Most of this comes from coal burning power plants and various refining industries where mercury is used. A considerable portion of the metal is also used to make various measuring instruments such as thermometers, barometers, and thermostats, as well as florescent lightbulbs. When these objects break or end their useful life, they get discarded and contribute to mercury pollution. In the United States, dentistry is the 5th largest consumer of mercury. However, of these, dentistry now remains one of the only major unregulated sources of mercury discharges to the environment.
Dentists use a tremendous amount of mercury.
A typical dentist removes between 700 and 800 fillings per year. In North America, there are about 100,000 dental practices. Altogether from these dental offices, great quantities of mercury in amalgam waste is generated and eventually discharged into the environment. To illustrate how much mercury dentists contribute to the environment, a comparison has to be made. According to research studies, a typical coal burning electrical power plant produces 48 pounds of mercury in one year.