[Analysis of maternal-fetal exchange in the study of environmental exposure to lead].
398 women at various stages of pregnancy and living in two areas subject to different levels of atmospheric pollution were examined. Blood samples were taken from about 200 women and their funiculi at the moment of parturition. The results showed a difference in lead concentrations in the blood and in the ratio of mother and funicular lead concentrations according to the place of residence. Several hypothesis to explain these results are formulated.