INVESTIGATIONS ON CEREBRAL MERCURY FROM D ENTAL AMALGAM FILLINGS THROUGH A DIRECT NOSE BRAIN TRANSPORT

The transport of mercury (Hg) from the ore-nasal to the cranial cavity via a direct route was investigated. In 55 deceased persons, Hg conce ntrations were measured in the olfactory bulb and the trigeminal gangl ion, and the number of dental amalgam fillings was assessed. For the p urpose of comparison, Hg concentrations were also determined in the oc cipital lobe cortex, the pituitary gland and the kidney cortex. Quanti tative Hg analysis was performed by cold vapor atomic absorption spect roscopy after acid digestion using high pressure microwave treatment. In the olfactory bulb (geom. mean 17.4 mu g/kg w.w.), the Hg concentra tion was significantly higher than in the occipital lobe cortex (geom. mean 9.2 mu g/kg w.w.) (p < 0.0001). No significant difference was fo und between the Hg concentration in the trigeminal ganglion (geom. mea n 12 mu g/kg w.w.) and the occipital lobe cortex (alpha = 0.005; p = 0 .0342). Regression analysis did not reveal a statistically significant correlation between the number of dental amalgam fillings and the Hg content in the olfactory bulb and the trigeminal ganglion, respectivel y (alpha = 0.01). Therefore, these results do not support the hypothes is of a significant flow of Hg from dental amalgam fillings to the cra nial cavity by a direct oro-nasal route. In contrast, a statistically significant correlation exists between the number of dental amalgam fi llings and the Hg concentration in the kidney cortex (r(2) = 0.317; p < 0.0001), and, to a lesser extent, the Hg concentration in the occipi tal lobe cortex (r(2) = 0.17; p = 0.0016). The highest Hg concentratio ns (geom. mean 93.1 mu g/kg w.w.) were detected in the kidney cortex, followed by the pituitary gland (geom. mean 30.0 mu g/kg w.w.). In thi s study, Hg concentration in the pituitary gland did not correlate wit h the number of dental amalgam fillings.