Correlation Between Mercury Concentrations in Hair and Dental Amalgam Fillings

To examine possible association between dental amalgam fillings and mercury burden, we measured the mercury concentrations in scalp hair samples from 74 female Japanese subjects aged 26-64 years who had a dietary habit of little fish-consumption. The hair mercury concentrations in the subjects with multiple amalgam fillings were significantly higher than those in the subjects with no amalgam fillings, and correlated with the number of amalgam fillings in the following regression equation: log Hg = 0.084 amalgam fillings + 3.377 (r = 0.339, p = 0.003). In addition, multiple regression analysis demonstrated that the hair mercury concentrations were significantly correlated with the amalgam fillings (r = 0.292; p = 0.014) and age (r = 0.284; p = 0.017) but not significantly with the body mass index (r = 0.060). A regression equation of log Hg = 0.071 amalgam fillings + 0.011 age + 0.006 BMI + 2.72 was obtained (r = 0.447), with 0.200 of the determination coefficient. These findings suggest that the dental amalgam fillings positively influence mercury accumulation in the hair and also, probably, in the body.