Dentists' mercury could hurt environment

By Marjory Sherman
Eagle-Tribune Writer

Monday, June 24, 2002

http://www.eagletribune.com/framesets/news.htm

While the debate over whether mercury fillings pose a health risk remains unresolved, there is more widespread worry about harm to the environment when mercury from old fillings reaches the waste stream.

"The only real issue in dental offices with regard to mercury is when we remove a silver filling, we grind out an old silver filling, the amalgam is sucked down into the waste water system and there is some evidence that the mercury is released in the ground water,'' said Methuen dentist Dr. Thomas Torrisi.

According to Mark E. Stone, researcher at the Naval Dental Research Institute in Great Lakes, Ill., elemental mercury in amalgams can become methylmercury, or a more dangerous form, when it is surrounded by bacteria, especially from sediment in the ground water.

Methylmercury is known to accumulate in fish and move up the biodiversity chain. People in the Merrimack Valley have already been warned against eating fish caught in local waterways, since many of those tested exhibited high levels of mercury.

In a report out this month, Health Care Without Harm and other groups charges that dentists are the third largest users of mercury in the country and the single largest polluter of mercury to the nation's waste water treatment plants.

In the process of restoring teeth, dentists use approximately 40 metric tons of mercury each year, most of which is released directly into the environment, said Bill Ravenisi of Health Care Without Harm.

"While many other industries, including hospitals, are phasing out the use of mercury products, dentists continue to use large amounts of mercury and dispose of it improperly. We call on American Dental Association and on dentists everywhere to pledge to stop polluting our environment and endangering our health,'' he said.

The Massachusetts Water Resources Authority is working with the Massachusetts Dental Society to find appropriate machinery for all 4,400 dentists in Massachusetts to use to separate amalgams from the waste stream before it goes into the water supply.

"We're not taking a position on whether mercury in amalgams is safe or not. Our concern is just what happens when it gets into the environment and keeping it out of the environment,'' said Peter Nugent of the Massachusetts Department of Environmental Protection.