McGill Researchers Discover Unexpected Chemical Contaminants in Human Milk
McGill researchers found various unexpected chemical contaminants, including pesticides and plastic additives, in human milk samples from Canada and South Africa. While concentrations were low, reaffirming breast milk's benefits, a non-targeted analysis identified novel compounds and an HIV drug metabolite. These findings highlight widespread chemical exposure, aiming to improve safety regulations and encourage further research into metabolic effects and potential health impacts, though more studies are needed, especially regarding associations with infant growth.
An interdisciplinary team, primarily from McGill University, has identified a diverse array of unexpected chemical contaminants within human milk samples collected from both Canada and South Africa. These detected substances encompass traces of pesticides, antimicrobials, and additives commonly found in plastics and personal-care products. Despite these findings, researchers, including Stéphane Bayen, reiterate that these chemicals were present at low concentrations and emphasize that breast milk remains the optimal nutritional source for infants, offering essential nutrients and protective antibodies.The study employed a non-targeted analysis method, a departure from earlier research focusing on individual chemicals, allowing for a broader discovery of unusual chemical residues. This approach led to the identification of several compounds previously unreported in human milk, alongside 8-hydroxyefavirenz—a breakdown product of the HIV medication efavirenz—in South African samples. The presence of this metabolite indicates its use by mothers during or prior to the sampling period.Analyzing 594 samples from 2018-2019 using high-resolution mass spectrometry, the team concluded that populations are exposed to a complex mix of chemical residues reflecting individual diet, environment, and lifestyle. The researchers suggest that establishing this baseline data is crucial for future efforts to reduce unwanted exposures and improve chemical safety regulations. While a preliminary association between certain bisphenol concentrations in breast milk and altered infant growth in South Africa was observed, Jonathan Chevrier cautions that these findings require replication before definitive conclusions can be drawn. The research, published across five papers, highlights the necessity of understanding all exposures during infants' critical developmental window.
