Posted: September 29, 2014
WASHINGTON – The U.S. Environmental Protection Agency (EPA) today proposed standards under the Clean Water Act to help cut discharges of dental amalgam to the environment. Amalgam is a mixture of mercury and other metals that dentists use to fill cavities. Mercury is discharged when dentists remove old fillings or remove excess amalgam when placing a new filling.
Studies show about half the mercury that enters Publicly Owned Treatment Works (POTWs) comes from dental offices. Mercury from amalgam can then make its way into the environment in a number of ways, including through discharge to water bodies. Contact with some microorganisms can help create methylmercury, a highly toxic form of mercury that builds up in fish, shellfish and fish-eating animals. Fish and shellfish are the main sources of human exposure to methylmercury.
In response, many states and localities have implemented amalgam discharge-cutting programs requiring amalgam separators and other Best Management Practices in dentist offices. The American Dental Association (ADA) also recommends separators and other Best Management Practices for amalgam.
EPA expects compliance with this proposed rule would cut metal discharge to POTWs, half of it from mercury, by at least 8.8 tons a year.