Potential health and environmental issues of mercury-contaminated amalgamators

Background. Dental amalgamators may become contaminated internally with met allic mercury. This A contamination may result from mercury leakage from ca psules during trituration or from the longterm accrual from microscopic ext erior contaminants that result from the industrial assembly process. The po tential health risk to dental personnel from this contamination is unknown. Methods. The authors assessed used amalgamators from the federal service in ventory for the amounts of mercury vapor levels, as well as the visual pres ence of mercury contamination. They evaluated these amalgamators for potent ial mercury vapor health risk, using established National Institute for Occ upational Safety and Health methods and American Conference of Governmental Industrial Hygienists standards. Results. Ten of the 11 amalgamators assessed had measurable mercury vapor l evels. Four amalgamators were found to have internal static mercury vapor l evels above Occupational Safety and Health Administration ceiling limit thr esholds During a simulated worst-case clinical use protocol, the authors fo und that that no amalgamators produced mercury vapor in the breathing space of dental personnel that exceeded established time-weighted federal mercur y vapor limits. Conclusions. Amalgamators may be contaminated internally with metallic merc ury. Although the authors detected mercury vapor from these units during ag gressive, simulated clinical use, dilution factors combined with room air e xchange were found to keep health risks below established federal safety th resholds. Clinical Implications. Dental personnel should be aware that amalgamators m ay be contaminated with mercury and produce minute amounts of mercury vapor . These contaminated amalgamators may require disposal as environmentally h azardous waste.