Preliminary Studies on the Distribution of Stable Pb and Pb-210 in the Maternal and Fetal Portions of Human Placentas

Fetal growth and survival are solely dependent on the placenta, making the characterization of toxic elements in this tissue crucial for understanding exposure during pregnancy. Stable lead (Pb) and Pb-210 are toxic elements of particular interest in this context. Stable Pb has been linked to developmental changes in children, while Pb-210, a beta-emitting radionuclide with a 22.3-year half-life, can increase cancer risk, particularly bone sarcomas, when present in excess. Placental uptake of stable Pb and Pb-210 can occur through ingestion of food and water, as well as inhalation of air, with smoking and air pollution being significant contributing factors. Recent research suggests that even low levels of environmental chemicals, especially potentially toxic elements, can significantly disrupt placental homeostasis. This preliminary study aimed at determining the concentrations of stable Pb and Pb-210 in the maternal and fetal portions of placentas from eight women who delivered at the Hospital das Clínicas, Faculdade de Medicina, University of São Paulo. Concentrations from 5.7 ± 1.2 ng g-1 to 210.3 ± 2.4 ng g-1 and from 31.5 ± 2.9 Bq kg-1 to 43.3 ± 3.1 Bq kg-1 were obtained for stable Pb and Pb-210, respectively. The results showed that both elements can cross the placental barrier and reach the fetal compartment, albeit at lower concentrations than in the maternal portion.