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Backers of an Arizona bill restricting dentists' use of mercury fillings say the law would protect the health of children, pregnant women and nursing mothers. Although not touted as a benefit of the legislation, reduced mercury use also might have an environmental pay off. A report released last year titled "Health Care without Harm" says dentists are the largest single contributors of wastewater mercury in the country. The report was authored by environmental and health professionals.

In its focus on the health of children, pregnant woman and nursing mothers, the Arizona bill prohibits dentists from using mercury fillings in such patients and also would require dentists to discuss with all patients the pros and cons of mercury amalgams. Some researchers say amalgams release toxic vapors that cause neurological damage and other health problems. The "silver" fillings dentists use to restore teeth are in fact 50 percent mercury.
 

As part of the Water Resources Research Center's seminar series, Bruce Johnson of Tucson Water and Mark Stratton of Metro Water discussed their visit to Kazikstan, undertaken through the Sister City program. The intent of their visit was to evaluate the city of Almaty's water security system, emergency preparedness plans and the condition of its water infrastructure. In terms of security, they found that Almaty relies more on physical security, with guards stationed at facilities, than the technical solutions applied in the United States. That the city lacks technical resources is apparent from the above photo of a chlorination storage room in a surface water treatment facility. The tanks are rusted, not maintained and unrestrained.

If such restrictions were to become law, it would likely mean that less mercury would be released into the environment. According to the above report, America's 150,000 dentists are the third-largest consumers of mercury in the country, with 41 tons used in 100 million fillings per year. The report says that most of the mercury eventually finds its way into the environment, with much of it rinsed down the drain.

Once the amalgam is released into water and soil it is transformed into highly toxic methyl mercury. The compound accumulates in the tissue of living organisms, becoming more concentrated in organisms higher up the food chain. Pregnant women and predatory animals are particularly at risk. Some countries have banned the use of amalgams.

Alternative filling materials are available. Also, cost effective devices can be installed to properly manage waste dental mercury, including amalgam separation filters to reduce mercury discharges. Yet only a small percentage of dentists nationwide are taking steps to collect and recycle mercury waste. Dental interests generally oppose restrictions on the use of amalgams.
 

There is some indication that mercury pollution may be declining in recent years. A report released by Mercury Policy Project indicates that Toronto has had a 50 percent drop in wastewater mercury over the past years, the result of using amalgam separators and applying best practices in dental surgeries. The project urges other dentists to adopt such practices.

A report titled "Dentist the Menace" discusses the uncontrolled release of dental mercury and is available on the web at http://www.noharm.org/library/docs/Dentist_the_Menace.pdf