MERCURY IN SALIVA AND FECES AFTER REMOVAL OF AMALGAM FILLINGS

The toxicological consequences of exposure to mercury (Hg) from dental amalgam fillings is a matter of debate in several countries. The purp ose of this study was to obtain data on Hg concentrations in saliva an d feces before and after removal of dental amalgam fillings, Tn additi on Hg concentrations in urine, blood, and plasma were determined, Ten subjects had all amalgam fillings removed at one dental session. Befor e removal, the median Ng concentration in feces was more than 10 times higher than in samples from an amalgam free reference group consistin g of 10 individuals (2.7 vs 0.23 mu mol Hg/kg dry weight, p < 0.001). A considerable increase of the Hg concentration in feces 2 days after amalgam removal (median 280 mu mol Hg/kg dry weight) was followed by a significant decrease. Sixty days after removal the median Hg concentr ation was still slightly higher than in samples from the reference gro up, Tn plasma, the median Hg concentration was 4 nmol/liter at baselin e. Two days after removal the median Hg concentration in plasma was in creased to 5 nmol/liter and declined subsequently to 1.3 nmol/liter by Day 60. In saliva, there was an exponential decline in the Hg concent ration during the first 2 weeks after amalgam removal (t(1/2) = 1.8 da ys). It was concluded that amalgam fillings are a significant source o f Hg in saliva and feces. Hg levels in all media decrease considerably after amalgam removal. The uptake of amalgam mercury in the GI tract in conjunction with removal of amalgam fillings seems to be low. (C) 1 997 Academic Press.