Dental amalgam controversy from the WHO concluded that dental amalgam contributes significantly to mercury body burden in humans with amalgam fillings and that dental amalgam is the most common form of exposure to elemental mercury in the general population, constituting a potentially significant source of exposure to elemental mercury. Estimates of daily intake from amalgam restorations range from 1 to 12.5 μg/day, with the majority of dental amalgam holders being exposed to less than 5 μg mercury/day. They also note that this will continue to decline as the number of amalgam restorations is declining. As public pressure demands more research on amalgam safety,
Chemical element whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than 1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element. Chemists and nuclear scientists have different definitions of a "pure element". In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the