Analysis of major and trace elements in breast milk: A health risks assessment study in Iran

Breast milk (BM) is a highly beneficial nutritional resource for infant health and growth; however, contamination of this primary food may pose a risk to infant health.

This study analyzed the concentrations of major and trace elements in 58 randomly selected BM samples from lactating mothers, assessed health risks to infants, and examined correlations between elemental levels and maternal dietary, sociodemographic, and lifestyle factors. Elemental analysis was performed using inductively coupled plasma mass spectrometry (ICP-MS).

The concentrations of essential trace elements followed the order of Fe > Zn > Cu > Mn > Se > Ni > Mo > Co, whereas toxic trace elements were ranked as Cr > Pb > As > Cd. The average concentrations of Cr, Pb, and As were 71.7, 28.4, and 23.2 μg/L, respectively. Concentrations of Cr, Pb, and As exceeded World Health Organization (WHO) limits in 100%, 93.0%, and 93.0% of samples, respectively. Significant associations were observed between Pb levels and chicken consumption, As levels and rice intake, lactation stage and several essential trace elements, as well as smoking exposure and Fe and Cu concentrations (p < 0.05). Both hazard index (HI) and total cancer risk (TCR) exceeded acceptable thresholds, indicating potential non-carcinogenic and carcinogenic risks under conservative exposure assumptions.

These findings highlight a considerable potential health risk associated with infant exposure to trace elements through BM and underscore the need for continuous biomonitoring, identification of exposure sources, and implementation of preventive strategies to reduce maternal and infant exposure to trace elements.