Human and Ecological Risk Assessment: An International Journal

Dental amalgam is 50% metallic mercury (Hg) by weight and causes Hg exposure. The first assessment of Hg exposure and risk from dental amalgam in Canada was published in 1996. Recent data provided the opportunity to update that assessment. During the Canadian Health Measures Survey (CHMS; 2007 to 2009) the number of tooth surfaces specifically restored with dental amalgam was recorded. Data were also collected on the concentration of Hg in urine of survey participants. These data were employed to determine Hg exposures in the Canadian population. Also determined was the number of amalgam-restored tooth surfaces that would not result in exposure exceeding the dose associated with Canada’s reference exposure level (REL) for Hg. Based on the CHMS data, 17.7 million Canadians aged ≥6 years collectively carry 191.1million amalgam surfaces, representing 76.4million amalgam-restored teeth. Average Hg exposures were: Children—0.065 μg Hg/kgday; Teens—0.032μg/kg-day; Adults—0.033μg/kg-day; and Seniors—0.041μg/kgday. Of Canadians with dental amalgam restorations, 80.4% experience a daily dose of Hg that exceeds the Canadian REL-associated dose. The number of amalgam surfaces that will not result in exceeding the REL-associated dose varied from two amalgam surfaces (children, both sexes) to seven surfaces (adult males).