Amalgam fillings release mercury vapor continuously at low levels. The release rate
is dependent on filling size, tooth and surface placement, chewing, food texture, tooth
grinding, and brushing teeth, as well as the surface area, composition, and age of the
amalgam. Correlations have been demonstrated between the number of amalgams and
expired breath21 and urinary mercury concentrations.22 Subjects with amalgam fillings
have more mercury in saliva and feces.23 The number of amalgam surfaces is correlated
with the mercury content of brain and kidney tissue at autopsy. Inorganic mercury
primarily affects the nervous and renal systems, although it may also have effects on the
immune, respiratory, cardiovascular, gastrointestinal, hematologic, and reproductive
systems. These toxic effects may be mediated by binding of mercury to sulfhydryl groups
of enzymes.