Rising mercury

Despite protests from the American Dental Association, any country that seriously discusses doing away with mercury thermometers because of their potential impact on health cannot be long from restricting the use of mercury dental fillings. Congress will soon work on the question while Maine reviews LD 1409, a concept bill that seeks to examine the long-term effects of these fillings and the steps the state should take to protect residents and the environment.

For one expert who testified last week, the answers are clear. Dr. Boyd Haley, chairman of the Department of Chemistry at the University of Kentucky, concludes that normal body loads of mercury in older adults produces two diagnostic hallmarks for Alzheimer’s Disease. Further, he says, in a test for mercury in the blood and urine of more than 1,000 U.S. soldiers, the vast majority, more than 87 percent, was traced to dental amalgams. Further still, the primary source of mercury in wastewater treatment plants came through feces and urine of people with these fillings. That is, he and other reputable scientists are identifying dental amalgams as a major source of this toxin in humans and in the environment.

The ADA will have none of this. It says 150 years of dentistry show that the amalgams are not a problem, as evidenced by the dentists themselves who spend a career around these products. Individual dentists in Maine, however, sometimes tell a different story. They note that the alternatives to the mercury amalgams are more expensive but that they are safer for their patients, themselves and their staff, and for the environment. The Legislature’s job in this case is not to start an argument among dentists but to look at the relative risk of mercury to the public and the level of importance of dental amalgams in contributing to that risk.

Mercury can be toxic to the nervous system. U.S. dentists, according to the U.S. Geological Survey, annually use a total of between 40 and 60 metric tons of mercury in their practices but other sources have attracted the attention of regulators. Bills in Congress would more tightly regulate mercury emissions from power plants and incinerators, would reduce mercury in light bulbs and eliminate it in thermometers, switches and other household products. Rep. Tom Allen, who has followed the mercury issue closely, will reintroduce a mercury-reduction bill after the congressional break that for the first time encourages states, communities, dentists and dental associations to work toward eliminating the mercury filling.

The potential for environmental damage alone would make mercury from dental offices endangered. A fair review of the studies of its human health effects by the Bureau of Health would take only several months. If the work by the bureau turns out as scientists like Dr. Haley suspect it will, lawmakers should begin a reduction and phase-out of this type of dental fillings.