Suspect screening of bisphenol A (BPA) structural analogues and functional alternatives in human milk from Canada and South Africa

Abstract

BACKGROUND : Plastic-related contaminants, such as bisphenols, can enter the maternal body and be transferred to breast milk. While common bisphenols such as bisphenol A, S, F and AF have been detected in previous studies, there is limited knowledge about the occurrence of other structurally similar compounds in human milk with potential endocrine-disrupting properties. OBJECTIVE : In this study, we investigated structural analogues and functional alternatives of bisphenol A (BPA) in 594 human milk samples collected from Canada (Montreal) and South Africa (Vhembe and Pretoria) using LC-Q-TOF-MS through suspect screening. METHODS : Suspect screening was performed using data collected from the milk samples using a customized database library (204 compounds). A retrospective semi-quantitative approach was then applied to estimate the levels of TGSA, D-8 and D-90 in human milk. RESULTS : This work revealed the presence of eleven compounds, including four compounds commonly used in thermal labels, four ultraviolet filters, and three synthetic antioxidants or metabolites. Retrospective semi-quantification of D-8, D-90 and TGSA revealed levels of up to 1.24, 1.98, and 0.72 ng/mL in milk, respectively. IMPACT STATEMENT : Several structural analogues and functional alternatives of bisphenol A were identified in human milk through non-targeted screening. Two other phenolic compounds (Irganox 1010 and BHT-COOH) were identified in human milk for the first time. This study highlights the importance of novel strategies in human milk biomonitoring to identify emerging contaminants to which breastfeeding infants are exposed.