Trace elements profiles of maternal blood, umbilical cord blood and placenta in Beijing, China.

Aim: Profiles of heavy metals such as chromium (Cr), manganese (Mn), arsenic (As), lead (Pb), and cadmium (Cd), and micronutrients such as ferrum (Fe), copper (Cu), zinc (Zn), and selenium (Se) in maternal and umbilical cord blood clots were investigated for assessing placenta function in the transport of micronutrients or heavy metal pollutants.Methods: Correlations between contents of elements in the two tissues were also analyzed.Results: Significantly lower levels of Cr, Pb, and Cd in umbilical cord blood clots than in maternal blood clots, and negative relationship between lead levels in maternal and umbilical cord blood (r=-.334, p=.016). Concentration of Mn in cord blood was significantly higher than that in maternal blood clots and positively related to the maternal level. The data also show that the placenta may work most strongly as a barrier against Cd and protects fetus from its harmful effect, while plays almost no role in preventing the transportation of As, Mn, and Pb.Conclusions: In conclusion, pregnant women should avoid exposure to environment polluted with heavy metals, particularly with As, Mn, and Pb.