Determination of mercury, cadmium and lead in human milk in Iran.

Breast milk contains both essential and nonessential trace elements. Mercury, cadmium and lead are nonessential, potentially toxic heavy metals with hematotoxic, neurotoxic and nephrotoxic properties even at very low concentrations. The objectives of this study were to determine the concentrations of mercury, cadmium and lead in the breast milk of healthy lactating women who were living in Isfahan, Iran. Concentrations of mercury, cadmium and lead were determined by graphite furnace atomic absorption spectrometry in 37 milk samples from healthy lactating women collected on first to sixth postpartum week. Accuracy of the analysis was checked by various methods including the use of reference material. The mean ± SD of the concentrations of mercury, cadmium and lead in human milk were 0.92 ± 0.54 μg/L (range 0.0-2.07 μg/L), 1.92 ± 1.04 μg/L (range 0.45-5.87 μg/L) and 7.11 ± 3.96 μg/L (range 3.06-19.47 μg/L), respectively. The results of this study showed that the concentrations of mercury, lead and cadmium in the milk samples from lactating women in Isfahan were high, which makes a major public health hazard for the inhabitants, especially neonatal and children, of the industrial locations. The results of the present study indicate a need for establishing safe intake values of heavy metals in human milk.