Mercury Pollution Declines by Half Over Last Decade

Cleaner energy and regulations are helping; but defying trend are steel mills, metal smelting plants, and some states

Read the full report, here.

Washington, D.C. – Mercury pollution from U.S. power plants plummeted by 54 percent between 2004 and 2014, with the improvement driven by air pollution control laws and a shift from coal to natural gas and more renewable energy.

Mercury emissions from factories that make or recycle steel and other metals increased about 40 percent, however.  The data in the Environmental Integrity’s report (“Mercury Falling”) is based on industrial emissions reported to the federal Toxics Release Inventory.

Three of the worst remaining mercury polluters in the U.S. are coal-fired power plants owned by the Luminant Corporation in Texas, with the plants ranking first, third and fifth on a list of the top 50 polluters included in the report.  The Lehigh Southwest cement kiln in California and a steel recycler in Alabama are the second and fourth largest emitters nationally, respectively.

The “Mercury Falling” report includes a list of the top 10 states with highest emissions of this pollutant in 2014.  Texas, Alabama, Ohio, Pennsylvania, and Indiana topped the list (in that order), with these five states together releasing about a third of the total mercury pollution in the U.S., according to the TRI data.

“The national decline is good news, because lower emissions reduce the public’s exposure to a highly toxic pollutant that is especially harmful to young children and developing fetuses,” said Eric Schaeffer, Executive Director of the Environmental Integrity Project.  “However, the progress has been uneven – and continued vigilance is important, especially for the metals industry and power plants in states like Texas.”

Emissions of mercury declined in 44 states, but rose in Arkansas, Arizona and Idaho, according to the TRI data from 2004 to 2014.

Other highlights from the “Mercury Falling” report include:

  • Overall, mercury emissions from U.S. industry fell 46 percent from 2004 to 2014, declining from 143,260 pounds to 76,779 pounds, according to the TRI data.
  • Mercury pollution from power plants declined 54 percent over this decade, from 94,526 pounds to 43,877 pounds.
  • Emissions of the toxic metal from steel mills and metal smelting plants rose from 10,929 pounds in 2004 to 15,384 pounds in 2014.
  • Over the same 10 year period, mercury emissions from all other industrial sources reporting to the federal Toxics Release Inventory dropped by about a third, from 48,734 to 32,902 pounds.

Three factors explain the overall decline in mercury emissions:

  • Coal consumption declined more than 16 percent between 2004 and 2014 as aging power plants plants retired, or reduced their output in the face of competition from gas and renewable energy.
  • Power plants installed wet scrubbers and sorbent injection systems to meet current or anticipated federal Clean Air Act standards.
  • Several state laws imposed limits well in advance of federal standards that will take full effect in 2016. For example, the Maryland General Assembly in 2006 passed a law that required its coal-fired power plants to reduce mercury emissions 80 percent by 2010 and 90 percent by 2013. The data in the “Mercury Falling” report show that Maryland actually reduced its emissions by 96 percent from 2004 to 2014.

The World Health Organization (WHO) considers mercury one of the top ten chemicals of public health concern. Exposure to mercury can lead to serious health problems, including damage to the brains of developing children whose mothers consume fish contaminated with the toxic metal after it falls from the air into waterways.

The Environmental Integrity Project is a 13-year-old nonprofit, nonpartisan organization, based in Washington D.C. and Austin, Texas, that works to hold polluters and governments accountable to protect public health.


Media contact: Tom Pelton, Environmental Integrity Project, 202-888-2703 or