Credit: Wikimedia Commons/ Anton Nosik
Breast milk is considered the best food for infants, but it can be contaminated with chemicals the mother is exposed to in daily life.
A group of scientists analyzed samples of breast milk from nursing mothers in Canada and South Africa for contaminants and found low levels of pesticides, parabens (endocrine disruptors in plastics), and bisphenols, including bisphenol A and S (endocrine disruptor) in many of the samples.
They published several research papers with their findings. They found contaminants, but at different levels, in the 594 breast milk samples of Canadians and South African women. Unfortunately, all breast milk samples showed some contamination - which can occur from personal care products, the packaging used in foods, in medications, household cleaning products, or even as a food additive.
For example, methyl paraben was detected in 96% of the Canadian human milk samples, followed by ethyl paraben (57%) and propyl paraben (37%). The pesticide propanil (an herbicide) was detected exclusively in South African breast milk samples, as was the antiretroviral drug Efavirenz used in HIV treatment.
BOTTOM LINE: The researchers stress that breast milk is the best food (the gold standard) for infants, but women should realize that chemicals they are exposed to do get into breastmilk. Therefore, try to avoid pesticides, read ingredient labels, and try to minimize exposure to harmful chemicals.
From Newsweek: Scientists Discover Pesticide Traces in Breast Milk
Researchers at McGill University have identified several unexpected chemical contaminants in human milk, finding traces of pesticides, antimicrobials and additives used in plastics and personal‑care products.
The team said the data, drawn from Canadian and South African samples, could help strengthen chemical safety regulations and improve protections for infants and parents.
“It is important to note that these chemicals were detected at low concentrations, and we do not fully understand the health effects of many of them. So, despite these findings, breast milk remains ideal for infants, as it has the nutrients infants need to develop as well as antibodies that protect them against diseases,” Stéphane Bayen, the study's co-author, said in a statement.
A group of scientists published the results across five papers after analyzing 594 human milk samples collected between 2018 and 2019 in Montreal, Vhembe and Pretoria.
The researchers used a non‑targeted analysis, allowing them to search broadly for unusual chemical residues rather than focusing on individual, pre‑selected substances. This approach enabled them to detect several compounds not previously reported in human milk.
Among the newly identified chemicals were antimicrobial preservatives 2‑ethylhexyl 4‑hydroxybenzoate and phenyl paraben. These ingredients are commonly added to soaps, disinfectants and personal‑care items. The researchers also found two plastic‑related antioxidant additives—Irganox 1010 and BHT‑COOH—used during manufacturing to package materials.
Additional contaminants included propanil, an agricultural herbicide, and chloroxylenol, an antimicrobial used in disinfectants and household products.
The research also identified potential links between certain contaminants and infant health.
The team reported that concentrations of bisphenol A (BPA) and bisphenol AF in breast milk were associated with altered growth among South African infants. While the study did not examine specific health outcomes, the association underlined the need for further investigation into how contaminants present in milk might influence early development.