Mercury & Selenium Concentrations in Maternal & Neonatal Scalp Hair: Relationship to Amalgam-Based Dental Treatment Received During Pregnancy

ercury and selenium concentrations were determined in scalp hair samples collected postpartum from 82 term pregnancy mothers and their neonates. Maternal mercury and selenium had median concentrations of 0.39 microgram/g (range 0.1-2.13 microg/g) and 0.75 microg/g (range 0.1-3.95 microg/g), respectively, and corresponding median neonatal values were 0.24 microg/g (range 0.1-1.93 mcrog/g) and 0.53 microg/g (range 0.1-3.0 microg/g). Amalgam based restorative dental treatment received during pregnancy by 27 mother (Group I) was associated with significantly higher mercury concentrations in neonates (p<0.0001) compared to those born to 55 mothers (Group II) with most recent history of such dental treatment was dated to periods ranging 1and 12 yr prior pregnancy. In Group I mother/neonate pairs, amalgam removal and replacement in 19 cases was associated with significantly higher mercury concentrations compared to 17 cases of new amalgam emplacement. Selenium concentrations showed no significant intergroup differences. However, the selenium/mercury molar ratio values were lowest in Group I neonates compared to their mothers and the Group II mother/neonate pairs. This decreased as mercury concentrations increased and this interrelation was statistically significant in both groups of mother/neonate pairs. The data from preliminary study suggest that amalgam-based dental treatment during pregnancy is associated with higher prenatal exposure to mercury, particularly in case of amalgam removal and replacement. The ability of peripheral biological tissues such as hair, to elicit such marked differ in neonatal mercury concentration provides supporting evidence of high fetal susceptibility to this form of mercury exposure. The data are discussed in relation to the differences between mother and fetal mercury metabolisms and to mercury-selenium metabolic interactive response to mercury exposure.

Razagui IB, Haswell SJ Biol Trace Elem Res,2001;81:1-19