Placental levels of metals and associated factors in urban and sub-urban areas of Seville (Spain)

Environmental exposure to metals among women, revealed their adverse effects on pregnancy. The fetus is exposed to these toxic elements only via the placenta which are able to accumulate there or cross it, compromising the protective functions of this organ. Numerous studies have shown associations between the prenatal exposition to some metals and an impact on cognitive, motor and intellectual development of the child. Sixty two placental samples were taken at delivery to determine the mineral content (Al, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, Zn) by ICP-OES. Among these metals, essential ones (B, Ca, Cu, Fe, Mg, Mn, Mo, Na, Zn) can have health beneficial effects at low levels however, in high concentration are potentially toxic. On the other hand, elements such as Al, Cd, Pb, are classified as toxic metals, no matter what its concentration is. The aim of this study is to find the potential relationships between these metals levels, newborn's parameters, pregnancy details and the epidemiologic information obtained using a questionnaire data from the participant pregnant women from Seville (Spain). The main maternal determinant of detectable placenta Cd levels was smoking during pregnancy. Other maternal factors that may affect placenta metal levels were gestational age (Al, B, Ba, and Pb) or dietary supplement (Fe). It has to be stressed that our results have to be interpreted with caution, because of the small study group and the low exposure levels, along with the lack of information on potential sources of exposure to these metals. The use of placenta samples obtained at delivery can be considered strength of this study since the concentration of some metals in placenta can indicate the extent of maternal exposure during gestation.