Blood and placental concentrations of cadmium, lead, and mercury in mothers and their newborns.

Placental transfer of cadmium, lead and mercury was studied under the conditions of environmental exposures of pregnant women to these heavy metals. Fifty pregnant women from industrial area and a similar control group from a semirural area were examined. Cadmium, lead and total mercury levels were determined in maternal erythrocytes and plasma, in placenta, and in erythrocytes and plasma of umbilical cord blood using atomic absorption spectrophotometry. Except for the cadmium plasma concentration in the control area, levels of the three metals were higher in maternal than in cord blood. The mean plasma values (arithmetic mean) of cadmium, lead, and mercury in industrial area were 0.53, 6.37, and 0.37 micrograms.100 ml-1 in maternal blood and 0.30, 4.82, and 0.31 micrograms.100 ml-1 in cord blood. Highest values of the correlation coefficients were found between the cadmium and mercury concentrations in maternal and cord blood erythrocytes. No striking effect of the place of residence of pregnant women on the heavy metal concentrations in biological materials could be found.