Mercury is a naturally occurring metal in the Earth’s crust and in coal.

Most human intake of mercury comes from eating certain types of fish or seafood containing a form of mercury called methylmercury.

"The electric power industry has reduced mercury and hazardous air pollutant emissions through compliance with the Mercury and Air Toxics Standards (MATS) rule which went into effect on April 16, 2012.  The rule requires coal-based power plants to reduce mercury emissions and non-mercury hazardous air pollutants (HAPs)—acid gases and non-mercury metals emissions.

As a result of MATS and other Clean Air Act regulations, from 2010 to 2017, the power sector has reduced mercury emissions by 86 percent and total emissions of hazardous air pollutants by 96 percent.  National total power sector mercury emissions have been reduced by 95 percent over the period 1990 to 2020 (from 59 to 3 tons per year).​

Learn more at EPA's Mercury Control site​.