Mercury vapor levels in a dental laboratory.

Mercury vapor levels associated with grinding amalgam models and mulling amalgams in the palm of the hand following trituration have been measured in a dental laboratory in inhalation position. The threshold limit value of airborne mercury of 0.05 mg/m3 was essentially exceeded in the grinding procedure of amalgam. Levels in excess of seven times this value were recorded. During mulling the mercury vapor level fluctuated around the threshold limit value. The mean mercury concentrations did not essentially exceed the threshold limit value.