Lead levels in pregnant women and newborns in La Oroya, Peru

Abstract

Objectives. To determine blood-lead (Pb) levels in pregnant women and neonates in a metallurgical city of Peru. Materials and methods. A cross-sectional study was carried out, the population of which consisted of pregnant women who had lived for at least two years in the city of La Oroya, at the time when the lead, copper and zinc foundries operated normally. A blood sample was obtained from the pregnant women before delivery and, after delivery, from the neonate’s umbilical cord and placenta. Lead levels in those samples were measured by graphite furnace atomic absorption spectrophotometry. Pearson’s squared regressions and correlations were determined. Results. Forty normal deliveries were studied. The average blood lead levels in the mother, umbilical cord and placenta were 27.4 ± 15.6 ug/dL; 19.0 ± 12.6 ug/dL and 319.0 ± 215.9 ug/100 g, respectively. 67.5% of the neonates registered levels higher than 10 ug/dL. Pb levels in the umbilical cord accounted for 69.4% of Pb level in maternal blood. The correlation coefficients between Pb levels in maternal blood and umbilical cord, maternal blood and placenta, and placenta and umbilical cord were 0.36; 0.48 and 0.33, respectively. Conclusions. At the time the foundry operated, pregnant women and newborns had high blood lead concentrations. Pb concentrations in the placenta and umbilical cord had moderate correlation with the Pb levels in maternal blood. Pb levels in maternal blood and umbilical cord were 1.5 times as high as in more distant areas.