The details of how dentists will have to do this "remains to be seen" and are still in the works, Jalil Isa, a spokesperson with the EPA, told DrBicuspid.com.
However, dental offices will be able to use "existing technology" -- most likely amalgam separators -- to meet the proposed requirements, the EPA said in a press release.
Until the rule is final, EPA encourages dental offices to voluntarily install amalgam separators. Twelve states and several municipalities already require the installation of amalgam separators in dental offices.
Approximately 50% of mercury entering local waste treatment plants comes from dental amalgam waste -- about 3.7 tons of mercury annually, according to the EPA. Once deposited, certain microorganisms can change elemental mercury into methylmercury, a highly toxic form that builds up in fish, shellfish, and animals that eat fish. Fish and shellfish are the main sources of methylmercury exposure to humans, and the EPA is concerned that methylmercury can damage children's developing brains and nervous systems even before they are born.
Amalgam separators can separate out 95% of the mercury normally discharged to the local waste treatment plant, the agency said.
Memorandum of understanding
Earlier this year, DrBicuspid.com reported that a Congressional oversight panel was pressing the EPA to require that all dentists in the U.S. install amalgam separators in their offices. In a May 26 hearing, a subcommittee of the House of Representatives Committee on Oversight and Government Reform demanded to know why the EPA exempts dentists from regulations that govern mercury emissions in other industries.
"There is no question that mercury should not be in the water supply, and we should do everything we can to get it out of there," Rep. Dan Burton (R-IN) said at that hearing. "And the biggest contaminators are dentists who are flushing this stuff down the drain, so we need to have these separators."
In 2008, the EPA and the National Association of Clean Water Agencies signed a memorandum of understanding (MOU) with the ADA in which the ADA agreed to urge its members to install the separators, begin tracking how many practices have installed them, and set goals for increasing that number. In exchange, the EPA exempted dentists from wastewater rules.
A 2009 ADA survey found that 40% to 51% of dentists use amalgam separators, but that dropped to 28% to 36% in states where they are not required by law. The response rate to the survey, done by mail and Internet, was so low that the ADA admitted it was uncertain about the accuracy of these numbers.
The 2010 ADA House of Delegates, which meets next week at the association's annual meeting in Orlando, FL, is expected to take up amalgam separator policy in advance of the EPA rulemaking, according to an ADA News story.
"The ADA agrees with the EPA that amalgam separators play an important role in minimizing the release of mercury into dental office wastewater, and that is why we promote their use," the ADA said in a statement. "That said, we cannot comment on the proposed EPA regulation announced today until the agency shares it with us. We remain committed to providing the best possible care, safely and responsibly. We will carefully review any proposal from the EPA with that foremost in mind."
The overall cost to a dentist to install an amalgam separator includes buying the separator, installing it, and annual operation and maintenance fees, the ADA has previously noted. The capital cost and installation are approximately $1,200, and the annual cost of owning and operating an amalgam separator is around $770.
Copyright © 2010 DrBicuspid.com
EPA pressed to require amalgam separators, June 2, 2010
ADA assures Congress of amalgam separator support, June 1, 2010
ADA, EPA sign agreement on dental amalgam discharge, January 12, 2009
EPA backs ADA's amalgam waste approach, September 26, 2008
ADA and Congress face off over amalgam separators, July 16, 2008