Endocrine disruptors are synthetic or natural chemicals that can mimic, block, or otherwise interfere with the body’s hormone systems, potentially causing adverse developmental, reproductive, neurological, and immune effects. The infancy period stands out as a critical window for exposure since hormonal signaling during early life orchestrates crucial developmental processes. Disruptions at this juncture may result in long-term health repercussions, sometimes emerging many years after initial exposure.

The study, spearheaded by Dr. Maria Elisabeth Street and her team at the University of Parma in Italy, employed data from the LIFE-MILCH project, which collected biospecimens from 336 mother-infant pairs at one, three, and six months postpartum. The multidisciplinary analysis quantified over fifty chemical entities, including bisphenols such as BPA and BPS, polycyclic aromatic hydrocarbons (PAHs), phthalates and their metabolites, various parabens, polar pesticides, and pyrethroids.

Bisphenol A (BPA), a well-known industrial compound used in plastic manufacturing, was particularly prevalent in breast milk samples one month after birth (51.2%) and remained consistently high by six months (49.8%). Correspondingly, infant urine contained BPA in approximately one-third of samples shortly after birth, with a dramatic increase to 67.6% at six months. This trend signifies sustained exposure and bioaccumulation potential during early infancy.

Bisphenol S (BPS), often used as a BPA substitute due to regulatory constraints on BPA, was detected in a substantial fraction of breast milk samples, rising from 10.7% to 18.3% between one and six months postpartum. Infant urine similarly reflected an increase, from 22.4% at birth to 41.2% at six months. This highlights a growing yet underappreciated concern regarding BPA analogs and their endocrine-disrupting properties.

Detection patterns for polycyclic aromatic hydrocarbons, compounds generated predominantly by incomplete combustion of organic materials, were infrequent in breast milk but consistently appeared in infants’ urine, with levels reaching as high as 27.7%. The presence in urine but scarcity in breast milk suggests alternative exposure routes, possibly through inhalation or dermal contact with environmental particulates.

Parabens, widely employed as preservatives in cosmetics and personal care products, were found in high proportions in breast milk. Methylparaben (MePB) and ethylparaben (EtPB) were found in 51.2% and 42.3% of samples one month postpartum, increasing slightly to 56.2% and 52.6% by six months, respectively. Corresponding urine samples indicated rising internal exposure over time, underscoring the pervasive nature of these compounds in domestic environments.

Glufosinate, a polar pesticide known for its herbicidal properties and potential neurotoxicity, appeared consistently in breast milk samples at both one month (27.4%) and three months (31.9%) postpartum. Infant urine samples revealed even higher levels, detected in 44.7% of samples immediately after birth and 38.2% at six months, raising alarm over agricultural pesticide residues infiltrating early nutrition pathways.

Phthalates, particularly dibutyl phthalate (DBP), commonly incorporated into plastics and personal care products, were found in over 90% of breast milk samples one month postpartum and remained prevalent at six months (86.5%). The concentration of phthalate metabolites in infant urine increased from 30.3% at birth to 79.4% by six months, confirming continuous and escalating exposure during this formative developmental phase.

The study’s meticulous chemical profiling indicates that the majority of these EDCs correlate strongly with maternal dietary habits as well as the use of household and personal care products. This nexus implicates routine environmental contact points as significant contributors to the contaminant burden encountered by nursing infants.

Extensive epidemiological research has already correlated exposure to many of these endocrine disruptors with neurodevelopmental delays, aberrant hormonal activation during the neonatal period, and androgenization effects including altered maturation of male reproductive tissues. Moreover, these chemicals have been associated with perturbations in growth trajectories, metabolic regulation, and obesity risk, casting a shadow on the future health prospects of exposed infants.

In response to these findings, Dr. Street and colleagues have launched a prevention campaign aimed at curbing exposure to these detrimental chemicals. Collaborations with manufacturers and regulatory stakeholders in Italy have resulted in agreements to monitor, reduce, and potentially reformulate products contributing to the chemical load in breast milk. The researchers advocate for robust public health initiatives worldwide to protect early life nutrition in the face of an evolving chemical landscape.

The evidence presented at ENDO 2026 advances our understanding of the ubiquitous nature of endocrine disruptors and their insidious passage into breast milk and infant physiology. It lays a scientific foundation for urgent regulatory and behavioral interventions to safeguard vulnerable populations during critical developmental windows and beyond. Protecting breastfeeding as the gold standard of infant nutrition requires acknowledging and mitigating the invisible threats posed by environmental contaminants.

This landmark study exemplifies how integrating longitudinal biomonitoring with epidemiological data provides powerful insights into early-life chemical exposures. As endocrine disruptors continue to permeate consumer products and environments globally, this research sends a clear message underscoring the need for interdisciplinary efforts to shield future generations from the hidden perils of chemical interference with hormonal systems.

Subject of Research: Exposure of infants to endocrine-disrupting chemicals (EDCs) through breast milk and urine analysis during the first six months of life.

Article Title: Investigation of Endocrine Disruptor Exposure in Breast Milk and Infant Urine Reveals Persistent Chemical Contamination in Early Life

News Publication Date: 2026

Web References: https://www.endocrine.org/news-and-advocacy/news-room

Keywords: Endocrine disruptors, infants, breast milk contamination, bisphenol A (BPA), bisphenol S (BPS), phthalates, parabens, pesticides, infant exposure, early development, hormonal interference, endocrine health

Bisphenols are a class of synthetic compounds primarily used in the manufacture of plastics and resins. Their presence extends into everyday items, from food packaging to thermal receipts, creating continuous and pervasive exposure. These compounds are recognized as endocrine-disrupting chemicals (EDCs), which means they have the capability to mimic or interfere with the body’s natural hormones. This interference is especially concerning during sensitive life stages such as infancy and early childhood when hormonal systems are still developing.

Previous studies have successfully detected bisphenol A, S, F, and AF in human biological matrices, including breast milk. However, the latest investigations go beyond these common variants, employing advanced suspect screening techniques that enable the identification of a broader spectrum of bisphenol analogues and their functional substitutes. This comprehensive approach is crucial because replacement chemicals, introduced as supposedly safer alternatives, may possess comparable or even greater toxicological profiles, yet remain underexplored.

The study in question analyzes breast milk samples collected from mothers in two geographically and socioeconomically distinct regions: Canada and South Africa. This dual-site approach allows for a comparative assessment that considers variations in environmental exposures, industrial practices, and regulatory frameworks. The findings suggest that contamination by bisphenol structural analogues extends beyond traditionally recognized forms, making these substances a ubiquitous threat across populations.

One of the key technological advancements facilitating this research is suspect screening, which leverages high-resolution mass spectrometry and expansive chemical databases to identify unknown or unexpected compounds without requiring prior standards or calibration curves. This method contrasts with targeted analytical strategies that may overlook emerging contaminants altogether. Its application to human milk represents a significant leap forward in exposure science.

The detection of bisphenol analogues and alternatives in human milk has profound implications for infant health. Breast milk is widely acknowledged as the optimal source of nutrition for newborns, providing not only calories but also essential antibodies and bioactive compounds. However, its capacity to act as a vehicle for chemical transfer from mother to child raises urgent concerns. Early life exposure to endocrine disruptors can alter developmental programming, potentially contributing to chronic diseases later in life.

From a mechanistic perspective, bisphenols exert their endocrine-disrupting effects by binding to estrogen receptors and other hormone receptors, thereby modulating gene expression and cellular signaling pathways. Such interactions can disturb reproductive, neurological, and metabolic development. The structural variation among bisphenol analogues might influence their binding affinity, persistence in the body, and ability to cross biological barriers such as the mammary gland epithelium.

This emerging body of evidence underscores the need for rigorous assessment and regulatory oversight of bisphenol substitutes. Many industries have replaced BPA with alternatives like BPS or BPF, often promoted as safer options in “BPA-free” products. Yet, the preliminary detection of a wider range of bisphenols in human milk prompts a reevaluation of these assumptions, urging caution and further toxicological investigation.

Environmental and social factors are likely to shape the exposure profile observed in the breast milk samples. For instance, dietary habits, consumer product usage, and local environmental contamination can influence the concentration and variety of bisphenols that accumulate in an individual. The comparison between Canadian and South African cohorts offers a nuanced lens to observe these variables, though more extensive studies are needed to ascertain global trends.

The detection of bisphenol contaminants also highlights a larger issue regarding the persistence and bioaccumulation of plastic-derived chemicals within human biological systems. Many bisphenol compounds exhibit lipophilicity and metabolic stability, facilitating their storage in adipose tissue and subsequent release during lactation. Such release mechanisms contribute to chronic low-dose exposure in nursing infants, a demographic particularly vulnerable to endocrine perturbations.

Given the complexity of bisphenol exposure pathways and biological effects, interdisciplinary collaboration is vital. Toxicologists, epidemiologists, chemists, and public health specialists must unite to further elucidate the risks posed and develop strategies for mitigation. Primary prevention approaches could include reformulating consumer products, improving waste management, and establishing stricter safety thresholds for bisphenol analogues.

Future research directions should prioritize longitudinal cohort studies that track mother-infant dyads over time to correlate bisphenol concentrations in breast milk with health outcomes in children. Additionally, mechanistic studies exploring the metabolic fate and receptor binding profiles of novel bisphenol alternatives will help clarify their endocrine-disrupting potential. Analytical method refinement remains crucial for detecting these compounds at trace levels within complex biological matrices.

Public awareness initiatives could play a transformative role in reducing exposure. Informing breastfeeding mothers and the general public about potential sources of bisphenol contamination and how to minimize contact with plastic materials may empower behavior changes. Advocacy for increased transparency from manufacturers regarding chemical contents in products can further facilitate safer consumer choices.

This new evidence about the prevalence of bisphenol analogues in human milk challenges the notion that alternative bisphenols offer a benign substitute to BPA. Instead, it calls for a paradigm shift in how chemical safety is evaluated—emphasizing comprehensive screening and pre-market toxicological testing. Such measures are essential to safeguard vulnerable populations, particularly infants during their critical window of development.

In the broader context of environmental health, this research adds to the mounting literature that links widespread chemical exposure to chronic disease burdens and developmental disorders. It exemplifies the entrenched nature of plastic pollution not only as an ecological problem but as a pervasive threat to human health across generations. Only concerted action at the scientific, regulatory, and societal levels can hope to reverse this trend.

In conclusion, the detection of bisphenol A structural analogues and functional alternatives in human breast milk from diverse populations underscores an urgent public health challenge. The complexity and variation in these compounds necessitate ongoing surveillance, advanced analytical methods, and critical examination of replacement chemicals once considered safe. Addressing these issues is imperative to protect the health of future generations from the insidious effects of endocrine-disrupting plastics.

Subject of Research: Detection and analysis of bisphenol A structural analogues and functional alternatives in human breast milk, assessing their potential as endocrine disruptors and implications for infant health.

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

Article References:
Chi, Z.H., Liu, L., Zheng, J. et al. Suspect screening of bisphenol A (BPA) structural analogues and functional alternatives in human milk from Canada and South Africa.
J Expo Sci Environ Epidemiol (2025). https://doi.org/10.1038/s41370-025-00782-2

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41370-025-00782-2