Acute exposure to mercury from amalgam: no short-time effect on the peripheral blood lymphocytes in healthy individuals.

Mercury, released from dental amalgam, has been considered to adversely affect the human immune system. This study has been performed in order to evaluate if an acute low-dose mercury exposure, achieved by total amalgam removal in 10 healthy individuals, would affect the immunocompetent cells in human blood when the mercury level in blood and plasma was increasing. Induction of lymphocyte proliferation, measured as spontaneous de novo DNA synthesis, and total T cells, CD4+ T cells, CD8+ T cells, and B cells, was studied prior to and 7, 31, and 48 h after amalgam removal. In addition, the levels of interleukin-6 (IL-6) and C-reactive protein (CRP) in serum/plasma were measured. Despite a significant increase of the plasma mercury levels within 24 h after intervention, no significant influence on the peripheral blood lymphocytes could be detected during the first 48 h. The serum IL-6 levels increased significantly within 48 h after intervention, but were still low and within normal range. No influence on the CRP levels up to 7 d after amalgam removal was detected.