The San Francisco Public Utilities Commission (SFPUC) is asking dentists throughout the city to help reduce mercury pollution in the Bay by improving the effectiveness of the way they collect particles from extracted amalgam fillings.  The new Dental Mercury Reduction Program—a joint project of the SFPUC Water Pollution Prevention Program and the San Francisco Department of the Environment in partnership with the San Francisco Dental Society and the California Dental Association—is requiring that all dental offices connected to the city’s sanitary sewer system to reduce their discharge of dental amalgam wastes to the lowest possible level.

Mercury contamination is a serious worldwide problem that affects both the environment and human health. When mercury is released into rivers, lakes or bays, it bioaccumulates in the food chain.  In San Francisco, the US Environmental Protection Agency (EPA) recently issued a public warning to limit intake of fish caught in the Bay because it routinely exceeds state health guidelines for mercury and other contaminants. Mercury comes from various sources, including abandoned mines, thermometers and particles from discharged amalgam fillings, which contain up to 45% of the element.

"We appreciate the opportunity to sit down with local regulators to discuss their challenges in meeting the different limits placed on them for certain substances, such as mercury in dental amalgam," said Dennis Kalebjian, DDS, president of the California Dental Association.  "California is such a large state with such varying geography -- one type of regulatory program cannot fit all situations."

Dentists must obtain a new wastewater discharge permit from the city. The permit requires them to install an improved amalgam separator device.  They are required to implement certain management practices, such as using substances other than bleach (which speeds the release of mercury from amalgam) to disinfect vacuum lines.

"Our local dental committee understood the pressing requirements this new limit placed on our local regulators," said Dr. Donna B. Hurowitz, Chair of the San Francisco Dental Society Wastewater Committee.  The San Francisco Dental Society plans ongoing educational outreach for our members as well as monitoring the permit results with the Water Pollution Prevention Program."

By targeting a specific source of potential contamination, the Dental Mercury Program follows the successful pollution prevention model of San Francisco’s mercury fever thermometer ban, enacted in April 2000. San Francisco was the first major city in country to ban mercury thermometers, and SFPUC and SF Environment collection programs have retired over 6,000 old mercury thermometers to date.  Subsequently, the California legislature enacted a statewide mercury thermometer ban in July 2002, and a bill limiting their use is currently under consideration in the U.S. Senate.

"San Francisco is a national leader in pollution prevention," said Department of the Environment director Jared Blumenfeld.  “The Dental Mercury Reduction Program is an important initial step in reducing the environmental health hazards associated with dental mercury, and we look forward to similar programs being adopted first in cities around the Bay, and then around the country."

The Water Pollution Prevention Program and Department of the Environment are providing educational brochures, workshops, and other technical support to the Dental Mercury Reduction Program and help dentists understand these requirements.