Endocrine Disrupting Chemicals in Human Milk: A Systematic Review of Concentrations and Potential Health Implications

Endocrine-disrupting chemicals (EDCs) disrupt the synthesis, transport, action, or metabolism of endogenous hormones in the human body. EDCs often enter the body through inhalation, ingestion, or dermal contact and can accumulate in the body. Remobilization or transfer of EDCs can occur during lactation, causing human milk to become contaminated with a variety of EDCs, which could expose nursing infants and children to these chemicals. Several studies have examined the concentration ranges for one or multiple EDC(s) in human milk. Additional studies document associations between EDC exposure and adverse health outcomes, many of which are in adult populations. It is therefore essential to understand the extent to which EDCs in human milk contribute to cumulative early-life exposures. We performed a literature review of peer-reviewed studies reporting concentrations of one or more of the following EDCs in human milk during or after 2004: bisphenols, organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), parabens, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFAS), and phthalates. We identified concentration ranges for each chemical detected in human milk and health impacts associated with early-life exposures to EDCs noted across studies from this review. Determining the presence of EDCs in human milk and the associated effects of exposure through nursing is essential to develop feeding recommendations that safeguard infant and child health.