Levels of Trace Elements in Human Breast Milk in Jordan: a Comparison with Infant Formula Milk Powder

Human breast milk and infant formula milk powder (IFMP) are the main nutritional sources for infants. In the literature, there is a lack of studies concerning levels of trace elements in human milk and IMP in Jordan. The aim of this research was the determination of levels of 24 trace elements in human breast milk from Jordanian mothers (n = 76) and IFMP from Jordanian market (n = 22). Elements were classified to essential (Mg, Fe, Zn, Cu, Mn, Ni, Cr, Mo, Co, and Se), non-essential (Al, Ag, Ba, Bi, Cs, Ga, Li, Rb, Sr, U, and V), and potentially toxic (As, Cd, and Pb). Inductively coupled plasma-mass spectrometry (ICP-MS) following a microwave digestion of samples with concentrated nitric acid and hydrogen peroxide was performed. Our results featured levels of each targeted element in human milk and IFMP (mean, standard deviation (SD), median, and range). Statistical analysis included a one-way analysis of variance (ANOVA), and Pearson's correlations. A sample toxicological analysis study for toxic elements As, Cd, and Pb was performed, and results were inspected. Levels of most elements including toxic elements are larger than in human milk samples, and comparable to in IFPMs to literature results. Mean levels of majority of the elements (17 out of 24) in human milk were significantly different than respective means in IFMP solutions. Positive correlation was observed between total toxic elements and Al, Cu, and Fe in human milk samples. Results of toxicological analysis demonstrated that most of IFMP samples do not represent a health hazard to infants regarding As, Cd, and Pb. The same applies for Cd in human milk samples. However, levels of As and Pb in 70% of human milk samples exceed the provisional tolerable weekly intake (PTWI) for As and Pb.