Heavy Metals Concentrations in Breast Milk and Related Factors among Early Postpartum Women

Purpose: As industries develop rapidly, the risk of heavy metals pollution and exposure in the environment and food is increasing. Even the slightest amount of heavy metals can be harmful to the human body, especially in newborn babies. This study aimed to estimate the heavy metals content in breast milk and identify related factors.Methods: Thirty-nine lactating mothers admitted to the postpartum care center in Changwon city between July 15 and September 20, 2019 were recruited. Barium, cadmium, cobalt, nickel, and lead concentrations in breast milk were measured using an inductively coupled plasma-optical emission spectrometer. Collected data were analyzed using independent t-test, 1-way analysis of variance, Mann-Whitney U-test, Kruskal-Wallis test, and Pearson correlation coefficients.Results: The average concentration of heavy metals in breast milk (mg/kg) were as fellow: barium, 3.68± 1.29; cadmium, 0.03±0.06; cobalt, 0.10±0.19; nickel, 0.22±0.27; and lead, 0.13±0.26. There was a significant difference between lead concentration and monthly household income (t=2.46, p=0.019). There was a difference between a family history of diabetes and hypertension and barium concentration (t=1.97, p=0.056) and between smoking history and nickel concentration (t=-1.95, p=0.058), but they were not statistically significant. A significantly positive correlation was observed between cobalt and cadmium concentrations (r=0.93, p<0.001), and a significant negative correlation was observed between nickel and cadmium concentrations (r=-0.40, p=0.010) and cobalt concentration (r=-0.46, p=0.003). In addition, lead concentration showed a significant negative correlation with age (r=-0.39, p=0.013).Conclusions: Guidelines for safe levels of heavy metals concentrations in breast milk need to be established and lactating mothers should consider the risk factors related to heavy metals poisoning such as dietary intake, smoking, and alcohol consumption.