EtP levels exceeded those reported in Korean and Chinese cohorts. EDI for MeP+EtP was 0.36 μg/kg/day in colostrum-fed neonates-∼28,000-fold below the EFSA ADI-yet body-weight-normalised EtP exposure was ∼1.5-fold higher than in older infants. CONCLUSIONS: Estimated paraben intake via breast milk was far below the EFSA group ADI, although a modest, transient increase in body-weight-normalised EtP exposure was observed during the colostrum period. TRIAL REGISTRATION NUMBER: Not applicable.