Minor effects of low exposure to inorganic mercury on the human immune system.

The influence of exposure to inorganic mercury on the immune system was examined in 36 workers occupationally exposed to mercury vapor, 14 individuals with skin hypersensitivity to mercury compounds, 21 subjects with health disturbances allegedly caused by dental amalgam fillings ("amalgam disease"), and 39 healthy referents. Concentrations of mercury in blood and urine and some parameters judged to mirror different effects on the immune system were determined. The latter included, white blood cell differential counts, serum immunoglobulins and autoantibodies, and in vitro production of the cytokines interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF alpha). Virtually all of the immunologic parameters were within normal ranges and did not differ significantly between the groups. In the group sensitized to mercury, there was a reduction of the in vitro production of both TNF alpha and IL-1 compared with the reference group's values. No significant correlations were noted between different mercury exposure estimates and the immunologic parameters.