From the Dentist's Chair to Our Water

Dentists and Mercury:
The most common use of mercury in dental operations is in dental amalgam. An amalgam being a mixture or blending of mercury with another metal. Amalgams are commonly used in dental fillings. It is made up of approximately 40 to 50% mercury, 25% silver and 25 to 35% mixture of copper, zinc and tin.

Amalgam particles enter wastewater from dental offices when dentists remove old fillings or place new fillings. Estimates of the contribution of mercury in wastewater from dentists range from 11% to 80%.

In a recent survey of seven major wastewater treatment plants in California, Minnesota, Ohio and Maine, dentists were identified as the largest contributors of mercury. There have been more than 20 studies from Europe, Canada and the US that identify the dental industry as the leading source of mercury to sewer systems.

Mercury contaminates our environment, therefore threatens public health and threatens the fishing industry.

Publicly owned treatment works are looking for ways to reduce metals at the source and meet stricter limits using cost effective pollution prevention.