The research, published in Journal of Chromatography B magazine, was carried out within a sample of 10 women from the province of Granada who breasted their babies and voluntarily participated in the study.
The researchers analysed the presence of five important emerging contaminants in these mothers' milk: metilparabens, etilparabens, propilparabens, butilparabens, and bisphenol A. All of them are dangerous chemicals.
The researchers' proposed methodology, that was applied to the milk samples from the above mentioned mothers, allows to assess the concentration of the analysed contaminant from 0.1 to 0.7 nanograms per millilitre of milk.
“Although the number of samples analysed in for work is small from a statistical point of view, it's worth stressing that almost all of the samples were contaminated with one or some of the studied chemicals. The tool we have developed opens the door to general, wider researches with a greater number of participants”, lead authors of this work and researchers from the UGR department of Analytical Chemistry, Rocío Rodríguez Gómez and Alberto Zafra Gómez, explain.
Synthetic chemical compounds
In the last decades, industrial development has greatly contributed to human exposure to numerous xenobiotic compounds that can cause adverse effects in our health. This is particularly important in the case of various synthetic chemical compounds called Endocrine Disrupting Chemicals (EDCs), which interfere with the hormones' normal functions.
“There is a wide range of chemical compounds that can be found in the food we eat, the air we breath and the water we consume. Among these synthetic chemical products, bisphenol A (BPA) and the parabens (PBs) are the most important”, says Alberto Zafra.
BPA is widely used in the manufacture of polycarbonate plastics and epoxi resins, and it's found in common, widely consumed products: canned food, packaging of food and water, drinking water piping, vehicles and planes, feeding bottles, and even human health-related products such as prosthesis and dental composites.
Meanwhile, PBs are chemical compounds widely used as bactericides and antimicrobian preservatives, specially against moulds and yeasts, in cosmetic and pharmaceutical products, foods and drinks. Be it individually or combined with other products, PBs are used in more than 13 200 formulations of all kind of cosmetic products.
“In the last years, the capability of this chemical substances to interfere with important, physiological functions has been proven. Moreover, it has also been proven that PBs are not metabolised in mammary cancer tissue, so it has drawn attention on its possible toxic and carcinogenic nature”, stresses the UGR researcher.
Personal care products
The main ways of human exposure to this compounds are via skin contact, direct ingestion, or inhalation. “The study of the exposure to EDCs is specially important in the case of breastfed babies fed with their mothers' milk, because they are in the first stages of their development and, for that, are more vulnerable and susceptible to changes in their endocrine systems”, lead author of this work says.
The research carried out at the UGR found BPA in 8 of the 10 analysed samples. In 5 of them, concentrations ranging from 0.6 to 2.1 ng/mL were observed.
Regarding to parabens, similar levels were observed in 70% of the samples (between 1 and 2 ng/mL), except in two of them. The first one showed slightly greater concentrations (1.3 to 5.4 ng/mL). The second one showed concentrations approximately ten times greater than the other samples.
Alberto Zafra says that “in general, our results confirm that these substances are ubiquitous, which could be due to massive, daily use of personal care products by the mothers”.
A valuable, biological fluid
The UGR researcher affirms that breast milk “is a valuable biological product that may serve as an indicator to the mother's exposure to different kinds of chemical compounds, specifically EDCs, as well as to the baby's exposure to them, as milk may be an important way of exposure to exogenous contaminants in the case of babies fed with it”.
“The control of these substances -he continues- may inform us about the incidence and occurrence of diseases and other adverse effects related to these kind of molecules, such as various kinds of cancer, changes in brain structure and function, behavioural changes, reproductive system disorders, metabolism and even immune system disorders, in the mother as well as in the child, in the medium and long term”.
Source: University of Granada
Full bibliographic information:
New method for the determination of parabens and bisphenol A in human milk samples using ultrasound-assisted extraction and clean-up with dispersive sorbents prior to UHPLC–MS/MS analysis
Journal of Chromatography B Volume 992, 15 June 2015,