Mercury Down The Drain | July 28, 2008 Issue - Vol. 86 Issue 30 | Chemical & Engineering News
Volume 86 Issue 30 | pp. 47-49
Issue Date: July 28, 2008

Mercury Down The Drain

Congress moves to limit discharge of dental mercury into wastewater
Department: Government & Policy
News Channels: Environmental SCENE
Americans are walking around with more than 1,000 tons of mercury in their mouths.
Credit: Bigstock
Americans are walking around with more than 1,000 tons of mercury in their mouths.
Credit: Bigstock

DESPITE EFFORTS to eliminate mercury from numerous products over the past few decades, a few holdouts remain. Among them are dental amalgam fillings. Dentists continue to use amalgam fillings, which contain about 50% mercury, because they are less expensive than currently available alternatives. Citing human health and environmental effects of the persistent, bioaccumulative, and neurotoxic metal, some members of Congress would like to put an end to that dental practice.

As part of an investigation that began last November, the Domestic Policy Subcommittee of the House of Representatives' Committee on Oversight & Government Reform held a hearing on July 8 to explore the feasibility of a mandatory mercury reduction program for dental offices.

The dental industry is by far the largest contributor of mercury to wastewater, testified Michael Bender, director of the Mercury Policy Project (MPP), a nonprofit organization that promotes policies that eliminate or reduce mercury uses and exposures. Each time a dentist applies, repairs, or removes an amalgam filling, mercury inevitably gets washed down the drain, he said. Amalgam separators, which cost between $750 and $3,000 to install, are available to trap 95 to 99% of that mercury, but in most states, dentists are not required to use them.

At the July 8 hearing, subcommittee Chairman Dennis J. Kucinich (D-Ohio) and others presented evidence that voluntary programs, implemented by some states to encourage dentists to capture mercury with amalgam separators, don't work. "Only after the failure of their voluntary programs to achieve their desired compliance goals did these governments switch to a mandatory program," Kucinich said. Those states that do have mandatory programs have seen significant reductions in the amount of mercury that dentists discharge into wastewater, he added.

The American Dental Association (ADA) endorses the use of amalgam separators for reducing mercury pollution from dental offices, but the group has aggressively tried to stop mandatory programs in favor of voluntary ones.

Just how aggressively became clear at the hearing. Curt McCormick, principal and owner of CWA Consulting Services and former regional pretreatment coordinator in the Environmental Protection Agency's Region 8 office in Denver, testified about the degree of influence ADA has had on strategies to control discharge of dental mercury. In 2004 and 2005, when McCormick, then with EPA, attempted to develop a program to require the use of dental amalgam separators in places where mercury is a problem, he faced pressure from ADA to make the program voluntary.

"Early on, ADA expressed its displeasure with Region 8, and, in particular, my program. ADA believed that the requirement of a mandatory mercury reduction program was unreasonable and that amalgam separators should not be required in any case," McCormick said.

According to McCormick, senior management at EPA's Region 8 office resisted pressures from not just ADA, but also the EPA Office of Water, which oversees the regional offices, to remove the mandatory requirement. Because the final program draft did not deviate from the original one, EPA's Office of Water told McCormick that the program would not be finalized. "ADA appears to have obtained a communication pathway with the Office of Water" to exert influence on the agency, McCormick testified. No final document was ever issued, he noted.

At the hearing, Rep. Diane E. Watson (D-Calif.) asked ADA's legal counsel, William J. Walsh, whether ADA exerted any influence over the outcome in Region 8. Walsh did not directly answer the question. Instead, he responded that McCormick's strategy precluded a voluntary program. He said that it would have wiped away EPA's efforts to reach consensus on the issue with small businesses, which may have been unable to afford amalgam separators. In addition, Walsh said that a mandatory program would require costly inspections and be difficult to enforce because there are about 100,000 dental facilities in the U.S.


DESPITE CONTRARY evidence presented by the subcommittee, Walsh maintained that "there is little incremental difference in the amount of amalgam collected and recycled using a voluntary separator program compared to a mandatory plan." He claimed that ADA's efforts to better educate dentists over the past few years have increased their willingness to cooperate in voluntary programs.

"Even if every dentist installed a separator, it would have little effect on the environment," Walsh emphasized. That's because amalgam separators and wastewater treatment facilities remove about the same amount of mercury, he claimed. If mercury is not captured in the dentist's office, it will be captured by the wastewater treatment plant, he added.

ADA, however, supports voluntary use of amalgam separators because they allow dentists to recycle waste mercury and prevent some mercury from ending up in sewage sludge, which could be incinerated or applied to agricultural fields.

Although the hearing focused primarily on reducing the environmental effects of dental amalgams, some members of Congress took the opportunity to question why mercury is still being used in peoples' mouths in the first place. They would like to ban mercury dental amalgams altogether because of concerns about their health effects. Other countries have already taken such action. Norway and Sweden both introduced such bans this year, MPP's Bender said.

Rep. Dan Burton (R-Ind.), convinced that his grandson developed autism because of mercury in childhood vaccines—despite the lack of scientific evidence to support that hypothesis—passionately stated at the hearing that mercury should never be introduced into the human body. To him, dental amalgams represent a potential route for mercury ingestion, and therefore they should be banned.

Supporting Burton's concern, Watson claimed that the mercury fillings she received as a child caused her headaches, memory loss, and splotchy skin. She eventually had them removed by a dentist in Mexico because her own dentist would not discuss the issue with her, she said. Once her mercury fillings were gone, her symptoms disappeared, she noted.

THE HUMAN health effects of mercury fillings have been debated for years. Until recently, the Food & Drug Administration, which regulates dental amalgams as medical devices, insisted that not enough scientific evidence exists to prove that they are unsafe. But in a recent move, brought on by a legal settlement in the case of Moms Against Mercury et al. v. Andrew von Eschenbach et al., FDA updated its website, stating that dental amalgams may pose a health risk to pregnant women, unborn fetuses, and children.

In 2002, FDA published a proposed rule that would reclassify dental mercury as a class II device with special controls, which could include labeling requirements, mandatory performance standards, or postmarket surveillance. Currently, dental mercury is considered a class I device, which is subject to less regulatory control. This spring, the agency reopened the proposed rule for public comment and accepted input until July 28. FDA will now finalize that rule within one year of the close of the comment period.

Some dentists aren't waiting for FDA to strengthen its dental amalgam policy. "I have been practicing dentistry for 35 years, the last 26 without using mercury fillings. I stopped using them when I discovered that the mercury was not locked in the amalgam, as I'd been told in dental school," Richard D. Fischer, former president of the International Academy of Oral Medicine & Toxicology, testified at the July 8 hearing. "As a health professional, I feel ethically bound to err on the side of caution."

Nonetheless, MPP estimates that 30 tons of mercury is still being used annually in the U.S. in dental amalgams. Bender, like many others, sees no reason for the continued use of amalgam fillings. "I think this dental sector is stuck in complacency and needs some kind of regulatory incentive to move forward," he says.

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