Polonium-210 levels in placental maternal-fetal barrier: A pilot study conducted in the city of Sao Paulo, Brazil

The accumulation of detectable amounts of radon progeny in the maternal-fetal placental barrier may be a risk factor for fetal development and lifelong disabilities. In this preliminary study, we analyzed the levels of alpha-emitting radon progeny Polonium-210 (210Po) (in Becquerel/kg) in the maternal-fetal placental barrier from placentas in Sao Paulo, SP, Brazil. Overall, there were higher levels of 210Po at the maternal portion of the placenta 1.45 (0.34) Bq/kg when compared to the fetal placental portion [1.08 (0.35) Bq/kg]. The presence of 210Po in the maternal-fetal placenta may indicate a potential risk of adverse pregnancy and fetal outcomes, including impaired placenta growth and fetus development potentially leading to lifelong disabilities. Future studies are warranted to identify the natural and anthropogenic sources of 210Po in urban areas and 210Po-related adverse pregnancy health outcomes.Implications: Our findings suggest that the presence of environmental 210Po in maternal and fetal placenta tissues may indicate a potential hazard risk of adverse pregnancy outcomes and fetal health. Future studies with a larger number of pregnant women should be able to identify more accurately the biological mechanisms of the exposures to natural and anthropogenic sources of 210Po, and help generate public health policies to mitigate it.