Lead concentrations in maternal and umbilical cord blood in areas with high and low air pollution.

The lead concentrations in maternal and umbilical cord blood were determined in 50 parturient women at delivery. Twenty-five lived in agricultural areas with low air pollution and 25 lived in urban areas with high air pollution. The mean lead concentrations (mean +/- SD) in maternal and umbilical cord blood and the correlation coefficient of mothers from urban areas with high air pollution were 37.2 +/- 4.7 ng/ml, 20 +/- 3.4 ng/ml and r = 57, respectively. The mean lead concentrations in maternal and umbilical cord blood and the correlation coefficient of mothers from agricultural areas with low air pollution were 20.5 +/- 5.6 ng/ml, 12.9 +/- 3.6 ng/ml and r = 0.70, respectively. Our results show that the difference in mean lead concentration between the blood of mothers both from urban and agricultural areas and the blood from the umbilical cords of their newborns was statistically significant (p < 0.001). The factors that control the transfer of lead from the mother's blood to the fetus are the quantity of the element in the mother's blood and the placenta itself which has a dynamic protective function that is amplified when maternal blood lead levels are raised.