Mercury vapor in amalgam waste discharged from dental office vacuum units.

Clinical procedures in dental offices generate quantities of waste slurry or fine particulate matter, much of which is derived from dental amalgam filling material. This mercury-containing material is discharged into waste streams via the dental office vacuum-pump system. This system also discharges large quantities of air, either into the atmosphere exterior to the office building or into the sewer system, depending on the type of equipment used. The purpose of this study was to investigate whether the discharged air contained mercury vapor.