Correlation between blood mercury levels in mothers and newborns in Itaituba, Pará State, Brazil

This study evaluated transplacental mercury transfer by measuring Hg in blood samples of mothers and newborns (umbilical cord) in hospitals in the municipality (county) of Itaituba, Pará State, Brazil. Epidemiological and mercury exposure data were collected, besides clinical birth data. Mercury tests were performed by cold-vapor atomic absorption spectrophotometry. A total of 1,510 women and an equal number of their newborns participated in the study. Mean blood mercury was 11.53 microg/L in mothers and 16.68 microg/L in newborns (umbilical cord). The highest Hg levels were in the 31-40-year maternal age group and their newborns, with 14.37 microg/L and 21.87 microg/L, respectively. However, in all age groups the mean mercury level was higher in newborns than in mothers. There was a strong positive correlation between Hg levels in newborns and mothers (r = 0.8019; p = 0.000), with a significant linear regression model (r = 0.5283; p = 0.000). The results highlight the importance of monitoring pregnant women exposed to mercury as part of public health surveillance.