Concentrations of bisphenols, parabens, and benzophenones in human breast milk: A systematic review and meta-analysis

Background: Breast milk is the main source of nutrition for infants but may be responsible for their exposure to environmental chemicals, including endocrine-disrupting chemicals. Aim: To review available evidence on the presence and concentrations of bisphenols, parabens (PBs), and benzo-phenones (BPs) in human milk and to explore factors related to exposure levels. Methods: A systematic review was carried out using Medline, Web of Science, and Scopus databases, conducting a comprehensive search of peer-reviewed original articles published during the period 2000-2020, including ep-idemiological and methodological studies. Inclusion criteria were met by 50 studies, which were compiled by cal-culating weighted detection frequencies and arithmetic mean concentrations of the chemicals. Their risk of bias was assessed using the ROBINS-I checklist. Results: Among the 50 reviewed studies, concentrations of bisphenols were assessed by 37 (74.0%), PBs by 21 (42.0%), and BPs by 10 (20.0%). Weighted detection frequencies were 63.6% for bisphenol-A (BPA), 27.9-63.4% for PBs, and 39.5% for benzophenone-3 (BP-3). Weighted mean concentrations were 1.4 ng/mL for BPA, 0.2-14.2 ng/mL for PBs, and 24.4 ng/mL for BP-3. Mean concentrations ranged among studies from 0.1 to 3.9 ng/mL for BPA, 0.1 to 1063.6 ng/mL for PBs, and 0.5 to 72.4 ng/mL for BP-3. The highest concentrations of BPA and PBs were reported in samples from Asia (versus America and Europe). Higher BPA and lower methyl-paraben concentrations were observed in samples collected after 2010. Elevated concentrations of these chemicals were associated with socio-demographic and lifestyle factors in eight studies (16.0%). Two epidemio-logical studies showed moderate/serious risk of bias. Conclusions: This systematic review contributes the first overview of the widespread presence and concentrations of bisphenols, PBs, and BPs in human breast milk, revealing geographical and temporal variations. The methodological heterogeneity of published studies underscores the need for well-conducted studies to assess the magnitude of exposure to these chemicals from human milk. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This systematic review highlights the widespread presence and concentrations of bisphenols, parabens, and benzo-phenones in human breast milk. Variations in levels of these chemicals are observed across geographical regions and time periods, with certain socio-demographic and lifestyle factors also influencing their concentrations.